GH-2026 implement changes necessary to support 1.13 snapshots

51 files changed, 2625 insertions, 1051 deletions

diff --git a/api/logic/BaseInstance.cpp b/api/logic/BaseInstance.cpp
index f52b2812..027b8f78 100644
--- a/api/logic/BaseInstance.cpp
+++ b/api/logic/BaseInstance.cpp
@@ -197,7 +197,7 @@ bool BaseInstance::canLaunch() const
 	return (!hasVersionBroken() && !isRunning());
 }
 
-bool BaseInstance::reload()
+bool BaseInstance::reloadSettings()
 {
 	return m_settings->reload();
 }
diff --git a/api/logic/BaseInstance.h b/api/logic/BaseInstance.h
index 26d4bc35..d0909031 100644
--- a/api/logic/BaseInstance.h
+++ b/api/logic/BaseInstance.h
@@ -30,6 +30,8 @@
 #include "MessageLevel.h"
 #include "pathmatcher/IPathMatcher.h"
 
+#include "net/Mode.h"
+
 #include "multimc_logic_export.h"
 
 class QDir;
@@ -148,7 +150,7 @@ public:
 	virtual SettingsObjectPtr settings() const;
 
 	/// returns a valid update task
-	virtual shared_qobject_ptr<Task> createUpdateTask() = 0;
+	virtual shared_qobject_ptr<Task> createUpdateTask(Net::Mode mode) = 0;
 
 	/// returns a valid launcher (task container)
 	virtual std::shared_ptr<LaunchTask> createLaunchTask(AuthSessionPtr account) = 0;
@@ -224,7 +226,7 @@ public:
 	virtual bool canEdit() const = 0;
 	virtual bool canExport() const = 0;
 
-	virtual bool reload();
+	bool reloadSettings();
 
 	/**
 	 * 'print' a verbose desription of the instance into a QStringList
diff --git a/api/logic/CMakeLists.txt b/api/logic/CMakeLists.txt
index 42bea98c..8a8ef495 100644
--- a/api/logic/CMakeLists.txt
+++ b/api/logic/CMakeLists.txt
@@ -239,8 +239,14 @@ set(MINECRAFT_SOURCES
 	minecraft/MinecraftInstance.h
 	minecraft/LaunchProfile.cpp
 	minecraft/LaunchProfile.h
+	minecraft/Component.cpp
+	minecraft/Component.h
 	minecraft/ComponentList.cpp
 	minecraft/ComponentList.h
+	minecraft/ComponentUpdateTask.cpp
+	minecraft/ComponentUpdateTask.h
+	minecraft/MinecraftLoadAndCheck.h
+	minecraft/MinecraftLoadAndCheck.cpp
 	minecraft/MinecraftUpdate.h
 	minecraft/MinecraftUpdate.cpp
 	minecraft/MojangVersionFormat.cpp
@@ -260,8 +266,6 @@ set(MINECRAFT_SOURCES
 	minecraft/MojangDownloadInfo.h
 	minecraft/VersionFile.cpp
 	minecraft/VersionFile.h
-	minecraft/ProfilePatch.cpp
-	minecraft/ProfilePatch.h
 	minecraft/VersionFilterData.h
 	minecraft/VersionFilterData.cpp
 	minecraft/Mod.h
diff --git a/api/logic/InstanceCreationTask.cpp b/api/logic/InstanceCreationTask.cpp
index 21892f82..8a68815a 100644
--- a/api/logic/InstanceCreationTask.cpp
+++ b/api/logic/InstanceCreationTask.cpp
@@ -5,6 +5,7 @@
 
 //FIXME: remove this
 #include "minecraft/MinecraftInstance.h"
+#include "minecraft/ComponentList.h"
 
 InstanceCreationTask::InstanceCreationTask(SettingsObjectPtr settings, const QString & stagingPath, BaseVersionPtr version,
 	const QString& instName, const QString& instIcon, const QString& instGroup)
@@ -25,11 +26,13 @@ void InstanceCreationTask::executeTask()
 		instanceSettings->suspendSave();
 		instanceSettings->registerSetting("InstanceType", "Legacy");
 		instanceSettings->set("InstanceType", "OneSix");
-		auto inst = new MinecraftInstance(m_globalSettings, instanceSettings, m_stagingPath);
-		inst->setComponentVersion("net.minecraft", m_version->descriptor());
-		inst->setName(m_instName);
-		inst->setIconKey(m_instIcon);
-		inst->init();
+		MinecraftInstance inst(m_globalSettings, instanceSettings, m_stagingPath);
+		auto components = inst.getComponentList();
+		components->buildingFromScratch();
+		components->setComponentVersion("net.minecraft", m_version->descriptor(), true);
+		inst.setName(m_instName);
+		inst.setIconKey(m_instIcon);
+		inst.init();
 		instanceSettings->resumeSave();
 	}
 	emitSucceeded();
diff --git a/api/logic/InstanceImportTask.cpp b/api/logic/InstanceImportTask.cpp
index e2782cd8..80f68458 100644
--- a/api/logic/InstanceImportTask.cpp
+++ b/api/logic/InstanceImportTask.cpp
@@ -242,7 +242,9 @@ void InstanceImportTask::processFlame()
 		mcVersion.remove(QRegExp("[.]+$"));
 		qWarning() << "Mysterious trailing dots removed from Minecraft version while importing pack.";
 	}
-	instance.setComponentVersion("net.minecraft", mcVersion);
+	auto components = instance.getComponentList();
+	components->buildingFromScratch();
+	components->setComponentVersion("net.minecraft", mcVersion, true);
 	if(!forgeVersion.isEmpty())
 	{
 		// FIXME: dirty, nasty, hack. Proper solution requires dependency resolution and knowledge of the metadata.
@@ -257,7 +259,7 @@ void InstanceImportTask::processFlame()
 				qWarning() << "Could not map recommended forge version for" << mcVersion;
 			}
 		}
-		instance.setComponentVersion("net.minecraftforge", forgeVersion);
+		components->setComponentVersion("net.minecraftforge", forgeVersion);
 	}
 	if (m_instIcon != "default")
 	{
diff --git a/api/logic/NullInstance.h b/api/logic/NullInstance.h
index f689c5ab..27a8a251 100644
--- a/api/logic/NullInstance.h
+++ b/api/logic/NullInstance.h
@@ -29,7 +29,7 @@ public:
 	{
 		return nullptr;
 	}
-	virtual shared_qobject_ptr< Task > createUpdateTask() override
+	virtual shared_qobject_ptr< Task > createUpdateTask(Net::Mode mode) override
 	{
 		return nullptr;
 	}
diff --git a/api/logic/ProblemProvider.h b/api/logic/ProblemProvider.h
index 4040f4fa..978710f0 100644
--- a/api/logic/ProblemProvider.h
+++ b/api/logic/ProblemProvider.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#include "multimc_logic_export.h"
+
 enum class ProblemSeverity
 {
 	None,
@@ -13,7 +15,7 @@ struct PatchProblem
 	QString m_description;
 };
 
-class ProblemProvider
+class MULTIMC_LOGIC_EXPORT ProblemProvider
 {
 public:
 	virtual ~ProblemProvider() {};
@@ -21,7 +23,7 @@ public:
 	virtual ProblemSeverity getProblemSeverity() const = 0;
 };
 
-class ProblemContainer : public ProblemProvider
+class MULTIMC_LOGIC_EXPORT ProblemContainer : public ProblemProvider
 {
 public:
 	const QList<PatchProblem> getProblems() const override
diff --git a/api/logic/launch/steps/Update.cpp b/api/logic/launch/steps/Update.cpp
index f06c39eb..42ca3c67 100644
--- a/api/logic/launch/steps/Update.cpp
+++ b/api/logic/launch/steps/Update.cpp
@@ -23,7 +23,7 @@ void Update::executeTask()
 		emitFailed(tr("Task aborted."));
 		return;
 	}
-	m_updateTask.reset(m_parent->instance()->createUpdateTask());
+	m_updateTask.reset(m_parent->instance()->createUpdateTask(m_mode));
 	if(m_updateTask)
 	{
 		connect(m_updateTask.get(), SIGNAL(finished()), this, SLOT(updateFinished()));
diff --git a/api/logic/launch/steps/Update.h b/api/logic/launch/steps/Update.h
index d855a1db..e9573bcd 100644
--- a/api/logic/launch/steps/Update.h
+++ b/api/logic/launch/steps/Update.h
@@ -19,13 +19,14 @@
 #include <QObjectPtr.h>
 #include <LoggedProcess.h>
 #include <java/JavaChecker.h>
+#include <net/Mode.h>
 
 // FIXME: stupid. should be defined by the instance type? or even completely abstracted away...
 class Update: public LaunchStep
 {
 	Q_OBJECT
 public:
-	explicit Update(LaunchTask *parent):LaunchStep(parent) {};
+	explicit Update(LaunchTask *parent, Net::Mode mode):LaunchStep(parent), m_mode(mode) {};
 	virtual ~Update() {};
 
 	void executeTask() override;
@@ -40,4 +41,5 @@ private slots:
 private:
 	shared_qobject_ptr<Task> m_updateTask;
 	bool m_aborted = false;
+	Net::Mode m_mode = Net::Mode::Offline;
 };
diff --git a/api/logic/meta/BaseEntity.cpp b/api/logic/meta/BaseEntity.cpp
index 6bac71ee..7cf327be 100644
--- a/api/logic/meta/BaseEntity.cpp
+++ b/api/logic/meta/BaseEntity.cpp
@@ -99,7 +99,7 @@ bool Meta::BaseEntity::loadLocalFile()
 	}
 }
 
-void Meta::BaseEntity::load()
+void Meta::BaseEntity::load(Net::Mode loadType)
 {
 	// load local file if nothing is loaded yet
 	if(!isLoaded())
@@ -110,7 +110,7 @@ void Meta::BaseEntity::load()
 		}
 	}
 	// if we need remote update, run the update task
-	if(!shouldStartRemoteUpdate())
+	if(loadType == Net::Mode::Offline || !shouldStartRemoteUpdate())
 	{
 		return;
 	}
diff --git a/api/logic/meta/BaseEntity.h b/api/logic/meta/BaseEntity.h
index 4483beab..4c74b1a7 100644
--- a/api/logic/meta/BaseEntity.h
+++ b/api/logic/meta/BaseEntity.h
@@ -20,6 +20,7 @@
 #include "QObjectPtr.h"
 
 #include "multimc_logic_export.h"
+#include "net/Mode.h"
 
 class Task;
 namespace Meta
@@ -54,7 +55,7 @@ public:
 	bool isLoaded() const;
 	bool shouldStartRemoteUpdate() const;
 
-	void load();
+	void load(Net::Mode loadType);
 	shared_qobject_ptr<Task> getCurrentTask();
 
 protected: /* methods */
diff --git a/api/logic/meta/JsonFormat.cpp b/api/logic/meta/JsonFormat.cpp
index d13c89df..2c313478 100644
--- a/api/logic/meta/JsonFormat.cpp
+++ b/api/logic/meta/JsonFormat.cpp
@@ -51,18 +51,11 @@ static VersionPtr parseCommonVersion(const QString &uid, const QJsonObject &obj)
 	version->setType(ensureString(obj, "type", QString()));
 	version->setParentUid(ensureString(obj, "parentUid", QString()));
 	version->setRecommended(ensureBoolean(obj, QString("recommended"), false));
-	if(obj.contains("requires"))
-	{
-		QHash<QString, QString> requires;
-		auto reqobj = requireObject(obj, "requires");
-		auto iter = reqobj.begin();
-		while(iter != reqobj.end())
-		{
-			requires[iter.key()] = requireString(iter.value());
-			iter++;
-		}
-		version->setRequires(requires);
-	}
+	version->setVolatile(ensureBoolean(obj, QString("volatile"), false));
+	RequireSet requires, conflicts;
+	parseRequires(obj, &requires, "requires");
+	parseRequires(obj, &conflicts, "conflicts");
+	version->setRequires(requires, conflicts);
 	return version;
 }
 
@@ -145,4 +138,53 @@ void parseVersion(const QJsonObject &obj, Version *ptr)
 		throw ParseException(QObject::tr("Unknown formatVersion: %1").arg(version));
 	}
 }
+
+/*
+[
+{"uid":"foo", "equals":"version"}
+]
+*/
+void parseRequires(const QJsonObject& obj, RequireSet* ptr, const char * keyName)
+{
+	if(obj.contains(keyName))
+	{
+		QSet<QString> requires;
+		auto reqArray = requireArray(obj, keyName);
+		auto iter = reqArray.begin();
+		while(iter != reqArray.end())
+		{
+			auto reqObject = requireObject(*iter);
+			auto uid = requireString(reqObject, "uid");
+			auto equals = ensureString(reqObject, "equals", QString());
+			auto suggests = ensureString(reqObject, "suggests", QString());
+			ptr->insert({uid, equals, suggests});
+			iter++;
+		}
+	}
 }
+void serializeRequires(QJsonObject& obj, RequireSet* ptr, const char * keyName)
+{
+	if(!ptr || ptr->empty())
+	{
+		return;
+	}
+	QJsonArray arrOut;
+	for(auto &iter: *ptr)
+	{
+		QJsonObject reqOut;
+		reqOut.insert("uid", iter.uid);
+		if(!iter.equalsVersion.isEmpty())
+		{
+			reqOut.insert("equals", iter.equalsVersion);
+		}
+		if(!iter.suggests.isEmpty())
+		{
+			reqOut.insert("suggests", iter.suggests);
+		}
+		arrOut.append(reqOut);
+	}
+	obj.insert(keyName, arrOut);
+}
+
+}
+
diff --git a/api/logic/meta/JsonFormat.h b/api/logic/meta/JsonFormat.h
index aaed07fc..9b9dcd91 100644
--- a/api/logic/meta/JsonFormat.h
+++ b/api/logic/meta/JsonFormat.h
@@ -20,6 +20,7 @@
 
 #include "Exception.h"
 #include "meta/BaseEntity.h"
+#include <set>
 
 namespace Meta
 {
@@ -32,9 +33,41 @@ class ParseException : public Exception
 public:
 	using Exception::Exception;
 };
+struct Require
+{
+	bool operator==(const Require & rhs) const
+	{
+		return uid == rhs.uid;
+	}
+	bool operator<(const Require & rhs) const
+	{
+		return uid < rhs.uid;
+	}
+	bool deepEquals(const Require & rhs) const
+	{
+		return uid == rhs.uid
+			&& equalsVersion == rhs.equalsVersion
+			&& suggests == rhs.suggests;
+	}
+	QString uid;
+	QString equalsVersion;
+	QString suggests;
+};
+
+inline Q_DECL_PURE_FUNCTION uint qHash(const Require &key, uint seed = 0) Q_DECL_NOTHROW
+{
+	return qHash(key.uid, seed);
+}
+
+using RequireSet = std::set<Require>;
 
 void parseIndex(const QJsonObject &obj, Index *ptr);
 void parseVersion(const QJsonObject &obj, Version *ptr);
 void parseVersionList(const QJsonObject &obj, VersionList *ptr);
 
+// FIXME: this has a different shape than the others...FIX IT!?
+void parseRequires(const QJsonObject &obj, RequireSet * ptr, const char * keyName = "requires");
+void serializeRequires(QJsonObject & objOut, RequireSet* ptr, const char * keyName = "requires");
 }
+
+Q_DECLARE_METATYPE(std::set<Meta::Require>);
\ No newline at end of file
diff --git a/api/logic/meta/Version.cpp b/api/logic/meta/Version.cpp
index bf739157..d82878a1 100644
--- a/api/logic/meta/Version.cpp
+++ b/api/logic/meta/Version.cpp
@@ -74,12 +74,20 @@ void Meta::Version::merge(const std::shared_ptr<BaseEntity> &other)
 	}
 	if (m_requires != version->m_requires)
 	{
-		setRequires(version->m_requires);
+		m_requires = version->m_requires;
+	}
+	if (m_conflicts != version->m_conflicts)
+	{
+		m_conflicts = version->m_conflicts;
 	}
 	if (m_parentUid != version->m_parentUid)
 	{
 		setParentUid(version->m_parentUid);
 	}
+	if(m_volatile != version->m_volatile)
+	{
+		setVolatile(version->m_volatile);
+	}
 	if(version->m_data)
 	{
 		setData(version->m_data);
@@ -109,12 +117,19 @@ void Meta::Version::setTime(const qint64 time)
 	emit timeChanged();
 }
 
-void Meta::Version::setRequires(const QHash<QString, QString> &requires)
+void Meta::Version::setRequires(const Meta::RequireSet &requires, const Meta::RequireSet &conflicts)
 {
 	m_requires = requires;
+	m_conflicts = conflicts;
 	emit requiresChanged();
 }
 
+void Meta::Version::setVolatile(bool volatile_)
+{
+	m_volatile = volatile_;
+}
+
+
 void Meta::Version::setData(const VersionFilePtr &data)
 {
 	m_data = data;
diff --git a/api/logic/meta/Version.h b/api/logic/meta/Version.h
index 2f92ee9f..61f253c6 100644
--- a/api/logic/meta/Version.h
+++ b/api/logic/meta/Version.h
@@ -28,6 +28,8 @@
 
 #include "multimc_logic_export.h"
 
+#include "JsonFormat.h"
+
 namespace Meta
 {
 using VersionPtr = std::shared_ptr<class Version>;
@@ -65,7 +67,7 @@ public: /* con/des */
 	{
 		return m_time;
 	}
-	const QHash<QString, QString> &requires() const
+	const Meta::RequireSet &requires() const
 	{
 		return m_requires;
 	}
@@ -77,6 +79,10 @@ public: /* con/des */
 	{
 		return m_recommended;
 	}
+	bool isLoaded() const
+	{
+		return m_data != nullptr;
+	}
 
 	void merge(const std::shared_ptr<BaseEntity> &other) override;
 	void parse(const QJsonObject &obj) override;
@@ -87,7 +93,8 @@ public: // for usage by format parsers only
 	void setParentUid(const QString &parentUid);
 	void setType(const QString &type);
 	void setTime(const qint64 time);
-	void setRequires(const QHash<QString, QString> &requires);
+	void setRequires(const Meta::RequireSet &requires, const Meta::RequireSet &conflicts);
+	void setVolatile(bool volatile_);
 	void setRecommended(bool recommended);
 	void setProvidesRecommendations();
 	void setData(const VersionFilePtr &data);
@@ -106,7 +113,9 @@ private:
 	QString m_version;
 	QString m_type;
 	qint64 m_time = 0;
-	QHash<QString, QString> m_requires;
+	Meta::RequireSet m_requires;
+	Meta::RequireSet m_conflicts;
+	bool m_volatile = false;
 	VersionFilePtr m_data;
 };
 }
diff --git a/api/logic/meta/VersionList.cpp b/api/logic/meta/VersionList.cpp
index 4da0fb76..8910c4d7 100644
--- a/api/logic/meta/VersionList.cpp
+++ b/api/logic/meta/VersionList.cpp
@@ -30,7 +30,7 @@ VersionList::VersionList(const QString &uid, QObject *parent)
 
 shared_qobject_ptr<Task> VersionList::getLoadTask()
 {
-	load();
+	load(Net::Mode::Online);
 	return getCurrentTask();
 }
 
@@ -81,10 +81,13 @@ QVariant VersionList::data(const QModelIndex &index, int role) const
 			return QVariant();
 		}
 		auto & reqs = version->requires();
-		auto iter = reqs.find(parentUid);
+		auto iter = std::find_if(reqs.begin(), reqs.end(), [&parentUid](const Require & req)
+		{
+			return req.uid == parentUid;
+		});
 		if (iter != reqs.end())
 		{
-			return iter.value();
+			return (*iter).equalsVersion;
 		}
 	}
 	case TypeRole: return version->type();
@@ -159,6 +162,7 @@ void VersionList::setVersions(const QVector<VersionPtr> &versions)
 		setupAddedVersion(i, m_versions.at(i));
 	}
 
+	// FIXME: this is dumb, we have 'recommended' as part of the metadata already...
 	auto recommendedIt = std::find_if(m_versions.constBegin(), m_versions.constEnd(), [](const VersionPtr &ptr) { return ptr->type() == "release"; });
 	m_recommended = recommendedIt == m_versions.constEnd() ? nullptr : *recommendedIt;
 	endResetModel();
@@ -169,6 +173,22 @@ void VersionList::parse(const QJsonObject& obj)
 	parseVersionList(obj, this);
 }
 
+// FIXME: this is dumb, we have 'recommended' as part of the metadata already...
+static const Meta::VersionPtr &getBetterVersion(const Meta::VersionPtr &a, const Meta::VersionPtr &b)
+{
+	if(!a)
+		return b;
+	if(!b)
+		return a;
+	if(a->type() == b->type())
+	{
+		// newer of same type wins
+		return (a->rawTime() > b->rawTime() ? a : b);
+	}
+	// 'release' type wins
+	return (a->type() == "release" ? a : b);
+}
+
 void VersionList::merge(const BaseEntity::Ptr &other)
 {
 	const VersionListPtr list = std::dynamic_pointer_cast<VersionList>(other);
@@ -199,10 +219,7 @@ void VersionList::merge(const BaseEntity::Ptr &other)
 		// connect it.
 		setupAddedVersion(m_versions.size(), version);
 		m_versions.append(version);
-		if (!m_recommended || (version->type() == "release" && version->rawTime() > m_recommended->rawTime()))
-		{
-			m_recommended = version;
-		}
+		m_recommended = getBetterVersion(m_recommended, version);
 	}
 	endResetModel();
 }
diff --git a/api/logic/minecraft/Component.cpp b/api/logic/minecraft/Component.cpp
new file mode 100644
index 00000000..db523142
--- /dev/null
+++ b/api/logic/minecraft/Component.cpp
@@ -0,0 +1,408 @@
+#include <meta/VersionList.h>
+#include <meta/Index.h>
+#include <Env.h>
+#include "Component.h"
+
+#include "meta/Version.h"
+#include "VersionFile.h"
+#include "minecraft/ComponentList.h"
+#include <FileSystem.h>
+#include <QSaveFile>
+#include "OneSixVersionFormat.h"
+#include <assert.h>
+
+Component::Component(ComponentList * parent, const QString& uid)
+{
+	assert(parent);
+	m_parent = parent;
+
+	m_uid = uid;
+}
+
+Component::Component(ComponentList * parent, std::shared_ptr<Meta::Version> version)
+{
+	assert(parent);
+	m_parent = parent;
+
+	m_metaVersion = version;
+	m_uid = version->uid();
+	m_version = m_cachedVersion = version->version();
+	m_cachedName = version->name();
+	m_loaded = version->isLoaded();
+}
+
+Component::Component(ComponentList * parent, const QString& uid, std::shared_ptr<VersionFile> file)
+{
+	assert(parent);
+	m_parent = parent;
+
+	m_file = file;
+	m_uid = uid;
+	m_cachedVersion = m_file->version;
+	m_cachedName = m_file->name;
+	m_loaded = true;
+}
+
+std::shared_ptr<Meta::Version> Component::getMeta()
+{
+	return m_metaVersion;
+}
+
+void Component::applyTo(LaunchProfile* profile)
+{
+	auto vfile = getVersionFile();
+	if(vfile)
+	{
+		vfile->applyTo(profile);
+	}
+	else
+	{
+		profile->applyProblemSeverity(getProblemSeverity());
+	}
+}
+
+std::shared_ptr<class VersionFile> Component::getVersionFile() const
+{
+	if(m_metaVersion)
+	{
+		if(!m_metaVersion->isLoaded())
+		{
+			m_metaVersion->load(Net::Mode::Online);
+		}
+		return m_metaVersion->data();
+	}
+	else
+	{
+		return m_file;
+	}
+}
+
+std::shared_ptr<class Meta::VersionList> Component::getVersionList() const
+{
+	// FIXME: what if the metadata index isn't loaded yet?
+	if(ENV.metadataIndex()->hasUid(m_uid))
+	{
+		return ENV.metadataIndex()->get(m_uid);
+	}
+	return nullptr;
+}
+
+int Component::getOrder()
+{
+	if(m_orderOverride)
+		return m_order;
+
+	auto vfile = getVersionFile();
+	if(vfile)
+	{
+		return vfile->order;
+	}
+	return 0;
+}
+void Component::setOrder(int order)
+{
+	m_orderOverride = true;
+	m_order = order;
+}
+QString Component::getID()
+{
+	return m_uid;
+}
+QString Component::getName()
+{
+	if (!m_cachedName.isEmpty())
+		return m_cachedName;
+	return m_uid;
+}
+QString Component::getVersion()
+{
+	return m_cachedVersion;
+}
+QString Component::getFilename()
+{
+	return m_parent->patchFilePathForUid(m_uid);
+}
+QDateTime Component::getReleaseDateTime()
+{
+	if(m_metaVersion)
+	{
+		return m_metaVersion->time();
+	}
+	auto vfile = getVersionFile();
+	if(vfile)
+	{
+		return vfile->releaseTime;
+	}
+	// FIXME: fake
+	return QDateTime::currentDateTime();
+}
+
+bool Component::isCustom()
+{
+	return m_file != nullptr;
+};
+
+bool Component::isCustomizable()
+{
+	if(m_metaVersion)
+	{
+		if(getVersionFile())
+		{
+			return true;
+		}
+	}
+	return false;
+}
+bool Component::isRemovable()
+{
+	return !m_important;
+}
+bool Component::isRevertible()
+{
+	if (isCustom())
+	{
+		if(ENV.metadataIndex()->hasUid(m_uid))
+		{
+			return true;
+		}
+	}
+	return false;
+}
+bool Component::isMoveable()
+{
+	// HACK, FIXME: this was too dumb and wouldn't follow dependency constraints anyway. For now hardcoded to 'true'.
+	return true;
+}
+bool Component::isVersionChangeable()
+{
+	auto list = getVersionList();
+	if(list)
+	{
+		if(!list->isLoaded())
+		{
+			list->load(Net::Mode::Online);
+		}
+		return list->count() != 0;
+	}
+	return false;
+}
+
+void Component::setImportant(bool state)
+{
+	if(m_important != state)
+	{
+		m_important = state;
+		emit dataChanged();
+	}
+}
+
+ProblemSeverity Component::getProblemSeverity() const
+{
+	auto file = getVersionFile();
+	if(file)
+	{
+		return file->getProblemSeverity();
+	}
+	return ProblemSeverity::Error;
+}
+
+const QList<PatchProblem> Component::getProblems() const
+{
+	auto file = getVersionFile();
+	if(file)
+	{
+		return file->getProblems();
+	}
+	return {{ProblemSeverity::Error, QObject::tr("Patch is not loaded yet.")}};
+}
+
+void Component::setVersion(const QString& version)
+{
+	if(version == m_version)
+	{
+		return;
+	}
+	m_version = version;
+	if(m_loaded)
+	{
+		// we are loaded and potentially have state to invalidate
+		if(m_file)
+		{
+			// we have a file... explicit version has been changed and there is nothing else to do.
+		}
+		else
+		{
+			// we don't have a file, therefore we are loaded with metadata
+			m_cachedVersion = version;
+			// see if the meta version is loaded
+			auto metaVersion = ENV.metadataIndex()->get(m_uid, version);
+			if(metaVersion->isLoaded())
+			{
+				// if yes, we can continue with that.
+				m_metaVersion = metaVersion;
+			}
+			else
+			{
+				// if not, we need loading
+				m_metaVersion.reset();
+				m_loaded = false;
+			}
+			updateCachedData();
+		}
+	}
+	else
+	{
+		// not loaded... assume it will be sorted out later by the update task
+	}
+	emit dataChanged();
+}
+
+bool Component::customize()
+{
+	if(isCustom())
+	{
+		return false;
+	}
+
+	auto filename = getFilename();
+	if(!FS::ensureFilePathExists(filename))
+	{
+		return false;
+	}
+	// FIXME: get rid of this try-catch.
+	try
+	{
+		QSaveFile jsonFile(filename);
+		if(!jsonFile.open(QIODevice::WriteOnly))
+		{
+			return false;
+		}
+		auto vfile = getVersionFile();
+		if(!vfile)
+		{
+			return false;
+		}
+		auto document = OneSixVersionFormat::versionFileToJson(vfile);
+		jsonFile.write(document.toJson());
+		if(!jsonFile.commit())
+		{
+			return false;
+		}
+		m_file = vfile;
+		m_metaVersion.reset();
+		emit dataChanged();
+	}
+	catch (Exception &error)
+	{
+		qWarning() << "Version could not be loaded:" << error.cause();
+	}
+	return true;
+}
+
+bool Component::revert()
+{
+	if(!isCustom())
+	{
+		// already not custom
+		return true;
+	}
+	auto filename = getFilename();
+	bool result = true;
+	// just kill the file and reload
+	if(QFile::exists(filename))
+	{
+		result = QFile::remove(filename);
+	}
+	if(result)
+	{
+		// file gone...
+		m_file.reset();
+
+		// check local cache for metadata...
+		auto version = ENV.metadataIndex()->get(m_uid, m_version);
+		if(version->isLoaded())
+		{
+			m_metaVersion = version;
+		}
+		else
+		{
+			m_metaVersion.reset();
+			m_loaded = false;
+		}
+		emit dataChanged();
+	}
+	return result;
+}
+
+/**
+ * deep inspecting compare for requirement sets
+ * By default, only uids are compared for set operations.
+ * This compares all fields of the Require structs in the sets.
+ */
+static bool deepCompare(const std::set<Meta::Require> & a, const std::set<Meta::Require> & b)
+{
+	// NOTE: this needs to be rewritten if the type of Meta::RequireSet changes
+	if(a.size() != b.size())
+	{
+		return false;
+	}
+	for(const auto & reqA :a)
+	{
+		const auto &iter2 = b.find(reqA);
+		if(iter2 == b.cend())
+		{
+			return false;
+		}
+		const auto & reqB = *iter2;
+		if(!reqA.deepEquals(reqB))
+		{
+			return false;
+		}
+	}
+	return true;
+}
+
+void Component::updateCachedData()
+{
+	auto file = getVersionFile();
+	if(file)
+	{
+		bool changed = false;
+		if(m_cachedName != file->name)
+		{
+			m_cachedName = file->name;
+			changed = true;
+		}
+		if(m_cachedVersion != file->version)
+		{
+			m_cachedVersion = file->version;
+			changed = true;
+		}
+		if(m_cachedVolatile != file->m_volatile)
+		{
+			m_cachedVolatile = file->m_volatile;
+			changed = true;
+		}
+		if(!deepCompare(m_cachedRequires, file->requires))
+		{
+			m_cachedRequires = file->requires;
+			changed = true;
+		}
+		if(!deepCompare(m_cachedConflicts, file->conflicts))
+		{
+			m_cachedConflicts = file->conflicts;
+			changed = true;
+		}
+		if(changed)
+		{
+			emit dataChanged();
+		}
+	}
+	else
+	{
+		// in case we removed all the metadata
+		m_cachedRequires.clear();
+		m_cachedConflicts.clear();
+		emit dataChanged();
+	}
+}
diff --git a/api/logic/minecraft/Component.h b/api/logic/minecraft/Component.h
new file mode 100644
index 00000000..4917149b
--- /dev/null
+++ b/api/logic/minecraft/Component.h
@@ -0,0 +1,104 @@
+#pragma once
+
+#include <memory>
+#include <QList>
+#include <QJsonDocument>
+#include <QDateTime>
+#include "meta/JsonFormat.h"
+#include "ProblemProvider.h"
+#include "QObjectPtr.h"
+#include "multimc_logic_export.h"
+
+class ComponentList;
+class LaunchProfile;
+namespace Meta
+{
+	class Version;
+	class VersionList;
+}
+class VersionFile;
+
+class MULTIMC_LOGIC_EXPORT Component : public QObject, public ProblemProvider
+{
+Q_OBJECT
+public:
+	Component(ComponentList * parent, const QString &uid);
+
+	// DEPRECATED: remove these constructors?
+	Component(ComponentList * parent, std::shared_ptr<Meta::Version> version);
+	Component(ComponentList * parent, const QString & uid, std::shared_ptr<VersionFile> file);
+
+	virtual ~Component(){};
+	void applyTo(LaunchProfile *profile);
+
+	bool isMoveable();
+	bool isCustomizable();
+	bool isRevertible();
+	bool isRemovable();
+	bool isCustom();
+	bool isVersionChangeable();
+
+	// DEPRECATED: explicit numeric order values, used for loading old non-component config. TODO: refactor and move to migration code
+	void setOrder(int order);
+	int getOrder();
+
+	QString getID();
+	QString getName();
+	QString getVersion();
+	std::shared_ptr<Meta::Version> getMeta();
+	QDateTime getReleaseDateTime();
+
+	QString getFilename();
+
+	std::shared_ptr<class VersionFile> getVersionFile() const;
+	std::shared_ptr<class Meta::VersionList> getVersionList() const;
+
+	void setImportant (bool state);
+
+	const QList<PatchProblem> getProblems() const override;
+	ProblemSeverity getProblemSeverity() const override;
+
+	void setVersion(const QString & version);
+	bool customize();
+	bool revert();
+
+	void updateCachedData();
+
+signals:
+	void dataChanged();
+
+public: /* data */
+	ComponentList * m_parent;
+
+	// BEGIN: persistent component list properties
+	/// ID of the component
+	QString m_uid;
+	/// version of the component - when there's a custom json override, this is also the version the component reverts to
+	QString m_version;
+	/// if true, this has been added automatically to satisfy dependencies and may be automatically removed
+	bool m_dependencyOnly = false;
+	/// if true, the component is either the main component of the instance, or otherwise important and cannot be removed.
+	bool m_important = false;
+
+	/// cached name for display purposes, taken from the version file (meta or local override)
+	QString m_cachedName;
+	/// cached version for display AND other purposes, taken from the version file (meta or local override)
+	QString m_cachedVersion;
+	/// cached set of requirements, taken from the version file (meta or local override)
+	Meta::RequireSet m_cachedRequires;
+	Meta::RequireSet m_cachedConflicts;
+	/// if true, the component is volatile and may be automatically removed when no longer needed
+	bool m_cachedVolatile = false;
+	// END: persistent component list properties
+
+	// DEPRECATED: explicit numeric order values, used for loading old non-component config. TODO: refactor and move to migration code
+	bool m_orderOverride = false;
+	int m_order = 0;
+
+	// load state
+	std::shared_ptr<Meta::Version> m_metaVersion;
+	std::shared_ptr<VersionFile> m_file;
+	bool m_loaded = false;
+};
+
+typedef shared_qobject_ptr<Component> ComponentPtr;
diff --git a/api/logic/minecraft/ComponentList.cpp b/api/logic/minecraft/ComponentList.cpp
index 34d3bc14..342c10b3 100644
--- a/api/logic/minecraft/ComponentList.cpp
+++ b/api/logic/minecraft/ComponentList.cpp
@@ -21,7 +21,6 @@
 #include <QJsonArray>
 #include <QDebug>
 
-#include "minecraft/ComponentList.h"
 #include "Exception.h"
 #include <minecraft/OneSixVersionFormat.h>
 #include <FileSystem.h>
@@ -30,67 +29,666 @@
 #include <meta/Index.h>
 #include <minecraft/MinecraftInstance.h>
 #include <QUuid>
+#include <QTimer>
+#include <Json.h>
+
+#include "ComponentList.h"
+#include "ComponentList_p.h"
+#include "ComponentUpdateTask.h"
 
 ComponentList::ComponentList(MinecraftInstance * instance)
 	: QAbstractListModel()
 {
-	m_instance = instance;
+	d.reset(new ComponentListData);
+	d->m_instance = instance;
+	d->m_saveTimer.setSingleShot(true);
+	d->m_saveTimer.setInterval(5000);
+	connect(&d->m_saveTimer, &QTimer::timeout, this, &ComponentList::save);
 }
 
 ComponentList::~ComponentList()
 {
+	if(saveIsScheduled())
+	{
+		d->m_saveTimer.stop();
+		save();
+	}
+}
+
+// BEGIN: component file format
+
+static const int currentComponentsFileVersion = 1;
+
+static QJsonObject componentToJsonV1(ComponentPtr component)
+{
+	QJsonObject obj;
+	// critical
+	obj.insert("uid", component->m_uid);
+	if(!component->m_version.isEmpty())
+	{
+		obj.insert("version", component->m_version);
+	}
+	if(component->m_dependencyOnly)
+	{
+		obj.insert("dependencyOnly", true);
+	}
+	if(component->m_important)
+	{
+		obj.insert("important", true);
+	}
+
+	// cached
+	if(!component->m_cachedVersion.isEmpty())
+	{
+		obj.insert("cachedVersion", component->m_cachedVersion);
+	}
+	if(!component->m_cachedName.isEmpty())
+	{
+		obj.insert("cachedName", component->m_cachedName);
+	}
+	Meta::serializeRequires(obj, &component->m_cachedRequires, "cachedRequires");
+	Meta::serializeRequires(obj, &component->m_cachedConflicts, "cachedConflicts");
+	if(component->m_cachedVolatile)
+	{
+		obj.insert("cachedVolatile", true);
+	}
+	return obj;
+}
+
+static ComponentPtr componentFromJsonV1(ComponentList * parent, const QString & componentJsonPattern, const QJsonObject &obj)
+{
+	// critical
+	auto uid = Json::requireString(obj.value("uid"));
+	auto filePath = componentJsonPattern.arg(uid);
+	auto component = new Component(parent, uid);
+	component->m_version = Json::ensureString(obj.value("version"));
+	component->m_dependencyOnly = Json::ensureBoolean(obj.value("dependencyOnly"), false);
+	component->m_important = Json::ensureBoolean(obj.value("important"), false);
+
+	// cached
+	// TODO @RESILIENCE: ignore invalid values/structure here?
+	component->m_cachedVersion = Json::ensureString(obj.value("cachedVersion"));
+	component->m_cachedName = Json::ensureString(obj.value("cachedName"));
+	Meta::parseRequires(obj, &component->m_cachedRequires, "cachedRequires");
+	Meta::parseRequires(obj, &component->m_cachedConflicts, "cachedConflicts");
+	component->m_cachedVolatile = Json::ensureBoolean(obj.value("volatile"), false);
+	return component;
+}
+
+// Save the given component container data to a file
+static bool saveComponentList(const QString & filename, const ComponentContainer & container)
+{
+	QJsonObject obj;
+	obj.insert("formatVersion", currentComponentsFileVersion);
+	QJsonArray orderArray;
+	for(auto component: container)
+	{
+		orderArray.append(componentToJsonV1(component));
+	}
+	obj.insert("components", orderArray);
+	QSaveFile outFile(filename);
+	if (!outFile.open(QFile::WriteOnly))
+	{
+		qCritical() << "Couldn't open" << outFile.fileName()
+					 << "for writing:" << outFile.errorString();
+		return false;
+	}
+	auto data = QJsonDocument(obj).toJson(QJsonDocument::Indented);
+	if(outFile.write(data) != data.size())
+	{
+		qCritical() << "Couldn't write all the data into" << outFile.fileName()
+					 << "because:" << outFile.errorString();
+		return false;
+	}
+	if(!outFile.commit())
+	{
+		qCritical() << "Couldn't save" << outFile.fileName()
+					 << "because:" << outFile.errorString();
+	}
+	return true;
+}
+
+// Read the given file into component containers
+static bool loadComponentList(ComponentList * parent, const QString & filename, const QString & componentJsonPattern, ComponentContainer & container)
+{
+	QFile componentsFile(filename);
+	if (!componentsFile.exists())
+	{
+		qWarning() << "Components file doesn't exist. This should never happen.";
+		return false;
+	}
+	if (!componentsFile.open(QFile::ReadOnly))
+	{
+		qCritical() << "Couldn't open" << componentsFile.fileName()
+					 << " for reading:" << componentsFile.errorString();
+		qWarning() << "Ignoring overriden order";
+		return false;
+	}
+
+	// and it's valid JSON
+	QJsonParseError error;
+	QJsonDocument doc = QJsonDocument::fromJson(componentsFile.readAll(), &error);
+	if (error.error != QJsonParseError::NoError)
+	{
+		qCritical() << "Couldn't parse" << componentsFile.fileName() << ":" << error.errorString();
+		qWarning() << "Ignoring overriden order";
+		return false;
+	}
+
+	// and then read it and process it if all above is true.
+	try
+	{
+		auto obj = Json::requireObject(doc);
+		// check order file version.
+		auto version = Json::requireInteger(obj.value("formatVersion"));
+		if (version != currentComponentsFileVersion)
+		{
+			throw JSONValidationError(QObject::tr("Invalid component file version, expected %1")
+										  .arg(currentComponentsFileVersion));
+		}
+		auto orderArray = Json::requireArray(obj.value("components"));
+		for(auto item: orderArray)
+		{
+			auto obj = Json::requireObject(item, "Component must be an object.");
+			container.append(componentFromJsonV1(parent, componentJsonPattern, obj));
+		}
+	}
+	catch (JSONValidationError &err)
+	{
+		qCritical() << "Couldn't parse" << componentsFile.fileName() << ": bad file format";
+		container.clear();
+		return false;
+	}
+	return true;
+}
+
+// END: component file format
+
+// BEGIN: save/load logic
+
+bool ComponentList::saveIsScheduled() const
+{
+	return d->dirty;
+}
+
+void ComponentList::buildingFromScratch()
+{
+	d->loaded = true;
+	d->dirty = true;
+}
+
+void ComponentList::scheduleSave()
+{
+	if(!d->loaded)
+	{
+		qDebug() << "Component list should never save if it didn't successfully load, instance:" << d->m_instance->name();
+		return;
+	}
+	if(!d->dirty)
+	{
+		d->dirty = true;
+		qDebug() << "Component list save is scheduled for" << d->m_instance->name();
+	}
+	d->m_saveTimer.start();
+}
+
+QString ComponentList::componentsFilePath() const
+{
+	return FS::PathCombine(d->m_instance->instanceRoot(), "mmc-pack.json");
+}
+
+QString ComponentList::patchesPattern() const
+{
+	return FS::PathCombine(d->m_instance->instanceRoot(), "patches", "%1.json");
+}
+
+QString ComponentList::patchFilePathForUid(const QString& uid) const
+{
+	return patchesPattern().arg(uid);
+}
+
+void ComponentList::save()
+{
+	qDebug() << "Component list save performed now for" << d->m_instance->name();
+	auto filename = componentsFilePath();
+	saveComponentList(filename, d->components);
+	d->dirty = false;
+}
+
+bool ComponentList::load()
+{
+	auto filename = componentsFilePath();
+	QFile componentsFile(filename);
+
+	// migrate old config to new one, if needed
+	if(!componentsFile.exists())
+	{
+		if(!migratePreComponentConfig())
+		{
+			// FIXME: the user should be notified...
+			qCritical() << "Failed to convert old pre-component config for instance" << d->m_instance->name();
+			return false;
+		}
+	}
+
+	// load the new component list and swap it with the current one...
+	ComponentContainer newComponents;
+	if(!loadComponentList(this, filename, patchesPattern(), newComponents))
+	{
+		qCritical() << "Failed to load the component config for instance" << d->m_instance->name();
+		return false;
+	}
+	else
+	{
+		// FIXME: actually use fine-grained updates, not this...
+		beginResetModel();
+		// disconnect all the old components
+		for(auto component: d->components)
+		{
+			disconnect(component.get(), &Component::dataChanged, this, &ComponentList::componentDataChanged);
+		}
+		d->components.clear();
+		d->componentIndex.clear();
+		for(auto component: newComponents)
+		{
+			if(d->componentIndex.contains(component->m_uid))
+			{
+				qWarning() << "Ignoring duplicate component entry" << component->m_uid;
+				continue;
+			}
+			connect(component.get(), &Component::dataChanged, this, &ComponentList::componentDataChanged);
+			d->components.append(component);
+			d->componentIndex[component->m_uid] = component;
+		}
+		endResetModel();
+		d->loaded = true;
+		return true;
+	}
+}
+
+void ComponentList::reload(Net::Mode netmode)
+{
+	// Do not reload when the update/resolve task is running. It is in control.
+	if(d->m_updateTask)
+	{
+		return;
+	}
+
+	// flush any scheduled saves to not lose state
+	if(saveIsScheduled())
+	{
+		save();
+	}
+
+	// FIXME: differentiate when a reapply is required by propagating state from components
+	invalidateLaunchProfile();
+
+	if(load())
+	{
+		resolve(netmode);
+	}
+}
+
+shared_qobject_ptr<Task> ComponentList::getCurrentTask()
+{
+	return d->m_updateTask;
 }
 
-void ComponentList::reload()
+void ComponentList::resolve(Net::Mode netmode)
+{
+	auto updateTask = new ComponentUpdateTask(ComponentUpdateTask::Mode::Resolution, netmode, this);
+	d->m_updateTask.reset(updateTask);
+	connect(updateTask, &ComponentUpdateTask::succeeded, this, &ComponentList::updateSucceeded);
+	connect(updateTask, &ComponentUpdateTask::failed, this, &ComponentList::updateFailed);
+	d->m_updateTask->start();
+}
+
+
+void ComponentList::updateSucceeded()
 {
-	beginResetModel();
-	load_internal();
-	reapplyPatches();
-	endResetModel();
+	qDebug() << "Component list update/resolve task succeeded for" << d->m_instance->name();
+	d->m_updateTask.reset();
+	invalidateLaunchProfile();
 }
 
-void ComponentList::clearPatches()
+void ComponentList::updateFailed(const QString& error)
 {
-	beginResetModel();
-	m_patches.clear();
-	endResetModel();
+	qDebug() << "Component list update/resolve task failed for" << d->m_instance->name() << "Reason:" << error;
+	d->m_updateTask.reset();
+	invalidateLaunchProfile();
 }
 
-void ComponentList::appendPatch(ProfilePatchPtr patch)
+// NOTE this is really old stuff, and only needs to be used when loading the old hardcoded component-unaware format (loadPreComponentConfig).
+static void upgradeDeprecatedFiles(QString root, QString instanceName)
 {
-	int index = m_patches.size();
+	auto versionJsonPath = FS::PathCombine(root, "version.json");
+	auto customJsonPath = FS::PathCombine(root, "custom.json");
+	auto mcJson = FS::PathCombine(root, "patches" , "net.minecraft.json");
+
+	QString sourceFile;
+	QString renameFile;
+
+	// convert old crap.
+	if(QFile::exists(customJsonPath))
+	{
+		sourceFile = customJsonPath;
+		renameFile = versionJsonPath;
+	}
+	else if(QFile::exists(versionJsonPath))
+	{
+		sourceFile = versionJsonPath;
+	}
+	if(!sourceFile.isEmpty() && !QFile::exists(mcJson))
+	{
+		if(!FS::ensureFilePathExists(mcJson))
+		{
+			qWarning() << "Couldn't create patches folder for" << instanceName;
+			return;
+		}
+		if(!renameFile.isEmpty() && QFile::exists(renameFile))
+		{
+			if(!QFile::rename(renameFile, renameFile + ".old"))
+			{
+				qWarning() << "Couldn't rename" << renameFile << "to" << renameFile + ".old" << "in" << instanceName;
+				return;
+			}
+		}
+		auto file = ProfileUtils::parseJsonFile(QFileInfo(sourceFile), false);
+		ProfileUtils::removeLwjglFromPatch(file);
+		file->uid = "net.minecraft";
+		file->version = file->minecraftVersion;
+		file->name = "Minecraft";
+
+		Meta::Require needsLwjgl;
+		needsLwjgl.uid = "org.lwjgl";
+		file->requires.insert(needsLwjgl);
+
+		if(!ProfileUtils::saveJsonFile(OneSixVersionFormat::versionFileToJson(file), mcJson))
+		{
+			return;
+		}
+		if(!QFile::rename(sourceFile, sourceFile + ".old"))
+		{
+			qWarning() << "Couldn't rename" << sourceFile << "to" << sourceFile + ".old" << "in" << instanceName;
+			return;
+		}
+	}
+}
+
+/*
+ * Migrate old layout to the component based one...
+ * - Part of the version information is taken from `instance.cfg` (fed to this class from outside).
+ * - Part is taken from the old order.json file.
+ * - Part is loaded from loose json files in the instance's `patches` directory.
+ */
+bool ComponentList::migratePreComponentConfig()
+{
+	// upgrade the very old files from the beginnings of MultiMC 5
+	upgradeDeprecatedFiles(d->m_instance->instanceRoot(), d->m_instance->name());
+
+	QList<ComponentPtr> components;
+	QSet<QString> loaded;
+
+	auto addBuiltinPatch = [&](const QString &uid, bool asDependency, const QString & emptyVersion, const Meta::Require & req, const Meta::Require & conflict)
+	{
+		auto jsonFilePath = FS::PathCombine(d->m_instance->instanceRoot(), "patches" , uid + ".json");
+		auto intendedVersion = d->getOldConfigVersion(uid);
+		// load up the base minecraft patch
+		ComponentPtr component;
+		if(QFile::exists(jsonFilePath))
+		{
+			if(intendedVersion.isEmpty())
+			{
+				intendedVersion = emptyVersion;
+			}
+			auto file = ProfileUtils::parseJsonFile(QFileInfo(jsonFilePath), false);
+			bool fileChanged = false;
+			// if uid is missing or incorrect, fix it
+			if(file->uid != uid)
+			{
+				file->uid = uid;
+				fileChanged = true;
+			}
+			// if version is missing, add it from the outside.
+			if(file->version.isEmpty())
+			{
+				file->version = intendedVersion;
+				fileChanged = true;
+			}
+			// if this is a dependency (LWJGL), mark it also as volatile
+			if(asDependency)
+			{
+				file->m_volatile = true;
+				fileChanged = true;
+			}
+			// insert requirements if needed
+			if(!req.uid.isEmpty())
+			{
+				file->requires.insert(req);
+				fileChanged = true;
+			}
+			// insert conflicts if needed
+			if(!conflict.uid.isEmpty())
+			{
+				file->conflicts.insert(conflict);
+				fileChanged = true;
+			}
+			if(fileChanged)
+			{
+				// FIXME: @QUALITY do not ignore return value
+				ProfileUtils::saveJsonFile(OneSixVersionFormat::versionFileToJson(file), jsonFilePath);
+			}
+			component = new Component(this, uid, file);
+			component->m_version = intendedVersion;
+		}
+		else if(!intendedVersion.isEmpty())
+		{
+			auto metaVersion = ENV.metadataIndex()->get(uid, intendedVersion);
+			component = new Component(this, metaVersion);
+		}
+		else
+		{
+			return;
+		}
+		component->m_dependencyOnly = asDependency;
+		component->m_important = !asDependency;
+		components.append(component);
+	};
+	// TODO: insert depends and conflicts here if these are customized files...
+	Meta::Require reqLwjgl;
+	reqLwjgl.uid = "org.lwjgl";
+	reqLwjgl.suggests = "2.9.1";
+	Meta::Require conflictLwjgl3;
+	conflictLwjgl3.uid = "org.lwjgl3";
+	Meta::Require nullReq;
+	addBuiltinPatch("org.lwjgl", true, "2.9.1", nullReq, conflictLwjgl3);
+	addBuiltinPatch("net.minecraft", false, QString(), reqLwjgl, nullReq);
+
+	// first, collect all other file-based patches and load them
+	QMap<QString, ComponentPtr> loadedComponents;
+	QDir patchesDir(FS::PathCombine(d->m_instance->instanceRoot(),"patches"));
+	for (auto info : patchesDir.entryInfoList(QStringList() << "*.json", QDir::Files))
+	{
+		// parse the file
+		qDebug() << "Reading" << info.fileName();
+		auto file = ProfileUtils::parseJsonFile(info, true);
+
+		// correct missing or wrong uid based on the file name
+		QString uid = info.completeBaseName();
+
+		// ignore builtins, they've been handled already
+		if (uid == "net.minecraft")
+			continue;
+		if (uid == "org.lwjgl")
+			continue;
+
+		// handle horrible corner cases
+		if(uid.isEmpty())
+		{
+			// if you have a file named '.json', make it just go away.
+			// FIXME: @QUALITY do not ignore return value
+			QFile::remove(info.absoluteFilePath());
+			continue;
+		}
+		bool fileChanged = false;
+		if(file->uid != uid)
+		{
+			file->uid = uid;
+			fileChanged = true;
+		}
+		if(fileChanged)
+		{
+			// FIXME: @QUALITY do not ignore return value
+			ProfileUtils::saveJsonFile(OneSixVersionFormat::versionFileToJson(file), info.absoluteFilePath());
+		}
+
+		auto component = new Component(this, file->uid, file);
+		auto version = d->getOldConfigVersion(file->uid);
+		if(!version.isEmpty())
+		{
+			component->m_version = version;
+		}
+		loadedComponents[file->uid] = component;
+	}
+	// try to load the other 'hardcoded' patches (forge, liteloader), if they weren't loaded from files
+	auto loadSpecial = [&](const QString & uid, int order)
+	{
+		auto patchVersion = d->getOldConfigVersion(uid);
+		if(!patchVersion.isEmpty() && !loadedComponents.contains(uid))
+		{
+			auto patch = new Component(this, ENV.metadataIndex()->get(uid, patchVersion));
+			patch->setOrder(order);
+			loadedComponents[uid] = patch;
+		}
+	};
+	loadSpecial("net.minecraftforge", 5);
+	loadSpecial("com.mumfrey.liteloader", 10);
+
+	// load the old order.json file, if present
+	ProfileUtils::PatchOrder userOrder;
+	ProfileUtils::readOverrideOrders(FS::PathCombine(d->m_instance->instanceRoot(), "order.json"), userOrder);
+
+	// now add all the patches by user sort order
+	for (auto uid : userOrder)
+	{
+		// ignore builtins
+		if (uid == "net.minecraft")
+			continue;
+		if (uid == "org.lwjgl")
+			continue;
+		// ordering has a patch that is gone?
+		if(!loadedComponents.contains(uid))
+		{
+			continue;
+		}
+		components.append(loadedComponents.take(uid));
+	}
+
+	// is there anything left to sort? - this is used when there are leftover components that aren't part of the order.json
+	if(!loadedComponents.isEmpty())
+	{
+		// inserting into multimap by order number as key sorts the patches and detects duplicates
+		QMultiMap<int, ComponentPtr> files;
+		auto iter = loadedComponents.begin();
+		while(iter != loadedComponents.end())
+		{
+			files.insert((*iter)->getOrder(), *iter);
+			iter++;
+		}
+
+		// then just extract the patches and put them in the list
+		for (auto order : files.keys())
+		{
+			const auto &values = files.values(order);
+			for(auto &value: values)
+			{
+				// TODO: put back the insertion of problem messages here, so the user knows about the id duplication
+				components.append(value);
+			}
+		}
+	}
+	// new we have a complete list of components...
+	return saveComponentList(componentsFilePath(), components);
+}
+
+// END: save/load
+
+void ComponentList::appendComponent(ComponentPtr component)
+{
+	insertComponent(d->components.size(), component);
+}
+
+void ComponentList::insertComponent(size_t index, ComponentPtr component)
+{
+	auto id = component->getID();
+	if(id.isEmpty())
+	{
+		qWarning() << "Attempt to add a component with empty ID!";
+		return;
+	}
+	if(d->componentIndex.contains(id))
+	{
+		qWarning() << "Attempt to add a component that is already present!";
+		return;
+	}
 	beginInsertRows(QModelIndex(), index, index);
-	m_patches.append(patch);
+	d->components.insert(index, component);
+	d->componentIndex[id] = component;
 	endInsertRows();
+	scheduleSave();
+}
+
+void ComponentList::componentDataChanged()
+{
+	auto objPtr = qobject_cast<Component *>(sender());
+	if(!objPtr)
+	{
+		qWarning() << "ComponentList got dataChenged signal from a non-Component!";
+		return;
+	}
+	// figure out which one is it... in a seriously dumb way.
+	int index = 0;
+	for (auto component: d->components)
+	{
+		if(component.get() == objPtr)
+		{
+			emit dataChanged(createIndex(index, 0), createIndex(index, columnCount(QModelIndex()) - 1));
+			scheduleSave();
+			return;
+		}
+		index++;
+	}
+	qWarning() << "ComponentList got dataChenged signal from a Component which does not belong to it!";
 }
 
 bool ComponentList::remove(const int index)
 {
-	auto patch = versionPatch(index);
+	auto patch = getComponent(index);
 	if (!patch->isRemovable())
 	{
-		qDebug() << "Patch" << patch->getID() << "is non-removable";
+		qWarning() << "Patch" << patch->getID() << "is non-removable";
 		return false;
 	}
 
-	if(!removePatch_internal(patch))
+	if(!removeComponent_internal(patch))
 	{
 		qCritical() << "Patch" << patch->getID() << "could not be removed";
 		return false;
 	}
 
 	beginRemoveRows(QModelIndex(), index, index);
-	m_patches.removeAt(index);
+	d->components.removeAt(index);
+	d->componentIndex.remove(patch->getID());
 	endRemoveRows();
-	reapplyPatches();
-	saveCurrentOrder();
+	invalidateLaunchProfile();
+	scheduleSave();
 	return true;
 }
 
 bool ComponentList::remove(const QString id)
 {
 	int i = 0;
-	for (auto patch : m_patches)
+	for (auto patch : d->components)
 	{
 		if (patch->getID() == id)
 		{
@@ -103,66 +701,62 @@ bool ComponentList::remove(const QString id)
 
 bool ComponentList::customize(int index)
 {
-	auto patch = versionPatch(index);
+	auto patch = getComponent(index);
 	if (!patch->isCustomizable())
 	{
 		qDebug() << "Patch" << patch->getID() << "is not customizable";
 		return false;
 	}
-	if(!customizePatch_internal(patch))
+	if(!patch->customize())
 	{
 		qCritical() << "Patch" << patch->getID() << "could not be customized";
 		return false;
 	}
-	reapplyPatches();
-	saveCurrentOrder();
-	// FIXME: maybe later in unstable
-	// emit dataChanged(createIndex(index, 0), createIndex(index, columnCount(QModelIndex()) - 1));
+	invalidateLaunchProfile();
+	scheduleSave();
 	return true;
 }
 
 bool ComponentList::revertToBase(int index)
 {
-	auto patch = versionPatch(index);
+	auto patch = getComponent(index);
 	if (!patch->isRevertible())
 	{
 		qDebug() << "Patch" << patch->getID() << "is not revertible";
 		return false;
 	}
-	if(!revertPatch_internal(patch))
+	if(!patch->revert())
 	{
 		qCritical() << "Patch" << patch->getID() << "could not be reverted";
 		return false;
 	}
-	reapplyPatches();
-	saveCurrentOrder();
-	// FIXME: maybe later in unstable
-	// emit dataChanged(createIndex(index, 0), createIndex(index, columnCount(QModelIndex()) - 1));
+	invalidateLaunchProfile();
+	scheduleSave();
 	return true;
 }
 
-ProfilePatchPtr ComponentList::versionPatch(const QString &id)
+ComponentPtr ComponentList::getComponent(const QString &id)
 {
-	for (auto patch : m_patches)
+	auto iter = d->componentIndex.find(id);
+	if (iter == d->componentIndex.end())
 	{
-		if (patch->getID() == id)
-		{
-			return patch;
-		}
+		return nullptr;
 	}
-	return nullptr;
+	return *iter;
 }
 
-ProfilePatchPtr ComponentList::versionPatch(int index)
+ComponentPtr ComponentList::getComponent(int index)
 {
-	if(index < 0 || index >= m_patches.size())
+	if(index < 0 || index >= d->components.size())
+	{
 		return nullptr;
-	return m_patches[index];
+	}
+	return d->components[index];
 }
 
 bool ComponentList::isVanilla()
 {
-	for(auto patchptr: m_patches)
+	for(auto patchptr: d->components)
 	{
 		if(patchptr->isCustom())
 			return false;
@@ -173,7 +767,7 @@ bool ComponentList::isVanilla()
 bool ComponentList::revertToVanilla()
 {
 	// remove patches, if present
-	auto VersionPatchesCopy = m_patches;
+	auto VersionPatchesCopy = d->components;
 	for(auto & it: VersionPatchesCopy)
 	{
 		if (!it->isCustom())
@@ -185,14 +779,14 @@ bool ComponentList::revertToVanilla()
 			if(!remove(it->getID()))
 			{
 				qWarning() << "Couldn't remove" << it->getID() << "from profile!";
-				reapplyPatches();
-				saveCurrentOrder();
+				invalidateLaunchProfile();
+				scheduleSave();
 				return false;
 			}
 		}
 	}
-	reapplyPatches();
-	saveCurrentOrder();
+	invalidateLaunchProfile();
+	scheduleSave();
 	return true;
 }
 
@@ -204,17 +798,17 @@ QVariant ComponentList::data(const QModelIndex &index, int role) const
 	int row = index.row();
 	int column = index.column();
 
-	if (row < 0 || row >= m_patches.size())
+	if (row < 0 || row >= d->components.size())
 		return QVariant();
 
-	auto patch = m_patches.at(row);
+	auto patch = d->components.at(row);
 
 	if (role == Qt::DisplayRole)
 	{
 		switch (column)
 		{
 		case 0:
-			return m_patches.at(row)->getName();
+			return d->components.at(row)->getName();
 		case 1:
 		{
 			if(patch->isCustom())
@@ -283,7 +877,7 @@ Qt::ItemFlags ComponentList::flags(const QModelIndex &index) const
 
 int ComponentList::rowCount(const QModelIndex &parent) const
 {
-	return m_patches.size();
+	return d->components.size();
 }
 
 int ComponentList::columnCount(const QModelIndex &parent) const
@@ -291,18 +885,6 @@ int ComponentList::columnCount(const QModelIndex &parent) const
 	return 2;
 }
 
-void ComponentList::saveCurrentOrder() const
-{
-	ProfileUtils::PatchOrder order;
-	for(auto item: m_patches)
-	{
-		if(!item->isMoveable())
-			continue;
-		order.append(item->getID());
-	}
-	saveOrder_internal(order);
-}
-
 void ComponentList::move(const int index, const MoveDirection direction)
 {
 	int theirIndex;
@@ -315,7 +897,7 @@ void ComponentList::move(const int index, const MoveDirection direction)
 		theirIndex = index + 1;
 	}
 
-	if (index < 0 || index >= m_patches.size())
+	if (index < 0 || index >= d->components.size())
 		return;
 	if (theirIndex >= rowCount())
 		theirIndex = rowCount() - 1;
@@ -325,43 +907,23 @@ void ComponentList::move(const int index, const MoveDirection direction)
 		return;
 	int togap = theirIndex > index ? theirIndex + 1 : theirIndex;
 
-	auto from = versionPatch(index);
-	auto to = versionPatch(theirIndex);
+	auto from = getComponent(index);
+	auto to = getComponent(theirIndex);
 
 	if (!from || !to || !to->isMoveable() || !from->isMoveable())
 	{
 		return;
 	}
 	beginMoveRows(QModelIndex(), index, index, QModelIndex(), togap);
-	m_patches.swap(index, theirIndex);
+	d->components.swap(index, theirIndex);
 	endMoveRows();
-	reapplyPatches();
-	saveCurrentOrder();
-}
-void ComponentList::resetOrder()
-{
-	resetOrder_internal();
-	reload();
+	invalidateLaunchProfile();
+	scheduleSave();
 }
 
-bool ComponentList::reapplyPatches()
+void ComponentList::invalidateLaunchProfile()
 {
-	try
-	{
-		m_profile.reset(new LaunchProfile);
-		for(auto file: m_patches)
-		{
-			qDebug() << "Applying" << file->getID() << (file->getProblemSeverity() == ProblemSeverity::Error ? "ERROR" : "GOOD");
-			file->applyTo(m_profile.get());
-		}
-	}
-	catch (Exception & error)
-	{
-		m_profile.reset();
-		qWarning() << "Couldn't apply profile patches because: " << error.cause();
-		return false;
-	}
-	return true;
+	d->m_profile.reset();
 }
 
 void ComponentList::installJarMods(QStringList selectedFiles)
@@ -374,224 +936,7 @@ void ComponentList::installCustomJar(QString selectedFile)
 	installCustomJar_internal(selectedFile);
 }
 
-
-/*
- * TODO: get rid of this. Get rid of all order numbers.
- */
-int ComponentList::getFreeOrderNumber()
-{
-	int largest = 100;
-	// yes, I do realize this is dumb. The order thing itself is dumb. and to be removed next.
-	for(auto thing: m_patches)
-	{
-		int order = thing->getOrder();
-		if(order > largest)
-			largest = order;
-	}
-	return largest + 1;
-}
-
-void ComponentList::upgradeDeprecatedFiles_internal()
-{
-	auto versionJsonPath = FS::PathCombine(m_instance->instanceRoot(), "version.json");
-	auto customJsonPath = FS::PathCombine(m_instance->instanceRoot(), "custom.json");
-	auto mcJson = FS::PathCombine(m_instance->instanceRoot(), "patches" , "net.minecraft.json");
-
-	QString sourceFile;
-	QString renameFile;
-
-	// convert old crap.
-	if(QFile::exists(customJsonPath))
-	{
-		sourceFile = customJsonPath;
-		renameFile = versionJsonPath;
-	}
-	else if(QFile::exists(versionJsonPath))
-	{
-		sourceFile = versionJsonPath;
-	}
-	if(!sourceFile.isEmpty() && !QFile::exists(mcJson))
-	{
-		if(!FS::ensureFilePathExists(mcJson))
-		{
-			qWarning() << "Couldn't create patches folder for" << m_instance->name();
-			return;
-		}
-		if(!renameFile.isEmpty() && QFile::exists(renameFile))
-		{
-			if(!QFile::rename(renameFile, renameFile + ".old"))
-			{
-				qWarning() << "Couldn't rename" << renameFile << "to" << renameFile + ".old" << "in" << m_instance->name();
-				return;
-			}
-		}
-		auto file = ProfileUtils::parseJsonFile(QFileInfo(sourceFile), false);
-		ProfileUtils::removeLwjglFromPatch(file);
-		file->uid = "net.minecraft";
-		file->version = file->minecraftVersion;
-		file->name = "Minecraft";
-		auto data = OneSixVersionFormat::versionFileToJson(file, false).toJson();
-		QSaveFile newPatchFile(mcJson);
-		if(!newPatchFile.open(QIODevice::WriteOnly))
-		{
-			newPatchFile.cancelWriting();
-			qWarning() << "Couldn't open main patch for writing in" << m_instance->name();
-			return;
-		}
-		newPatchFile.write(data);
-		if(!newPatchFile.commit())
-		{
-			qWarning() << "Couldn't save main patch in" << m_instance->name();
-			return;
-		}
-		if(!QFile::rename(sourceFile, sourceFile + ".old"))
-		{
-			qWarning() << "Couldn't rename" << sourceFile << "to" << sourceFile + ".old" << "in" << m_instance->name();
-			return;
-		}
-	}
-}
-
-void ComponentList::loadDefaultBuiltinPatches_internal()
-{
-	auto addBuiltinPatch = [&](const QString &uid, const QString intendedVersion, int order)
-	{
-		auto jsonFilePath = FS::PathCombine(m_instance->instanceRoot(), "patches" , uid + ".json");
-		// load up the base minecraft patch
-		ProfilePatchPtr profilePatch;
-		if(QFile::exists(jsonFilePath))
-		{
-			auto file = ProfileUtils::parseJsonFile(QFileInfo(jsonFilePath), false);
-			if(file->version.isEmpty())
-			{
-				file->version = intendedVersion;
-			}
-			profilePatch = std::make_shared<ProfilePatch>(file, jsonFilePath);
-			profilePatch->setVanilla(false);
-			profilePatch->setRevertible(true);
-		}
-		else
-		{
-			auto metaVersion = ENV.metadataIndex()->get(uid, intendedVersion);
-			profilePatch = std::make_shared<ProfilePatch>(metaVersion);
-			profilePatch->setVanilla(true);
-		}
-		profilePatch->setOrder(order);
-		appendPatch(profilePatch);
-	};
-	addBuiltinPatch("net.minecraft", m_instance->getComponentVersion("net.minecraft"), -2);
-	addBuiltinPatch("org.lwjgl", m_instance->getComponentVersion("org.lwjgl"), -1);
-}
-
-void ComponentList::loadUserPatches_internal()
-{
-	// first, collect all patches (that are not builtins of OneSix) and load them
-	QMap<QString, ProfilePatchPtr> loadedPatches;
-	QDir patchesDir(FS::PathCombine(m_instance->instanceRoot(),"patches"));
-	for (auto info : patchesDir.entryInfoList(QStringList() << "*.json", QDir::Files))
-	{
-		// parse the file
-		qDebug() << "Reading" << info.fileName();
-		auto file = ProfileUtils::parseJsonFile(info, true);
-		// ignore builtins
-		if (file->uid == "net.minecraft")
-			continue;
-		if (file->uid == "org.lwjgl")
-			continue;
-		auto patch = std::make_shared<ProfilePatch>(file, info.filePath());
-		patch->setRemovable(true);
-		patch->setMovable(true);
-		if(ENV.metadataIndex()->hasUid(file->uid))
-		{
-			// FIXME: requesting a uid/list creates it in the index... this allows reverting to possibly invalid versions...
-			patch->setRevertible(true);
-		}
-		loadedPatches[file->uid] = patch;
-	}
-	// these are 'special'... if not already loaded from instance files, grab them from the metadata repo.
-	auto loadSpecial = [&](const QString & uid, int order)
-	{
-		auto patchVersion = m_instance->getComponentVersion(uid);
-		if(!patchVersion.isEmpty() && !loadedPatches.contains(uid))
-		{
-			auto patch = std::make_shared<ProfilePatch>(ENV.metadataIndex()->get(uid, patchVersion));
-			patch->setOrder(order);
-			patch->setVanilla(true);
-			patch->setRemovable(true);
-			patch->setMovable(true);
-			loadedPatches[uid] = patch;
-		}
-	};
-	loadSpecial("net.minecraftforge", 5);
-	loadSpecial("com.mumfrey.liteloader", 10);
-
-	// now add all the patches by user sort order
-	ProfileUtils::PatchOrder userOrder;
-	ProfileUtils::readOverrideOrders(FS::PathCombine(m_instance->instanceRoot(), "order.json"), userOrder);
-	for (auto uid : userOrder)
-	{
-		// ignore builtins
-		if (uid == "net.minecraft")
-			continue;
-		if (uid == "org.lwjgl")
-			continue;
-		// ordering has a patch that is gone?
-		if(!loadedPatches.contains(uid))
-		{
-			continue;
-		}
-		appendPatch(loadedPatches.take(uid));
-	}
-
-	// is there anything left to sort?
-	if(loadedPatches.isEmpty())
-	{
-		// TODO: save the order here?
-		return;
-	}
-
-	// inserting into multimap by order number as key sorts the patches and detects duplicates
-	QMultiMap<int, ProfilePatchPtr> files;
-	auto iter = loadedPatches.begin();
-	while(iter != loadedPatches.end())
-	{
-		files.insert((*iter)->getOrder(), *iter);
-		iter++;
-	}
-
-	// then just extract the patches and put them in the list
-	for (auto order : files.keys())
-	{
-		const auto &values = files.values(order);
-		for(auto &value: values)
-		{
-			// TODO: put back the insertion of problem messages here, so the user knows about the id duplication
-			appendPatch(value);
-		}
-	}
-	// TODO: save the order here?
-}
-
-
-void ComponentList::load_internal()
-{
-	clearPatches();
-	upgradeDeprecatedFiles_internal();
-	loadDefaultBuiltinPatches_internal();
-	loadUserPatches_internal();
-}
-
-bool ComponentList::saveOrder_internal(ProfileUtils::PatchOrder order) const
-{
-	return ProfileUtils::writeOverrideOrders(FS::PathCombine(m_instance->instanceRoot(), "order.json"), order);
-}
-
-bool ComponentList::resetOrder_internal()
-{
-	return QDir(m_instance->instanceRoot()).remove("order.json");
-}
-
-bool ComponentList::removePatch_internal(ProfilePatchPtr patch)
+bool ComponentList::removeComponent_internal(ComponentPtr patch)
 {
 	bool ok = true;
 	// first, remove the patch file. this ensures it's not used anymore
@@ -605,10 +950,6 @@ bool ComponentList::removePatch_internal(ProfilePatchPtr patch)
 			return false;
 		}
 	}
-	if(!m_instance->getComponentVersion(patch->getID()).isEmpty())
-	{
-		m_instance->setComponentVersion(patch->getID(), QString());
-	}
 
 	// FIXME: we need a generic way of removing local resources, not just jar mods...
 	auto preRemoveJarMod = [&](LibraryPtr jarMod) -> bool
@@ -618,7 +959,7 @@ bool ComponentList::removePatch_internal(ProfilePatchPtr patch)
 			return true;
 		}
 		QStringList jar, temp1, temp2, temp3;
-		jarMod->getApplicableFiles(currentSystem, jar, temp1, temp2, temp3, m_instance->jarmodsPath().absolutePath());
+		jarMod->getApplicableFiles(currentSystem, jar, temp1, temp2, temp3, d->m_instance->jarmodsPath().absolutePath());
 		QFileInfo finfo (jar[0]);
 		if(finfo.exists())
 		{
@@ -633,90 +974,27 @@ bool ComponentList::removePatch_internal(ProfilePatchPtr patch)
 		return true;
 	};
 
-	auto &jarMods = patch->getVersionFile()->jarMods;
-	for(auto &jarmod: jarMods)
-	{
-		ok &= preRemoveJarMod(jarmod);
-	}
-	return ok;
-}
-
-bool ComponentList::customizePatch_internal(ProfilePatchPtr patch)
-{
-	if(patch->isCustom())
-	{
-		return false;
-	}
-
-	auto filename = FS::PathCombine(m_instance->instanceRoot(), "patches" , patch->getID() + ".json");
-	if(!FS::ensureFilePathExists(filename))
-	{
-		return false;
-	}
-	// FIXME: get rid of this try-catch.
-	try
+	auto vFile = patch->getVersionFile();
+	if(vFile)
 	{
-		QSaveFile jsonFile(filename);
-		if(!jsonFile.open(QIODevice::WriteOnly))
-		{
-			return false;
-		}
-		auto vfile = patch->getVersionFile();
-		if(!vfile)
+		auto &jarMods = vFile->jarMods;
+		for(auto &jarmod: jarMods)
 		{
-			return false;
-		}
-		auto document = OneSixVersionFormat::versionFileToJson(vfile, true);
-		jsonFile.write(document.toJson());
-		if(!jsonFile.commit())
-		{
-			return false;
+			ok &= preRemoveJarMod(jarmod);
 		}
-		load_internal();
-	}
-	catch (Exception &error)
-	{
-		qWarning() << "Version could not be loaded:" << error.cause();
-	}
-	return true;
-}
-
-bool ComponentList::revertPatch_internal(ProfilePatchPtr patch)
-{
-	if(!patch->isCustom())
-	{
-		// already not custom
-		return true;
-	}
-	auto filename = patch->getFilename();
-	if(!QFile::exists(filename))
-	{
-		// already gone / not custom
-		return true;
 	}
-	// just kill the file and reload
-	bool result = QFile::remove(filename);
-	// FIXME: get rid of this try-catch.
-	try
-	{
-		load_internal();
-	}
-	catch (Exception &error)
-	{
-		qWarning() << "Version could not be loaded:" << error.cause();
-	}
-	return result;
+	return ok;
 }
 
 bool ComponentList::installJarMods_internal(QStringList filepaths)
 {
-	QString patchDir = FS::PathCombine(m_instance->instanceRoot(), "patches");
+	QString patchDir = FS::PathCombine(d->m_instance->instanceRoot(), "patches");
 	if(!FS::ensureFolderPathExists(patchDir))
 	{
 		return false;
 	}
 
-	if (!FS::ensureFolderPathExists(m_instance->jarModsDir()))
+	if (!FS::ensureFolderPathExists(d->m_instance->jarModsDir()))
 	{
 		return false;
 	}
@@ -729,7 +1007,7 @@ bool ComponentList::installJarMods_internal(QStringList filepaths)
 		QString target_filename = id + ".jar";
 		QString target_id = "org.multimc.jarmod." + id;
 		QString target_name = sourceInfo.completeBaseName() + " (jar mod)";
-		QString finalPath = FS::PathCombine(m_instance->jarModsDir(), target_filename);
+		QString finalPath = FS::PathCombine(d->m_instance->jarModsDir(), target_filename);
 
 		QFileInfo targetInfo(finalPath);
 		if(targetInfo.exists())
@@ -751,7 +1029,6 @@ bool ComponentList::installJarMods_internal(QStringList filepaths)
 		f->jarMods.append(jarMod);
 		f->name = target_name;
 		f->uid = target_id;
-		f->order = getFreeOrderNumber();
 		QString patchFileName = FS::PathCombine(patchDir, target_id + ".json");
 
 		QFile file(patchFileName);
@@ -761,28 +1038,25 @@ bool ComponentList::installJarMods_internal(QStringList filepaths)
 						<< "for reading:" << file.errorString();
 			return false;
 		}
-		file.write(OneSixVersionFormat::versionFileToJson(f, true).toJson());
+		file.write(OneSixVersionFormat::versionFileToJson(f).toJson());
 		file.close();
 
-		auto patch = std::make_shared<ProfilePatch>(f, patchFileName);
-		patch->setMovable(true);
-		patch->setRemovable(true);
-		appendPatch(patch);
+		appendComponent(new Component(this, f->uid, f));
 	}
-	saveCurrentOrder();
-	reapplyPatches();
+	scheduleSave();
+	invalidateLaunchProfile();
 	return true;
 }
 
 bool ComponentList::installCustomJar_internal(QString filepath)
 {
-	QString patchDir = FS::PathCombine(m_instance->instanceRoot(), "patches");
+	QString patchDir = FS::PathCombine(d->m_instance->instanceRoot(), "patches");
 	if(!FS::ensureFolderPathExists(patchDir))
 	{
 		return false;
 	}
 
-	QString libDir = m_instance->getLocalLibraryPath();
+	QString libDir = d->m_instance->getLocalLibraryPath();
 	if (!FS::ensureFolderPathExists(libDir))
 	{
 		return false;
@@ -816,7 +1090,6 @@ bool ComponentList::installCustomJar_internal(QString filepath)
 	f->mainJar = jarMod;
 	f->name = target_name;
 	f->uid = target_id;
-	f->order = getFreeOrderNumber();
 	QString patchFileName = FS::PathCombine(patchDir, target_id + ".json");
 
 	QFile file(patchFileName);
@@ -826,25 +1099,74 @@ bool ComponentList::installCustomJar_internal(QString filepath)
 					<< "for reading:" << file.errorString();
 		return false;
 	}
-	file.write(OneSixVersionFormat::versionFileToJson(f, true).toJson());
+	file.write(OneSixVersionFormat::versionFileToJson(f).toJson());
 	file.close();
 
-	auto patch = std::make_shared<ProfilePatch>(f, patchFileName);
-	patch->setMovable(true);
-	patch->setRemovable(true);
-	appendPatch(patch);
+	appendComponent(new Component(this, f->uid, f));
 
-	saveCurrentOrder();
-	reapplyPatches();
+	scheduleSave();
+	invalidateLaunchProfile();
 	return true;
 }
 
 std::shared_ptr<LaunchProfile> ComponentList::getProfile() const
 {
-	return m_profile;
+	if(!d->m_profile)
+	{
+		try
+		{
+			auto profile = std::make_shared<LaunchProfile>();
+			for(auto file: d->components)
+			{
+				qDebug() << "Applying" << file->getID() << (file->getProblemSeverity() == ProblemSeverity::Error ? "ERROR" : "GOOD");
+				file->applyTo(profile.get());
+			}
+			d->m_profile = profile;
+		}
+		catch (Exception & error)
+		{
+			qWarning() << "Couldn't apply profile patches because: " << error.cause();
+		}
+	}
+	return d->m_profile;
+}
+
+void ComponentList::setOldConfigVersion(const QString& uid, const QString& version)
+{
+	if(version.isEmpty())
+	{
+		return;
+	}
+	d->m_oldConfigVersions[uid] = version;
+}
+
+bool ComponentList::setComponentVersion(const QString& uid, const QString& version, bool important)
+{
+	auto iter = d->componentIndex.find(uid);
+	if(iter != d->componentIndex.end())
+	{
+		// set existing
+		(*iter)->setVersion(version);
+		(*iter)->setImportant(important);
+		return true;
+	}
+	else
+	{
+		// add new
+		auto component = new Component(this, uid);
+		component->m_version = version;
+		component->m_important = important;
+		appendComponent(component);
+		return true;
+	}
 }
 
-void ComponentList::clearProfile()
+QString ComponentList::getComponentVersion(const QString& uid) const
 {
-	m_profile.reset();
+	const auto iter = d->componentIndex.find(uid);
+	if (iter != d->componentIndex.end())
+	{
+		return (*iter)->getVersion();
+	}
+	return QString();
 }
diff --git a/api/logic/minecraft/ComponentList.h b/api/logic/minecraft/ComponentList.h
index 0811a829..7971650d 100644
--- a/api/logic/minecraft/ComponentList.h
+++ b/api/logic/minecraft/ComponentList.h
@@ -23,19 +23,21 @@
 
 #include "Library.h"
 #include "LaunchProfile.h"
-#include "ProfilePatch.h"
+#include "Component.h"
 #include "ProfileUtils.h"
 #include "BaseVersion.h"
 #include "MojangDownloadInfo.h"
 #include "multimc_logic_export.h"
+#include "net/Mode.h"
 
 class MinecraftInstance;
-
+struct ComponentListData;
+class ComponentUpdateTask;
 
 class MULTIMC_LOGIC_EXPORT ComponentList : public QAbstractListModel
 {
 	Q_OBJECT
-
+	friend ComponentUpdateTask;
 public:
 	explicit ComponentList(MinecraftInstance * instance);
 	virtual ~ComponentList();
@@ -46,6 +48,9 @@ public:
 	virtual int columnCount(const QModelIndex &parent) const override;
 	virtual Qt::ItemFlags flags(const QModelIndex &index) const override;
 
+	/// call this to explicitly mark the component list as loaded - this is used to build a new component list from scratch.
+	void buildingFromScratch();
+
 	/// is this version unchanged by the user?
 	bool isVanilla();
 
@@ -58,68 +63,76 @@ public:
 	/// install a jar/zip as a replacement for the main jar
 	void installCustomJar(QString selectedFile);
 
-	/// DEPRECATED, remove ASAP
-	int getFreeOrderNumber();
-
 	enum MoveDirection { MoveUp, MoveDown };
-	/// move patch file # up or down the list
+	/// move component file # up or down the list
 	void move(const int index, const MoveDirection direction);
 
-	/// remove patch file # - including files/records
+	/// remove component file # - including files/records
 	bool remove(const int index);
 
-	/// remove patch file by id - including files/records
+	/// remove component file by id - including files/records
 	bool remove(const QString id);
 
 	bool customize(int index);
 
 	bool revertToBase(int index);
 
-	void resetOrder();
+	/// reload the list, reload all components, resolve dependencies
+	void reload(Net::Mode netmode);
 
-	/// reload all profile patches from storage, clear the profile and apply the patches
-	void reload();
+	// reload all components, resolve dependencies
+	void resolve(Net::Mode netmode);
 
-	/// apply the patches. Catches all the errors and returns true/false for success/failure
-	bool reapplyPatches();
+	/// get current running task...
+	shared_qobject_ptr<Task> getCurrentTask();
 
 	std::shared_ptr<LaunchProfile> getProfile() const;
-	void clearProfile();
+
+	// NOTE: used ONLY by MinecraftInstance to provide legacy version mappings from instance config
+	void setOldConfigVersion(const QString &uid, const QString &version);
+
+	QString getComponentVersion(const QString &uid) const;
+
+	bool setComponentVersion(const QString &uid, const QString &version, bool important = false);
+
+	QString patchFilePathForUid(const QString &uid) const;
 public:
-	/// get the profile patch by id
-	ProfilePatchPtr versionPatch(const QString &id);
+	/// get the profile component by id
+	ComponentPtr getComponent(const QString &id);
+
+	/// get the profile component by index
+	ComponentPtr getComponent(int index);
+
+private:
+	void scheduleSave();
+	bool saveIsScheduled() const;
 
-	/// get the profile patch by index
-	ProfilePatchPtr versionPatch(int index);
+	/// apply the component patches. Catches all the errors and returns true/false for success/failure
+	void invalidateLaunchProfile();
 
-	/// save the current patch order
-	void saveCurrentOrder() const;
+	/// Add the component to the internal list of patches
+	void appendComponent(ComponentPtr component);
+	/// insert component so that its index is ideally the specified one (returns real index)
+	void insertComponent(size_t index, ComponentPtr component);
 
-	/// Remove all the patches
-	void clearPatches();
+	QString componentsFilePath() const;
+	QString patchesPattern() const;
 
-	/// Add the patch object to the internal list of patches
-	void appendPatch(ProfilePatchPtr patch);
+private slots:
+	void save();
+	void updateSucceeded();
+	void updateFailed(const QString & error);
+	void componentDataChanged();
 
 private:
-	void load_internal();
-	bool resetOrder_internal();
-	bool saveOrder_internal(ProfileUtils::PatchOrder order) const;
+	bool load();
 	bool installJarMods_internal(QStringList filepaths);
     bool installCustomJar_internal(QString filepath);
-	bool removePatch_internal(ProfilePatchPtr patch);
-	bool customizePatch_internal(ProfilePatchPtr patch);
-	bool revertPatch_internal(ProfilePatchPtr patch);
-	void loadDefaultBuiltinPatches_internal();
-	void loadUserPatches_internal();
-	void upgradeDeprecatedFiles_internal();
+	bool removeComponent_internal(ComponentPtr patch);
 
-private: /* data */
-	/// list of attached profile patches
-	QList<ProfilePatchPtr> m_patches;
+	bool migratePreComponentConfig();
 
-	// the instance this belongs to
-	MinecraftInstance *m_instance;
+private: /* data */
 
-	std::shared_ptr<LaunchProfile> m_profile;
+	std::unique_ptr<ComponentListData> d;
 };
diff --git a/api/logic/minecraft/ComponentList_p.h b/api/logic/minecraft/ComponentList_p.h
new file mode 100644
index 00000000..26ca5049
--- /dev/null
+++ b/api/logic/minecraft/ComponentList_p.h
@@ -0,0 +1,42 @@
+#pragma once
+
+#include "Component.h"
+#include <map>
+#include <QTimer>
+#include <QList>
+#include <QMap>
+
+class MinecraftInstance;
+using ComponentContainer = QList<ComponentPtr>;
+using ComponentIndex = QMap<QString, ComponentPtr>;
+using ConnectionList = QList<QMetaObject::Connection>;
+
+struct ComponentListData
+{
+	// the instance this belongs to
+	MinecraftInstance *m_instance;
+
+	// the launch profile (volatile, temporary thing created on demand)
+	std::shared_ptr<LaunchProfile> m_profile;
+
+	// version information migrated from instance.cfg file. Single use on migration!
+	std::map<QString, QString> m_oldConfigVersions;
+	QString getOldConfigVersion(const QString& uid) const
+	{
+		const auto iter = m_oldConfigVersions.find(uid);
+		if(iter != m_oldConfigVersions.cend())
+		{
+			return (*iter).second;
+		}
+		return QString();
+	}
+
+	// persistent list of components and related machinery
+	ComponentContainer components;
+	ComponentIndex componentIndex;
+	bool dirty = false;
+	QTimer m_saveTimer;
+	shared_qobject_ptr<Task> m_updateTask;
+	bool loaded = false;
+};
+
diff --git a/api/logic/minecraft/ComponentUpdateTask.cpp b/api/logic/minecraft/ComponentUpdateTask.cpp
new file mode 100644
index 00000000..e03318c5
--- /dev/null
+++ b/api/logic/minecraft/ComponentUpdateTask.cpp
@@ -0,0 +1,688 @@
+#include "ComponentUpdateTask.h"
+
+#include "ComponentList_p.h"
+#include "ComponentList.h"
+#include "Component.h"
+#include <Env.h>
+#include <meta/Index.h>
+#include <meta/VersionList.h>
+#include <meta/Version.h>
+#include "ComponentUpdateTask_p.h"
+#include <cassert>
+#include <Version.h>
+#include "net/Mode.h"
+#include "OneSixVersionFormat.h"
+
+/*
+ * This is responsible for loading the components of a component list AND resolving dependency issues between them
+ */
+
+/*
+ * FIXME: the 'one shot async task' nature of this does not fit the intended usage
+ * Really, it should be a reactor/state machine that receives input from the application
+ * and dynamically adapts to changing requirements...
+ *
+ * The reactor should be the only entry into manipulating the ComponentList.
+ * See: https://en.wikipedia.org/wiki/Reactor_pattern
+ */
+
+/*
+ * Or make this operate on a snapshot of the ComponentList state, then merge results in as long as the snapshot and ComponentList didn't change?
+ * If the component list changes, start over.
+ */
+
+ComponentUpdateTask::ComponentUpdateTask(Mode mode, Net::Mode netmode, ComponentList* list, QObject* parent)
+	: Task(parent)
+{
+	d.reset(new ComponentUpdateTaskData);
+	d->m_list = list;
+	d->mode = mode;
+	d->netmode = netmode;
+}
+
+ComponentUpdateTask::~ComponentUpdateTask()
+{
+}
+
+void ComponentUpdateTask::executeTask()
+{
+	qDebug() << "Loading components";
+	loadComponents();
+}
+
+namespace
+{
+enum class LoadResult
+{
+	LoadedLocal,
+	RequiresRemote,
+	Failed
+};
+
+LoadResult composeLoadResult(LoadResult a, LoadResult b)
+{
+	if (a < b)
+	{
+		return b;
+	}
+	return a;
+}
+
+static LoadResult loadComponent(ComponentPtr component, shared_qobject_ptr<Task>& loadTask, Net::Mode netmode)
+{
+	if(component->m_loaded)
+	{
+		qDebug() << component->getName() << "is already loaded";
+		return LoadResult::LoadedLocal;
+	}
+
+	LoadResult result = LoadResult::Failed;
+	auto customPatchFilename = component->getFilename();
+	if(QFile::exists(customPatchFilename))
+	{
+		// if local file exists...
+
+		// check for uid problems inside...
+		bool fileChanged = false;
+		auto file = ProfileUtils::parseJsonFile(QFileInfo(customPatchFilename), false);
+		if(file->uid != component->m_uid)
+		{
+			file->uid = component->m_uid;
+			fileChanged = true;
+		}
+		if(fileChanged)
+		{
+			// FIXME: @QUALITY do not ignore return value
+			ProfileUtils::saveJsonFile(OneSixVersionFormat::versionFileToJson(file), customPatchFilename);
+		}
+
+		component->m_file = file;
+		component->m_loaded = true;
+		result = LoadResult::LoadedLocal;
+	}
+	else
+	{
+		auto metaVersion = ENV.metadataIndex()->get(component->m_uid, component->m_version);
+		component->m_metaVersion = metaVersion;
+		if(metaVersion->isLoaded())
+		{
+			component->m_loaded = true;
+			result = LoadResult::LoadedLocal;
+		}
+		else
+		{
+			metaVersion->load(netmode);
+			loadTask = metaVersion->getCurrentTask();
+			if(loadTask)
+				result = LoadResult::RequiresRemote;
+			else if (metaVersion->isLoaded())
+				result = LoadResult::LoadedLocal;
+			else
+				result = LoadResult::Failed;
+		}
+	}
+	return result;
+}
+
+static LoadResult loadComponentList(ComponentPtr component, shared_qobject_ptr<Task>& loadTask, Net::Mode netmode)
+{
+	if(component->m_loaded)
+	{
+		qDebug() << component->getName() << "is already loaded";
+		return LoadResult::LoadedLocal;
+	}
+
+	LoadResult result = LoadResult::Failed;
+	auto metaList = ENV.metadataIndex()->get(component->m_uid);
+	if(metaList->isLoaded())
+	{
+		component->m_loaded = true;
+		result = LoadResult::LoadedLocal;
+	}
+	else
+	{
+		metaList->load(netmode);
+		loadTask = metaList->getCurrentTask();
+		result = LoadResult::RequiresRemote;
+	}
+	return result;
+}
+
+static LoadResult loadIndex(shared_qobject_ptr<Task>& loadTask, Net::Mode netmode)
+{
+	// FIXME: DECIDE. do we want to run the update task anyway?
+	if(ENV.metadataIndex()->isLoaded())
+	{
+		qDebug() << "Index is already loaded";
+		return LoadResult::LoadedLocal;
+	}
+	ENV.metadataIndex()->load(netmode);
+	loadTask = ENV.metadataIndex()->getCurrentTask();
+	if(loadTask)
+	{
+		return LoadResult::RequiresRemote;
+	}
+	// FIXME: this is assuming the load succeeded... did it really?
+	return LoadResult::LoadedLocal;
+}
+}
+
+void ComponentUpdateTask::loadComponents()
+{
+	LoadResult result = LoadResult::LoadedLocal;
+	size_t taskIndex = 0;
+	size_t componentIndex = 0;
+	d->remoteLoadSuccessful = true;
+	// load the main index (it is needed to determine if components can revert)
+	{
+		// FIXME: tear out as a method? or lambda?
+		shared_qobject_ptr<Task> indexLoadTask;
+		auto singleResult = loadIndex(indexLoadTask, d->netmode);
+		result = composeLoadResult(result, singleResult);
+		if(indexLoadTask)
+		{
+			qDebug() << "Remote loading is being run for metadata index";
+			RemoteLoadStatus status;
+			status.type = RemoteLoadStatus::Type::Index;
+			d->remoteLoadStatusList.append(status);
+			connect(indexLoadTask.get(), &Task::succeeded, [=]()
+			{
+				remoteLoadSucceeded(taskIndex);
+			});
+			connect(indexLoadTask.get(), &Task::failed, [=](const QString & error)
+			{
+				remoteLoadFailed(taskIndex, error);
+			});
+			taskIndex++;
+		}
+	}
+	// load all the components OR their lists...
+	for (auto component: d->m_list->d->components)
+	{
+		shared_qobject_ptr<Task> loadTask;
+		LoadResult singleResult;
+		RemoteLoadStatus::Type loadType;
+		// FIXME: to do this right, we need to load the lists and decide on which versions to use during dependency resolution. For now, ignore all that...
+#if 0
+		switch(d->mode)
+		{
+			case Mode::Launch:
+			{
+				singleResult = loadComponent(component, loadTask, d->netmode);
+				loadType = RemoteLoadStatus::Type::Version;
+				break;
+			}
+			case Mode::Resolution:
+			{
+				singleResult = loadComponentList(component, loadTask, d->netmode);
+				loadType = RemoteLoadStatus::Type::List;
+				break;
+			}
+		}
+#else
+		singleResult = loadComponent(component, loadTask, d->netmode);
+		loadType = RemoteLoadStatus::Type::Version;
+#endif
+		if(singleResult == LoadResult::LoadedLocal)
+		{
+			component->updateCachedData();
+		}
+		result = composeLoadResult(result, singleResult);
+		if (loadTask)
+		{
+			qDebug() << "Remote loading is being run for" << component->getName();
+			connect(loadTask.get(), &Task::succeeded, [=]()
+			{
+				remoteLoadSucceeded(taskIndex);
+			});
+			connect(loadTask.get(), &Task::failed, [=](const QString & error)
+			{
+				remoteLoadFailed(taskIndex, error);
+			});
+			RemoteLoadStatus status;
+			status.type = loadType;
+			status.componentListIndex = componentIndex;
+			d->remoteLoadStatusList.append(status);
+			taskIndex++;
+		}
+		componentIndex++;
+	}
+	d->remoteTasksInProgress = taskIndex;
+	switch(result)
+	{
+		case LoadResult::LoadedLocal:
+		{
+			// Everything got loaded. Advance to dependency resolution.
+			resolveDependencies(d->mode == Mode::Launch || d->netmode == Net::Mode::Offline);
+			break;
+		}
+		case LoadResult::RequiresRemote:
+		{
+			// we wait for signals.
+			break;
+		}
+		case LoadResult::Failed:
+		{
+			emitFailed(tr("Some component metadata load tasks failed."));
+			break;
+		}
+	}
+}
+
+namespace
+{
+	struct RequireEx : public Meta::Require
+	{
+		size_t indexOfFirstDependee = 0;
+	};
+	struct RequireCompositionResult
+	{
+		bool ok;
+		RequireEx outcome;
+	};
+	using RequireExSet = std::set<RequireEx>;
+}
+
+static RequireCompositionResult composeRequirement(const RequireEx & a, const RequireEx & b)
+{
+	assert(a.uid == b.uid);
+	RequireEx out;
+	out.uid = a.uid;
+	out.indexOfFirstDependee = std::min(a.indexOfFirstDependee, b.indexOfFirstDependee);
+	if(a.equalsVersion.isEmpty())
+	{
+		out.equalsVersion = b.equalsVersion;
+	}
+	else if (b.equalsVersion.isEmpty())
+	{
+		out.equalsVersion = a.equalsVersion;
+	}
+	else if (a.equalsVersion == b.equalsVersion)
+	{
+		out.equalsVersion = a.equalsVersion;
+	}
+	else
+	{
+		// FIXME: mark error as explicit version conflict
+		return {false, out};
+	}
+
+	if(a.suggests.isEmpty())
+	{
+		out.suggests = b.suggests;
+	}
+	else if (b.suggests.isEmpty())
+	{
+		out.suggests = a.suggests;
+	}
+	else
+	{
+		Version aVer(a.suggests);
+		Version bVer(b.suggests);
+		out.suggests = (aVer < bVer ? b.suggests : a.suggests);
+	}
+	return {true, out};
+}
+
+// gather the requirements from all components, finding any obvious conflicts
+static bool gatherRequirementsFromComponents(const ComponentContainer & input, RequireExSet & output)
+{
+	bool succeeded = true;
+	size_t componentNum = 0;
+	for(auto component: input)
+	{
+		auto &componentRequires = component->m_cachedRequires;
+		for(const auto & componentRequire: componentRequires)
+		{
+			auto found = std::find_if(output.cbegin(), output.cend(), [componentRequire](const Meta::Require & req){
+				return req.uid == componentRequire.uid;
+			});
+
+			RequireEx componenRequireEx;
+			componenRequireEx.uid = componentRequire.uid;
+			componenRequireEx.suggests = componentRequire.suggests;
+			componenRequireEx.equalsVersion = componentRequire.equalsVersion;
+			componenRequireEx.indexOfFirstDependee = componentNum;
+
+			if(found != output.cend())
+			{
+				// found... process it further
+				auto result = composeRequirement(componenRequireEx, *found);
+				if(result.ok)
+				{
+					output.erase(componenRequireEx);
+					output.insert(result.outcome);
+				}
+				else
+				{
+					qCritical()
+						<< "Conflicting requirements:"
+						<< componentRequire.uid
+						<< "versions:"
+						<< componentRequire.equalsVersion
+						<< ";"
+						<< (*found).equalsVersion;
+				}
+				succeeded &= result.ok;
+			}
+			else
+			{
+				// not found, accumulate
+				output.insert(componenRequireEx);
+			}
+		}
+		componentNum++;
+	}
+	return succeeded;
+}
+
+/// Get list of uids that can be trivially removed because nothing is depending on them anymore (and they are installed as deps)
+static void getTrivialRemovals(const ComponentContainer & components, const RequireExSet & reqs, QStringList &toRemove)
+{
+	for(const auto & component: components)
+	{
+		if(!component->m_dependencyOnly)
+			continue;
+		if(!component->m_cachedVolatile)
+			continue;
+		RequireEx reqNeedle;
+		reqNeedle.uid = component->m_uid;
+		const auto iter = reqs.find(reqNeedle);
+		if(iter == reqs.cend())
+		{
+			toRemove.append(component->m_uid);
+		}
+	}
+}
+
+/**
+ * handles:
+ * - trivial addition (there is an unmet requirement and it can be trivially met by adding something)
+ * - trivial version conflict of dependencies == explicit version required and installed is different
+ *
+ * toAdd - set of requirements than mean adding a new component
+ * toChange - set of requirements that mean changing version of an existing component
+ */
+static bool getTrivialComponentChanges(const ComponentIndex & index, const RequireExSet & input, RequireExSet & toAdd, RequireExSet & toChange)
+{
+	enum class Decision
+	{
+		Undetermined,
+		Met,
+		Missing,
+		VersionNotSame,
+		LockedVersionNotSame
+	} decision = Decision::Undetermined;
+
+	QString reqStr;
+	bool succeeded = true;
+	// list the composed requirements and say if they are met or unmet
+	for(auto & req: input)
+	{
+		do
+		{
+			if(req.equalsVersion.isEmpty())
+			{
+				reqStr = QString("Req: %1").arg(req.uid);
+				if(index.contains(req.uid))
+				{
+					decision = Decision::Met;
+				}
+				else
+				{
+					toAdd.insert(req);
+					decision = Decision::Missing;
+				}
+				break;
+			}
+			else
+			{
+				reqStr = QString("Req: %1 == %2").arg(req.uid, req.equalsVersion);
+				const auto & compIter = index.find(req.uid);
+				if(compIter == index.cend())
+				{
+					toAdd.insert(req);
+					decision = Decision::Missing;
+					break;
+				}
+				auto & comp = (*compIter);
+				if(comp->getVersion() != req.equalsVersion)
+				{
+					if(comp->m_dependencyOnly)
+					{
+						decision = Decision::VersionNotSame;
+					}
+					else
+					{
+						decision = Decision::LockedVersionNotSame;
+					}
+					break;
+				}
+				decision = Decision::Met;
+			}
+		} while(false);
+		switch(decision)
+		{
+			case Decision::Undetermined:
+				qCritical() << "No decision for" << reqStr;
+				succeeded = false;
+				break;
+			case Decision::Met:
+				qDebug() << reqStr << "Is met.";
+				break;
+			case Decision::Missing:
+				qDebug() << reqStr << "Is missing and should be added at" << req.indexOfFirstDependee;
+				toAdd.insert(req);
+				break;
+			case Decision::VersionNotSame:
+				qDebug() << reqStr << "already has different version that can be changed.";
+				toChange.insert(req);
+				break;
+			case Decision::LockedVersionNotSame:
+				qDebug() << reqStr << "already has different version that cannot be changed.";
+				succeeded = false;
+				break;
+		}
+	}
+	return succeeded;
+}
+
+// FIXME, TODO: decouple dependency resolution from loading
+// FIXME: This works directly with the ComponentList internals. It shouldn't! It needs richer data types than ComponentList uses.
+// FIXME: throw all this away and use a graph
+void ComponentUpdateTask::resolveDependencies(bool checkOnly)
+{
+	qDebug() << "Resolving dependencies";
+	/*
+	 * this is a naive dependency resolving algorithm. all it does is check for following conditions and react in simple ways:
+	 * 1. There are conflicting dependencies on the same uid with different exact version numbers
+	 *    -> hard error
+	 * 2. A dependency has non-matching exact version number
+	 *    -> hard error
+	 * 3. A dependency is entirely missing and needs to be injected before the dependee(s)
+	 *    -> requirements are injected
+	 *
+	 * NOTE: this is a placeholder and should eventually be replaced with something 'serious'
+	 */
+	auto & components = d->m_list->d->components;
+	auto & componentIndex = d->m_list->d->componentIndex;
+
+	RequireExSet allRequires;
+	QStringList toRemove;
+	do
+	{
+		allRequires.clear();
+		toRemove.clear();
+		if(!gatherRequirementsFromComponents(components, allRequires))
+		{
+			emitFailed(tr("Conflicting requirements detected during dependency checking!"));
+			return;
+		}
+		getTrivialRemovals(components, allRequires, toRemove);
+		if(!toRemove.isEmpty())
+		{
+			qDebug() << "Removing obsolete components...";
+			for(auto & remove : toRemove)
+			{
+				qDebug() << "Removing" << remove;
+				d->m_list->remove(remove);
+			}
+		}
+	} while (!toRemove.isEmpty());
+	RequireExSet toAdd;
+	RequireExSet toChange;
+	bool succeeded = getTrivialComponentChanges(componentIndex, allRequires, toAdd, toChange);
+	if(!succeeded)
+	{
+		emitFailed(tr("Instance has conflicting dependencies."));
+		return;
+	}
+	if(checkOnly)
+	{
+		if(toAdd.size() || toChange.size())
+		{
+			emitFailed(tr("Instance has unresolved dependencies while loading/checking for launch."));
+		}
+		else
+		{
+			emitSucceeded();
+		}
+		return;
+	}
+
+	bool recursionNeeded = false;
+	if(toAdd.size())
+	{
+		// add stuff...
+		for(auto &add: toAdd)
+		{
+			ComponentPtr component = new Component(d->m_list, add.uid);
+			if(!add.equalsVersion.isEmpty())
+			{
+				// exact version
+				qDebug() << "Adding" << add.uid << "version" << add.equalsVersion << "at position" << add.indexOfFirstDependee;
+				component->m_version = add.equalsVersion;
+			}
+			else
+			{
+				// version needs to be decided
+				qDebug() << "Adding" << add.uid << "at position" << add.indexOfFirstDependee;
+// ############################################################################################################
+// HACK HACK HACK HACK FIXME: this is a placeholder for deciding what version to use. For now, it is hardcoded.
+				if(!add.suggests.isEmpty())
+				{
+					component->m_version = add.suggests;
+				}
+				else
+				{
+					if(add.uid == "org.lwjgl")
+					{
+						component->m_version = "2.9.1";
+					}
+					else if (add.uid == "org.lwjgl3")
+					{
+						component->m_version = "3.1.2";
+					}
+				}
+// HACK HACK HACK HACK FIXME: this is a placeholder for deciding what version to use. For now, it is hardcoded.
+// ############################################################################################################
+			}
+			component->m_dependencyOnly = true;
+			// FIXME: this should not work directly with the component list
+			d->m_list->insertComponent(add.indexOfFirstDependee, component);
+			componentIndex[add.uid] = component;
+		}
+		recursionNeeded = true;
+	}
+	if(toChange.size())
+	{
+		// change a version of something that exists
+		for(auto &change: toChange)
+		{
+			// FIXME: this should not work directly with the component list
+			qDebug() << "Setting version of " << change.uid << "to" << change.equalsVersion;
+			auto component = componentIndex[change.uid];
+			component->setVersion(change.equalsVersion);
+		}
+		recursionNeeded = true;
+	}
+
+	if(recursionNeeded)
+	{
+		loadComponents();
+	}
+	else
+	{
+		emitSucceeded();
+	}
+}
+
+void ComponentUpdateTask::remoteLoadSucceeded(size_t taskIndex)
+{
+	auto &taskSlot = d->remoteLoadStatusList[taskIndex];
+	if(taskSlot.finished)
+	{
+		qWarning() << "Got multiple results from remote load task" << taskIndex;
+		return;
+	}
+	qDebug() << "Remote task" << taskIndex << "succeeded";
+	taskSlot.succeeded = false;
+	taskSlot.finished = true;
+	d->remoteTasksInProgress --;
+	// update the cached data of the component from the downloaded version file.
+	if (taskSlot.type == RemoteLoadStatus::Type::Version)
+	{
+		auto component = d->m_list->getComponent(taskSlot.componentListIndex);
+		component->m_loaded = true;
+		component->updateCachedData();
+	}
+	checkIfAllFinished();
+}
+
+
+void ComponentUpdateTask::remoteLoadFailed(size_t taskIndex, const QString& msg)
+{
+	auto &taskSlot = d->remoteLoadStatusList[taskIndex];
+	if(taskSlot.finished)
+	{
+		qWarning() << "Got multiple results from remote load task" << taskIndex;
+		return;
+	}
+	qDebug() << "Remote task" << taskIndex << "failed: " << msg;
+	d->remoteLoadSuccessful = false;
+	taskSlot.succeeded = false;
+	taskSlot.finished = true;
+	taskSlot.error = msg;
+	d->remoteTasksInProgress --;
+	checkIfAllFinished();
+}
+
+void ComponentUpdateTask::checkIfAllFinished()
+{
+	if(d->remoteTasksInProgress)
+	{
+		// not yet...
+		return;
+	}
+	if(d->remoteLoadSuccessful)
+	{
+		// nothing bad happened... clear the temp load status and proceed with looking at dependencies
+		d->remoteLoadStatusList.clear();
+		resolveDependencies(d->mode == Mode::Launch);
+	}
+	else
+	{
+		// remote load failed... report error and bail
+		QStringList allErrorsList;
+		for(auto & item: d->remoteLoadStatusList)
+		{
+			if(!item.succeeded)
+			{
+				allErrorsList.append(item.error);
+			}
+		}
+		auto allErrors = allErrorsList.join("\n");
+		emitFailed(tr("Component metadata update task failed while downloading from remote server:\n%1").arg(allErrors));
+		d->remoteLoadStatusList.clear();
+	}
+}
diff --git a/api/logic/minecraft/ComponentUpdateTask.h b/api/logic/minecraft/ComponentUpdateTask.h
new file mode 100644
index 00000000..11d122b6
--- /dev/null
+++ b/api/logic/minecraft/ComponentUpdateTask.h
@@ -0,0 +1,37 @@
+#pragma once
+
+#include "tasks/Task.h"
+#include "net/Mode.h"
+
+#include <memory>
+class ComponentList;
+struct ComponentUpdateTaskData;
+
+class ComponentUpdateTask : public Task
+{
+	Q_OBJECT
+public:
+	enum class Mode
+	{
+		Launch,
+		Resolution
+	};
+
+public:
+	explicit ComponentUpdateTask(Mode mode, Net::Mode netmode, ComponentList * list, QObject *parent = 0);
+	virtual ~ComponentUpdateTask();
+
+protected:
+	void executeTask();
+
+private:
+	void loadComponents();
+	void resolveDependencies(bool checkOnly);
+
+	void remoteLoadSucceeded(size_t index);
+	void remoteLoadFailed(size_t index, const QString &msg);
+	void checkIfAllFinished();
+
+private:
+	std::unique_ptr<ComponentUpdateTaskData> d;
+};
diff --git a/api/logic/minecraft/ComponentUpdateTask_p.h b/api/logic/minecraft/ComponentUpdateTask_p.h
new file mode 100644
index 00000000..a5216506
--- /dev/null
+++ b/api/logic/minecraft/ComponentUpdateTask_p.h
@@ -0,0 +1,32 @@
+#pragma once
+
+#include <cstddef>
+#include <QString>
+#include <QList>
+#include "net/Mode.h"
+
+class ComponentList;
+
+struct RemoteLoadStatus
+{
+	enum class Type
+	{
+		Index,
+		List,
+		Version
+	} type = Type::Version;
+	size_t componentListIndex = 0;
+	bool finished = false;
+	bool succeeded = false;
+	QString error;
+};
+
+struct ComponentUpdateTaskData
+{
+	ComponentList * m_list = nullptr;
+	QList<RemoteLoadStatus> remoteLoadStatusList;
+	bool remoteLoadSuccessful = true;
+	size_t remoteTasksInProgress = 0;
+	ComponentUpdateTask::Mode mode;
+	Net::Mode netmode;
+};
diff --git a/api/logic/minecraft/MinecraftInstance.cpp b/api/logic/minecraft/MinecraftInstance.cpp
index 76e70e5b..b7deed77 100644
--- a/api/logic/minecraft/MinecraftInstance.cpp
+++ b/api/logic/minecraft/MinecraftInstance.cpp
@@ -34,6 +34,7 @@
 #include "ComponentList.h"
 #include "AssetsUtils.h"
 #include "MinecraftUpdate.h"
+#include "MinecraftLoadAndCheck.h"
 
 #define IBUS "@im=ibus"
 
@@ -63,12 +64,6 @@ private:
 MinecraftInstance::MinecraftInstance(SettingsObjectPtr globalSettings, SettingsObjectPtr settings, const QString &rootDir)
 	: BaseInstance(globalSettings, settings, rootDir)
 {
-	// FIXME: remove these
-	m_settings->registerSetting({"IntendedVersion", "MinecraftVersion"}, "");
-	m_settings->registerSetting("LWJGLVersion", "2.9.1");
-	m_settings->registerSetting("ForgeVersion", "");
-	m_settings->registerSetting("LiteloaderVersion", "");
-
 	// Java Settings
 	auto javaOverride = m_settings->registerSetting("OverrideJava", false);
 	auto locationOverride = m_settings->registerSetting("OverrideJavaLocation", false);
@@ -101,51 +96,28 @@ MinecraftInstance::MinecraftInstance(SettingsObjectPtr globalSettings, SettingsO
 	// Minecraft launch method
 	auto launchMethodOverride = m_settings->registerSetting("OverrideMCLaunchMethod", false);
 	m_settings->registerOverride(globalSettings->getSetting("MCLaunchMethod"), launchMethodOverride);
-}
-
-void MinecraftInstance::init()
-{
-	createProfile();
-}
-
-QString MinecraftInstance::typeName() const
-{
-	return "Minecraft";
-}
 
+	// DEPRECATED: Read what versions the user configuration thinks should be used
+	m_settings->registerSetting({"IntendedVersion", "MinecraftVersion"}, "");
+	m_settings->registerSetting("LWJGLVersion", "");
+	m_settings->registerSetting("ForgeVersion", "");
+	m_settings->registerSetting("LiteloaderVersion", "");
 
-bool MinecraftInstance::reload()
-{
-	if (BaseInstance::reload())
-	{
-		try
-		{
-			reloadProfile();
-			return true;
-		}
-		catch (...)
-		{
-			return false;
-		}
-	}
-	return false;
-}
-
-void MinecraftInstance::createProfile()
-{
 	m_components.reset(new ComponentList(this));
+	m_components->setOldConfigVersion("net.minecraft", m_settings->get("IntendedVersion").toString());
+	auto setting = m_settings->getSetting("LWJGLVersion");
+	m_components->setOldConfigVersion("org.lwjgl", m_settings->get("LWJGLVersion").toString());
+	m_components->setOldConfigVersion("net.minecraftforge", m_settings->get("ForgeVersion").toString());
+	m_components->setOldConfigVersion("com.mumfrey.liteloader", m_settings->get("LiteloaderVersion").toString());
 }
 
-void MinecraftInstance::reloadProfile()
+void MinecraftInstance::init()
 {
-	m_components->reload();
-	emit versionReloaded();
 }
 
-void MinecraftInstance::clearProfile()
+QString MinecraftInstance::typeName() const
 {
-	m_components->clearProfile();
-	emit versionReloaded();
+	return "Minecraft";
 }
 
 std::shared_ptr<ComponentList> MinecraftInstance::getComponentList() const
@@ -771,7 +743,7 @@ QString MinecraftInstance::getStatusbarDescription()
 	}
 
 	QString description;
-	description.append(tr("Minecraft %1 (%2)").arg(getComponentVersion("net.minecraft")).arg(typeName()));
+	description.append(tr("Minecraft %1 (%2)").arg(m_components->getComponentVersion("net.minecraft")).arg(typeName()));
 	if(totalTimePlayed() > 0)
 	{
 		description.append(tr(", played for %1").arg(prettifyTimeDuration(totalTimePlayed())));
@@ -783,9 +755,20 @@ QString MinecraftInstance::getStatusbarDescription()
 	return description;
 }
 
-shared_qobject_ptr<Task> MinecraftInstance::createUpdateTask()
+shared_qobject_ptr<Task> MinecraftInstance::createUpdateTask(Net::Mode mode)
 {
-	return shared_qobject_ptr<Task>(new OneSixUpdate(this));
+	switch (mode)
+	{
+		case Net::Mode::Offline:
+		{
+			return shared_qobject_ptr<Task>(new MinecraftLoadAndCheck(this));
+		}
+		case Net::Mode::Online:
+		{
+			return shared_qobject_ptr<Task>(new OneSixUpdate(this));
+		}
+	}
+	return nullptr;
 }
 
 std::shared_ptr<LaunchTask> MinecraftInstance::createLaunchTask(AuthSessionPtr session)
@@ -827,11 +810,14 @@ std::shared_ptr<LaunchTask> MinecraftInstance::createLaunchTask(AuthSessionPtr s
 	if(session->status != AuthSession::PlayableOffline)
 	{
 		process->appendStep(std::make_shared<ClaimAccount>(pptr, session));
-		process->appendStep(std::make_shared<Update>(pptr));
+		process->appendStep(std::make_shared<Update>(pptr, Net::Mode::Online));
+	}
+	else
+	{
+		process->appendStep(std::make_shared<Update>(pptr, Net::Mode::Offline));
 	}
 
 	// if there are any jar mods
-	if(getJarMods().size())
 	{
 		auto step = std::make_shared<ModMinecraftJar>(pptr);
 		process->appendStep(step);
@@ -900,53 +886,6 @@ JavaVersion MinecraftInstance::getJavaVersion() const
 	return JavaVersion(settings()->get("JavaVersion").toString());
 }
 
-bool MinecraftInstance::setComponentVersion(const QString& uid, const QString& version)
-{
-	if(uid == "net.minecraft")
-	{
-		settings()->set("IntendedVersion", version);
-	}
-	else if (uid == "org.lwjgl")
-	{
-		settings()->set("LWJGLVersion", version);
-	}
-	else if (uid == "net.minecraftforge")
-	{
-		settings()->set("ForgeVersion", version);
-	}
-	else if (uid == "com.mumfrey.liteloader")
-	{
-		settings()->set("LiteloaderVersion", version);
-	}
-	if(getComponentList())
-	{
-		clearProfile();
-	}
-	emit propertiesChanged(this);
-	return true;
-}
-
-QString MinecraftInstance::getComponentVersion(const QString& uid) const
-{
-	if(uid == "net.minecraft")
-	{
-		return settings()->get("IntendedVersion").toString();
-	}
-	else if(uid == "org.lwjgl")
-	{
-		return settings()->get("LWJGLVersion").toString();
-	}
-	else if(uid == "net.minecraftforge")
-	{
-		return settings()->get("ForgeVersion").toString();
-	}
-	else if(uid == "com.mumfrey.liteloader")
-	{
-		return settings()->get("LiteloaderVersion").toString();
-	}
-	return QString();
-}
-
 std::shared_ptr<ModList> MinecraftInstance::loaderModList() const
 {
 	if (!m_loader_mod_list)
diff --git a/api/logic/minecraft/MinecraftInstance.h b/api/logic/minecraft/MinecraftInstance.h
index cea7c60a..13a3753e 100644
--- a/api/logic/minecraft/MinecraftInstance.h
+++ b/api/logic/minecraft/MinecraftInstance.h
@@ -53,12 +53,7 @@ public:
 
 
 	//////  Profile management //////
-	void createProfile();
 	std::shared_ptr<ComponentList> getComponentList() const;
-	void reloadProfile();
-	void clearProfile();
-	bool reload() override;
-
 
 	//////  Mod Lists  //////
 	std::shared_ptr<ModList> loaderModList() const;
@@ -69,7 +64,7 @@ public:
 
 
 	//////  Launch stuff //////
-	shared_qobject_ptr<Task> createUpdateTask() override;
+	shared_qobject_ptr<Task> createUpdateTask(Net::Mode mode) override;
 	std::shared_ptr<LaunchTask> createLaunchTask(AuthSessionPtr account) override;
 	QStringList extraArguments() const override;
 	QStringList verboseDescription(AuthSessionPtr session) override;
@@ -105,11 +100,6 @@ public:
 
 	virtual JavaVersion getJavaVersion() const;
 
-	// FIXME: remove
-	QString getComponentVersion(const QString &uid) const;
-	// FIXME: remove
-	bool setComponentVersion(const QString &uid, const QString &version);
-
 signals:
 	void versionReloaded();
 
diff --git a/api/logic/minecraft/MinecraftLoadAndCheck.cpp b/api/logic/minecraft/MinecraftLoadAndCheck.cpp
new file mode 100644
index 00000000..c64bbddf
--- /dev/null
+++ b/api/logic/minecraft/MinecraftLoadAndCheck.cpp
@@ -0,0 +1,45 @@
+#include "MinecraftLoadAndCheck.h"
+#include "MinecraftInstance.h"
+#include "ComponentList.h"
+
+MinecraftLoadAndCheck::MinecraftLoadAndCheck(MinecraftInstance *inst, QObject *parent) : Task(parent), m_inst(inst)
+{
+}
+
+void MinecraftLoadAndCheck::executeTask()
+{
+	// add offline metadata load task
+	auto components = m_inst->getComponentList();
+	components->reload(Net::Mode::Offline);
+	m_task = components->getCurrentTask();
+
+	if(!m_task)
+	{
+		emitSucceeded();
+		return;
+	}
+	connect(m_task.get(), &Task::succeeded, this, &MinecraftLoadAndCheck::subtaskSucceeded);
+	connect(m_task.get(), &Task::failed, this, &MinecraftLoadAndCheck::subtaskFailed);
+	connect(m_task.get(), &Task::progress, this, &MinecraftLoadAndCheck::progress);
+	connect(m_task.get(), &Task::status, this, &MinecraftLoadAndCheck::setStatus);
+}
+
+void MinecraftLoadAndCheck::subtaskSucceeded()
+{
+	if(isFinished())
+	{
+		qCritical() << "OneSixUpdate: Subtask" << sender() << "succeeded, but work was already done!";
+		return;
+	}
+	emitSucceeded();
+}
+
+void MinecraftLoadAndCheck::subtaskFailed(QString error)
+{
+	if(isFinished())
+	{
+		qCritical() << "OneSixUpdate: Subtask" << sender() << "failed, but work was already done!";
+		return;
+	}
+	emitFailed(error);
+}
diff --git a/api/logic/minecraft/MinecraftLoadAndCheck.h b/api/logic/minecraft/MinecraftLoadAndCheck.h
new file mode 100644
index 00000000..f41c3d2f
--- /dev/null
+++ b/api/logic/minecraft/MinecraftLoadAndCheck.h
@@ -0,0 +1,47 @@
+/* Copyright 2013-2017 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <QObject>
+#include <QList>
+#include <QUrl>
+
+#include "tasks/Task.h"
+#include <quazip.h>
+
+#include "QObjectPtr.h"
+
+class MinecraftVersion;
+class MinecraftInstance;
+
+class MinecraftLoadAndCheck : public Task
+{
+	Q_OBJECT
+public:
+	explicit MinecraftLoadAndCheck(MinecraftInstance *inst, QObject *parent = 0);
+	void executeTask() override;
+
+private slots:
+	void subtaskSucceeded();
+	void subtaskFailed(QString error);
+
+private:
+	MinecraftInstance *m_inst = nullptr;
+	shared_qobject_ptr<Task> m_task;
+	QString m_preFailure;
+	QString m_fail_reason;
+};
+
diff --git a/api/logic/minecraft/MinecraftUpdate.cpp b/api/logic/minecraft/MinecraftUpdate.cpp
index 529cf13e..12b11544 100644
--- a/api/logic/minecraft/MinecraftUpdate.cpp
+++ b/api/logic/minecraft/MinecraftUpdate.cpp
@@ -39,40 +39,24 @@
 
 OneSixUpdate::OneSixUpdate(MinecraftInstance *inst, QObject *parent) : Task(parent), m_inst(inst)
 {
+}
+
+void OneSixUpdate::executeTask()
+{
+	m_tasks.clear();
 	// create folders
 	{
 		m_tasks.append(std::make_shared<FoldersTask>(m_inst));
 	}
 
-	// add metadata update tasks, if necessary
+	// add metadata update task if necessary
 	{
-		/*
-		 * FIXME: there are some corner cases here that remain unhandled:
-		 * what if local load succeeds but remote fails? The version is still usable...
-		 * We should not rely on the remote to be there... and prefer local files if it does not respond.
-		 */
-		qDebug() << "Updating patches...";
-		auto profile = m_inst->getComponentList();
-		m_inst->reloadProfile();
-		for(int i = 0; i < profile->rowCount(); i++)
+		auto components = m_inst->getComponentList();
+		components->reload(Net::Mode::Online);
+		auto task = components->getCurrentTask();
+		if(task)
 		{
-			auto patch = profile->versionPatch(i);
-			auto id = patch->getID();
-			auto metadata = patch->getMeta();
-			if(metadata)
-			{
-				metadata->load();
-				auto task = metadata->getCurrentTask();
-				if(task)
-				{
-					qDebug() << "Loading remote meta patch" << id;
-					m_tasks.append(task.unwrap());
-				}
-			}
-			else
-			{
-				qDebug() << "Ignoring local patch" << id;
-			}
+			m_tasks.append(task.unwrap());
 		}
 	}
 
@@ -90,10 +74,7 @@ OneSixUpdate::OneSixUpdate(MinecraftInstance *inst, QObject *parent) : Task(pare
 	{
 		m_tasks.append(std::make_shared<AssetUpdateTask>(m_inst));
 	}
-}
 
-void OneSixUpdate::executeTask()
-{
 	if(!m_preFailure.isEmpty())
 	{
 		emitFailed(m_preFailure);
diff --git a/api/logic/minecraft/OneSixVersionFormat.cpp b/api/logic/minecraft/OneSixVersionFormat.cpp
index 7ebf514f..d91eae58 100644
--- a/api/logic/minecraft/OneSixVersionFormat.cpp
+++ b/api/logic/minecraft/OneSixVersionFormat.cpp
@@ -192,6 +192,19 @@ VersionFilePtr OneSixVersionFormat::versionFileFromJson(const QJsonDocument &doc
 		out->mainJar = lib;
 	}
 
+	if (root.contains("requires"))
+	{
+		Meta::parseRequires(root, &out->requires);
+	}
+	if (root.contains("conflicts"))
+	{
+		Meta::parseRequires(root, &out->conflicts);
+	}
+	if (root.contains("volatile"))
+	{
+		out->m_volatile = requireBoolean(root, "volatile");
+	}
+
 	/* removed features that shouldn't be used */
 	if (root.contains("tweakers"))
 	{
@@ -216,13 +229,9 @@ VersionFilePtr OneSixVersionFormat::versionFileFromJson(const QJsonDocument &doc
 	return out;
 }
 
-QJsonDocument OneSixVersionFormat::versionFileToJson(const VersionFilePtr &patch, bool saveOrder)
+QJsonDocument OneSixVersionFormat::versionFileToJson(const VersionFilePtr &patch)
 {
 	QJsonObject root;
-	if (saveOrder)
-	{
-		root.insert("order", patch->order);
-	}
 	writeString(root, "name", patch->name);
 
 	writeString(root, "uid", patch->uid);
@@ -266,6 +275,18 @@ QJsonDocument OneSixVersionFormat::versionFileToJson(const VersionFilePtr &patch
 		}
 		root.insert("mods", array);
 	}
+	if(!patch->requires.empty())
+	{
+		Meta::serializeRequires(root, &patch->requires, "requires");
+	}
+	if(!patch->conflicts.empty())
+	{
+		Meta::serializeRequires(root, &patch->conflicts, "conflicts");
+	}
+	if(patch->m_volatile)
+	{
+		root.insert("volatile", true);
+	}
 	// write the contents to a json document.
 	{
 		QJsonDocument out;
diff --git a/api/logic/minecraft/OneSixVersionFormat.h b/api/logic/minecraft/OneSixVersionFormat.h
index 2306ac8e..8b782db0 100644
--- a/api/logic/minecraft/OneSixVersionFormat.h
+++ b/api/logic/minecraft/OneSixVersionFormat.h
@@ -10,7 +10,7 @@ class OneSixVersionFormat
 public:
 	// version files / profile patches
 	static VersionFilePtr versionFileFromJson(const QJsonDocument &doc, const QString &filename, const bool requireOrder);
-	static QJsonDocument versionFileToJson(const VersionFilePtr &patch, bool saveOrder);
+	static QJsonDocument versionFileToJson(const VersionFilePtr &patch);
 
 	// libraries
 	static LibraryPtr libraryFromJson(const QJsonObject &libObj, const QString &filename);
diff --git a/api/logic/minecraft/ProfilePatch.cpp b/api/logic/minecraft/ProfilePatch.cpp
deleted file mode 100644
index b7a5a37a..00000000
--- a/api/logic/minecraft/ProfilePatch.cpp
+++ /dev/null
@@ -1,188 +0,0 @@
-#include <meta/VersionList.h>
-#include <meta/Index.h>
-#include <Env.h>
-#include "ProfilePatch.h"
-
-#include "meta/Version.h"
-#include "VersionFile.h"
-#include "minecraft/ComponentList.h"
-
-ProfilePatch::ProfilePatch(std::shared_ptr<Meta::Version> version)
-	:m_metaVersion(version)
-{
-}
-
-ProfilePatch::ProfilePatch(std::shared_ptr<VersionFile> file, const QString& filename)
-	:m_file(file), m_filename(filename)
-{
-}
-
-std::shared_ptr<Meta::Version> ProfilePatch::getMeta()
-{
-	return m_metaVersion;
-}
-
-void ProfilePatch::applyTo(LaunchProfile* profile)
-{
-	auto vfile = getVersionFile();
-	if(vfile)
-	{
-		vfile->applyTo(profile);
-	}
-	else
-	{
-		profile->applyProblemSeverity(getProblemSeverity());
-	}
-}
-
-std::shared_ptr<class VersionFile> ProfilePatch::getVersionFile() const
-{
-	if(m_metaVersion)
-	{
-		if(!m_metaVersion->isLoaded())
-		{
-			m_metaVersion->load();
-		}
-		return m_metaVersion->data();
-	}
-	else
-	{
-		return m_file;
-	}
-}
-
-std::shared_ptr<class Meta::VersionList> ProfilePatch::getVersionList() const
-{
-	if(m_metaVersion)
-	{
-		return ENV.metadataIndex()->get(m_metaVersion->uid());
-	}
-	return nullptr;
-}
-
-int ProfilePatch::getOrder()
-{
-	if(m_orderOverride)
-		return m_order;
-
-	auto vfile = getVersionFile();
-	if(vfile)
-	{
-		return vfile->order;
-	}
-	return 0;
-}
-void ProfilePatch::setOrder(int order)
-{
-	m_orderOverride = true;
-	m_order = order;
-}
-QString ProfilePatch::getID()
-{
-	if(m_metaVersion)
-		return m_metaVersion->uid();
-	return getVersionFile()->uid;
-}
-QString ProfilePatch::getName()
-{
-	if(m_metaVersion)
-		return m_metaVersion->name();
-	return getVersionFile()->name;
-}
-QString ProfilePatch::getVersion()
-{
-	if(m_metaVersion)
-		return m_metaVersion->version();
-	return getVersionFile()->version;
-}
-QString ProfilePatch::getFilename()
-{
-	return m_filename;
-}
-QDateTime ProfilePatch::getReleaseDateTime()
-{
-	if(m_metaVersion)
-	{
-		return m_metaVersion->time();
-	}
-	return getVersionFile()->releaseTime;
-}
-
-bool ProfilePatch::isCustom()
-{
-	return !m_isVanilla;
-};
-
-bool ProfilePatch::isCustomizable()
-{
-	if(m_metaVersion)
-	{
-		if(getVersionFile())
-		{
-			return true;
-		}
-	}
-	return false;
-}
-bool ProfilePatch::isRemovable()
-{
-	return m_isRemovable;
-}
-bool ProfilePatch::isRevertible()
-{
-	return m_isRevertible;
-}
-bool ProfilePatch::isMoveable()
-{
-	return m_isMovable;
-}
-bool ProfilePatch::isVersionChangeable()
-{
-	auto list = getVersionList();
-	if(list)
-	{
-		if(!list->isLoaded())
-		{
-			list->load();
-		}
-		return list->count() != 0;
-	}
-	return false;
-}
-
-void ProfilePatch::setVanilla (bool state)
-{
-	m_isVanilla = state;
-}
-void ProfilePatch::setRemovable (bool state)
-{
-	m_isRemovable = state;
-}
-void ProfilePatch::setRevertible (bool state)
-{
-	m_isRevertible = state;
-}
-void ProfilePatch::setMovable (bool state)
-{
-	m_isMovable = state;
-}
-
-ProblemSeverity ProfilePatch::getProblemSeverity() const
-{
-	auto file = getVersionFile();
-	if(file)
-	{
-		return file->getProblemSeverity();
-	}
-	return ProblemSeverity::Error;
-}
-
-const QList<PatchProblem> ProfilePatch::getProblems() const
-{
-	auto file = getVersionFile();
-	if(file)
-	{
-		return file->getProblems();
-	}
-	return {{ProblemSeverity::Error, QObject::tr("Patch is not loaded yet.")}};
-}
diff --git a/api/logic/minecraft/ProfilePatch.h b/api/logic/minecraft/ProfilePatch.h
deleted file mode 100644
index 80825342..00000000
--- a/api/logic/minecraft/ProfilePatch.h
+++ /dev/null
@@ -1,71 +0,0 @@
-#pragma once
-
-#include <memory>
-#include <QList>
-#include <QJsonDocument>
-#include <QDateTime>
-#include "ProblemProvider.h"
-
-class ComponentList;
-class LaunchProfile;
-namespace Meta
-{
-	class Version;
-	class VersionList;
-}
-class VersionFile;
-
-class ProfilePatch : public ProblemProvider
-{
-public:
-	ProfilePatch(std::shared_ptr<Meta::Version> version);
-	ProfilePatch(std::shared_ptr<VersionFile> file, const QString &filename = QString());
-
-	virtual ~ProfilePatch(){};
-	virtual void applyTo(LaunchProfile *profile);
-
-	virtual bool isMoveable();
-	virtual bool isCustomizable();
-	virtual bool isRevertible();
-	virtual bool isRemovable();
-	virtual bool isCustom();
-	virtual bool isVersionChangeable();
-
-	virtual void setOrder(int order);
-	virtual int getOrder();
-
-	virtual QString getID();
-	virtual QString getName();
-	virtual QString getVersion();
-	virtual std::shared_ptr<Meta::Version> getMeta();
-	virtual QDateTime getReleaseDateTime();
-
-	virtual QString getFilename();
-
-	virtual std::shared_ptr<class VersionFile> getVersionFile() const;
-	virtual std::shared_ptr<class Meta::VersionList> getVersionList() const;
-
-	void setVanilla (bool state);
-	void setRemovable (bool state);
-	void setRevertible (bool state);
-	void setMovable (bool state);
-
-	const QList<PatchProblem> getProblems() const override;
-	ProblemSeverity getProblemSeverity() const override;
-
-protected:
-	// Properties for UI and version manipulation from UI in general
-	bool m_isMovable = false;
-	bool m_isRevertible = false;
-	bool m_isRemovable = false;
-	bool m_isVanilla = false;
-
-	bool m_orderOverride = false;
-	int m_order = 0;
-
-	std::shared_ptr<Meta::Version> m_metaVersion;
-	std::shared_ptr<VersionFile> m_file;
-	QString m_filename;
-};
-
-typedef std::shared_ptr<ProfilePatch> ProfilePatchPtr;
diff --git a/api/logic/minecraft/ProfileUtils.cpp b/api/logic/minecraft/ProfileUtils.cpp
index c8722f7e..a6d2028d 100644
--- a/api/logic/minecraft/ProfileUtils.cpp
+++ b/api/logic/minecraft/ProfileUtils.cpp
@@ -14,38 +14,6 @@ namespace ProfileUtils
 
 static const int currentOrderFileVersion = 1;
 
-bool writeOverrideOrders(QString path, const PatchOrder &order)
-{
-	QJsonObject obj;
-	obj.insert("version", currentOrderFileVersion);
-	QJsonArray orderArray;
-	for(auto str: order)
-	{
-		orderArray.append(str);
-	}
-	obj.insert("order", orderArray);
-	QSaveFile orderFile(path);
-	if (!orderFile.open(QFile::WriteOnly))
-	{
-		qCritical() << "Couldn't open" << orderFile.fileName()
-					 << "for writing:" << orderFile.errorString();
-		return false;
-	}
-	auto data = QJsonDocument(obj).toJson(QJsonDocument::Indented);
-	if(orderFile.write(data) != data.size())
-	{
-		qCritical() << "Couldn't write all the data into" << orderFile.fileName()
-					 << "because:" << orderFile.errorString();
-		return false;
-	}
-	if(!orderFile.commit())
-	{
-		qCritical() << "Couldn't save" << orderFile.fileName()
-					 << "because:" << orderFile.errorString();
-	}
-	return true;
-}
-
 bool readOverrideOrders(QString path, PatchOrder &order)
 {
 	QFile orderFile(path);
@@ -154,6 +122,25 @@ VersionFilePtr parseJsonFile(const QFileInfo &fileInfo, const bool requireOrder)
 	return guardedParseJson(doc, fileInfo.completeBaseName(), fileInfo.absoluteFilePath(), requireOrder);
 }
 
+bool saveJsonFile(const QJsonDocument doc, const QString & filename)
+{
+	auto data = doc.toJson();
+	QSaveFile jsonFile(filename);
+	if(!jsonFile.open(QIODevice::WriteOnly))
+	{
+		jsonFile.cancelWriting();
+		qWarning() << "Couldn't open" << filename << "for writing";
+		return false;
+	}
+	jsonFile.write(data);
+	if(!jsonFile.commit())
+	{
+		qWarning() << "Couldn't save" << filename;
+		return false;
+	}
+	return true;
+}
+
 VersionFilePtr parseBinaryJsonFile(const QFileInfo &fileInfo)
 {
 	QFile file(fileInfo.absoluteFilePath());
diff --git a/api/logic/minecraft/ProfileUtils.h b/api/logic/minecraft/ProfileUtils.h
index 267fd42b..351c36cb 100644
--- a/api/logic/minecraft/ProfileUtils.h
+++ b/api/logic/minecraft/ProfileUtils.h
@@ -16,6 +16,9 @@ bool writeOverrideOrders(QString path, const PatchOrder &order);
 /// Parse a version file in JSON format
 VersionFilePtr parseJsonFile(const QFileInfo &fileInfo, const bool requireOrder);
 
+/// Save a JSON file (in any format)
+bool saveJsonFile(const QJsonDocument doc, const QString & filename);
+
 /// Parse a version file in binary JSON format
 VersionFilePtr parseBinaryJsonFile(const QFileInfo &fileInfo);
 
diff --git a/api/logic/minecraft/VersionFile.h b/api/logic/minecraft/VersionFile.h
index 60acaad6..c032f7ea 100644
--- a/api/logic/minecraft/VersionFile.h
+++ b/api/logic/minecraft/VersionFile.h
@@ -10,6 +10,7 @@
 #include "minecraft/Rule.h"
 #include "ProblemProvider.h"
 #include "Library.h"
+#include <meta/JsonFormat.h>
 
 class ComponentList;
 class VersionFile;
@@ -29,9 +30,6 @@ public: /* data */
 	/// MultiMC: order hint for this version file if no explicit order is set
 	int order = 0;
 
-	/// MultiMC: filename of the file this was loaded from
-	// QString filename;
-
 	/// MultiMC: human readable name of this package
 	QString name;
 
@@ -77,7 +75,7 @@ public: /* data */
 	/// Mojang: list of libraries to add to the version
 	QList<LibraryPtr> libraries;
 
-	// The main jar (Minecraft version library, normally)
+	/// The main jar (Minecraft version library, normally)
 	LibraryPtr mainJar;
 
 	/// MultiMC: list of attached traits of this version file - used to enable features
@@ -89,6 +87,21 @@ public: /* data */
 	/// MultiMC: list of mods added to this version
 	QList<LibraryPtr> mods;
 
+	/**
+	 * MultiMC: set of packages this depends on
+	 * NOTE: this is shared with the meta format!!!
+	 */
+	Meta::RequireSet requires;
+
+	/**
+	 * MultiMC: set of packages this conflicts with
+	 * NOTE: this is shared with the meta format!!!
+	 */
+	Meta::RequireSet conflicts;
+
+	/// is volatile -- may be removed as soon as it is no longer needed by something else
+	bool m_volatile = false;
+
 public:
 	// Mojang: DEPRECATED list of 'downloads' - client jar, server jar, windows server exe, maybe more.
 	QMap <QString, std::shared_ptr<MojangDownloadInfo>> mojangDownloads;
diff --git a/api/logic/minecraft/launch/ModMinecraftJar.cpp b/api/logic/minecraft/launch/ModMinecraftJar.cpp
index 6407ade0..9b5d3b20 100644
--- a/api/logic/minecraft/launch/ModMinecraftJar.cpp
+++ b/api/logic/minecraft/launch/ModMinecraftJar.cpp
@@ -25,6 +25,11 @@ void ModMinecraftJar::executeTask()
 {
 	auto m_inst = std::dynamic_pointer_cast<MinecraftInstance>(m_parent->instance());
 
+	if(!m_inst->getJarMods().size())
+	{
+		emitSucceeded();
+		return;
+	}
 	// nuke obsolete stripped jar(s) if needed
 	if(!FS::ensureFolderPathExists(m_inst->binRoot()))
 	{
diff --git a/api/logic/minecraft/legacy/LegacyInstance.cpp b/api/logic/minecraft/legacy/LegacyInstance.cpp
index 0b69acf2..a6b745d8 100644
--- a/api/logic/minecraft/legacy/LegacyInstance.cpp
+++ b/api/logic/minecraft/legacy/LegacyInstance.cpp
@@ -71,7 +71,7 @@ bool LegacyInstance::shouldUseCustomBaseJar() const
 }
 
 
-shared_qobject_ptr<Task> LegacyInstance::createUpdateTask()
+shared_qobject_ptr<Task> LegacyInstance::createUpdateTask(Net::Mode)
 {
 	return nullptr;
 }
diff --git a/api/logic/minecraft/legacy/LegacyInstance.h b/api/logic/minecraft/legacy/LegacyInstance.h
index 64564591..ef590cae 100644
--- a/api/logic/minecraft/legacy/LegacyInstance.h
+++ b/api/logic/minecraft/legacy/LegacyInstance.h
@@ -93,7 +93,7 @@ public:
 	};
 
 	virtual bool shouldUpdate() const;
-	virtual shared_qobject_ptr<Task> createUpdateTask() override;
+	virtual shared_qobject_ptr<Task> createUpdateTask(Net::Mode mode) override;
 
 	virtual QString typeName() const override;
 
diff --git a/api/logic/minecraft/legacy/LegacyUpgradeTask.cpp b/api/logic/minecraft/legacy/LegacyUpgradeTask.cpp
index fab48005..6cda3e4d 100644
--- a/api/logic/minecraft/legacy/LegacyUpgradeTask.cpp
+++ b/api/logic/minecraft/legacy/LegacyUpgradeTask.cpp
@@ -67,69 +67,70 @@ void LegacyUpgradeTask::copyFinished()
 	auto instanceSettings = std::make_shared<INISettingsObject>(FS::PathCombine(m_stagingPath, "instance.cfg"));
 	instanceSettings->registerSetting("InstanceType", "Legacy");
 	instanceSettings->set("InstanceType", "OneSix");
-	std::shared_ptr<MinecraftInstance> inst(new MinecraftInstance(m_globalSettings, instanceSettings, m_stagingPath));
-	inst->setName(m_newName);
-	inst->init();
-
-	QString preferredVersionNumber = decideVersion(legacyInst->currentVersionId(), legacyInst->intendedVersionId());
-	if(preferredVersionNumber.isNull())
+	// NOTE: this scope ensures the instance is fully saved before we emitSucceeded
 	{
-		// try to decide version based on the jar(s?)
-		preferredVersionNumber = classparser::GetMinecraftJarVersion(legacyInst->baseJar());
+		MinecraftInstance inst(m_globalSettings, instanceSettings, m_stagingPath);
+		inst.setName(m_newName);
+		inst.init();
+
+		QString preferredVersionNumber = decideVersion(legacyInst->currentVersionId(), legacyInst->intendedVersionId());
 		if(preferredVersionNumber.isNull())
 		{
-			preferredVersionNumber = classparser::GetMinecraftJarVersion(legacyInst->runnableJar());
+			// try to decide version based on the jar(s?)
+			preferredVersionNumber = classparser::GetMinecraftJarVersion(legacyInst->baseJar());
 			if(preferredVersionNumber.isNull())
 			{
-				emitFailed(tr("Could not decide Minecraft version."));
-				return;
+				preferredVersionNumber = classparser::GetMinecraftJarVersion(legacyInst->runnableJar());
+				if(preferredVersionNumber.isNull())
+				{
+					emitFailed(tr("Could not decide Minecraft version."));
+					return;
+				}
 			}
 		}
-	}
-	inst->setComponentVersion("net.minecraft", preferredVersionNumber);
+		auto components = inst.getComponentList();
+		components->buildingFromScratch();
+		components->setComponentVersion("net.minecraft", preferredVersionNumber, true);
 
-	// BUG: reloadProfile should not be necessary, but setComponentVersion voids the profile created by init()!
-	inst->reloadProfile();
-	auto profile = inst->getComponentList();
-
-	if(legacyInst->shouldUseCustomBaseJar())
-	{
-		QString jarPath = legacyInst->customBaseJar();
-		qDebug() << "Base jar is custom! : " << jarPath;
-		// FIXME: handle case when the jar is unreadable?
-		// TODO: check the hash, if it's the same as the upstream jar, do not do this
-		profile->installCustomJar(jarPath);
-	}
+		if(legacyInst->shouldUseCustomBaseJar())
+		{
+			QString jarPath = legacyInst->customBaseJar();
+			qDebug() << "Base jar is custom! : " << jarPath;
+			// FIXME: handle case when the jar is unreadable?
+			// TODO: check the hash, if it's the same as the upstream jar, do not do this
+			components->installCustomJar(jarPath);
+		}
 
-	auto jarMods = legacyInst->getJarMods();
-	for(auto & jarMod: jarMods)
-	{
-		QString modPath = jarMod.filename().absoluteFilePath();
-		qDebug() << "jarMod: " << modPath;
-		profile->installJarMods({modPath});
-	}
+		auto jarMods = legacyInst->getJarMods();
+		for(auto & jarMod: jarMods)
+		{
+			QString modPath = jarMod.filename().absoluteFilePath();
+			qDebug() << "jarMod: " << modPath;
+			components->installJarMods({modPath});
+		}
 
-	// remove all the extra garbage we no longer need
-	auto removeAll = [&](const QString &root, const QStringList &things)
-	{
-		for(auto &thing : things)
+		// remove all the extra garbage we no longer need
+		auto removeAll = [&](const QString &root, const QStringList &things)
 		{
-			auto removePath = FS::PathCombine(root, thing);
-			QFileInfo stat(removePath);
-			if(stat.isDir())
+			for(auto &thing : things)
 			{
-				FS::deletePath(removePath);
+				auto removePath = FS::PathCombine(root, thing);
+				QFileInfo stat(removePath);
+				if(stat.isDir())
+				{
+					FS::deletePath(removePath);
+				}
+				else
+				{
+					QFile::remove(removePath);
+				}
 			}
-			else
-			{
-				QFile::remove(removePath);
-			}
-		}
-	};
-	QStringList rootRemovables = {"modlist", "version", "instMods"};
-	QStringList mcRemovables = {"bin", "MultiMCLauncher.jar", "icon.png"};
-	removeAll(inst->instanceRoot(), rootRemovables);
-	removeAll(inst->minecraftRoot(), mcRemovables);
+		};
+		QStringList rootRemovables = {"modlist", "version", "instMods"};
+		QStringList mcRemovables = {"bin", "MultiMCLauncher.jar", "icon.png"};
+		removeAll(inst.instanceRoot(), rootRemovables);
+		removeAll(inst.minecraftRoot(), mcRemovables);
+	}
 	emitSucceeded();
 }
 
diff --git a/api/logic/minecraft/update/FMLLibrariesTask.cpp b/api/logic/minecraft/update/FMLLibrariesTask.cpp
index 56ecee43..1bd339e4 100644
--- a/api/logic/minecraft/update/FMLLibrariesTask.cpp
+++ b/api/logic/minecraft/update/FMLLibrariesTask.cpp
@@ -15,7 +15,6 @@ void FMLLibrariesTask::executeTask()
 	MinecraftInstance *inst = (MinecraftInstance *)m_inst;
 	auto components = inst->getComponentList();
 	auto profile = components->getProfile();
-	bool forge_present = false;
 
 	if (!profile->hasTrait("legacyFML"))
 	{
@@ -23,7 +22,7 @@ void FMLLibrariesTask::executeTask()
 		return;
 	}
 
-	QString version = inst->getComponentVersion("net.minecraft");
+	QString version = components->getComponentVersion("net.minecraft");
 	auto &fmlLibsMapping = g_VersionFilterData.fmlLibsMapping;
 	if (!fmlLibsMapping.contains(version))
 	{
@@ -35,9 +34,7 @@ void FMLLibrariesTask::executeTask()
 
 	// determine if we need some libs for FML or forge
 	setStatus(tr("Checking for FML libraries..."));
-	forge_present = (components->versionPatch("net.minecraftforge") != nullptr);
-	// we don't...
-	if (!forge_present)
+	if(!components->getComponent("net.minecraftforge"))
 	{
 		emitSucceeded();
 		return;
diff --git a/api/logic/minecraft/update/LibrariesTask.cpp b/api/logic/minecraft/update/LibrariesTask.cpp
index 80d45d97..0bec61c1 100644
--- a/api/logic/minecraft/update/LibrariesTask.cpp
+++ b/api/logic/minecraft/update/LibrariesTask.cpp
@@ -13,12 +13,6 @@ void LibrariesTask::executeTask()
 	setStatus(tr("Getting the library files from Mojang..."));
 	qDebug() << m_inst->name() << ": downloading libraries";
 	MinecraftInstance *inst = (MinecraftInstance *)m_inst;
-	inst->reloadProfile();
-	if(inst->hasVersionBroken())
-	{
-		emitFailed(tr("Failed to load the version description files - check the instance for errors."));
-		return;
-	}
 
 	// Build a list of URLs that will need to be downloaded.
 	auto components = inst->getComponentList();
diff --git a/api/logic/net/Mode.h b/api/logic/net/Mode.h
new file mode 100644
index 00000000..62e26d92
--- /dev/null
+++ b/api/logic/net/Mode.h
@@ -0,0 +1,10 @@
+#pragma once
+
+namespace Net
+{
+enum class Mode
+{
+	Offline,
+	Online
+};
+}
diff --git a/application/LaunchController.cpp b/application/LaunchController.cpp
index d451e652..70b71eaf 100644
--- a/application/LaunchController.cpp
+++ b/application/LaunchController.cpp
@@ -192,7 +192,7 @@ void LaunchController::launchInstance()
 	Q_ASSERT_X(m_instance != NULL, "launchInstance", "instance is NULL");
 	Q_ASSERT_X(m_session.get() != nullptr, "launchInstance", "session is NULL");
 
-	if(!m_instance->reload())
+	if(!m_instance->reloadSettings())
 	{
 		QMessageBox::critical(m_parentWidget, tr("Error"), tr("Couldn't load the instance profile."));
 		emitFailed(tr("Couldn't load the instance profile."));
diff --git a/application/MainWindow.cpp b/application/MainWindow.cpp
index 908a126c..9f9772c8 100644
--- a/application/MainWindow.cpp
+++ b/application/MainWindow.cpp
@@ -1303,7 +1303,7 @@ void MainWindow::finalizeInstance(InstancePtr inst)
 	if (MMC->accounts()->anyAccountIsValid())
 	{
 		ProgressDialog loadDialog(this);
-		auto update = inst->createUpdateTask();
+		auto update = inst->createUpdateTask(Net::Mode::Online);
 		connect(update.get(), &Task::failed, [this](QString reason)
 				{
 					QString error = QString("Instance load failed: %1").arg(reason);
diff --git a/application/dialogs/NewInstanceDialog.cpp b/application/dialogs/NewInstanceDialog.cpp
index d1a2bbfa..9fa20856 100644
--- a/application/dialogs/NewInstanceDialog.cpp
+++ b/application/dialogs/NewInstanceDialog.cpp
@@ -71,7 +71,7 @@ NewInstanceDialog::NewInstanceDialog(const QString & initialGroup, const QString
 	}
 	else
 	{
-		vlist->load();
+		vlist->load(Net::Mode::Online);
 		auto task = vlist->getLoadTask();
 		if(vlist->isLoaded())
 		{
diff --git a/application/pages/ModFolderPage.cpp b/application/pages/ModFolderPage.cpp
index be1c8289..4ef5d71c 100644
--- a/application/pages/ModFolderPage.cpp
+++ b/application/pages/ModFolderPage.cpp
@@ -106,15 +106,15 @@ bool CoreModFolderPage::shouldDisplay() const
 		auto version = inst->getComponentList();
 		if (!version)
 			return true;
-		if(!version->versionPatch("net.minecraftforge"))
+		if(!version->getComponent("net.minecraftforge"))
 		{
 			return false;
 		}
-		if(!version->versionPatch("net.minecraft"))
+		if(!version->getComponent("net.minecraft"))
 		{
 			return false;
 		}
-		if(version->versionPatch("net.minecraft")->getReleaseDateTime() < g_VersionFilterData.legacyCutoffDate)
+		if(version->getComponent("net.minecraft")->getReleaseDateTime() < g_VersionFilterData.legacyCutoffDate)
 		{
 			return true;
 		}
diff --git a/application/pages/VersionPage.cpp b/application/pages/VersionPage.cpp
index d65d6bc7..c9f3453f 100644
--- a/application/pages/VersionPage.cpp
+++ b/application/pages/VersionPage.cpp
@@ -103,10 +103,10 @@ VersionPage::VersionPage(MinecraftInstance *inst, QWidget *parent)
 {
 	ui->setupUi(this);
 	ui->tabWidget->tabBar()->hide();
+	m_profile = m_inst->getComponentList();
 
 	reloadComponentList();
 
-	m_profile = m_inst->getComponentList();
 	if (m_profile)
 	{
 		auto proxy = new IconProxy(ui->packageView);
@@ -142,7 +142,7 @@ void VersionPage::packageCurrent(const QModelIndex &current, const QModelIndex &
 		return;
 	}
 	int row = current.row();
-	auto patch = m_profile->versionPatch(row);
+	auto patch = m_profile->getComponent(row);
 	auto severity = patch->getProblemSeverity();
 	switch(severity)
 	{
@@ -196,7 +196,7 @@ bool VersionPage::reloadComponentList()
 {
 	try
 	{
-		m_inst->reloadProfile();
+		m_profile->reload(Net::Mode::Online);
 		return true;
 	}
 	catch (Exception &e)
@@ -262,19 +262,6 @@ void VersionPage::on_jarBtn_clicked()
 	updateButtons();
 }
 
-void VersionPage::on_resetOrderBtn_clicked()
-{
-	try
-	{
-		m_profile->resetOrder();
-	}
-	catch (Exception &e)
-	{
-		QMessageBox::critical(this, tr("Error"), e.cause());
-	}
-	updateButtons();
-}
-
 void VersionPage::on_moveUpBtn_clicked()
 {
 	try
@@ -308,7 +295,7 @@ void VersionPage::on_changeVersionBtn_clicked()
 	{
 		return;
 	}
-	auto patch = m_profile->versionPatch(versionRow);
+	auto patch = m_profile->getComponent(versionRow);
 	auto name = patch->getName();
 	auto list = patch->getVersionList();
 	if(!list)
@@ -331,8 +318,10 @@ void VersionPage::on_changeVersionBtn_clicked()
 	}
 
 	qDebug() << "Change" << uid << "to" << vselect.selectedVersion()->descriptor();
+	bool important = false;
 	if(uid == "net.minecraft")
 	{
+		important = true;
 		if (!m_profile->isVanilla())
 		{
 			auto result = CustomMessageBox::selectable(
@@ -348,14 +337,14 @@ void VersionPage::on_changeVersionBtn_clicked()
 			reloadComponentList();
 		}
 	}
-	m_inst->setComponentVersion(uid, vselect.selectedVersion()->descriptor());
+	m_profile->setComponentVersion(uid, vselect.selectedVersion()->descriptor(), important);
 	doUpdate();
 	m_container->refreshContainer();
 }
 
 int VersionPage::doUpdate()
 {
-	auto updateTask = m_inst->createUpdateTask();
+	auto updateTask = m_inst->createUpdateTask(Net::Mode::Online);
 	if (!updateTask)
 	{
 		return 1;
@@ -376,20 +365,58 @@ void VersionPage::on_forgeBtn_clicked()
 		return;
 	}
 	VersionSelectDialog vselect(vlist.get(), tr("Select Forge version"), this);
-	vselect.setExactFilter(BaseVersionList::ParentVersionRole, m_inst->getComponentVersion("net.minecraft"));
-	vselect.setEmptyString(tr("No Forge versions are currently available for Minecraft ") + m_inst->getComponentVersion("net.minecraft"));
+	vselect.setExactFilter(BaseVersionList::ParentVersionRole, m_profile->getComponentVersion("net.minecraft"));
+	vselect.setEmptyString(tr("No Forge versions are currently available for Minecraft ") + m_profile->getComponentVersion("net.minecraft"));
 	vselect.setEmptyErrorString(tr("Couldn't load or download the Forge version lists!"));
 	if (vselect.exec() && vselect.selectedVersion())
 	{
 		auto vsn = vselect.selectedVersion();
-		m_inst->setComponentVersion("net.minecraftforge", vsn->descriptor());
-		m_profile->reload();
+		m_profile->setComponentVersion("net.minecraftforge", vsn->descriptor());
+		m_profile->resolve(Net::Mode::Online);
 		// m_profile->installVersion();
 		preselect(m_profile->rowCount(QModelIndex())-1);
 		m_container->refreshContainer();
 	}
 }
 
+// TODO: use something like this... except the final decision of what to show has to be deferred until the lists are known
+/*
+void VersionPage::on_liteloaderBtn_clicked()
+{
+	QString uid = "com.mumfrey.liteloader";
+	auto vlist = ENV.metadataIndex()->get(uid);
+	if(!vlist)
+	{
+		return;
+	}
+	VersionSelectDialog vselect(vlist.get(), tr("Select %1 version").arg(vlist->name()), this);
+	auto parentUid = vlist->parentUid();
+	if(!parentUid.isEmpty())
+	{
+		auto parentvlist = ENV.metadataIndex()->get(parentUid);
+		vselect.setExactFilter(BaseVersionList::ParentVersionRole, m_profile->getComponentVersion(parentUid));
+		vselect.setEmptyString(
+			tr("No %1 versions are currently available for %2 %3")
+				.arg(vlist->name())
+				.arg(parentvlist->name())
+				.arg(m_profile->getComponentVersion(parentUid)));
+	}
+	else
+	{
+		vselect.setEmptyString(tr("No %1 versions are currently available"));
+	}
+	vselect.setEmptyErrorString(tr("Couldn't load or download the %1 version lists!").arg(vlist->name()));
+	if (vselect.exec() && vselect.selectedVersion())
+	{
+		auto vsn = vselect.selectedVersion();
+		m_profile->setComponentVersion(uid, vsn->descriptor());
+		m_profile->resolve();
+		preselect(m_profile->rowCount(QModelIndex())-1);
+		m_container->refreshContainer();
+	}
+}
+*/
+
 void VersionPage::on_liteloaderBtn_clicked()
 {
 	auto vlist = ENV.metadataIndex()->get("com.mumfrey.liteloader");
@@ -398,14 +425,14 @@ void VersionPage::on_liteloaderBtn_clicked()
 		return;
 	}
 	VersionSelectDialog vselect(vlist.get(), tr("Select LiteLoader version"), this);
-	vselect.setExactFilter(BaseVersionList::ParentVersionRole, m_inst->getComponentVersion("net.minecraft"));
-	vselect.setEmptyString(tr("No LiteLoader versions are currently available for Minecraft ") + m_inst->getComponentVersion("net.minecraft"));
+	vselect.setExactFilter(BaseVersionList::ParentVersionRole, m_profile->getComponentVersion("net.minecraft"));
+	vselect.setEmptyString(tr("No LiteLoader versions are currently available for Minecraft ") + m_profile->getComponentVersion("net.minecraft"));
 	vselect.setEmptyErrorString(tr("Couldn't load or download the LiteLoader version lists!"));
 	if (vselect.exec() && vselect.selectedVersion())
 	{
 		auto vsn = vselect.selectedVersion();
-		m_inst->setComponentVersion("com.mumfrey.liteloader", vsn->descriptor());
-		m_profile->reload();
+		m_profile->setComponentVersion("com.mumfrey.liteloader", vsn->descriptor());
+		m_profile->resolve(Net::Mode::Online);
 		// m_profile->installVersion(vselect.selectedVersion());
 		preselect(m_profile->rowCount(QModelIndex())-1);
 		m_container->refreshContainer();
@@ -441,7 +468,7 @@ void VersionPage::updateButtons(int row)
 {
 	if(row == -1)
 		row = currentRow();
-	auto patch = m_profile->versionPatch(row);
+	auto patch = m_profile->getComponent(row);
 	if (!patch)
 	{
 		ui->removeBtn->setDisabled(true);
@@ -470,14 +497,14 @@ void VersionPage::onGameUpdateError(QString error)
 								 QMessageBox::Warning)->show();
 }
 
-ProfilePatchPtr VersionPage::current()
+ComponentPtr VersionPage::current()
 {
 	auto row = currentRow();
 	if(row < 0)
 	{
 		return nullptr;
 	}
-	return m_profile->versionPatch(row);
+	return m_profile->getComponent(row);
 }
 
 int VersionPage::currentRow()
@@ -496,7 +523,7 @@ void VersionPage::on_customizeBtn_clicked()
 	{
 		return;
 	}
-	auto patch = m_profile->versionPatch(version);
+	auto patch = m_profile->getComponent(version);
 	if(!patch->getVersionFile())
 	{
 		// TODO: wait for the update task to finish here...
diff --git a/application/pages/VersionPage.h b/application/pages/VersionPage.h
index 0ac10a14..809b2c0c 100644
--- a/application/pages/VersionPage.h
+++ b/application/pages/VersionPage.h
@@ -53,7 +53,6 @@ private slots:
 	void on_liteloaderBtn_clicked();
 	void on_reloadBtn_clicked();
 	void on_removeBtn_clicked();
-	void on_resetOrderBtn_clicked();
 	void on_moveUpBtn_clicked();
 	void on_moveDownBtn_clicked();
 	void on_jarmodBtn_clicked();
@@ -68,7 +67,7 @@ private slots:
 	void on_changeVersionBtn_clicked();
 
 private:
-	ProfilePatchPtr current();
+	ComponentPtr current();
 	int currentRow();
 	void updateButtons(int row = -1);
 	void preselect(int row = 0);
diff --git a/application/pages/VersionPage.ui b/application/pages/VersionPage.ui
index afb33164..b6da3294 100644
--- a/application/pages/VersionPage.ui
+++ b/application/pages/VersionPage.ui
@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>693</width>
-    <height>788</height>
+    <height>833</height>
    </rect>
   </property>
   <layout class="QVBoxLayout" name="verticalLayout">
@@ -218,16 +218,6 @@
           </widget>
          </item>
          <item>
-          <widget class="QPushButton" name="resetOrderBtn">
-           <property name="toolTip">
-            <string>Reset apply order of packages.</string>
-           </property>
-           <property name="text">
-            <string>Reset order</string>
-           </property>
-          </widget>
-         </item>
-         <item>
           <widget class="QPushButton" name="reloadBtn">
            <property name="toolTip">
             <string>Reload all packages.</string>
@@ -300,7 +290,6 @@
   <tabstop>liteloaderBtn</tabstop>
   <tabstop>modBtn</tabstop>
   <tabstop>jarmodBtn</tabstop>
-  <tabstop>resetOrderBtn</tabstop>
   <tabstop>reloadBtn</tabstop>
  </tabstops>
  <resources/>
diff --git a/application/pages/global/PackagesPage.cpp b/application/pages/global/PackagesPage.cpp
index e15ddbab..7b117d0b 100644
--- a/application/pages/global/PackagesPage.cpp
+++ b/application/pages/global/PackagesPage.cpp
@@ -38,10 +38,17 @@ static QString formatRequires(const VersionPtr &version)
 	auto iter = reqs.begin();
 	while (iter != reqs.end())
 	{
-		auto &uid = iter.key();
-		auto &version = iter.value();
+		auto &uid = iter->uid;
+		auto &version = iter->equalsVersion;
 		const QString readable = ENV.metadataIndex()->hasUid(uid) ? ENV.metadataIndex()->get(uid)->humanReadable() : uid;
-		lines.append(QString("%1 (%2)").arg(readable, version));
+		if(!version.isEmpty())
+		{
+			lines.append(QString("%1 (%2)").arg(readable, version));
+		}
+		else
+		{
+			lines.append(QString("%1").arg(readable));
+		}
 		iter++;
 	}
 	return lines.join('\n');
@@ -95,7 +102,7 @@ QIcon PackagesPage::icon() const
 
 void PackagesPage::on_refreshIndexBtn_clicked()
 {
-	ENV.metadataIndex()->load();
+	ENV.metadataIndex()->load(Net::Mode::Online);
 }
 void PackagesPage::on_refreshFileBtn_clicked()
 {
@@ -104,7 +111,7 @@ void PackagesPage::on_refreshFileBtn_clicked()
 	{
 		return;
 	}
-	list->load();
+	list->load(Net::Mode::Online);
 }
 void PackagesPage::on_refreshVersionBtn_clicked()
 {
@@ -113,7 +120,7 @@ void PackagesPage::on_refreshVersionBtn_clicked()
 	{
 		return;
 	}
-	version->load();
+	version->load(Net::Mode::Online);
 }
 
 void PackagesPage::on_fileSearchEdit_textChanged(const QString &search)
@@ -156,7 +163,7 @@ void PackagesPage::updateCurrentVersionList(const QModelIndex &index)
 		ui->fileName->setText(list->name());
 		m_versionProxy->setSourceModel(list.get());
 		ui->refreshFileBtn->setText(tr("Refresh %1").arg(list->humanReadable()));
-		list->load();
+		list->load(Net::Mode::Offline);
 	}
 	else
 	{
@@ -213,5 +220,5 @@ void PackagesPage::updateVersion()
 
 void PackagesPage::opened()
 {
-	ENV.metadataIndex()->load();
+	ENV.metadataIndex()->load(Net::Mode::Offline);
 }