NOISSUE Granular instance reload

22 files changed, 1402 insertions, 772 deletions

diff --git a/api/gui/icons/IconList.cpp b/api/gui/icons/IconList.cpp
index 4f9fb09f..b6be007f 100644
--- a/api/gui/icons/IconList.cpp
+++ b/api/gui/icons/IconList.cpp
@@ -243,7 +243,7 @@ int IconList::rowCount(const QModelIndex &parent) const
 	return icons.size();
 }
 
-void IconList::installIcons(QStringList iconFiles)
+void IconList::installIcons(const QStringList &iconFiles)
 {
 	for (QString file : iconFiles)
 	{
@@ -261,7 +261,7 @@ void IconList::installIcons(QStringList iconFiles)
 	}
 }
 
-bool IconList::iconFileExists(QString key)
+bool IconList::iconFileExists(const QString &key) const
 {
 	auto iconEntry = icon(key);
 	if(!iconEntry)
@@ -271,7 +271,7 @@ bool IconList::iconFileExists(QString key)
 	return iconEntry->has(IconType::FileBased);
 }
 
-const MMCIcon *IconList::icon(QString key)
+const MMCIcon *IconList::icon(const QString &key) const
 {
 	int iconIdx = getIconIndex(key);
 	if (iconIdx == -1)
@@ -279,7 +279,7 @@ const MMCIcon *IconList::icon(QString key)
 	return &icons[iconIdx];
 }
 
-bool IconList::deleteIcon(QString key)
+bool IconList::deleteIcon(const QString &key)
 {
 	int iconIdx = getIconIndex(key);
 	if (iconIdx == -1)
diff --git a/api/gui/icons/IconList.h b/api/gui/icons/IconList.h
index 7aeb7067..24ff4454 100644
--- a/api/gui/icons/IconList.h
+++ b/api/gui/icons/IconList.h
@@ -44,18 +44,19 @@ public:
 	virtual QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
 	virtual int rowCount(const QModelIndex &parent = QModelIndex()) const override;
 
-	virtual bool addIcon(QString key, QString name, QString path, IconType type) override;
-	bool deleteIcon(QString key);
-	bool iconFileExists(QString key);
+	bool addIcon(const QString &key, const QString &name, const QString &path, const IconType type) override;
+	void saveIcon(const QString &key, const QString &path, const char * format) const override;
+	bool deleteIcon(const QString &key) override;
+	bool iconFileExists(const QString &key) const override;
 
 	virtual QStringList mimeTypes() const override;
 	virtual Qt::DropActions supportedDropActions() const override;
 	virtual bool dropMimeData(const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent) override;
 	virtual Qt::ItemFlags flags(const QModelIndex &index) const override;
 
-	void installIcons(QStringList iconFiles);
+	void installIcons(const QStringList &iconFiles) override;
 
-	const MMCIcon * icon(QString key);
+	const MMCIcon * icon(const QString &key) const;
 
 	void startWatching();
 	void stopWatching();
diff --git a/api/logic/BaseInstance.cpp b/api/logic/BaseInstance.cpp
index 9dee2c38..452e657a 100644
--- a/api/logic/BaseInstance.cpp
+++ b/api/logic/BaseInstance.cpp
@@ -17,6 +17,7 @@
 
 #include <QFileInfo>
 #include <QDir>
+#include <QDebug>
 
 #include "settings/INISettingsObject.h"
 #include "settings/Setting.h"
@@ -74,10 +75,32 @@ void BaseInstance::iconUpdated(QString key)
 	}
 }
 
+void BaseInstance::invalidate()
+{
+	changeStatus(Status::Gone);
+	qDebug() << "Instance" << id() << "has been invalidated.";
+}
+
 void BaseInstance::nuke()
 {
+	changeStatus(Status::Gone);
+	qDebug() << "Instance" << id() << "has been deleted by MultiMC.";
 	FS::deletePath(instanceRoot());
-	emit nuked(this);
+}
+
+void BaseInstance::changeStatus(BaseInstance::Status newStatus)
+{
+	Status status = currentStatus();
+	if(status != newStatus)
+	{
+		m_status = newStatus;
+		emit statusChanged(status, newStatus);
+	}
+}
+
+BaseInstance::Status BaseInstance::currentStatus() const
+{
+	return m_status;
 }
 
 QString BaseInstance::id() const
@@ -278,3 +301,19 @@ std::shared_ptr<LaunchTask> BaseInstance::getLaunchTask()
 {
 	return m_launchProcess;
 }
+
+void BaseInstance::setProvider(BaseInstanceProvider* provider)
+{
+	// only once.
+	assert(!m_provider);
+	if(m_provider)
+	{
+		qWarning() << "Provider set more than once for instance" << id();
+	}
+	m_provider = provider;
+}
+
+BaseInstanceProvider* BaseInstance::provider() const
+{
+	return m_provider;
+}
diff --git a/api/logic/BaseInstance.h b/api/logic/BaseInstance.h
index ebaaeb83..56d3d6cb 100644
--- a/api/logic/BaseInstance.h
+++ b/api/logic/BaseInstance.h
@@ -14,6 +14,7 @@
  */
 
 #pragma once
+#include <cassert>
 
 #include <QObject>
 #include "QObjectPtr.h"
@@ -35,6 +36,7 @@ class QDir;
 class Task;
 class LaunchTask;
 class BaseInstance;
+class BaseInstanceProvider;
 
 // pointer for lazy people
 typedef std::shared_ptr<BaseInstance> InstancePtr;
@@ -54,6 +56,13 @@ protected:
 	/// no-touchy!
 	BaseInstance(SettingsObjectPtr globalSettings, SettingsObjectPtr settings, const QString &rootDir);
 
+public: /* types */
+	enum class Status
+	{
+		Present,
+		Gone // either nuked or invalidated
+	};
+
 public:
 	/// virtual destructor to make sure the destruction is COMPLETE
 	virtual ~BaseInstance() {};
@@ -66,6 +75,14 @@ public:
 	/// responsible of cleaning up the husk
 	void nuke();
 
+	/***
+	 * the instance has been invalidated - it is no longer tracked by MultiMC for some reason,
+	 * but it has not necessarily been deleted.
+	 *
+	 * Happens when the instance folder changes to some other location, or the instance is removed by external means.
+	 */
+	void invalidate();
+
 	/// The instance's ID. The ID SHALL be determined by MMC internally. The ID IS guaranteed to
 	/// be unique.
 	virtual QString id() const;
@@ -75,6 +92,9 @@ public:
 	int64_t totalTimePlayed() const;
 	void resetTimePlayed();
 
+	void setProvider(BaseInstanceProvider * provider);
+	BaseInstanceProvider * provider() const;
+
 	/// get the type of this instance
 	QString instanceType() const;
 
@@ -219,6 +239,11 @@ public:
 	 */
 	virtual QStringList verboseDescription(AuthSessionPtr session) = 0;
 
+	Status currentStatus() const;
+
+protected:
+	void changeStatus(Status newStatus);
+
 signals:
 	/*!
 	 * \brief Signal emitted when properties relevant to the instance view change
@@ -228,10 +253,6 @@ signals:
 	 * \brief Signal emitted when groups are affected in any way
 	 */
 	void groupChanged();
-	/*!
-	 * \brief The instance just got nuked. Hurray!
-	 */
-	void nuked(BaseInstance *inst);
 
 	void flagsChanged();
 
@@ -239,10 +260,12 @@ signals:
 
 	void runningStatusChanged(bool running);
 
+	void statusChanged(Status from, Status to);
+
 protected slots:
 	void iconUpdated(QString key);
 
-protected:
+protected: /* data */
 	QString m_rootDir;
 	QString m_group;
 	SettingsObjectPtr m_settings;
@@ -250,6 +273,10 @@ protected:
 	bool m_isRunning = false;
 	std::shared_ptr<LaunchTask> m_launchProcess;
 	QDateTime m_timeStarted;
+	BaseInstanceProvider * m_provider = nullptr;
+
+private: /* data */
+	Status m_status = Status::Present;
 };
 
 Q_DECLARE_METATYPE(std::shared_ptr<BaseInstance>)
diff --git a/api/logic/BaseInstanceProvider.h b/api/logic/BaseInstanceProvider.h
new file mode 100644
index 00000000..f6833650
--- /dev/null
+++ b/api/logic/BaseInstanceProvider.h
@@ -0,0 +1,57 @@
+#pragma once
+
+#include <QObject>
+#include <QString>
+#include "BaseInstance.h"
+#include "settings/SettingsObject.h"
+
+#include "multimc_logic_export.h"
+
+using InstanceId = QString;
+using InstanceLocator = std::pair<InstancePtr, int>;
+
+enum class InstCreateError
+{
+	NoCreateError = 0,
+	NoSuchVersion,
+	UnknownCreateError,
+	InstExists,
+	CantCreateDir
+};
+
+class MULTIMC_LOGIC_EXPORT BaseInstanceProvider : public QObject
+{
+	Q_OBJECT
+public:
+	BaseInstanceProvider(SettingsObjectPtr settings) : m_globalSettings(settings)
+	{
+		// nil
+	}
+public:
+	virtual QList<InstanceId> discoverInstances() = 0;
+	virtual InstancePtr loadInstance(const InstanceId &id) = 0;
+	virtual void loadGroupList() = 0;
+	virtual void saveGroupList() = 0;
+
+	virtual QString getStagedInstancePath()
+	{
+		return QString();
+	}
+	virtual bool commitStagedInstance(const QString & keyPath, const QString & path, const QString& instanceName, const QString & groupName)
+	{
+		return false;
+	}
+	virtual bool destroyStagingPath(const QString & path)
+	{
+		return true;
+	}
+
+signals:
+	// Emit this when the list of provided instances changed
+	void instancesChanged();
+	// Emit when the set of groups your provider supplies changes.
+	void groupsChanged(QSet<QString> groups);
+
+protected:
+	SettingsObjectPtr m_globalSettings;
+};
diff --git a/api/logic/CMakeLists.txt b/api/logic/CMakeLists.txt
index c430b53f..0741fb1a 100644
--- a/api/logic/CMakeLists.txt
+++ b/api/logic/CMakeLists.txt
@@ -8,8 +8,17 @@ set(CORE_SOURCES
 	BaseInstaller.cpp
 	BaseVersionList.h
 	BaseVersionList.cpp
+	InstanceCreationTask.h
+	InstanceCreationTask.cpp
+	InstanceCopyTask.h
+	InstanceCopyTask.cpp
+	InstanceImportTask.h
+	InstanceImportTask.cpp
 	InstanceList.h
 	InstanceList.cpp
+	BaseInstanceProvider.h
+	FolderInstanceProvider.h
+	FolderInstanceProvider.cpp
 	BaseVersion.h
 	BaseInstance.h
 	BaseInstance.cpp
@@ -276,6 +285,8 @@ set(MINECRAFT_SOURCES
 	minecraft/ftb/LegacyFTBInstance.cpp
 	minecraft/ftb/FTBProfileStrategy.h
 	minecraft/ftb/FTBProfileStrategy.cpp
+	minecraft/ftb/FTBInstanceProvider.cpp
+	minecraft/ftb/FTBInstanceProvider.h
 	minecraft/ftb/FTBPlugin.h
 	minecraft/ftb/FTBPlugin.cpp
 
diff --git a/api/logic/FolderInstanceProvider.cpp b/api/logic/FolderInstanceProvider.cpp
new file mode 100644
index 00000000..a1f3f1f2
--- /dev/null
+++ b/api/logic/FolderInstanceProvider.cpp
@@ -0,0 +1,356 @@
+#include "FolderInstanceProvider.h"
+#include "settings/INISettingsObject.h"
+#include "FileSystem.h"
+#include "minecraft/onesix/OneSixInstance.h"
+#include "minecraft/legacy/LegacyInstance.h"
+#include "NullInstance.h"
+
+#include <QDir>
+#include <QDirIterator>
+#include <QFileSystemWatcher>
+#include <QJsonDocument>
+#include <QJsonObject>
+#include <QJsonArray>
+#include <QUuid>
+
+const static int GROUP_FILE_FORMAT_VERSION = 1;
+
+struct WatchLock
+{
+	WatchLock(QFileSystemWatcher * watcher, const QString& instDir)
+		: m_watcher(watcher), m_instDir(instDir)
+	{
+		m_watcher->removePath(m_instDir);
+	}
+	~WatchLock()
+	{
+		m_watcher->addPath(m_instDir);
+	}
+	QFileSystemWatcher * m_watcher;
+	QString m_instDir;
+};
+
+FolderInstanceProvider::FolderInstanceProvider(SettingsObjectPtr settings, const QString& instDir)
+	: BaseInstanceProvider(settings)
+{
+	m_instDir = instDir;
+	if (!QDir::current().exists(m_instDir))
+	{
+		QDir::current().mkpath(m_instDir);
+	}
+	m_watcher = new QFileSystemWatcher(this);
+	connect(m_watcher, &QFileSystemWatcher::directoryChanged, this, &FolderInstanceProvider::instanceDirContentsChanged);
+	m_watcher->addPath(m_instDir);
+}
+
+QList< InstanceId > FolderInstanceProvider::discoverInstances()
+{
+	QList<InstanceId> out;
+	QDirIterator iter(m_instDir, QDir::Dirs | QDir::NoDot | QDir::NoDotDot | QDir::Readable, QDirIterator::FollowSymlinks);
+	while (iter.hasNext())
+	{
+		QString subDir = iter.next();
+		QFileInfo dirInfo(subDir);
+		if (!QFileInfo(FS::PathCombine(subDir, "instance.cfg")).exists())
+			continue;
+		// if it is a symlink, ignore it if it goes to the instance folder
+		if(dirInfo.isSymLink())
+		{
+			QFileInfo targetInfo(dirInfo.symLinkTarget());
+			QFileInfo instDirInfo(m_instDir);
+			if(targetInfo.canonicalPath() == instDirInfo.canonicalFilePath())
+			{
+				qDebug() << "Ignoring symlink" << subDir << "that leads into the instances folder";
+				continue;
+			}
+		}
+		auto id = dirInfo.fileName();
+		out.append(id);
+		qDebug() << "Found instance ID" << id;
+	}
+	return out;
+}
+
+InstancePtr FolderInstanceProvider::loadInstance(const InstanceId& id)
+{
+	if(!m_groupsLoaded)
+	{
+		loadGroupList();
+	}
+
+	auto instanceRoot = FS::PathCombine(m_instDir, id);
+	auto instanceSettings = std::make_shared<INISettingsObject>(FS::PathCombine(instanceRoot, "instance.cfg"));
+	InstancePtr inst;
+
+	instanceSettings->registerSetting("InstanceType", "Legacy");
+
+	QString inst_type = instanceSettings->get("InstanceType").toString();
+
+	if (inst_type == "OneSix" || inst_type == "Nostalgia")
+	{
+		inst.reset(new OneSixInstance(m_globalSettings, instanceSettings, instanceRoot));
+	}
+	else if (inst_type == "Legacy")
+	{
+		inst.reset(new LegacyInstance(m_globalSettings, instanceSettings, instanceRoot));
+	}
+	else
+	{
+		inst.reset(new NullInstance(m_globalSettings, instanceSettings, instanceRoot));
+	}
+	inst->init();
+	inst->setProvider(this);
+	auto iter = groupMap.find(id);
+	if (iter != groupMap.end())
+	{
+		inst->setGroupInitial((*iter));
+	}
+	connect(inst.get(), &BaseInstance::groupChanged, this, &FolderInstanceProvider::groupChanged);
+	qDebug() << "Loaded instance " << inst->name() << " from " << inst->instanceRoot();
+	return inst;
+}
+
+#include "InstanceImportTask.h"
+Task * FolderInstanceProvider::zipImportTask(const QUrl sourceUrl, const QString& instName, const QString& instGroup, const QString& instIcon)
+{
+	return new InstanceImportTask(m_globalSettings, sourceUrl, this, instName, instGroup, instIcon);
+}
+
+#include "InstanceCreationTask.h"
+Task * FolderInstanceProvider::creationTask(BaseVersionPtr version, const QString& instName, const QString& instGroup, const QString& instIcon)
+{
+	return new InstanceCreationTask(m_globalSettings, this, version, instName, instIcon, instGroup);
+}
+
+#include "InstanceCopyTask.h"
+Task * FolderInstanceProvider::copyTask(const InstancePtr& oldInstance, const QString& instName, const QString& instGroup, const QString& instIcon, bool copySaves)
+{
+	return new InstanceCopyTask(m_globalSettings, this, oldInstance, instName, instIcon, instGroup, copySaves);
+}
+
+void FolderInstanceProvider::saveGroupList()
+{
+	WatchLock foo(m_watcher, m_instDir);
+	QString groupFileName = m_instDir + "/instgroups.json";
+	QMap<QString, QSet<QString>> reverseGroupMap;
+	for (auto iter = groupMap.begin(); iter != groupMap.end(); iter++)
+	{
+		QString id = iter.key();
+		QString group = iter.value();
+		if (group.isEmpty())
+			continue;
+
+		if (!reverseGroupMap.count(group))
+		{
+			QSet<QString> set;
+			set.insert(id);
+			reverseGroupMap[group] = set;
+		}
+		else
+		{
+			QSet<QString> &set = reverseGroupMap[group];
+			set.insert(id);
+		}
+	}
+	QJsonObject toplevel;
+	toplevel.insert("formatVersion", QJsonValue(QString("1")));
+	QJsonObject groupsArr;
+	for (auto iter = reverseGroupMap.begin(); iter != reverseGroupMap.end(); iter++)
+	{
+		auto list = iter.value();
+		auto name = iter.key();
+		QJsonObject groupObj;
+		QJsonArray instanceArr;
+		groupObj.insert("hidden", QJsonValue(QString("false")));
+		for (auto item : list)
+		{
+			instanceArr.append(QJsonValue(item));
+		}
+		groupObj.insert("instances", instanceArr);
+		groupsArr.insert(name, groupObj);
+	}
+	toplevel.insert("groups", groupsArr);
+	QJsonDocument doc(toplevel);
+	try
+	{
+		FS::write(groupFileName, doc.toJson());
+	}
+	catch(FS::FileSystemException & e)
+	{
+		qCritical() << "Failed to write instance group file :" << e.cause();
+	}
+}
+
+void FolderInstanceProvider::loadGroupList()
+{
+	QSet<QString> groupSet;
+
+	QString groupFileName = m_instDir + "/instgroups.json";
+
+	// if there's no group file, fail
+	if (!QFileInfo(groupFileName).exists())
+		return;
+
+	QByteArray jsonData;
+	try
+	{
+		jsonData = FS::read(groupFileName);
+	}
+	catch (FS::FileSystemException & e)
+	{
+		qCritical() << "Failed to read instance group file :" << e.cause();
+		return;
+	}
+
+	QJsonParseError error;
+	QJsonDocument jsonDoc = QJsonDocument::fromJson(jsonData, &error);
+
+	// if the json was bad, fail
+	if (error.error != QJsonParseError::NoError)
+	{
+		qCritical() << QString("Failed to parse instance group file: %1 at offset %2")
+							.arg(error.errorString(), QString::number(error.offset))
+							.toUtf8();
+		return;
+	}
+
+	// if the root of the json wasn't an object, fail
+	if (!jsonDoc.isObject())
+	{
+		qWarning() << "Invalid group file. Root entry should be an object.";
+		return;
+	}
+
+	QJsonObject rootObj = jsonDoc.object();
+
+	// Make sure the format version matches, otherwise fail.
+	if (rootObj.value("formatVersion").toVariant().toInt() != GROUP_FILE_FORMAT_VERSION)
+		return;
+
+	// Get the groups. if it's not an object, fail
+	if (!rootObj.value("groups").isObject())
+	{
+		qWarning() << "Invalid group list JSON: 'groups' should be an object.";
+		return;
+	}
+
+	groupMap.clear();
+
+	// Iterate through all the groups.
+	QJsonObject groupMapping = rootObj.value("groups").toObject();
+	for (QJsonObject::iterator iter = groupMapping.begin(); iter != groupMapping.end(); iter++)
+	{
+		QString groupName = iter.key();
+
+		// If not an object, complain and skip to the next one.
+		if (!iter.value().isObject())
+		{
+			qWarning() << QString("Group '%1' in the group list should "
+								   "be an object.")
+							   .arg(groupName)
+							   .toUtf8();
+			continue;
+		}
+
+		QJsonObject groupObj = iter.value().toObject();
+		if (!groupObj.value("instances").isArray())
+		{
+			qWarning() << QString("Group '%1' in the group list is invalid. "
+								   "It should contain an array "
+								   "called 'instances'.")
+							   .arg(groupName)
+							   .toUtf8();
+			continue;
+		}
+
+		// keep a list/set of groups for choosing
+		groupSet.insert(groupName);
+
+		// Iterate through the list of instances in the group.
+		QJsonArray instancesArray = groupObj.value("instances").toArray();
+
+		for (QJsonArray::iterator iter2 = instancesArray.begin(); iter2 != instancesArray.end();
+			 iter2++)
+		{
+			groupMap[(*iter2).toString()] = groupName;
+		}
+	}
+	m_groupsLoaded = true;
+	emit groupsChanged(groupSet);
+}
+
+void FolderInstanceProvider::groupChanged()
+{
+	// save the groups. save all of them.
+	auto instance = (BaseInstance *) QObject::sender();
+	auto id = instance->id();
+	groupMap[id] = instance->group();
+	emit groupsChanged({instance->group()});
+	saveGroupList();
+}
+
+
+void FolderInstanceProvider::instanceDirContentsChanged(const QString& path)
+{
+	Q_UNUSED(path);
+	emit instancesChanged();
+}
+
+void FolderInstanceProvider::on_InstFolderChanged(const Setting &setting, QVariant value)
+{
+	QString newInstDir = value.toString();
+	if(newInstDir != m_instDir)
+	{
+		if(m_groupsLoaded)
+		{
+			saveGroupList();
+		}
+		m_instDir = newInstDir;
+		m_groupsLoaded = false;
+		emit instancesChanged();
+	}
+}
+
+QString FolderInstanceProvider::getStagedInstancePath()
+{
+	QString key = QUuid::createUuid().toString();
+	QString relPath = FS::PathCombine("_MMC_TEMP/" , key);
+	QDir rootPath(m_instDir);
+	auto path = FS::PathCombine(m_instDir, relPath);
+	if(!rootPath.mkpath(relPath))
+	{
+		return QString();
+	}
+	return path;
+}
+
+bool FolderInstanceProvider::commitStagedInstance(const QString& keyPath, const QString& path, const QString& instanceName,
+	const QString& groupName)
+{
+	if(!path.contains(keyPath))
+	{
+		qWarning() << "It is not possible to commit" << path << "because it is not in" << keyPath;
+		return false;
+	}
+	QDir dir;
+	QString instID = FS::DirNameFromString(instanceName, m_instDir);
+	{
+		WatchLock lock(m_watcher, m_instDir);
+		if(!dir.rename(path, FS::PathCombine(m_instDir, instID)))
+		{
+			destroyStagingPath(keyPath);
+			return false;
+		}
+		groupMap[instID] = groupName;
+		emit groupsChanged({groupName});
+		emit instancesChanged();
+	}
+	saveGroupList();
+	return destroyStagingPath(keyPath);
+}
+
+bool FolderInstanceProvider::destroyStagingPath(const QString& keyPath)
+{
+	return FS::deletePath(keyPath);
+}
+
diff --git a/api/logic/FolderInstanceProvider.h b/api/logic/FolderInstanceProvider.h
new file mode 100644
index 00000000..f350a96d
--- /dev/null
+++ b/api/logic/FolderInstanceProvider.h
@@ -0,0 +1,63 @@
+#pragma once
+
+#include "BaseInstanceProvider.h"
+#include <QMap>
+
+class QFileSystemWatcher;
+
+class MULTIMC_LOGIC_EXPORT FolderInstanceProvider : public BaseInstanceProvider
+{
+	Q_OBJECT
+public:
+	FolderInstanceProvider(SettingsObjectPtr settings, const QString & instDir);
+
+public:
+	/// used by InstanceList to @return a list of plausible IDs to probe for
+	QList<InstanceId> discoverInstances() override;
+
+	/// used by InstanceList to (re)load an instance with the given @id.
+	InstancePtr loadInstance(const InstanceId& id) override;
+
+
+	// create instance in this provider
+	Task * creationTask(BaseVersionPtr version, const QString &instName, const QString &instGroup, const QString &instIcon);
+
+	// copy instance to this provider
+	Task * copyTask(const InstancePtr &oldInstance, const QString& instName, const QString& instGroup, const QString& instIcon, bool copySaves);
+
+	// import zipped instance into this provider
+	Task * zipImportTask(const QUrl sourceUrl, const QString &instName, const QString &instGroup, const QString &instIcon);
+
+	/**
+	 * Create a new empty staging area for instance creation and @return a path/key top commit it later.
+	 * Used by instance manipulation tasks.
+	 */
+	QString getStagedInstancePath() override;
+	/**
+	 * Commit the staging area given by @keyPath to the provider - used when creation succeeds.
+	 * Used by instance manipulation tasks.
+	 */
+	bool commitStagedInstance(const QString & keyPath, const QString & path, const QString& instanceName, const QString & groupName) override;
+	/**
+	 * Destroy a previously created staging area given by @keyPath - used when creation fails.
+	 * Used by instance manipulation tasks.
+	 */
+	bool destroyStagingPath(const QString & keyPath) override;
+
+public slots:
+	void on_InstFolderChanged(const Setting &setting, QVariant value);
+
+private slots:
+	void instanceDirContentsChanged(const QString &path);
+	void groupChanged();
+
+private: /* methods */
+	void loadGroupList() override;
+	void saveGroupList() override;
+
+private: /* data */
+	QString m_instDir;
+	QFileSystemWatcher * m_watcher;
+	QMap<QString, QString> groupMap;
+	bool m_groupsLoaded = false;
+};
diff --git a/api/logic/InstanceCopyTask.cpp b/api/logic/InstanceCopyTask.cpp
new file mode 100644
index 00000000..1e231478
--- /dev/null
+++ b/api/logic/InstanceCopyTask.cpp
@@ -0,0 +1,53 @@
+#include "InstanceCopyTask.h"
+#include "BaseInstanceProvider.h"
+#include "settings/INISettingsObject.h"
+#include "FileSystem.h"
+#include "NullInstance.h"
+#include "pathmatcher/RegexpMatcher.h"
+
+InstanceCopyTask::InstanceCopyTask(SettingsObjectPtr settings, BaseInstanceProvider* target, InstancePtr origInstance, const QString& instName, const QString& instIcon, const QString& instGroup, bool copySaves)
+{
+	m_globalSettings = settings;
+	m_target = target;
+	m_origInstance = origInstance;
+	m_instName = instName;
+	m_instIcon = instIcon;
+	m_instGroup = instGroup;
+	m_copySaves = copySaves;
+}
+
+void InstanceCopyTask::executeTask()
+{
+	setStatus(tr("Copying instance %1").arg(m_origInstance->name()));
+	std::unique_ptr<IPathMatcher> matcher;
+	if(!m_copySaves)
+	{
+		// FIXME: get this from the original instance type...
+		auto matcherReal = new RegexpMatcher("[.]?minecraft/saves");
+		matcherReal->caseSensitive(false);
+		matcher.reset(matcherReal);
+	}
+
+	QString stagingPath = m_target->getStagedInstancePath();
+	FS::copy folderCopy(m_origInstance->instanceRoot(), stagingPath);
+	folderCopy.followSymlinks(false).blacklist(matcher.get());
+	if (!folderCopy())
+	{
+		m_target->destroyStagingPath(stagingPath);
+		emitFailed(tr("Instance folder copy failed."));
+		return;
+	}
+
+	// FIXME: shouldn't this be able to report errors?
+	auto instanceSettings = std::make_shared<INISettingsObject>(FS::PathCombine(stagingPath, "instance.cfg"));
+	instanceSettings->registerSetting("InstanceType", "Legacy");
+
+	// FIXME: and this too? errors???
+	m_origInstance->copy(stagingPath);
+
+	InstancePtr inst(new NullInstance(m_globalSettings, instanceSettings, stagingPath));
+	inst->setName(m_instName);
+	inst->setIconKey(m_instIcon);
+	m_target->commitStagedInstance(stagingPath, stagingPath, m_instName, m_instGroup);
+	emitSucceeded();
+}
diff --git a/api/logic/InstanceCopyTask.h b/api/logic/InstanceCopyTask.h
new file mode 100644
index 00000000..a663ddbd
--- /dev/null
+++ b/api/logic/InstanceCopyTask.h
@@ -0,0 +1,34 @@
+#pragma once
+
+#include "tasks/Task.h"
+#include "multimc_logic_export.h"
+#include "net/NetJob.h"
+#include <QUrl>
+#include "settings/SettingsObject.h"
+#include "BaseVersion.h"
+#include "BaseInstance.h"
+
+class BaseInstanceProvider;
+
+class MULTIMC_LOGIC_EXPORT InstanceCopyTask : public Task
+{
+	Q_OBJECT
+public:
+	explicit InstanceCopyTask(SettingsObjectPtr settings, BaseInstanceProvider * target, InstancePtr origInstance, const QString &instName,
+		const QString &instIcon, const QString &instGroup, bool copySaves);
+
+protected:
+	//! Entry point for tasks.
+	virtual void executeTask() override;
+
+private: /* data */
+	SettingsObjectPtr m_globalSettings;
+	BaseInstanceProvider * m_target = nullptr;
+	InstancePtr m_origInstance;
+	QString m_instName;
+	QString m_instIcon;
+	QString m_instGroup;
+	bool m_copySaves = false;
+};
+
+
diff --git a/api/logic/InstanceCreationTask.cpp b/api/logic/InstanceCreationTask.cpp
new file mode 100644
index 00000000..00156701
--- /dev/null
+++ b/api/logic/InstanceCreationTask.cpp
@@ -0,0 +1,46 @@
+#include "InstanceCreationTask.h"
+#include "BaseInstanceProvider.h"
+#include "settings/INISettingsObject.h"
+#include "FileSystem.h"
+
+//FIXME: remove this
+#include "minecraft/MinecraftVersion.h"
+#include "minecraft/onesix/OneSixInstance.h"
+
+InstanceCreationTask::InstanceCreationTask(SettingsObjectPtr settings, BaseInstanceProvider* target, BaseVersionPtr version,
+	const QString& instName, const QString& instIcon, const QString& instGroup)
+{
+	m_globalSettings = settings;
+	m_target = target;
+	m_instName = instName;
+	m_instIcon = instIcon;
+	m_instGroup = instGroup;
+	m_version = version;
+}
+
+void InstanceCreationTask::executeTask()
+{
+	setStatus(tr("Creating instance from version %1").arg(m_version->name()));
+	auto minecraftVersion = std::dynamic_pointer_cast<MinecraftVersion>(m_version);
+	if(!minecraftVersion)
+	{
+		emitFailed(tr("The supplied version is not a Minecraft version."));
+		return ;
+	}
+
+	QString stagingPath = m_target->getStagedInstancePath();
+	QDir rootDir(stagingPath);
+
+	auto instanceSettings = std::make_shared<INISettingsObject>(FS::PathCombine(stagingPath, "instance.cfg"));
+	instanceSettings->registerSetting("InstanceType", "Legacy");
+
+	auto mcVer = std::dynamic_pointer_cast<MinecraftVersion>(m_version);
+	instanceSettings->set("InstanceType", "OneSix");
+	InstancePtr inst(new OneSixInstance(m_globalSettings, instanceSettings, stagingPath));
+	inst->setIntendedVersionId(m_version->descriptor());
+	inst->setName(m_instName);
+	inst->setIconKey(m_instIcon);
+	inst->init();
+	m_target->commitStagedInstance(stagingPath, stagingPath, m_instName, m_instGroup);
+	emitSucceeded();
+}
diff --git a/api/logic/InstanceCreationTask.h b/api/logic/InstanceCreationTask.h
new file mode 100644
index 00000000..b4ade320
--- /dev/null
+++ b/api/logic/InstanceCreationTask.h
@@ -0,0 +1,31 @@
+#pragma once
+
+#include "tasks/Task.h"
+#include "multimc_logic_export.h"
+#include "net/NetJob.h"
+#include <QUrl>
+#include "settings/SettingsObject.h"
+#include "BaseVersion.h"
+
+class BaseInstanceProvider;
+
+class MULTIMC_LOGIC_EXPORT InstanceCreationTask : public Task
+{
+	Q_OBJECT
+public:
+	explicit InstanceCreationTask(SettingsObjectPtr settings, BaseInstanceProvider * target, BaseVersionPtr version, const QString &instName,
+		const QString &instIcon, const QString &instGroup);
+
+protected:
+	//! Entry point for tasks.
+	virtual void executeTask() override;
+
+private: /* data */
+	SettingsObjectPtr m_globalSettings;
+	BaseInstanceProvider * m_target;
+	BaseVersionPtr m_version;
+	QString m_instName;
+	QString m_instIcon;
+	QString m_instGroup;
+};
+
diff --git a/api/logic/InstanceImportTask.cpp b/api/logic/InstanceImportTask.cpp
new file mode 100644
index 00000000..99f2553f
--- /dev/null
+++ b/api/logic/InstanceImportTask.cpp
@@ -0,0 +1,146 @@
+
+#include "InstanceImportTask.h"
+#include "BaseInstance.h"
+#include "BaseInstanceProvider.h"
+#include "FileSystem.h"
+#include "Env.h"
+#include "MMCZip.h"
+#include "NullInstance.h"
+#include "settings/INISettingsObject.h"
+#include "icons/IIconList.h"
+
+InstanceImportTask::InstanceImportTask(SettingsObjectPtr settings, const QUrl sourceUrl, BaseInstanceProvider * target,
+	const QString &instName, const QString &instIcon, const QString &instGroup)
+{
+	m_globalSettings = settings;
+	m_sourceUrl = sourceUrl;
+	m_target = target;
+	m_instName = instName;
+	m_instIcon = instIcon;
+	m_instGroup = instGroup;
+}
+
+void InstanceImportTask::executeTask()
+{
+	InstancePtr newInstance;
+
+	if (m_sourceUrl.isLocalFile())
+	{
+		m_archivePath = m_sourceUrl.toLocalFile();
+		extractAndTweak();
+	}
+	else
+	{
+		setStatus(tr("Downloading modpack:\n%1").arg(m_sourceUrl.toString()));
+		m_downloadRequired = true;
+
+		const QString path = m_sourceUrl.host() + '/' + m_sourceUrl.path();
+		auto entry = ENV.metacache()->resolveEntry("general", path);
+		entry->setStale(true);
+		m_filesNetJob.reset(new NetJob(tr("Modpack download")));
+		m_filesNetJob->addNetAction(Net::Download::makeCached(m_sourceUrl, entry));
+		m_archivePath = entry->getFullPath();
+		auto job = m_filesNetJob.get();
+		connect(job, &NetJob::succeeded, this, &InstanceImportTask::downloadSucceeded);
+		connect(job, &NetJob::progress, this, &InstanceImportTask::downloadProgressChanged);
+		connect(job, &NetJob::failed, this, &InstanceImportTask::downloadFailed);
+		m_filesNetJob->start();
+	}
+}
+
+void InstanceImportTask::downloadSucceeded()
+{
+	extractAndTweak();
+}
+
+void InstanceImportTask::downloadFailed(QString reason)
+{
+	emitFailed(reason);
+}
+
+void InstanceImportTask::downloadProgressChanged(qint64 current, qint64 total)
+{
+	setProgress(current / 2, total);
+}
+
+static QFileInfo findRecursive(const QString &dir, const QString &name)
+{
+	for (const auto info : QDir(dir).entryInfoList(QDir::NoDotAndDotDot | QDir::Dirs | QDir::Files, QDir::DirsLast))
+	{
+		if (info.isFile() && info.fileName() == name)
+		{
+			return info;
+		}
+		else if (info.isDir())
+		{
+			const QFileInfo res = findRecursive(info.absoluteFilePath(), name);
+			if (res.isFile() && res.exists())
+			{
+				return res;
+			}
+		}
+	}
+	return QFileInfo();
+}
+
+void InstanceImportTask::extractAndTweak()
+{
+	setStatus(tr("Extracting modpack"));
+	QString stagingPath = m_target->getStagedInstancePath();
+	QDir extractDir(stagingPath);
+	qDebug() << "Attempting to create instance from" << m_archivePath;
+	if (MMCZip::extractDir(m_archivePath, extractDir.absolutePath()).isEmpty())
+	{
+		m_target->destroyStagingPath(stagingPath);
+		emitFailed(tr("Failed to extract modpack"));
+		return;
+	}
+	const QFileInfo instanceCfgFile = findRecursive(extractDir.absolutePath(), "instance.cfg");
+	if (!instanceCfgFile.isFile() || !instanceCfgFile.exists())
+	{
+		m_target->destroyStagingPath(stagingPath);
+		emitFailed(tr("Archive does not contain instance.cfg"));
+		return;
+	}
+
+	// FIXME: copy from FolderInstanceProvider!!! FIX IT!!!
+	auto instanceSettings = std::make_shared<INISettingsObject>(instanceCfgFile.absoluteFilePath());
+	instanceSettings->registerSetting("InstanceType", "Legacy");
+
+	QString actualDir = instanceCfgFile.absolutePath();
+	NullInstance instance(m_globalSettings, instanceSettings, actualDir);
+
+	// reset time played on import... because packs.
+	instance.resetTimePlayed();
+
+	// set a new nice name
+	instance.setName(m_instName);
+
+	// if the icon was specified by user, use that. otherwise pull icon from the pack
+	if (m_instIcon != "default")
+	{
+		instance.setIconKey(m_instIcon);
+	}
+	else
+	{
+		m_instIcon = instance.iconKey();
+		auto importIconPath = FS::PathCombine(instance.instanceRoot(), m_instIcon + ".png");
+		if (QFile::exists(importIconPath))
+		{
+			// import icon
+			auto iconList = ENV.icons();
+			if (iconList->iconFileExists(m_instIcon))
+			{
+				iconList->deleteIcon(m_instIcon);
+			}
+			iconList->installIcons({importIconPath});
+		}
+	}
+	if (!m_target->commitStagedInstance(stagingPath, actualDir, m_instName, m_instGroup))
+	{
+		m_target->destroyStagingPath(stagingPath);
+		emitFailed(tr("Unable to commit instance"));
+		return;
+	}
+	emitSucceeded();
+}
diff --git a/api/logic/InstanceImportTask.h b/api/logic/InstanceImportTask.h
new file mode 100644
index 00000000..a551ec68
--- /dev/null
+++ b/api/logic/InstanceImportTask.h
@@ -0,0 +1,40 @@
+#pragma once
+
+#include "tasks/Task.h"
+#include "multimc_logic_export.h"
+#include "net/NetJob.h"
+#include <QUrl>
+#include "settings/SettingsObject.h"
+
+class BaseInstanceProvider;
+
+class MULTIMC_LOGIC_EXPORT InstanceImportTask : public Task
+{
+	Q_OBJECT
+public:
+	explicit InstanceImportTask(SettingsObjectPtr settings, const QUrl sourceUrl, BaseInstanceProvider * target, const QString &instName,
+		const QString &instIcon, const QString &instGroup);
+
+protected:
+	//! Entry point for tasks.
+	virtual void executeTask() override;
+
+private:
+	void extractAndTweak();
+
+private slots:
+	void downloadSucceeded();
+	void downloadFailed(QString reason);
+	void downloadProgressChanged(qint64 current, qint64 total);
+
+private: /* data */
+	SettingsObjectPtr m_globalSettings;
+	NetJobPtr m_filesNetJob;
+	QUrl m_sourceUrl;
+	BaseInstanceProvider * m_target;
+	QString m_archivePath;
+	bool m_downloadRequired = false;
+	QString m_instName;
+	QString m_instIcon;
+	QString m_instGroup;
+};
diff --git a/api/logic/InstanceList.cpp b/api/logic/InstanceList.cpp
index d89b8ea7..9bdcc113 100644
--- a/api/logic/InstanceList.cpp
+++ b/api/logic/InstanceList.cpp
@@ -16,39 +16,21 @@
 #include <QDir>
 #include <QSet>
 #include <QFile>
-#include <QDirIterator>
 #include <QThread>
 #include <QTextStream>
-#include <QJsonDocument>
-#include <QJsonObject>
-#include <QJsonArray>
 #include <QXmlStreamReader>
-#include <QRegularExpression>
 #include <QDebug>
 
 #include "InstanceList.h"
 #include "BaseInstance.h"
 
-//FIXME: this really doesn't belong *here*
-#include "minecraft/onesix/OneSixInstance.h"
-#include "minecraft/legacy/LegacyInstance.h"
-#include "minecraft/ftb/FTBPlugin.h"
-#include "minecraft/MinecraftVersion.h"
-#include "settings/INISettingsObject.h"
-#include "NullInstance.h"
-#include "FileSystem.h"
-#include "pathmatcher/RegexpMatcher.h"
-
-const static int GROUP_FILE_FORMAT_VERSION = 1;
+#include "FolderInstanceProvider.h"
 
 InstanceList::InstanceList(SettingsObjectPtr globalSettings, const QString &instDir, QObject *parent)
 	: QAbstractListModel(parent), m_instDir(instDir)
 {
 	m_globalSettings = globalSettings;
-	if (!QDir::current().exists(m_instDir))
-	{
-		QDir::current().mkpath(m_instDir);
-	}
+	resumeWatch();
 }
 
 InstanceList::~InstanceList()
@@ -120,34 +102,11 @@ Qt::ItemFlags InstanceList::flags(const QModelIndex &index) const
 	return f;
 }
 
-void InstanceList::groupChanged()
-{
-	// save the groups. save all of them.
-	saveGroupList();
-}
-
 QStringList InstanceList::getGroups()
 {
 	return m_groups.toList();
 }
 
-void InstanceList::suspendGroupSaving()
-{
-	suspendedGroupSave = true;
-}
-
-void InstanceList::resumeGroupSaving()
-{
-	if(suspendedGroupSave)
-	{
-		suspendedGroupSave = false;
-		if(queuedGroupSave)
-		{
-			saveGroupList();
-		}
-	}
-}
-
 void InstanceList::deleteGroup(const QString& name)
 {
 	for(auto & instance: m_instances)
@@ -160,230 +119,180 @@ void InstanceList::deleteGroup(const QString& name)
 	}
 }
 
-void InstanceList::saveGroupList()
+static QMap<InstanceId, InstanceLocator> getIdMapping(const QList<InstancePtr> &list)
 {
-	if(suspendedGroupSave)
+	QMap<InstanceId, InstanceLocator> out;
+	int i = 0;
+	for(auto & item: list)
 	{
-		queuedGroupSave = true;
-		return;
+		auto id = item->id();
+		if(out.contains(id))
+		{
+			qWarning() << "Duplicate ID" << id << "in instance list";
+		}
+		out[id] = std::make_pair(item, i);
+		i++;
 	}
+	return out;
+}
 
-	QString groupFileName = m_instDir + "/instgroups.json";
-	QMap<QString, QSet<QString>> groupMap;
-	for (auto instance : m_instances)
-	{
-		QString id = instance->id();
-		QString group = instance->group();
-		if (group.isEmpty())
-			continue;
+InstanceList::InstListError InstanceList::loadList(bool complete)
+{
+	auto existingIds = getIdMapping(m_instances);
 
-		// keep a list/set of groups for choosing
-		m_groups.insert(group);
+	QList<InstancePtr> newList;
 
-		if (!groupMap.count(group))
+	auto processIds = [&](BaseInstanceProvider * provider, QList<InstanceId> ids)
+	{
+		for(auto & id: ids)
 		{
-			QSet<QString> set;
-			set.insert(id);
-			groupMap[group] = set;
+			if(existingIds.contains(id))
+			{
+				auto instPair = existingIds[id];
+				/*
+				auto & instPtr = instPair.first;
+				auto & instIdx = instPair.second;
+				*/
+				existingIds.remove(id);
+				qDebug() << "Should keep and soft-reload" << id;
+			}
+			else
+			{
+				InstancePtr instPtr = provider->loadInstance(id);
+				newList.append(instPtr);
+			}
 		}
-		else
+	};
+	if(complete)
+	{
+		for(auto & item: m_providers)
 		{
-			QSet<QString> &set = groupMap[group];
-			set.insert(id);
+			processIds(item.get(), item->discoverInstances());
 		}
 	}
-	QJsonObject toplevel;
-	toplevel.insert("formatVersion", QJsonValue(QString("1")));
-	QJsonObject groupsArr;
-	for (auto iter = groupMap.begin(); iter != groupMap.end(); iter++)
+	else
 	{
-		auto list = iter.value();
-		auto name = iter.key();
-		QJsonObject groupObj;
-		QJsonArray instanceArr;
-		groupObj.insert("hidden", QJsonValue(QString("false")));
-		for (auto item : list)
+		for (auto & item: m_updatedProviders)
 		{
-			instanceArr.append(QJsonValue(item));
+			processIds(item, item->discoverInstances());
 		}
-		groupObj.insert("instances", instanceArr);
-		groupsArr.insert(name, groupObj);
 	}
-	toplevel.insert("groups", groupsArr);
-	QJsonDocument doc(toplevel);
-	try
+
+	// TODO: looks like a general algorithm with a few specifics inserted. Do something about it.
+	if(!existingIds.isEmpty())
 	{
-		FS::write(groupFileName, doc.toJson());
+		// get the list of removed instances and sort it by their original index, from last to first
+		auto deadList = existingIds.values();
+		auto orderSortPredicate = [](const InstanceLocator & a, const InstanceLocator & b) -> bool
+		{
+			return a.second > b.second;
+		};
+		std::sort(deadList.begin(), deadList.end(), orderSortPredicate);
+		// remove the contiguous ranges of rows
+		int front_bookmark = -1;
+		int back_bookmark = -1;
+		int currentItem = -1;
+		auto removeNow = [&]()
+		{
+			beginRemoveRows(QModelIndex(), front_bookmark, back_bookmark);
+			m_instances.erase(m_instances.begin() + front_bookmark, m_instances.begin() + back_bookmark + 1);
+			endRemoveRows();
+			front_bookmark = -1;
+			back_bookmark = currentItem;
+		};
+		for(auto & removedItem: deadList)
+		{
+			auto instPtr = removedItem.first;
+			if(!complete && !m_updatedProviders.contains(instPtr->provider()))
+			{
+				continue;
+			}
+			instPtr->invalidate();
+			currentItem = removedItem.second;
+			if(back_bookmark == -1)
+			{
+				// no bookmark yet
+				back_bookmark = currentItem;
+			}
+			else if(currentItem == front_bookmark - 1)
+			{
+				// part of contiguous sequence, continue
+			}
+			else
+			{
+				// seam between previous and current item
+				removeNow();
+			}
+			front_bookmark = currentItem;
+		}
+		if(back_bookmark != -1)
+		{
+			removeNow();
+		}
 	}
-	catch(FS::FileSystemException & e)
+	if(newList.size())
 	{
-		qCritical() << "Failed to write instance group file :" << e.cause();
+		add(newList);
 	}
+	m_updatedProviders.clear();
+	return NoError;
 }
 
-void InstanceList::loadGroupList(QMap<QString, QString> &groupMap)
+void InstanceList::add(const QList<InstancePtr> &t)
 {
-	QString groupFileName = m_instDir + "/instgroups.json";
-
-	// if there's no group file, fail
-	if (!QFileInfo(groupFileName).exists())
-		return;
-
-	QByteArray jsonData;
-	try
-	{
-		jsonData = FS::read(groupFileName);
-	}
-	catch (FS::FileSystemException & e)
-	{
-		qCritical() << "Failed to read instance group file :" << e.cause();
-		return;
-	}
-
-	QJsonParseError error;
-	QJsonDocument jsonDoc = QJsonDocument::fromJson(jsonData, &error);
-
-	// if the json was bad, fail
-	if (error.error != QJsonParseError::NoError)
+	beginInsertRows(QModelIndex(), m_instances.count(), m_instances.count() + t.size() - 1);
+	m_instances.append(t);
+	for(auto & ptr : t)
 	{
-		qCritical() << QString("Failed to parse instance group file: %1 at offset %2")
-							.arg(error.errorString(), QString::number(error.offset))
-							.toUtf8();
-		return;
+		connect(ptr.get(), &BaseInstance::propertiesChanged, this, &InstanceList::propertiesChanged);
 	}
+	endInsertRows();
+}
 
-	// if the root of the json wasn't an object, fail
-	if (!jsonDoc.isObject())
+void InstanceList::resumeWatch()
+{
+	if(m_watchLevel > 0)
 	{
-		qWarning() << "Invalid group file. Root entry should be an object.";
+		qWarning() << "Bad suspend level resume in instance list";
 		return;
 	}
-
-	QJsonObject rootObj = jsonDoc.object();
-
-	// Make sure the format version matches, otherwise fail.
-	if (rootObj.value("formatVersion").toVariant().toInt() != GROUP_FILE_FORMAT_VERSION)
-		return;
-
-	// Get the groups. if it's not an object, fail
-	if (!rootObj.value("groups").isObject())
+	m_watchLevel++;
+	if(m_watchLevel > 0 && !m_updatedProviders.isEmpty())
 	{
-		qWarning() << "Invalid group list JSON: 'groups' should be an object.";
-		return;
-	}
-
-	// Iterate through all the groups.
-	QJsonObject groupMapping = rootObj.value("groups").toObject();
-	for (QJsonObject::iterator iter = groupMapping.begin(); iter != groupMapping.end(); iter++)
-	{
-		QString groupName = iter.key();
-
-		// If not an object, complain and skip to the next one.
-		if (!iter.value().isObject())
-		{
-			qWarning() << QString("Group '%1' in the group list should "
-								   "be an object.")
-							   .arg(groupName)
-							   .toUtf8();
-			continue;
-		}
-
-		QJsonObject groupObj = iter.value().toObject();
-		if (!groupObj.value("instances").isArray())
-		{
-			qWarning() << QString("Group '%1' in the group list is invalid. "
-								   "It should contain an array "
-								   "called 'instances'.")
-							   .arg(groupName)
-							   .toUtf8();
-			continue;
-		}
-
-		// keep a list/set of groups for choosing
-		m_groups.insert(groupName);
-
-		// Iterate through the list of instances in the group.
-		QJsonArray instancesArray = groupObj.value("instances").toArray();
-
-		for (QJsonArray::iterator iter2 = instancesArray.begin(); iter2 != instancesArray.end();
-			 iter2++)
-		{
-			groupMap[(*iter2).toString()] = groupName;
-		}
+		loadList();
 	}
 }
 
-InstanceList::InstListError InstanceList::loadList()
+void InstanceList::suspendWatch()
 {
-	// load the instance groups
-	QMap<QString, QString> groupMap;
-	loadGroupList(groupMap);
+	m_watchLevel --;
+}
 
-	QList<InstancePtr> tempList;
+void InstanceList::providerUpdated()
+{
+	auto provider = dynamic_cast<BaseInstanceProvider *>(QObject::sender());
+	if(!provider)
 	{
-		QDirIterator iter(m_instDir, QDir::Dirs | QDir::NoDot | QDir::NoDotDot | QDir::Readable,
-						  QDirIterator::FollowSymlinks);
-		while (iter.hasNext())
-		{
-			QString subDir = iter.next();
-			if (!QFileInfo(FS::PathCombine(subDir, "instance.cfg")).exists())
-				continue;
-			qDebug() << "Loading MultiMC instance from " << subDir;
-			InstancePtr instPtr;
-			auto error = loadInstance(instPtr, subDir);
-			if(!continueProcessInstance(instPtr, error, subDir, groupMap))
-				continue;
-			tempList.append(instPtr);
-		}
+		qWarning() << "InstanceList::providerUpdated triggered by a non-provider";
+		return;
 	}
-
-	// FIXME: generalize
-	FTBPlugin::loadInstances(m_globalSettings, groupMap, tempList);
-
-	beginResetModel();
-	m_instances.clear();
-	for(auto inst: tempList)
+	m_updatedProviders.insert(provider);
+	if(m_watchLevel == 1)
 	{
-		connect(inst.get(), SIGNAL(propertiesChanged(BaseInstance *)), this,
-				SLOT(propertiesChanged(BaseInstance *)));
-		connect(inst.get(), SIGNAL(groupChanged()), this, SLOT(groupChanged()));
-		connect(inst.get(), SIGNAL(nuked(BaseInstance *)), this,
-				SLOT(instanceNuked(BaseInstance *)));
-		m_instances.append(inst);
+		loadList();
 	}
-	endResetModel();
-	emit dataIsInvalid();
-	return NoError;
-}
-
-/// Clear all instances. Triggers notifications.
-void InstanceList::clear()
-{
-	beginResetModel();
-	saveGroupList();
-	m_instances.clear();
-	endResetModel();
-	emit dataIsInvalid();
 }
 
-void InstanceList::on_InstFolderChanged(const Setting &setting, QVariant value)
+void InstanceList::groupsPublished(QSet<QString> newGroups)
 {
-	m_instDir = value.toString();
-	loadList();
+	m_groups.unite(newGroups);
 }
 
-/// Add an instance. Triggers notifications, returns the new index
-int InstanceList::add(InstancePtr t)
+void InstanceList::addInstanceProvider(BaseInstanceProvider* provider)
 {
-	beginInsertRows(QModelIndex(), m_instances.size(), m_instances.size());
-	m_instances.append(t);
-	t->setParent(this);
-	connect(t.get(), SIGNAL(propertiesChanged(BaseInstance *)), this,
-			SLOT(propertiesChanged(BaseInstance *)));
-	connect(t.get(), SIGNAL(groupChanged()), this, SLOT(groupChanged()));
-	connect(t.get(), SIGNAL(nuked(BaseInstance *)), this, SLOT(instanceNuked(BaseInstance *)));
-	endInsertRows();
-	return count() - 1;
+	connect(provider, &BaseInstanceProvider::instancesChanged, this, &InstanceList::providerUpdated);
+	connect(provider, &BaseInstanceProvider::groupsChanged, this, &InstanceList::groupsPublished);
+	m_providers.append(provider);
 }
 
 InstancePtr InstanceList::getInstanceById(QString instId) const
@@ -418,157 +327,6 @@ int InstanceList::getInstIndex(BaseInstance *inst) const
 	return -1;
 }
 
-bool InstanceList::continueProcessInstance(InstancePtr instPtr, const int error,
-										   const QDir &dir, QMap<QString, QString> &groupMap)
-{
-	if (error != InstanceList::NoLoadError && error != InstanceList::NotAnInstance)
-	{
-		QString errorMsg = QString("Failed to load instance %1: ")
-							   .arg(QFileInfo(dir.absolutePath()).baseName())
-							   .toUtf8();
-
-		switch (error)
-		{
-		default:
-			errorMsg += QString("Unknown instance loader error %1").arg(error);
-			break;
-		}
-		qCritical() << errorMsg.toUtf8();
-		return false;
-	}
-	else if (!instPtr)
-	{
-		qCritical() << QString("Error loading instance %1. Instance loader returned null.")
-							.arg(QFileInfo(dir.absolutePath()).baseName())
-							.toUtf8();
-		return false;
-	}
-	else
-	{
-		auto iter = groupMap.find(instPtr->id());
-		if (iter != groupMap.end())
-		{
-			instPtr->setGroupInitial((*iter));
-		}
-		qDebug() << "Loaded instance " << instPtr->name() << " from " << dir.absolutePath();
-		return true;
-	}
-}
-
-InstanceList::InstLoadError
-InstanceList::loadInstance(InstancePtr &inst, const QString &instDir)
-{
-	auto instanceSettings = std::make_shared<INISettingsObject>(FS::PathCombine(instDir, "instance.cfg"));
-
-	instanceSettings->registerSetting("InstanceType", "Legacy");
-
-	QString inst_type = instanceSettings->get("InstanceType").toString();
-
-	// FIXME: replace with a map lookup, where instance classes register their types
-	if (inst_type == "OneSix" || inst_type == "Nostalgia")
-	{
-		inst.reset(new OneSixInstance(m_globalSettings, instanceSettings, instDir));
-	}
-	else if (inst_type == "Legacy")
-	{
-		inst.reset(new LegacyInstance(m_globalSettings, instanceSettings, instDir));
-	}
-	else
-	{
-		inst.reset(new NullInstance(m_globalSettings, instanceSettings, instDir));
-	}
-	inst->init();
-	return NoLoadError;
-}
-
-InstanceList::InstCreateError
-InstanceList::createInstance(InstancePtr &inst, BaseVersionPtr version, const QString &instDir)
-{
-	QDir rootDir(instDir);
-
-	qDebug() << instDir.toUtf8();
-	if (!rootDir.exists() && !rootDir.mkpath("."))
-	{
-		qCritical() << "Can't create instance folder" << instDir;
-		return InstanceList::CantCreateDir;
-	}
-
-	if (!version)
-	{
-		qCritical() << "Can't create instance for non-existing MC version";
-		return InstanceList::NoSuchVersion;
-	}
-
-	auto instanceSettings = std::make_shared<INISettingsObject>(FS::PathCombine(instDir, "instance.cfg"));
-	instanceSettings->registerSetting("InstanceType", "Legacy");
-
-	auto minecraftVersion = std::dynamic_pointer_cast<MinecraftVersion>(version);
-	if(minecraftVersion)
-	{
-		auto mcVer = std::dynamic_pointer_cast<MinecraftVersion>(version);
-		instanceSettings->set("InstanceType", "OneSix");
-		inst.reset(new OneSixInstance(m_globalSettings, instanceSettings, instDir));
-		inst->setIntendedVersionId(version->descriptor());
-		inst->init();
-		return InstanceList::NoCreateError;
-	}
-	return InstanceList::NoSuchVersion;
-}
-
-InstanceList::InstCreateError
-InstanceList::copyInstance(InstancePtr &newInstance, InstancePtr &oldInstance, const QString &instDir, bool copySaves)
-{
-	QDir rootDir(instDir);
-	std::unique_ptr<IPathMatcher> matcher;
-	if(!copySaves)
-	{
-		auto matcherReal = new RegexpMatcher("[.]?minecraft/saves");
-		matcherReal->caseSensitive(false);
-		matcher.reset(matcherReal);
-	}
-
-	qDebug() << instDir.toUtf8();
-	FS::copy folderCopy(oldInstance->instanceRoot(), instDir);
-	folderCopy.followSymlinks(false).blacklist(matcher.get());
-	if (!folderCopy())
-	{
-		FS::deletePath(instDir);
-		return InstanceList::CantCreateDir;
-	}
-
-	INISettingsObject settings_obj(FS::PathCombine(instDir, "instance.cfg"));
-	settings_obj.registerSetting("InstanceType", "Legacy");
-	QString inst_type = settings_obj.get("InstanceType").toString();
-
-	oldInstance->copy(instDir);
-
-	auto error = loadInstance(newInstance, instDir);
-
-	switch (error)
-	{
-	case NoLoadError:
-		return NoCreateError;
-	case NotAnInstance:
-		rootDir.removeRecursively();
-		return CantCreateDir;
-	default:
-	case UnknownLoadError:
-		rootDir.removeRecursively();
-		return UnknownCreateError;
-	}
-}
-
-void InstanceList::instanceNuked(BaseInstance *inst)
-{
-	int i = getInstIndex(inst);
-	if (i != -1)
-	{
-		beginRemoveRows(QModelIndex(), i, i);
-		m_instances.removeAt(i);
-		endRemoveRows();
-	}
-}
-
 void InstanceList::propertiesChanged(BaseInstance *inst)
 {
 	int i = getInstIndex(inst);
@@ -577,3 +335,5 @@ void InstanceList::propertiesChanged(BaseInstance *inst)
 		emit dataChanged(index(i), index(i));
 	}
 }
+
+#include "InstanceList.moc"
diff --git a/api/logic/InstanceList.h b/api/logic/InstanceList.h
index 074cca7c..b643de85 100644
--- a/api/logic/InstanceList.h
+++ b/api/logic/InstanceList.h
@@ -18,24 +18,22 @@
 #include <QObject>
 #include <QAbstractListModel>
 #include <QSet>
+#include <QList>
 
 #include "BaseInstance.h"
+#include "BaseInstanceProvider.h"
 
 #include "multimc_logic_export.h"
 
+#include "QObjectPtr.h"
+
+class QFileSystemWatcher;
 class BaseInstance;
 class QDir;
 
 class MULTIMC_LOGIC_EXPORT InstanceList : public QAbstractListModel
 {
 	Q_OBJECT
-private:
-	void loadGroupList(QMap<QString, QString> &groupList);
-	void suspendGroupSaving();
-	void resumeGroupSaving();
-
-public slots:
-	void saveGroupList();
 
 public:
 	explicit InstanceList(SettingsObjectPtr globalSettings, const QString &instDir, QObject *parent = 0);
@@ -64,124 +62,47 @@ public:
 		UnknownError
 	};
 
-	enum InstLoadError
-	{
-		NoLoadError = 0,
-		UnknownLoadError,
-		NotAnInstance
-	};
-
-	enum InstCreateError
-	{
-		NoCreateError = 0,
-		NoSuchVersion,
-		UnknownCreateError,
-		InstExists,
-		CantCreateDir
-	};
-
-	QString instDir() const
-	{
-		return m_instDir;
-	}
-
-	/*!
-	 * \brief Get the instance at index
-	 */
 	InstancePtr at(int i) const
 	{
 		return m_instances.at(i);
 	}
-	;
 
-	/*!
-	 * \brief Get the count of loaded instances
-	 */
 	int count() const
 	{
 		return m_instances.count();
 	}
-	;
 
-	/// Clear all instances. Triggers notifications.
-	void clear();
+	InstListError loadList(bool complete = false);
 
-	/// Add an instance. Triggers notifications, returns the new index
-	int add(InstancePtr t);
+	/// Add an instance provider. Takes ownership of it. Should only be done before the first load.
+	void addInstanceProvider(BaseInstanceProvider * provider);
 
-	/// Get an instance by ID
 	InstancePtr getInstanceById(QString id) const;
-
 	QModelIndex getInstanceIndexById(const QString &id) const;
-
-	// FIXME: instead of iterating through all instances and forming a set, keep the set around
 	QStringList getGroups();
 
 	void deleteGroup(const QString & name);
 
-	/*!
-	 * \brief Creates a stub instance
-	 *
-	 * \param inst Pointer to store the created instance in.
-	 * \param version Game version to use for the instance
-	 * \param instDir The new instance's directory.
-	 * \return An InstCreateError error code.
-	 * - InstExists if the given instance directory is already an instance.
-	 * - CantCreateDir if the given instance directory cannot be created.
-	 */
-	InstCreateError createInstance(InstancePtr &inst, BaseVersionPtr version,
-								   const QString &instDir);
-
-	/*!
-	 * \brief Creates a copy of an existing instance with a new name
-	 *
-	 * \param newInstance Pointer to store the created instance in.
-	 * \param oldInstance The instance to copy
-	 * \param instDir The new instance's directory.
-	 * \return An InstCreateError error code.
-	 * - InstExists if the given instance directory is already an instance.
-	 * - CantCreateDir if the given instance directory cannot be created.
-	 */
-	InstCreateError copyInstance(InstancePtr &newInstance, InstancePtr &oldInstance,
-								 const QString &instDir, bool copySaves);
-
-	/*!
-	 * \brief Loads an instance from the given directory.
-	 * Checks the instance's INI file to figure out what the instance's type is first.
-	 * \param inst Pointer to store the loaded instance in.
-	 * \param instDir The instance's directory.
-	 * \return An InstLoadError error code.
-	 * - NotAnInstance if the given instance directory isn't a valid instance.
-	 */
-	InstLoadError loadInstance(InstancePtr &inst, const QString &instDir);
-
 signals:
 	void dataIsInvalid();
 
-public slots:
-	void on_InstFolderChanged(const Setting &setting, QVariant value);
-
-	/*!
-	 * \brief Loads the instance list. Triggers notifications.
-	 */
-	InstListError loadList();
-
 private slots:
 	void propertiesChanged(BaseInstance *inst);
-	void instanceNuked(BaseInstance *inst);
-	void groupChanged();
+	void groupsPublished(QSet<QString>);
+	void providerUpdated();
 
 private:
 	int getInstIndex(BaseInstance *inst) const;
-
-public:
-	static bool continueProcessInstance(InstancePtr instPtr, const int error, const QDir &dir, QMap<QString, QString> &groupMap);
+	void suspendWatch();
+	void resumeWatch();
+	void add(const QList<InstancePtr> &list);
 
 protected:
+	int m_watchLevel = 0;
+	QSet<BaseInstanceProvider *> m_updatedProviders;
 	QString m_instDir;
 	QList<InstancePtr> m_instances;
 	QSet<QString> m_groups;
 	SettingsObjectPtr m_globalSettings;
-	bool suspendedGroupSave = false;
-	bool queuedGroupSave = false;
+	QVector<shared_qobject_ptr<BaseInstanceProvider>> m_providers;
 };
diff --git a/api/logic/icons/IIconList.h b/api/logic/icons/IIconList.h
index ec94cb35..ebf99d05 100644
--- a/api/logic/icons/IIconList.h
+++ b/api/logic/icons/IIconList.h
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <QString>
+#include <QStringList>
 #include "multimc_logic_export.h"
 
 enum IconType : unsigned
@@ -16,6 +17,9 @@ class MULTIMC_LOGIC_EXPORT IIconList
 {
 public:
 	virtual ~IIconList();
-	virtual bool addIcon(QString key, QString name, QString path, IconType type) = 0;
+	virtual bool addIcon(const QString &key, const QString &name, const QString &path, const IconType type) = 0;
+	virtual bool deleteIcon(const QString &key) = 0;
+	virtual void saveIcon(const QString &key, const QString &path, const char * format) const = 0;
+	virtual bool iconFileExists(const QString &key) const = 0;
+	virtual void installIcons(const QStringList &iconFiles) = 0;
 };
-
diff --git a/api/logic/minecraft/ftb/FTBInstanceProvider.cpp b/api/logic/minecraft/ftb/FTBInstanceProvider.cpp
new file mode 100644
index 00000000..a583c039
--- /dev/null
+++ b/api/logic/minecraft/ftb/FTBInstanceProvider.cpp
@@ -0,0 +1,278 @@
+#include "FTBInstanceProvider.h"
+
+#include <QDir>
+#include <QDebug>
+#include <QXmlStreamReader>
+#include <QRegularExpression>
+
+#include <settings/INISettingsObject.h>
+#include <FileSystem.h>
+
+#include "Env.h"
+#include "minecraft/MinecraftVersion.h"
+
+#include "LegacyFTBInstance.h"
+#include "OneSixFTBInstance.h"
+
+inline uint qHash(FTBRecord record)
+{
+	return qHash(record.instanceDir);
+}
+
+FTBInstanceProvider::FTBInstanceProvider(SettingsObjectPtr settings)
+	: BaseInstanceProvider(settings)
+{
+	// nil
+}
+
+QList<InstanceId> FTBInstanceProvider::discoverInstances()
+{
+	// nothing to load when we don't have
+	if (m_globalSettings->get("TrackFTBInstances").toBool() != true)
+	{
+		return {};
+	}
+	m_records.clear();
+	discoverFTBEntries();
+	return m_records.keys();
+}
+
+InstancePtr FTBInstanceProvider::loadInstance(const InstanceId& id)
+{
+	// process the records we acquired.
+	auto iter = m_records.find(id);
+	if(iter == m_records.end())
+	{
+		qWarning() << "Cannot load instance" << id << "without a record";
+		return nullptr;
+	}
+	auto & record = m_records[id];
+	qDebug() << "Loading FTB instance from " << record.instanceDir;
+	QString iconKey = record.iconKey;
+	auto icons = ENV.icons();
+	if(icons)
+	{
+		icons->addIcon(iconKey, iconKey, FS::PathCombine(record.templateDir, record.logo), IconType::Transient);
+	}
+	auto settingsFilePath = FS::PathCombine(record.instanceDir, "instance.cfg");
+	qDebug() << "ICON get!";
+
+	if (QFileInfo(settingsFilePath).exists())
+	{
+		auto instPtr = loadInstance(record);
+		if (!instPtr)
+		{
+			qWarning() << "Couldn't load instance config:" << settingsFilePath;
+			if(!QFile::remove(settingsFilePath))
+			{
+				qWarning() << "Couldn't remove broken instance config!";
+				return nullptr;
+			}
+			// failed to load, but removed the poisonous file
+		}
+		else
+		{
+			return InstancePtr(instPtr);
+		}
+	}
+	auto instPtr = createInstance(record);
+	if (!instPtr)
+	{
+		qWarning() << "Couldn't create FTB instance!";
+		return nullptr;
+	}
+	return InstancePtr(instPtr);
+}
+
+void FTBInstanceProvider::discoverFTBEntries()
+{
+	QDir dir = QDir(m_globalSettings->get("FTBLauncherLocal").toString());
+	QDir dataDir = QDir(m_globalSettings->get("FTBRoot").toString());
+	if (!dataDir.exists())
+	{
+		qDebug() << "The FTB directory specified does not exist. Please check your settings";
+		return;
+	}
+	else if (!dir.exists())
+	{
+		qDebug() << "The FTB launcher data directory specified does not exist. Please check "
+					"your settings";
+		return;
+	}
+	dir.cd("ModPacks");
+	auto allFiles = dir.entryList(QDir::Readable | QDir::Files, QDir::Name);
+	for (auto filename : allFiles)
+	{
+		if (!filename.endsWith(".xml"))
+			continue;
+		auto fpath = dir.absoluteFilePath(filename);
+		QFile f(fpath);
+		qDebug() << "Discovering FTB instances -- " << fpath;
+		if (!f.open(QFile::ReadOnly))
+			continue;
+
+		// read the FTB packs XML.
+		QXmlStreamReader reader(&f);
+		while (!reader.atEnd())
+		{
+			switch (reader.readNext())
+			{
+			case QXmlStreamReader::StartElement:
+			{
+				if (reader.name() == "modpack")
+				{
+					QXmlStreamAttributes attrs = reader.attributes();
+					FTBRecord record;
+					record.dirName = attrs.value("dir").toString();
+					record.instanceDir = dataDir.absoluteFilePath(record.dirName);
+					record.templateDir = dir.absoluteFilePath(record.dirName);
+					QDir test(record.instanceDir);
+					qDebug() << dataDir.absolutePath() << record.instanceDir << record.dirName;
+					if (!test.exists())
+						continue;
+					record.name = attrs.value("name").toString();
+					record.logo = attrs.value("logo").toString();
+					QString logo = record.logo;
+					record.iconKey = logo.remove(QRegularExpression("\\..*"));
+					auto customVersions = attrs.value("customMCVersions");
+					if (!customVersions.isNull())
+					{
+						QMap<QString, QString> versionMatcher;
+						QString customVersionsStr = customVersions.toString();
+						QStringList list = customVersionsStr.split(';');
+						for (auto item : list)
+						{
+							auto segment = item.split('^');
+							if (segment.size() != 2)
+							{
+								qCritical() << "FTB: Segment of size < 2 in "
+											<< customVersionsStr;
+								continue;
+							}
+							versionMatcher[segment[0]] = segment[1];
+						}
+						auto actualVersion = attrs.value("version").toString();
+						if (versionMatcher.contains(actualVersion))
+						{
+							record.mcVersion = versionMatcher[actualVersion];
+						}
+						else
+						{
+							record.mcVersion = attrs.value("mcVersion").toString();
+						}
+					}
+					else
+					{
+						record.mcVersion = attrs.value("mcVersion").toString();
+					}
+					record.description = attrs.value("description").toString();
+					auto id = "FTB/" + record.dirName;
+					m_records[id] = record;
+				}
+				break;
+			}
+			case QXmlStreamReader::EndElement:
+				break;
+			case QXmlStreamReader::Characters:
+				break;
+			default:
+				break;
+			}
+		}
+		f.close();
+	}
+}
+
+InstancePtr FTBInstanceProvider::loadInstance(const FTBRecord & record) const
+{
+	InstancePtr inst;
+
+	auto m_settings = std::make_shared<INISettingsObject>(FS::PathCombine(record.instanceDir, "instance.cfg"));
+	m_settings->registerSetting("InstanceType", "Legacy");
+
+	qDebug() << "Loading existing " << record.name;
+
+	QString inst_type = m_settings->get("InstanceType").toString();
+	if (inst_type == "LegacyFTB")
+	{
+		inst.reset(new LegacyFTBInstance(m_globalSettings, m_settings, record.instanceDir));
+	}
+	else if (inst_type == "OneSixFTB")
+	{
+		inst.reset(new OneSixFTBInstance(m_globalSettings, m_settings, record.instanceDir));
+	}
+	else
+	{
+		return nullptr;
+	}
+	qDebug() << "Construction " << record.instanceDir;
+
+	SettingsObject::Lock lock(inst->settings());
+	inst->init();
+	qDebug() << "Init " << record.instanceDir;
+	inst->setGroupInitial("FTB");
+	/**
+	 * FIXME: this does not respect the user's preferences. BUT, it would work nicely with the planned pack support
+	 *        -> instead of changing the user values, change pack values (defaults you can look at and revert to)
+	 */
+	/*
+	inst->setName(record.name);
+	inst->setIconKey(record.iconKey);
+	inst->setNotes(record.description);
+	*/
+	if (inst->intendedVersionId() != record.mcVersion)
+	{
+		inst->setIntendedVersionId(record.mcVersion);
+	}
+	qDebug() << "Loaded instance " << inst->name() << " from " << inst->instanceRoot();
+	return inst;
+}
+
+InstancePtr FTBInstanceProvider::createInstance(const FTBRecord & record) const
+{
+	QDir rootDir(record.instanceDir);
+
+	InstancePtr inst;
+
+	qDebug() << "Converting " << record.name << " as new.";
+
+	auto mcVersion = std::dynamic_pointer_cast<MinecraftVersion>(ENV.getVersion("net.minecraft", record.mcVersion));
+	if (!mcVersion)
+	{
+		qCritical() << "Can't load instance " << record.instanceDir
+					<< " because minecraft version " << record.mcVersion
+					<< " can't be resolved.";
+		return nullptr;
+	}
+
+	if (!rootDir.exists() && !rootDir.mkpath("."))
+	{
+		qCritical() << "Can't create instance folder" << record.instanceDir;
+		return nullptr;
+	}
+
+	auto m_settings = std::make_shared<INISettingsObject>(FS::PathCombine(record.instanceDir, "instance.cfg"));
+	m_settings->registerSetting("InstanceType", "Legacy");
+
+	if (mcVersion->usesLegacyLauncher())
+	{
+		m_settings->set("InstanceType", "LegacyFTB");
+		inst.reset(new LegacyFTBInstance(m_globalSettings, m_settings, record.instanceDir));
+	}
+	else
+	{
+		m_settings->set("InstanceType", "OneSixFTB");
+		inst.reset(new OneSixFTBInstance(m_globalSettings, m_settings, record.instanceDir));
+	}
+	// initialize
+	{
+		SettingsObject::Lock lock(inst->settings());
+		inst->setIntendedVersionId(mcVersion->descriptor());
+		inst->init();
+		inst->setGroupInitial("FTB");
+		inst->setName(record.name);
+		inst->setIconKey(record.iconKey);
+		inst->setNotes(record.description);
+	}
+	return inst;
+}
diff --git a/api/logic/minecraft/ftb/FTBInstanceProvider.h b/api/logic/minecraft/ftb/FTBInstanceProvider.h
new file mode 100644
index 00000000..fb3ecb6c
--- /dev/null
+++ b/api/logic/minecraft/ftb/FTBInstanceProvider.h
@@ -0,0 +1,45 @@
+#pragma once
+
+#include "BaseInstanceProvider.h"
+#include <QMap>
+
+class QFileSystemWatcher;
+
+struct MULTIMC_LOGIC_EXPORT FTBRecord
+{
+	QString dirName;
+	QString name;
+	QString logo;
+	QString iconKey;
+	QString mcVersion;
+	QString description;
+	QString instanceDir;
+	QString templateDir;
+	bool operator==(const FTBRecord other) const
+	{
+		return instanceDir == other.instanceDir;
+	}
+};
+
+class MULTIMC_LOGIC_EXPORT FTBInstanceProvider : public BaseInstanceProvider
+{
+	Q_OBJECT
+
+public:
+	FTBInstanceProvider (SettingsObjectPtr settings);
+
+public:
+	QList<InstanceId> discoverInstances() override;
+	InstancePtr loadInstance(const InstanceId& id) override;
+	void loadGroupList() override {};
+	void saveGroupList() override {};
+
+private: /* methods */
+	void discoverFTBEntries();
+	InstancePtr createInstance(const FTBRecord & record) const;
+	InstancePtr loadInstance(const FTBRecord & record) const;
+
+
+private:
+	QMap<InstanceId, FTBRecord> m_records;
+};
diff --git a/api/logic/minecraft/ftb/FTBPlugin.cpp b/api/logic/minecraft/ftb/FTBPlugin.cpp
index 134257bf..d14eea63 100644
--- a/api/logic/minecraft/ftb/FTBPlugin.cpp
+++ b/api/logic/minecraft/ftb/FTBPlugin.cpp
@@ -8,291 +8,9 @@
 #include <minecraft/MinecraftVersionList.h>
 #include <settings/INISettingsObject.h>
 #include <FileSystem.h>
-#include "QDebug"
-#include <QXmlStreamReader>
-#include <QRegularExpression>
-
-struct FTBRecord
-{
-	QString dirName;
-	QString name;
-	QString logo;
-	QString iconKey;
-	QString mcVersion;
-	QString description;
-	QString instanceDir;
-	QString templateDir;
-	bool operator==(const FTBRecord other) const
-	{
-		return instanceDir == other.instanceDir;
-	}
-};
-
-inline uint qHash(FTBRecord record)
-{
-	return qHash(record.instanceDir);
-}
-
-QSet<FTBRecord> discoverFTBInstances(SettingsObjectPtr globalSettings)
-{
-	QSet<FTBRecord> records;
-	QDir dir = QDir(globalSettings->get("FTBLauncherLocal").toString());
-	QDir dataDir = QDir(globalSettings->get("FTBRoot").toString());
-	if (!dataDir.exists())
-	{
-		qDebug() << "The FTB directory specified does not exist. Please check your settings";
-		return records;
-	}
-	else if (!dir.exists())
-	{
-		qDebug() << "The FTB launcher data directory specified does not exist. Please check "
-					"your settings";
-		return records;
-	}
-	dir.cd("ModPacks");
-	auto allFiles = dir.entryList(QDir::Readable | QDir::Files, QDir::Name);
-	for (auto filename : allFiles)
-	{
-		if (!filename.endsWith(".xml"))
-			continue;
-		auto fpath = dir.absoluteFilePath(filename);
-		QFile f(fpath);
-		qDebug() << "Discovering FTB instances -- " << fpath;
-		if (!f.open(QFile::ReadOnly))
-			continue;
-
-		// read the FTB packs XML.
-		QXmlStreamReader reader(&f);
-		while (!reader.atEnd())
-		{
-			switch (reader.readNext())
-			{
-			case QXmlStreamReader::StartElement:
-			{
-				if (reader.name() == "modpack")
-				{
-					QXmlStreamAttributes attrs = reader.attributes();
-					FTBRecord record;
-					record.dirName = attrs.value("dir").toString();
-					record.instanceDir = dataDir.absoluteFilePath(record.dirName);
-					record.templateDir = dir.absoluteFilePath(record.dirName);
-					QDir test(record.instanceDir);
-					qDebug() << dataDir.absolutePath() << record.instanceDir << record.dirName;
-					if (!test.exists())
-						continue;
-					record.name = attrs.value("name").toString();
-					record.logo = attrs.value("logo").toString();
-					QString logo = record.logo;
-					record.iconKey = logo.remove(QRegularExpression("\\..*"));
-					auto customVersions = attrs.value("customMCVersions");
-					if (!customVersions.isNull())
-					{
-						QMap<QString, QString> versionMatcher;
-						QString customVersionsStr = customVersions.toString();
-						QStringList list = customVersionsStr.split(';');
-						for (auto item : list)
-						{
-							auto segment = item.split('^');
-							if (segment.size() != 2)
-							{
-								qCritical() << "FTB: Segment of size < 2 in "
-											<< customVersionsStr;
-								continue;
-							}
-							versionMatcher[segment[0]] = segment[1];
-						}
-						auto actualVersion = attrs.value("version").toString();
-						if (versionMatcher.contains(actualVersion))
-						{
-							record.mcVersion = versionMatcher[actualVersion];
-						}
-						else
-						{
-							record.mcVersion = attrs.value("mcVersion").toString();
-						}
-					}
-					else
-					{
-						record.mcVersion = attrs.value("mcVersion").toString();
-					}
-					record.description = attrs.value("description").toString();
-					records.insert(record);
-				}
-				break;
-			}
-			case QXmlStreamReader::EndElement:
-				break;
-			case QXmlStreamReader::Characters:
-				break;
-			default:
-				break;
-			}
-		}
-		f.close();
-	}
-	return records;
-}
-
-InstancePtr loadInstance(SettingsObjectPtr globalSettings, QMap<QString, QString> &groupMap, const FTBRecord & record)
-{
-	InstancePtr inst;
-
-	auto m_settings = std::make_shared<INISettingsObject>(FS::PathCombine(record.instanceDir, "instance.cfg"));
-	m_settings->registerSetting("InstanceType", "Legacy");
-
-	qDebug() << "Loading existing " << record.name;
-
-	QString inst_type = m_settings->get("InstanceType").toString();
-	if (inst_type == "LegacyFTB")
-	{
-		inst.reset(new LegacyFTBInstance(globalSettings, m_settings, record.instanceDir));
-	}
-	else if (inst_type == "OneSixFTB")
-	{
-		inst.reset(new OneSixFTBInstance(globalSettings, m_settings, record.instanceDir));
-	}
-	else
-	{
-		return nullptr;
-	}
-	qDebug() << "Construction " << record.instanceDir;
-
-	SettingsObject::Lock lock(inst->settings());
-	inst->init();
-	qDebug() << "Init " << record.instanceDir;
-	inst->setGroupInitial("FTB");
-	/**
-	 * FIXME: this does not respect the user's preferences. BUT, it would work nicely with the planned pack support
-	 *        -> instead of changing the user values, change pack values (defaults you can look at and revert to)
-	 */
-	/*
-	inst->setName(record.name);
-	inst->setIconKey(record.iconKey);
-	inst->setNotes(record.description);
-	*/
-	if (inst->intendedVersionId() != record.mcVersion)
-	{
-		inst->setIntendedVersionId(record.mcVersion);
-	}
-	qDebug() << "Post-Process " << record.instanceDir;
-	if (!InstanceList::continueProcessInstance(inst, InstanceList::NoCreateError, record.instanceDir, groupMap))
-	{
-		return nullptr;
-	}
-	qDebug() << "Final " << record.instanceDir;
-	return inst;
-}
-
-InstancePtr createInstance(SettingsObjectPtr globalSettings, QMap<QString, QString> &groupMap, const FTBRecord & record)
-{
-	QDir rootDir(record.instanceDir);
-
-	InstancePtr inst;
-
-	qDebug() << "Converting " << record.name << " as new.";
-
-	auto mcVersion = std::dynamic_pointer_cast<MinecraftVersion>(ENV.getVersion("net.minecraft", record.mcVersion));
-	if (!mcVersion)
-	{
-		qCritical() << "Can't load instance " << record.instanceDir
-					<< " because minecraft version " << record.mcVersion
-					<< " can't be resolved.";
-		return nullptr;
-	}
 
-	if (!rootDir.exists() && !rootDir.mkpath("."))
-	{
-		qCritical() << "Can't create instance folder" << record.instanceDir;
-		return nullptr;
-	}
-
-	auto m_settings = std::make_shared<INISettingsObject>(FS::PathCombine(record.instanceDir, "instance.cfg"));
-	m_settings->registerSetting("InstanceType", "Legacy");
-
-	if (mcVersion->usesLegacyLauncher())
-	{
-		m_settings->set("InstanceType", "LegacyFTB");
-		inst.reset(new LegacyFTBInstance(globalSettings, m_settings, record.instanceDir));
-	}
-	else
-	{
-		m_settings->set("InstanceType", "OneSixFTB");
-		inst.reset(new OneSixFTBInstance(globalSettings, m_settings, record.instanceDir));
-	}
-	// initialize
-	{
-		SettingsObject::Lock lock(inst->settings());
-		inst->setIntendedVersionId(mcVersion->descriptor());
-		inst->init();
-		inst->setGroupInitial("FTB");
-		inst->setName(record.name);
-		inst->setIconKey(record.iconKey);
-		inst->setNotes(record.description);
-		qDebug() << "Post-Process " << record.instanceDir;
-		if (!InstanceList::continueProcessInstance(inst, InstanceList::NoCreateError, record.instanceDir, groupMap))
-		{
-			return nullptr;
-		}
-	}
-	return inst;
-}
-
-void FTBPlugin::loadInstances(SettingsObjectPtr globalSettings, QMap<QString, QString> &groupMap, QList<InstancePtr> &tempList)
-{
-	// nothing to load when we don't have
-	if (globalSettings->get("TrackFTBInstances").toBool() != true)
-	{
-		return;
-	}
-
-	auto records = discoverFTBInstances(globalSettings);
-	if (!records.size())
-	{
-		qDebug() << "No FTB instances to load.";
-		return;
-	}
-	qDebug() << "Loading FTB instances! -- got " << records.size();
-	// process the records we acquired.
-	for (auto record : records)
-	{
-		qDebug() << "Loading FTB instance from " << record.instanceDir;
-		QString iconKey = record.iconKey;
-		auto icons = ENV.icons();
-		if(icons)
-		{
-			icons->addIcon(iconKey, iconKey, FS::PathCombine(record.templateDir, record.logo), IconType::Transient);
-		}
-		auto settingsFilePath = FS::PathCombine(record.instanceDir, "instance.cfg");
-		qDebug() << "ICON get!";
-
-		if (QFileInfo(settingsFilePath).exists())
-		{
-			auto instPtr = loadInstance(globalSettings, groupMap, record);
-			if (!instPtr)
-			{
-				qWarning() << "Couldn't load instance config:" << settingsFilePath;
-				if(!QFile::remove(settingsFilePath))
-				{
-					qWarning() << "Couldn't remove broken instance config!";
-					continue;
-				}
-				// failed to load, but removed the poisonous file
-			}
-			else
-			{
-				tempList.append(InstancePtr(instPtr));
-				continue;
-			}
-		}
-		auto instPtr = createInstance(globalSettings, groupMap, record);
-		if (!instPtr)
-		{
-			qWarning() << "Couldn't create FTB instance!";
-			continue;
-		}
-		tempList.append(InstancePtr(instPtr));
-	}
-}
+#include <QDebug>
+#include <QRegularExpression>
 
 #ifdef Q_OS_WIN32
 #include <windows.h>
diff --git a/api/logic/minecraft/ftb/FTBPlugin.h b/api/logic/minecraft/ftb/FTBPlugin.h
index 6851d8a5..e1b56545 100644
--- a/api/logic/minecraft/ftb/FTBPlugin.h
+++ b/api/logic/minecraft/ftb/FTBPlugin.h
@@ -9,5 +9,4 @@ class MULTIMC_LOGIC_EXPORT FTBPlugin
 {
 public:
 	static void initialize(SettingsObjectPtr globalSettings);
-	static void loadInstances(SettingsObjectPtr globalSettings, QMap<QString, QString> &groupMap, QList<InstancePtr> &tempList);
 };
diff --git a/api/logic/tasks/ThreadTask.h b/api/logic/tasks/ThreadTask.h
index 718dbc91..46ce3a36 100644
--- a/api/logic/tasks/ThreadTask.h
+++ b/api/logic/tasks/ThreadTask.h
@@ -1,8 +1,9 @@
 #pragma once
 
 #include "Task.h"
+#include "multimc_logic_export.h"
 
-class ThreadTask : public Task
+class MULTIMC_LOGIC_EXPORT ThreadTask : public Task
 {
 	Q_OBJECT
 public: