13 files changed, 646 insertions, 331 deletions

diff --git a/logic/minecraft/MinecraftVersion.cpp b/logic/minecraft/MinecraftVersion.cpp
index a2e5a50a..2191e8af 100644
--- a/logic/minecraft/MinecraftVersion.cpp
+++ b/logic/minecraft/MinecraftVersion.cpp
@@ -1,2 +1,95 @@
 #include "MinecraftVersion.h"
+#include "VersionFinal.h"
 
+bool MinecraftVersion::usesLegacyLauncher()
+{
+	return m_traits.contains("legacyLaunch") || m_traits.contains("aplhaLaunch");
+}
+QString MinecraftVersion::descriptor()
+{
+	return m_descriptor;
+}
+QString MinecraftVersion::name()
+{
+	return m_name;
+}
+QString MinecraftVersion::typeString() const
+{
+	if (is_latest && is_snapshot)
+	{
+		return QObject::tr("Latest snapshot");
+	}
+	else if (is_latest)
+	{
+		return QObject::tr("Latest release");
+	}
+	else if (is_snapshot)
+	{
+		return QObject::tr("Snapshot");
+	}
+	else
+	{
+		return QObject::tr("Regular release");
+	}
+}
+bool MinecraftVersion::hasJarMods()
+{
+	return false;
+}
+bool MinecraftVersion::isVanilla()
+{
+	return true;
+}
+
+void MinecraftVersion::applyTo(VersionFinal *version)
+{
+	// FIXME: make this work.
+	if(m_versionSource != Builtin)
+	{
+		return;
+	}
+	if (!m_descriptor.isNull())
+	{
+		version->id = m_descriptor;
+	}
+	if (!m_mainClass.isNull())
+	{
+		version->mainClass = m_mainClass;
+	}
+	if (!m_appletClass.isNull())
+	{
+		version->appletClass = m_appletClass;
+	}
+	if (!m_processArguments.isNull())
+	{
+		version->vanillaProcessArguments = m_processArguments;
+		version->processArguments = m_processArguments;
+	}
+	if (!m_type.isNull())
+	{
+		version->type = m_type;
+	}
+	if (!m_releaseTimeString.isNull())
+	{
+		version->m_releaseTimeString = m_releaseTimeString;
+		version->m_releaseTime = m_releaseTime;
+	}
+	if (!m_updateTimeString.isNull())
+	{
+		version->m_updateTimeString = m_updateTimeString;
+		version->m_updateTime = m_updateTime;
+	}
+	version->traits.unite(m_traits);
+}
+int MinecraftVersion::getOrder()
+{
+	return order;
+}
+void MinecraftVersion::setOrder(int order)
+{
+	this->order = order;
+}
+QList<JarmodPtr> MinecraftVersion::getJarMods()
+{
+	return QList<JarmodPtr>();
+}
diff --git a/logic/minecraft/MinecraftVersion.h b/logic/minecraft/MinecraftVersion.h
index dab08bb1..6a1c54cb 100644
--- a/logic/minecraft/MinecraftVersion.h
+++ b/logic/minecraft/MinecraftVersion.h
@@ -15,16 +15,18 @@
 
 #pragma once
 
-#include "logic/BaseVersion.h"
-#include "VersionPatch.h"
 #include <QStringList>
 #include <QSet>
+#include <QDateTime>
+
+#include "logic/BaseVersion.h"
+#include "VersionPatch.h"
+#include "VersionFile.h"
+
+class VersionFinal;
 
 struct MinecraftVersion : public BaseVersion, public VersionPatch
 {
-	/// The version's timestamp - this is primarily used for sorting versions in a list.
-	qint64 timestamp;
-
 	/// The URL that this version will be downloaded from. maybe.
 	QString download_url;
 
@@ -34,16 +36,20 @@ struct MinecraftVersion : public BaseVersion, public VersionPatch
 	/// is this a snapshot?
 	bool is_snapshot = false;
 
-	/// is this a built-in version that comes with MultiMC?
-	bool is_builtin = false;
-	
+	/// where is this from?
+	enum VersionSource
+	{
+		Builtin,
+		Mojang
+	} m_versionSource = Builtin;
+
 	/// the human readable version name
 	QString m_name;
 
 	/// the version ID.
 	QString m_descriptor;
 
-	/// version traits. generally launcher business...
+	/// version traits. added by MultiMC
 	QSet<QString> m_traits;
 
 	/// The main class this version uses (if any, can be empty).
@@ -52,57 +58,47 @@ struct MinecraftVersion : public BaseVersion, public VersionPatch
 	/// The applet class this version uses (if any, can be empty).
 	QString m_appletClass;
 
-	bool usesLegacyLauncher()
-	{
-		return m_traits.contains("legacyLaunch") || m_traits.contains("aplhaLaunch");
-	}
-	
-	virtual QString descriptor() override
-	{
-		return m_descriptor;
-	}
+	/// The process arguments used by this version
+	QString m_processArguments;
 
-	virtual QString name() override
-	{
-		return m_name;
-	}
+	/// The type of this release
+	QString m_type;
 
-	virtual QString typeString() const override
+	/// the time this version was actually released by Mojang, as string and as QDateTime
+	QString m_releaseTimeString;
+	QDateTime m_releaseTime;
+
+	/// the time this version was last updated by Mojang, as string and as QDateTime
+	QString m_updateTimeString;
+	QDateTime m_updateTime;
+
+	/// order of this file... default = -2
+	int order = -2;
+
+	bool usesLegacyLauncher();
+	virtual QString descriptor() override;
+	virtual QString name() override;
+	virtual QString typeString() const override;
+	virtual bool hasJarMods() override;
+	virtual bool isVanilla() override;
+	virtual void applyTo(VersionFinal *version) override;
+	virtual int getOrder();
+	virtual void setOrder(int order);
+	virtual QList<JarmodPtr> getJarMods() override;
+	virtual QString getPatchID()
 	{
-		if (is_latest && is_snapshot)
-		{
-			return QObject::tr("Latest snapshot");
-		}
-		else if(is_latest)
-		{
-			return QObject::tr("Latest release");
-		}
-		else if(is_snapshot)
-		{
-			return QObject::tr("Snapshot");
-		}
-		else if(is_builtin)
-		{
-			return QObject::tr("Museum piece");
-		}
-		else
-		{
-			return QObject::tr("Regular release");
-		}
+		return "net.minecraft";
 	}
-	
-	virtual bool hasJarMods() override
+	virtual QString getPatchVersion()
 	{
-		return false;
+		return m_descriptor;
 	}
-	
-	virtual bool isVanilla() override
+	virtual QString getPatchName()
 	{
-		return true;
+		return "Minecraft";
 	}
-	
-	virtual void applyTo(VersionFinal *version)
+	virtual QString getPatchFilename()
 	{
-		// umm... what now?
-	}
+		return QString();
+	};
 };
diff --git a/logic/minecraft/MinecraftVersionList.cpp b/logic/minecraft/MinecraftVersionList.cpp
index cdf5fa77..1aa220e8 100644
--- a/logic/minecraft/MinecraftVersionList.cpp
+++ b/logic/minecraft/MinecraftVersionList.cpp
@@ -16,7 +16,8 @@
 #include "MinecraftVersionList.h"
 #include "MultiMC.h"
 #include "logic/net/URLConstants.h"
-#include <logic/MMCJson.h>
+#include "logic/MMCJson.h"
+#include "ParseUtils.h"
 
 #include <QtXml>
 
@@ -30,11 +31,6 @@
 
 #include <QtNetwork>
 
-inline QDateTime timeFromS3Time(QString str)
-{
-	return QDateTime::fromString(str, Qt::ISODate);
-}
-
 MinecraftVersionList::MinecraftVersionList(QObject *parent) : BaseVersionList(parent)
 {
 	loadBuiltinList();
@@ -64,7 +60,7 @@ static bool cmpVersions(BaseVersionPtr first, BaseVersionPtr second)
 {
 	auto left = std::dynamic_pointer_cast<MinecraftVersion>(first);
 	auto right = std::dynamic_pointer_cast<MinecraftVersion>(second);
-	return left->timestamp > right->timestamp;
+	return left->m_releaseTime > right->m_releaseTime;
 }
 
 void MinecraftVersionList::sortInternal()
@@ -79,55 +75,55 @@ void MinecraftVersionList::loadBuiltinList()
 	QFile filez(versionList.absoluteFilePath());
 	filez.open(QIODevice::ReadOnly);
 	auto data = filez.readAll();
-	
+
 	// parse the data as json
 	QJsonParseError jsonError;
 	QJsonDocument jsonDoc = QJsonDocument::fromJson(data, &jsonError);
 	QJsonObject root = jsonDoc.object();
-	
+
 	// parse all the versions
 	for (const auto version : MMCJson::ensureArray(root.value("versions")))
 	{
 		QJsonObject versionObj = version.toObject();
 		QString versionID = versionObj.value("id").toString("");
-		QString versionTimeStr = versionObj.value("releaseTime").toString("");
 		QString versionTypeStr = versionObj.value("type").toString("");
-		QSet<QString> traits;
-		if (versionObj.contains("+traits"))
+		if (versionID.isEmpty() || versionTypeStr.isEmpty())
 		{
-			for (auto traitVal : MMCJson::ensureArray(versionObj.value("+traits")))
-			{
-				traits.insert(MMCJson::ensureString(traitVal));
-			}
-		}
-		if (versionID.isEmpty() || versionTimeStr.isEmpty() || versionTypeStr.isEmpty())
-		{
-			// FIXME: log this somewhere
+			QLOG_ERROR() << "Parsed version is missing ID or type";
 			continue;
 		}
+
+		// Now, we construct the version object and add it to the list.
+		std::shared_ptr<MinecraftVersion> mcVersion(new MinecraftVersion());
+		mcVersion->m_name = mcVersion->m_descriptor = versionID;
+
 		// Parse the timestamp.
-		QDateTime versionTime = timeFromS3Time(versionTimeStr);
-		if (!versionTime.isValid())
+		try
+		{
+			parse_timestamp(versionObj.value("releaseTime").toString(""),
+							mcVersion->m_releaseTimeString, mcVersion->m_releaseTime);
+		}
+		catch (MMCError &e)
 		{
-			// FIXME: log this somewhere
+			QLOG_ERROR() << "Error while parsing version" << versionID << ":" << e.cause();
 			continue;
 		}
-		// Get the download URL.
-		QString dlUrl = "http://" + URLConstants::AWS_DOWNLOAD_VERSIONS + versionID + "/";
 
-		// main class and applet class
-		QString mainClass = versionObj.value("type").toString("");
-		QString appletClass = versionObj.value("type").toString("");
+		// Get the download URL.
+		mcVersion->download_url =
+			"http://" + URLConstants::AWS_DOWNLOAD_VERSIONS + versionID + "/";
 
-		// Now, we construct the version object and add it to the list.
-		std::shared_ptr<MinecraftVersion> mcVersion(new MinecraftVersion());
-		mcVersion->m_name = mcVersion->m_descriptor = versionID;
-		mcVersion->timestamp = versionTime.toMSecsSinceEpoch();
-		mcVersion->download_url = dlUrl;
-		mcVersion->is_builtin = true;
-		mcVersion->m_appletClass = appletClass;
-		mcVersion->m_mainClass = mainClass;
-		mcVersion->m_traits = traits;
+		mcVersion->m_versionSource = MinecraftVersion::Builtin;
+		mcVersion->m_appletClass = versionObj.value("appletClass").toString("");
+		mcVersion->m_mainClass = versionObj.value("mainClass").toString("");
+		mcVersion->m_processArguments = versionObj.value("processArguments").toString("legacy");
+		if (versionObj.contains("+traits"))
+		{
+			for (auto traitVal : MMCJson::ensureArray(versionObj.value("+traits")))
+			{
+				mcVersion->m_traits.insert(MMCJson::ensureString(traitVal));
+			}
+		}
 		m_vlist.append(mcVersion);
 	}
 }
@@ -265,62 +261,77 @@ void MCVListLoadTask::list_downloaded()
 		// Load the version info.
 		if (!version.isObject())
 		{
-			// FIXME: log this somewhere
+			QLOG_ERROR() << "Error while parsing version list : invalid JSON structure";
 			continue;
 		}
 		QJsonObject versionObj = version.toObject();
 		QString versionID = versionObj.value("id").toString("");
-		QString versionTimeStr = versionObj.value("releaseTime").toString("");
-		QString versionTypeStr = versionObj.value("type").toString("");
-		if (versionID.isEmpty() || versionTimeStr.isEmpty() || versionTypeStr.isEmpty())
+		if (versionID.isEmpty())
 		{
-			// FIXME: log this somewhere
+			QLOG_ERROR() << "Error while parsing version : version ID is missing";
 			continue;
 		}
+		// Get the download URL.
+		QString dlUrl = "http://" + URLConstants::AWS_DOWNLOAD_VERSIONS + versionID + "/";
 
-		// Parse the timestamp.
-		QDateTime versionTime = timeFromS3Time(versionTimeStr);
-		if (!versionTime.isValid())
-		{
-			// FIXME: log this somewhere
-			continue;
-		}
-		// OneSix or Legacy. use filter to determine type
-		if (versionTypeStr == "release")
-		{
-			is_latest = (versionID == latestReleaseID);
-			is_snapshot = false;
-		}
-		else if (versionTypeStr == "snapshot") // It's a snapshot... yay
-		{
-			is_latest = (versionID == latestSnapshotID);
-			is_snapshot = true;
-		}
-		else if (versionTypeStr == "old_alpha")
-		{
-			is_latest = false;
-			is_snapshot = false;
-		}
-		else if (versionTypeStr == "old_beta")
+		// Now, we construct the version object and add it to the list.
+		std::shared_ptr<MinecraftVersion> mcVersion(new MinecraftVersion());
+		mcVersion->m_name = mcVersion->m_descriptor = versionID;
+
+		try
 		{
-			is_latest = false;
-			is_snapshot = false;
+			// Parse the timestamps.
+			parse_timestamp(versionObj.value("releaseTime").toString(""),
+							mcVersion->m_releaseTimeString, mcVersion->m_releaseTime);
+
+			parse_timestamp(versionObj.value("time").toString(""),
+							mcVersion->m_updateTimeString, mcVersion->m_updateTime);
 		}
-		else
+		catch (MMCError &e)
 		{
-			// FIXME: log this somewhere
+			QLOG_ERROR() << "Error while parsing version" << versionID << ":" << e.cause();
 			continue;
 		}
-		// Get the download URL.
-		QString dlUrl = "http://" + URLConstants::AWS_DOWNLOAD_VERSIONS + versionID + "/";
 
-		// Now, we construct the version object and add it to the list.
-		std::shared_ptr<MinecraftVersion> mcVersion(new MinecraftVersion());
-		mcVersion->m_name = mcVersion->m_descriptor = versionID;
-		mcVersion->timestamp = versionTime.toMSecsSinceEpoch();
+		mcVersion->m_versionSource = MinecraftVersion::Builtin;
 		mcVersion->download_url = dlUrl;
-		mcVersion->is_latest = is_latest;
-		mcVersion->is_snapshot = is_snapshot;
+		{
+			QString versionTypeStr = versionObj.value("type").toString("");
+			if (versionTypeStr.isEmpty())
+			{
+				// FIXME: log this somewhere
+				continue;
+			}
+			// OneSix or Legacy. use filter to determine type
+			if (versionTypeStr == "release")
+			{
+				is_latest = (versionID == latestReleaseID);
+				is_snapshot = false;
+			}
+			else if (versionTypeStr == "snapshot") // It's a snapshot... yay
+			{
+				is_latest = (versionID == latestSnapshotID);
+				is_snapshot = true;
+			}
+			else if (versionTypeStr == "old_alpha")
+			{
+				is_latest = false;
+				is_snapshot = false;
+			}
+			else if (versionTypeStr == "old_beta")
+			{
+				is_latest = false;
+				is_snapshot = false;
+			}
+			else
+			{
+				// FIXME: log this somewhere
+				continue;
+			}
+			mcVersion->m_type = versionTypeStr;
+			mcVersion->is_latest = is_latest;
+			mcVersion->is_snapshot = is_snapshot;
+		}
 		tempList.append(mcVersion);
 	}
 	m_list->updateListData(tempList);
diff --git a/logic/minecraft/ParseUtils.cpp b/logic/minecraft/ParseUtils.cpp
new file mode 100644
index 00000000..67460ca4
--- /dev/null
+++ b/logic/minecraft/ParseUtils.cpp
@@ -0,0 +1,23 @@
+#include <QDateTime>
+#include <QString>
+#include "ParseUtils.h"
+#include <logic/MMCJson.h>
+
+QDateTime timeFromS3Time(QString str)
+{
+	return QDateTime::fromString(str, Qt::ISODate);
+}
+
+void parse_timestamp (const QString & raw, QString & save_here, QDateTime & parse_here)
+{
+	save_here = raw;
+	if (save_here.isEmpty())
+	{
+		throw JSONValidationError("The timestamp is empty!");
+	}
+	parse_here = timeFromS3Time(save_here);
+	if (!parse_here.isValid())
+	{
+		throw JSONValidationError("The timestamp not a valid timestamp!");
+	}
+}
diff --git a/logic/minecraft/ParseUtils.h b/logic/minecraft/ParseUtils.h
new file mode 100644
index 00000000..73cf526a
--- /dev/null
+++ b/logic/minecraft/ParseUtils.h
@@ -0,0 +1,14 @@
+#pragma once
+#include <QString>
+#include <QDateTime>
+
+/**
+ * parse the S3 timestamp in 'raw' and fill the forwarded variables.
+ * return true/false for success/failure
+ */
+void parse_timestamp (const QString &raw, QString &save_here, QDateTime &parse_here);
+
+/**
+ * take the timestamp used by S3 and turn it into QDateTime
+ */
+QDateTime timeFromS3Time(QString str);
diff --git a/logic/minecraft/VersionBuildError.h b/logic/minecraft/VersionBuildError.h
new file mode 100644
index 00000000..ae479851
--- /dev/null
+++ b/logic/minecraft/VersionBuildError.h
@@ -0,0 +1,58 @@
+#include "MMCError.h"
+
+class VersionBuildError : public MMCError
+{
+public:
+	VersionBuildError(QString cause) : MMCError(cause) {};
+	virtual ~VersionBuildError() noexcept
+	{
+	}
+};
+
+/**
+ * the base version file was meant for a newer version of the vanilla launcher than we support
+ */
+class LauncherVersionError : public VersionBuildError
+{
+public:
+	LauncherVersionError(int actual, int supported)
+		: VersionBuildError(QObject::tr(
+			  "The base version file of this instance was meant for a newer (%1) "
+			  "version of the vanilla launcher than this version of MultiMC supports (%2).")
+								.arg(actual)
+								.arg(supported)) {};
+	virtual ~LauncherVersionError() noexcept
+	{
+	}
+};
+
+/**
+ * some patch was intended for a different version of minecraft
+ */
+class MinecraftVersionMismatch : public VersionBuildError
+{
+public:
+	MinecraftVersionMismatch(QString fileId, QString mcVersion, QString parentMcVersion)
+		: VersionBuildError(QObject::tr("The patch %1 is for a different version of Minecraft "
+										"(%2) than that of the instance (%3).")
+								.arg(fileId)
+								.arg(mcVersion)
+								.arg(parentMcVersion)) {};
+	virtual ~MinecraftVersionMismatch() noexcept
+	{
+	}
+};
+
+/**
+ * files required for the version are not (yet?) present
+ */
+class VersionIncomplete : public VersionBuildError
+{
+public:
+	VersionIncomplete(QString missingPatch)
+		: VersionBuildError(QObject::tr("Version is incomplete: missing %1.")
+								.arg(missingPatch)) {};
+	virtual ~VersionIncomplete() noexcept
+	{
+	}
+};
\ No newline at end of file
diff --git a/logic/minecraft/VersionBuilder.cpp b/logic/minecraft/VersionBuilder.cpp
index 56eef424..d19c2877 100644
--- a/logic/minecraft/VersionBuilder.cpp
+++ b/logic/minecraft/VersionBuilder.cpp
@@ -23,12 +23,17 @@
 #include <QObject>
 #include <QDir>
 #include <QDebug>
+#include <qresource.h>
 #include <modutils.h>
 
+#include "MultiMC.h"
 #include "logic/minecraft/VersionBuilder.h"
 #include "logic/minecraft/VersionFinal.h"
 #include "logic/minecraft/OneSixRule.h"
+#include "logic/minecraft/VersionPatch.h"
 #include "logic/minecraft/VersionFile.h"
+#include "VersionBuildError.h"
+#include "MinecraftVersionList.h"
 
 #include "logic/OneSixInstance.h"
 #include "logic/MMCJson.h"
@@ -39,16 +44,17 @@ VersionBuilder::VersionBuilder()
 {
 }
 
-void VersionBuilder::build(VersionFinal *version, OneSixInstance *instance, const QStringList &external)
+void VersionBuilder::build(VersionFinal *version, OneSixInstance *instance,
+						   const QStringList &external)
 {
 	VersionBuilder builder;
 	builder.m_version = version;
 	builder.m_instance = instance;
-	builder.buildInternal(external);
+	builder.external_patches = external;
+	builder.buildInternal();
 }
 
-void VersionBuilder::readJsonAndApplyToVersion(VersionFinal *version,
-													 const QJsonObject &obj)
+void VersionBuilder::readJsonAndApplyToVersion(VersionFinal *version, const QJsonObject &obj)
 {
 	VersionBuilder builder;
 	builder.m_version = version;
@@ -56,88 +62,143 @@ void VersionBuilder::readJsonAndApplyToVersion(VersionFinal *version,
 	builder.readJsonAndApply(obj);
 }
 
-void VersionBuilder::buildInternal(const QStringList &external)
+void VersionBuilder::buildFromCustomJson()
 {
-	m_version->versionFiles.clear();
+	QLOG_INFO() << "Building version from custom.json within the instance.";
+	QLOG_INFO() << "Reading custom.json";
+	auto file = parseJsonFile(QFileInfo(instance_root.absoluteFilePath("custom.json")), false);
+	file->name = "custom.json";
+	file->filename = "custom.json";
+	file->fileId = "org.multimc.custom.json";
+	file->order = -1;
+	file->version = QString();
+	m_version->VersionPatches.append(file);
+	// QObject::tr("The version descriptors of this instance are not compatible with the
+	// current version of MultiMC"));
+	// QObject::tr("Error while applying %1. Please check MultiMC-0.log for more info.")
+	// some final touches
+	m_version->finalize();
+	return;
+}
 
-	QDir root(m_instance->instanceRoot());
-	QDir patches(root.absoluteFilePath("patches/"));
+void VersionBuilder::buildFromVersionJson()
+{
+	QLOG_INFO() << "Building version from version.json and patches within the instance.";
+	QLOG_INFO() << "Reading version.json";
+	auto file = parseJsonFile(QFileInfo(instance_root.absoluteFilePath("version.json")), false);
+	file->name = "Minecraft";
+	file->fileId = "org.multimc.version.json";
+	file->order = -1;
+	file->version = m_instance->intendedVersionId();
+	file->mcVersion = m_instance->intendedVersionId();
+	m_version->VersionPatches.append(file);
 
-	// if we do external files, do just those.
-	if (!external.isEmpty())
+	// load all patches, put into map for ordering, apply in the right order
+	readInstancePatches();
+
+	// some final touches
+	m_version->finalize();
+}
+
+void VersionBuilder::readInstancePatches()
+{
+	QDir patches(instance_root.absoluteFilePath("patches/"));
+	QMap<int, QPair<QString, VersionFilePtr>> files;
+	for (auto info : patches.entryInfoList(QStringList() << "*.json", QDir::Files))
 	{
-		int externalOrder = -1;
-		for (auto fileName : external)
+		QLOG_INFO() << "Reading" << info.fileName();
+		auto file = parseJsonFile(info, true);
+		if(file->fileId == "net.minecraft")
+			continue;
+		if(file->fileId == "org.lwjgl")
+			continue;
+		if (files.contains(file->order))
 		{
-			QLOG_INFO() << "Reading" << fileName;
-			auto file =
-				parseJsonFile(QFileInfo(fileName), false, fileName.endsWith("pack.json"));
-			file->name = QFileInfo(fileName).fileName();
-			file->fileId = "org.multimc.external." + file->name;
-			file->order = (externalOrder += 1);
-			file->version = QString();
-			file->mcVersion = QString();
-			m_version->versionFiles.append(file);
+			throw VersionBuildError(QObject::tr("%1 has the same order as %2")
+										.arg(file->fileId, files[file->order].second->fileId));
 		}
+		files.insert(file->order, qMakePair(info.fileName(), file));
 	}
-	// else, if there's custom json, we just do that.
-	else if (QFile::exists(root.absoluteFilePath("custom.json")))
-	{
-		QLOG_INFO() << "Reading custom.json";
-		auto file = parseJsonFile(QFileInfo(root.absoluteFilePath("custom.json")), false);
-		file->name = "custom.json";
-		file->filename = "custom.json";
-		file->fileId = "org.multimc.custom.json";
-		file->order = -1;
-		file->version = QString();
-		m_version->versionFiles.append(file);
-		// QObject::tr("The version descriptors of this instance are not compatible with the
-		// current version of MultiMC"));
-		// QObject::tr("Error while applying %1. Please check MultiMC-0.log for more info.")
+	for (auto order : files.keys())
+	{
+		auto &filePair = files[order];
+		m_version->VersionPatches.append(filePair.second);
 	}
-	// version.json -> patches/*.json -> user.json
-	else
-		do
-		{
-			// version.json
-			QLOG_INFO() << "Reading version.json";
-			auto file = parseJsonFile(QFileInfo(root.absoluteFilePath("version.json")), false);
-			file->name = "Minecraft";
-			file->fileId = "org.multimc.version.json";
-			file->order = -1;
-			file->version = m_instance->intendedVersionId();
-			file->mcVersion = m_instance->intendedVersionId();
-			m_version->versionFiles.append(file);
-			// QObject::tr("Error while applying %1. Please check MultiMC-0.log for more
-			// info.").arg(root.absoluteFilePath("version.json")));
-
-			// patches/
-			// load all, put into map for ordering, apply in the right order
-
-			QMap<int, QPair<QString, VersionFilePtr>> files;
-			for (auto info : patches.entryInfoList(QStringList() << "*.json", QDir::Files))
-			{
-				QLOG_INFO() << "Reading" << info.fileName();
-				auto file = parseJsonFile(info, true);
-				if (files.contains(file->order))
-				{
-					throw VersionBuildError(QObject::tr("%1 has the same order as %2").arg(
-						file->fileId, files[file->order].second->fileId));
-				}
-				files.insert(file->order, qMakePair(info.fileName(), file));
-			}
-			for (auto order : files.keys())
-			{
-				auto &filePair = files[order];
-				m_version->versionFiles.append(filePair.second);
-			}
-		} while (0);
+}
 
+void VersionBuilder::buildFromExternalPatches()
+{
+	QLOG_INFO() << "Building version from external files.";
+	int externalOrder = -1;
+	for (auto fileName : external_patches)
+	{
+		QLOG_INFO() << "Reading" << fileName;
+		auto file = parseJsonFile(QFileInfo(fileName), false, fileName.endsWith("pack.json"));
+		file->name = QFileInfo(fileName).fileName();
+		file->fileId = "org.multimc.external." + file->name;
+		file->order = (externalOrder += 1);
+		file->version = QString();
+		file->mcVersion = QString();
+		m_version->VersionPatches.append(file);
+	}
 	// some final touches
 	m_version->finalize();
 }
 
+void VersionBuilder::buildFromMultilayer()
+{
+	QLOG_INFO() << "Building version from multilayered sources.";
+	// just the builtin stuff for now
+	auto minecraftList = MMC->minecraftlist();
+	auto mcversion = minecraftList->findVersion(m_instance->intendedVersionId());
+	auto minecraftPatch = std::dynamic_pointer_cast<VersionPatch>(mcversion);
+	if(!minecraftPatch)
+	{
+		throw VersionIncomplete("net.minecraft");
+	}
+	minecraftPatch->setOrder(-2);
+	m_version->VersionPatches.append(minecraftPatch);
 
+	QResource LWJGL(":/versions/LWJGL/2.9.1.json");
+	auto lwjgl = parseJsonFile(LWJGL.absoluteFilePath(), false, false);
+	auto lwjglPatch = std::dynamic_pointer_cast<VersionPatch>(lwjgl);
+	if(!lwjglPatch)
+	{
+		throw VersionIncomplete("org.lwjgl");
+	}
+	lwjglPatch->setOrder(-1);
+	m_version->VersionPatches.append(lwjglPatch);
+
+	// load all patches, put into map for ordering, apply in the right order
+	readInstancePatches();
+
+	m_version->finalize();
+}
+
+void VersionBuilder::buildInternal()
+{
+	m_version->VersionPatches.clear();
+	instance_root = QDir(m_instance->instanceRoot());
+	// if we do external files, do just those.
+	if (!external_patches.isEmpty())
+	{
+		buildFromExternalPatches();
+	}
+	// else, if there's custom json, we just do that.
+	else if (QFile::exists(instance_root.absoluteFilePath("custom.json")))
+	{
+		buildFromCustomJson();
+	}
+	// version.json -> patches/*.json
+	else if (QFile::exists(instance_root.absoluteFilePath("version.json")))
+	{
+		buildFromVersionJson();
+	}
+	else
+	{
+		buildFromMultilayer();
+	}
+}
 
 void VersionBuilder::readJsonAndApply(const QJsonObject &obj)
 {
@@ -147,14 +208,14 @@ void VersionBuilder::readJsonAndApply(const QJsonObject &obj)
 	// QObject::tr("Error while reading. Please check MultiMC-0.log for more info."));
 
 	file->applyTo(m_version);
-	m_version->versionFiles.append(file);
+	m_version->VersionPatches.append(file);
 	// QObject::tr("Error while applying. Please check MultiMC-0.log for more info."));
 	// QObject::tr("The version descriptors of this instance are not compatible with the current
 	// version of MultiMC"));
 }
 
-VersionFilePtr VersionBuilder::parseJsonFile(const QFileInfo &fileInfo,
-												   const bool requireOrder, bool isFTB)
+VersionFilePtr VersionBuilder::parseJsonFile(const QFileInfo &fileInfo, const bool requireOrder,
+											 bool isFTB)
 {
 	QFile file(fileInfo.absoluteFilePath());
 	if (!file.open(QFile::ReadOnly))
@@ -166,9 +227,10 @@ VersionFilePtr VersionBuilder::parseJsonFile(const QFileInfo &fileInfo,
 	QJsonDocument doc = QJsonDocument::fromJson(file.readAll(), &error);
 	if (error.error != QJsonParseError::NoError)
 	{
-		throw JSONValidationError(QObject::tr("Unable to process the version file %1: %2 at %3.")
-									  .arg(fileInfo.fileName(), error.errorString())
-									  .arg(error.offset));
+		throw JSONValidationError(
+			QObject::tr("Unable to process the version file %1: %2 at %3.")
+				.arg(fileInfo.fileName(), error.errorString())
+				.arg(error.offset));
 	}
 	return VersionFile::fromJson(doc, file.fileName(), requireOrder, isFTB);
 	// QObject::tr("Error while reading %1. Please check MultiMC-0.log for more
@@ -226,7 +288,7 @@ QMap<QString, int> VersionBuilder::readOverrideOrders(OneSixInstance *instance)
 }
 
 bool VersionBuilder::writeOverrideOrders(const QMap<QString, int> &order,
-											   OneSixInstance *instance)
+										 OneSixInstance *instance)
 {
 	QJsonObject obj;
 	for (auto it = order.cbegin(); it != order.cend(); ++it)
diff --git a/logic/minecraft/VersionBuilder.h b/logic/minecraft/VersionBuilder.h
index ac93ef11..c56e6c18 100644
--- a/logic/minecraft/VersionBuilder.h
+++ b/logic/minecraft/VersionBuilder.h
@@ -37,8 +37,17 @@ public:
 private:
 	VersionFinal *m_version;
 	OneSixInstance *m_instance;
-
-	void buildInternal(const QStringList& external);
+	QStringList external_patches;
+	QDir instance_root;
+	
+	void buildInternal();
+	void buildFromExternalPatches();
+	void buildFromCustomJson();
+	void buildFromVersionJson();
+	void buildFromMultilayer();
+	
+	void readInstancePatches();
+	
 	void readJsonAndApply(const QJsonObject &obj);
 
 	VersionFilePtr parseJsonFile(const QFileInfo &fileInfo, const bool requireOrder,
diff --git a/logic/minecraft/VersionFile.cpp b/logic/minecraft/VersionFile.cpp
index e1b03e6c..bc9c42c1 100644
--- a/logic/minecraft/VersionFile.cpp
+++ b/logic/minecraft/VersionFile.cpp
@@ -8,10 +8,13 @@
 #include "logic/minecraft/OneSixLibrary.h"
 #include "logic/minecraft/VersionFinal.h"
 #include "logic/minecraft/JarMod.h"
+#include "ParseUtils.h"
 
 #include "logic/MMCJson.h"
 using namespace MMCJson;
 
+#include "VersionBuildError.h"
+
 #define CURRENT_MINIMUM_LAUNCHER_VERSION 14
 
 int findLibrary(QList<OneSixLibraryPtr> haystack, const QString &needle)
@@ -23,7 +26,7 @@ int findLibrary(QList<OneSixLibraryPtr> haystack, const QString &needle)
 		if (QRegExp(needle, Qt::CaseSensitive, QRegExp::WildcardUnix).indexIn(chunk) != -1)
 		{
 			// only one is allowed.
-			if(retval != -1)
+			if (retval != -1)
 				return -1;
 			retval = i;
 		}
@@ -32,7 +35,7 @@ int findLibrary(QList<OneSixLibraryPtr> haystack, const QString &needle)
 }
 
 VersionFilePtr VersionFile::fromJson(const QJsonDocument &doc, const QString &filename,
-								  const bool requireOrder, const bool isFTB)
+									 const bool requireOrder, const bool isFTB)
 {
 	VersionFilePtr out(new VersionFile());
 	if (doc.isEmpty() || doc.isNull())
@@ -41,7 +44,6 @@ VersionFilePtr VersionFile::fromJson(const QJsonDocument &doc, const QString &fi
 	}
 	if (!doc.isObject())
 	{
-		throw JSONValidationError("The root of " + filename + " is not an object");
 	}
 
 	QJsonObject root = doc.object();
@@ -65,7 +67,7 @@ VersionFilePtr VersionFile::fromJson(const QJsonDocument &doc, const QString &fi
 	out->mcVersion = root.value("mcVersion").toString();
 	out->filename = filename;
 
-	auto readString = [root, filename](const QString & key, QString & variable)
+	auto readString = [root](const QString & key, QString & variable)
 	{
 		if (root.contains(key))
 		{
@@ -73,6 +75,16 @@ VersionFilePtr VersionFile::fromJson(const QJsonDocument &doc, const QString &fi
 		}
 	};
 
+	auto readStringRet = [root](const QString & key)->QString
+	{
+		if (root.contains(key))
+		{
+			return ensureString(root.value(key));
+		}
+		return QString();
+	}
+	;
+
 	// FIXME: This should be ignored when applying.
 	if (!isFTB)
 	{
@@ -86,8 +98,14 @@ VersionFilePtr VersionFile::fromJson(const QJsonDocument &doc, const QString &fi
 	readString("+minecraftArguments", out->addMinecraftArguments);
 	readString("-minecraftArguments", out->removeMinecraftArguments);
 	readString("type", out->type);
-	readString("releaseTime", out->versionReleaseTime);
-	readString("time", out->versionFileUpdateTime);
+	if (out->isVanilla())
+	{
+		parse_timestamp(readStringRet("releaseTime"), out->m_releaseTimeString,
+						out->m_releaseTime);
+		parse_timestamp(readStringRet("time"), out->m_updateTimeString, out->m_updateTime);
+	}
+
+	readStringRet("time");
 	readString("assets", out->assets);
 
 	if (root.contains("minimumLauncherVersion"))
@@ -284,7 +302,8 @@ void VersionFile::applyTo(VersionFinal *version)
 	{
 		if (minimumLauncherVersion > CURRENT_MINIMUM_LAUNCHER_VERSION)
 		{
-			throw LauncherVersionError(minimumLauncherVersion, CURRENT_MINIMUM_LAUNCHER_VERSION);
+			throw LauncherVersionError(minimumLauncherVersion,
+									   CURRENT_MINIMUM_LAUNCHER_VERSION);
 		}
 	}
 
@@ -311,23 +330,28 @@ void VersionFile::applyTo(VersionFinal *version)
 	}
 	if (!processArguments.isNull())
 	{
-		if(isVanilla())
+		if (isVanilla())
 		{
 			version->vanillaProcessArguments = processArguments;
 		}
 		version->processArguments = processArguments;
 	}
-	if (!type.isNull())
+	if(isVanilla())
 	{
-		version->type = type;
-	}
-	if (!versionReleaseTime.isNull())
-	{
-		version->versionReleaseTime = versionReleaseTime;
-	}
-	if (!versionFileUpdateTime.isNull())
-	{
-		version->time = versionFileUpdateTime;
+		if (!type.isNull())
+		{
+			version->type = type;
+		}
+		if (!m_releaseTimeString.isNull())
+		{
+			version->m_releaseTimeString = m_releaseTimeString;
+			version->m_releaseTime = m_releaseTime;
+		}
+		if (!m_updateTimeString.isNull())
+		{
+			version->m_updateTimeString = m_updateTimeString;
+			version->m_updateTime = m_updateTime;
+		}
 	}
 	if (!assets.isNull())
 	{
@@ -335,11 +359,12 @@ void VersionFile::applyTo(VersionFinal *version)
 	}
 	if (minimumLauncherVersion >= 0)
 	{
-		version->minimumLauncherVersion = minimumLauncherVersion;
+		if(version->minimumLauncherVersion < minimumLauncherVersion)
+			version->minimumLauncherVersion = minimumLauncherVersion;
 	}
 	if (!overwriteMinecraftArguments.isNull())
 	{
-		if(isVanilla())
+		if (isVanilla())
 		{
 			version->vanillaMinecraftArguments = overwriteMinecraftArguments;
 		}
@@ -374,7 +399,7 @@ void VersionFile::applyTo(VersionFinal *version)
 		{
 			libs.append(createLibrary(lib));
 		}
-		if(isVanilla())
+		if (isVanilla())
 			version->vanillaLibraries = libs;
 		version->libraries = libs;
 	}
@@ -498,7 +523,7 @@ void VersionFile::applyTo(VersionFinal *version)
 		case RawLibrary::Replace:
 		{
 			QString toReplace;
-			if(lib->insertData.isEmpty())
+			if (lib->insertData.isEmpty())
 			{
 				const int startOfVersion = lib->name.lastIndexOf(':') + 1;
 				toReplace = QString(lib->name).replace(startOfVersion, INT_MAX, '*');
diff --git a/logic/minecraft/VersionFile.h b/logic/minecraft/VersionFile.h
index 82b16913..9c632d6f 100644
--- a/logic/minecraft/VersionFile.h
+++ b/logic/minecraft/VersionFile.h
@@ -2,6 +2,7 @@
 
 #include <QString>
 #include <QStringList>
+#include <QDateTime>
 #include <memory>
 #include "logic/minecraft/OpSys.h"
 #include "logic/minecraft/OneSixRule.h"
@@ -11,46 +12,8 @@
 #include "JarMod.h"
 
 class VersionFinal;
-
-
-class VersionBuildError : public MMCError
-{
-public:
-	VersionBuildError(QString cause) : MMCError(cause) {};
-	virtual ~VersionBuildError() noexcept {}
-};
-
-/**
- * the base version file was meant for a newer version of the vanilla launcher than we support
- */
-class LauncherVersionError : public VersionBuildError
-{
-public:
-	LauncherVersionError(int actual, int supported)
-		: VersionBuildError(QObject::tr(
-			  "The base version file of this instance was meant for a newer (%1) "
-			  "version of the vanilla launcher than this version of MultiMC supports (%2).")
-								.arg(actual)
-								.arg(supported)) {};
-	virtual ~LauncherVersionError() noexcept {}
-};
-
-/**
- * some patch was intended for a different version of minecraft
- */
-class MinecraftVersionMismatch : public VersionBuildError
-{
-public:
-	MinecraftVersionMismatch(QString fileId, QString mcVersion, QString parentMcVersion)
-		: VersionBuildError(QObject::tr("The patch %1 is for a different version of Minecraft "
-										"(%2) than that of the instance (%3).")
-								.arg(fileId)
-								.arg(mcVersion)
-								.arg(parentMcVersion)) {};
-	virtual ~MinecraftVersionMismatch() noexcept {}
-};
-
 struct VersionFile;
+
 typedef std::shared_ptr<VersionFile> VersionFilePtr;
 class VersionFile : public VersionPatch
 {
@@ -62,7 +25,35 @@ public: /* methods */
 	virtual void applyTo(VersionFinal *version) override;
 	virtual bool isVanilla() override;
 	virtual bool hasJarMods() override;
-	
+	virtual int getOrder() override
+	{
+		return order;
+	}
+	virtual void setOrder(int order) override
+	{
+		this->order = order;
+	}
+	virtual QList<JarmodPtr> getJarMods() override
+	{
+		return jarMods;
+	}
+	virtual QString getPatchID() override
+	{
+		return fileId;
+	}
+	virtual QString getPatchName() override
+	{
+		return name;
+	}
+	virtual QString getPatchVersion() override
+	{
+		return version;
+	}
+	virtual QString getPatchFilename() override
+	{
+		return filename;
+	}
+
 public: /* data */
 	int order = 0;
 	QString name;
@@ -81,8 +72,16 @@ public: /* data */
 	QString removeMinecraftArguments;
 	QString processArguments;
 	QString type;
-	QString versionReleaseTime;
-	QString versionFileUpdateTime;
+
+	/// the time this version was actually released by Mojang, as string and as QDateTime
+	QString m_releaseTimeString;
+	QDateTime m_releaseTime;
+
+	/// the time this version was last updated by Mojang, as string and as QDateTime
+	QString m_updateTimeString;
+	QDateTime m_updateTime;
+
+	/// asset group used by this ... thing.
 	QString assets;
 	int minimumLauncherVersion = -1;
 
diff --git a/logic/minecraft/VersionFinal.cpp b/logic/minecraft/VersionFinal.cpp
index 07f58778..cc61da71 100644
--- a/logic/minecraft/VersionFinal.cpp
+++ b/logic/minecraft/VersionFinal.cpp
@@ -39,8 +39,10 @@ void VersionFinal::reload(const QStringList &external)
 void VersionFinal::clear()
 {
 	id.clear();
-	time.clear();
-	versionReleaseTime.clear();
+	m_updateTimeString.clear();
+	m_updateTime = QDateTime();
+	m_releaseTimeString.clear();
+	m_releaseTime = QDateTime();
 	type.clear();
 	assets.clear();
 	processArguments.clear();
@@ -56,17 +58,13 @@ void VersionFinal::clear()
 
 bool VersionFinal::canRemove(const int index) const
 {
-	if (index < versionFiles.size())
-	{
-		return versionFiles.at(index)->fileId != "org.multimc.version.json";
-	}
-	return false;
+	return VersionPatches.at(index)->isMoveable();
 }
 
-bool VersionFinal::preremove(VersionFilePtr versionfile)
+bool VersionFinal::preremove(VersionPatchPtr patch)
 {
 	bool ok = true;
-	for(auto & jarmod: versionfile->jarMods)
+	for(auto & jarmod: patch->getJarMods())
 	{
 		QString fullpath =PathCombine(m_instance->jarModsDir(), jarmod->name);
 		QFileInfo finfo (fullpath);
@@ -80,14 +78,14 @@ bool VersionFinal::remove(const int index)
 {
 	if (!canRemove(index))
 		return false;
-	if(!preremove(versionFiles[index]))
+	if(!preremove(VersionPatches[index]))
 	{
 		return false;
 	}
-	if(!QFile::remove(versionFiles.at(index)->filename))
+	if(!QFile::remove(VersionPatches.at(index)->getPatchFilename()))
 		return false;
 	beginResetModel();
-	versionFiles.removeAt(index);
+	VersionPatches.removeAt(index);
 	reapply(true);
 	endResetModel();
 	return true;
@@ -96,9 +94,9 @@ bool VersionFinal::remove(const int index)
 bool VersionFinal::remove(const QString id)
 {
 	int i = 0;
-	for (auto file : versionFiles)
+	for (auto patch : VersionPatches)
 	{
-		if (file->fileId == id)
+		if (patch->getPatchID() == id)
 		{
 			return remove(i);
 		}
@@ -109,18 +107,18 @@ bool VersionFinal::remove(const QString id)
 
 QString VersionFinal::versionFileId(const int index) const
 {
-	if (index < 0 || index >= versionFiles.size())
+	if (index < 0 || index >= VersionPatches.size())
 	{
 		return QString();
 	}
-	return versionFiles.at(index)->fileId;
+	return VersionPatches.at(index)->getPatchID();
 }
 
-VersionFilePtr VersionFinal::versionPatch(const QString &id)
+VersionPatchPtr VersionFinal::versionPatch(const QString &id)
 {
-	for (auto file : versionFiles)
+	for (auto file : VersionPatches)
 	{
-		if (file->fileId == id)
+		if (file->getPatchID() == id)
 		{
 			return file;
 		}
@@ -128,6 +126,14 @@ VersionFilePtr VersionFinal::versionPatch(const QString &id)
 	return 0;
 }
 
+VersionPatchPtr VersionFinal::versionPatch(int index)
+{
+	if(index < 0 || index >= VersionPatches.size())
+		return 0;
+	return VersionPatches[index];
+}
+
+
 bool VersionFinal::hasJarMods()
 {
 	return !jarMods.isEmpty();
@@ -146,7 +152,7 @@ bool VersionFinal::removeFtbPack()
 bool VersionFinal::isVanilla()
 {
 	QDir patches(PathCombine(m_instance->instanceRoot(), "patches/"));
-	if(versionFiles.size() > 1)
+	if(VersionPatches.size() > 1)
 		return false;
 	if(QFile::exists(PathCombine(m_instance->instanceRoot(), "custom.json")))
 		return false;
@@ -156,22 +162,22 @@ bool VersionFinal::isVanilla()
 bool VersionFinal::revertToVanilla()
 {
 	beginResetModel();
-	auto it = versionFiles.begin();
-	while (it != versionFiles.end())
+	auto it = VersionPatches.begin();
+	while (it != VersionPatches.end())
 	{
-		if ((*it)->fileId != "org.multimc.version.json")
+		if ((*it)->isMoveable())
 		{
 			if(!preremove(*it))
 			{
 				endResetModel();
 				return false;
 			}
-			if(!QFile::remove((*it)->filename))
+			if(!QFile::remove((*it)->getPatchFilename()))
 			{
 				endResetModel();
 				return false;
 			}
-			it = versionFiles.erase(it);
+			it = VersionPatches.erase(it);
 		}
 		else
 			it++;
@@ -233,7 +239,7 @@ QVariant VersionFinal::data(const QModelIndex &index, int role) const
 	int row = index.row();
 	int column = index.column();
 
-	if (row < 0 || row >= versionFiles.size())
+	if (row < 0 || row >= VersionPatches.size())
 		return QVariant();
 
 	if (role == Qt::DisplayRole)
@@ -241,9 +247,9 @@ QVariant VersionFinal::data(const QModelIndex &index, int role) const
 		switch (column)
 		{
 		case 0:
-			return versionFiles.at(row)->name;
+			return VersionPatches.at(row)->getPatchName();
 		case 1:
-			return versionFiles.at(row)->version;
+			return VersionPatches.at(row)->getPatchVersion();
 		default:
 			return QVariant();
 		}
@@ -278,7 +284,7 @@ Qt::ItemFlags VersionFinal::flags(const QModelIndex &index) const
 
 int VersionFinal::rowCount(const QModelIndex &parent) const
 {
-	return versionFiles.size();
+	return VersionPatches.size();
 }
 
 int VersionFinal::columnCount(const QModelIndex &parent) const
@@ -288,13 +294,12 @@ int VersionFinal::columnCount(const QModelIndex &parent) const
 
 QMap<QString, int> VersionFinal::getExistingOrder() const
 {
-
 	QMap<QString, int> order;
 	// default
 	{
-		for (auto file : versionFiles)
+		for (auto file : VersionPatches)
 		{
-			order.insert(file->fileId, file->order);
+			order.insert(file->getPatchID(), file->getOrder());
 		}
 	}
 	// overriden
@@ -314,39 +319,37 @@ QMap<QString, int> VersionFinal::getExistingOrder() const
 void VersionFinal::move(const int index, const MoveDirection direction)
 {
 	int theirIndex;
+	int theirIndex_qt;
 	if (direction == MoveUp)
 	{
-		theirIndex = index - 1;
+		theirIndex_qt = theirIndex = index - 1;
 	}
 	else
 	{
 		theirIndex = index + 1;
+		theirIndex_qt = index + 2;
 	}
-	if (theirIndex < 0 || theirIndex >= versionFiles.size())
-	{
-		return;
-	}
-	const QString ourId = versionFileId(index);
-	const QString theirId = versionFileId(theirIndex);
-	if (ourId.isNull() || ourId.startsWith("org.multimc.") ||
-			theirId.isNull() || theirId.startsWith("org.multimc."))
+	auto from = versionPatch(index);
+	auto to = versionPatch(theirIndex);
+	
+	if (!from || !to || !from->isMoveable() || !from->isMoveable())
 	{
 		return;
 	}
 	if(direction == MoveDown)
 	{
-		beginMoveRows(QModelIndex(), index, index, QModelIndex(), theirIndex+1);
+		beginMoveRows(QModelIndex(), index, index, QModelIndex(), theirIndex_qt);
 	}
 	else
 	{
-		beginMoveRows(QModelIndex(), index, index, QModelIndex(), theirIndex);
+		beginMoveRows(QModelIndex(), index, index, QModelIndex(), theirIndex_qt);
 	}
-	versionFiles.swap(index, theirIndex);
+	VersionPatches.swap(index, theirIndex);
 	endMoveRows();
 
 	auto order = getExistingOrder();
-	order[ourId] = theirIndex;
-	order[theirId] = index;
+	order[from->getPatchID()] = theirIndex;
+	order[to->getPatchID()] = index;
 
 	if (!VersionBuilder::writeOverrideOrders(order, m_instance))
 	{
@@ -375,14 +378,14 @@ void VersionFinal::reapply(const bool alreadyReseting)
 	auto existingOrders = getExistingOrder();
 	QList<int> orders = existingOrders.values();
 	std::sort(orders.begin(), orders.end());
-	QList<VersionFilePtr> newVersionFiles;
+	QList<VersionPatchPtr> newVersionFiles;
 	for (auto order : orders)
 	{
 		auto file = versionPatch(existingOrders.key(order));
 		newVersionFiles.append(file);
 		file->applyTo(this);
 	}
-	versionFiles.swap(newVersionFiles);
+	VersionPatches.swap(newVersionFiles);
 	finalize();
 	if (!alreadyReseting)
 	{
diff --git a/logic/minecraft/VersionFinal.h b/logic/minecraft/VersionFinal.h
index 7be981ed..83a88263 100644
--- a/logic/minecraft/VersionFinal.h
+++ b/logic/minecraft/VersionFinal.h
@@ -83,16 +83,21 @@ public:
 	static std::shared_ptr<VersionFinal> fromJson(const QJsonObject &obj);
 
 private:
-	bool preremove(VersionFilePtr);
+	bool preremove(VersionPatchPtr patch);
 	
 	// data members
 public:
 	/// the ID - determines which jar to use! ACTUALLY IMPORTANT!
 	QString id;
-	/// Last updated time - as a string
-	QString time;
-	/// Release time - as a string
-	QString versionReleaseTime;
+
+	/// the time this version was actually released by Mojang, as string and as QDateTime
+	QString m_releaseTimeString;
+	QDateTime m_releaseTime;
+
+	/// the time this version was last updated by Mojang, as string and as QDateTime
+	QString m_updateTimeString;
+	QDateTime m_updateTime;
+
 	/// Release type - "release" or "snapshot"
 	QString type;
 	/// Assets type - "legacy" or a version ID
@@ -164,8 +169,9 @@ public:
 	*/
 	// QList<Rule> rules;
 
-	QList<VersionFilePtr> versionFiles;
-	VersionFilePtr versionPatch(const QString &id);
+	QList<VersionPatchPtr> VersionPatches;
+	VersionPatchPtr versionPatch(const QString &id);
+	VersionPatchPtr versionPatch(int index);
 
 private:
 	OneSixInstance *m_instance;
diff --git a/logic/minecraft/VersionPatch.h b/logic/minecraft/VersionPatch.h
index c2258787..cdb80199 100644
--- a/logic/minecraft/VersionPatch.h
+++ b/logic/minecraft/VersionPatch.h
@@ -1,6 +1,8 @@
 #pragma once
 
 #include <memory>
+#include <QList>
+#include "JarMod.h"
 
 class VersionFinal;
 class VersionPatch
@@ -8,8 +10,22 @@ class VersionPatch
 public:
 	virtual ~VersionPatch(){};
 	virtual void applyTo(VersionFinal *version) = 0;
+	
 	virtual bool isVanilla() = 0;
 	virtual bool hasJarMods() = 0;
+	virtual QList<JarmodPtr> getJarMods() = 0;
+	
+	virtual bool isMoveable()
+	{
+		return getOrder() >= 0;
+	}
+	virtual void setOrder(int order) = 0;
+	virtual int getOrder() = 0;
+	
+	virtual QString getPatchID() = 0;
+	virtual QString getPatchName() = 0;
+	virtual QString getPatchVersion() = 0;
+	virtual QString getPatchFilename() = 0;
 };
 
 typedef std::shared_ptr<VersionPatch> VersionPatchPtr;