Working on legacy support, incomplete.

10 files changed, 1038 insertions, 0 deletions

diff --git a/backend/CMakeLists.txt b/backend/CMakeLists.txt
index 68d01f08..7a92d5cf 100644
--- a/backend/CMakeLists.txt
+++ b/backend/CMakeLists.txt
@@ -28,6 +28,8 @@ BaseUpdate.h
 BaseInstance.h
 BaseInstance_p.h
 MinecraftProcess.h
+Mod.h
+ModList.h
 
 # network stuffs
 net/DownloadJob.h
@@ -38,6 +40,7 @@ net/NetWorker.h
 LegacyInstance.h
 LegacyInstance_p.h
 LegacyUpdate.h
+LegacyForge.h
 
 # 1.6 instances
 OneSixAssets.h
@@ -68,6 +71,8 @@ InstanceFactory.cpp
 BaseUpdate.cpp
 BaseInstance.cpp
 MinecraftProcess.cpp
+Mod.cpp
+ModList.cpp
 
 # network stuffs
 net/NetWorker.cpp
@@ -76,6 +81,7 @@ net/DownloadJob.cpp
 # legacy instances
 LegacyInstance.cpp
 LegacyUpdate.cpp
+LegacyForge.cpp
 
 # 1.6 instances
 OneSixAssets.cpp
diff --git a/backend/LegacyForge.cpp b/backend/LegacyForge.cpp
new file mode 100644
index 00000000..adcf487c
--- /dev/null
+++ b/backend/LegacyForge.cpp
@@ -0,0 +1,57 @@
+// 
+//  Copyright 2012 MultiMC Contributors
+// 
+//    Licensed under the Apache License, Version 2.0 (the "License");
+//    you may not use this file except in compliance with the License.
+//    You may obtain a copy of the License at
+// 
+//        http://www.apache.org/licenses/LICENSE-2.0
+// 
+//    Unless required by applicable law or agreed to in writing, software
+//    distributed under the License is distributed on an "AS IS" BASIS,
+//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//    See the License for the specific language governing permissions and
+//    limitations under the License.
+//
+
+#include "LegacyForge.h"
+
+MinecraftForge::MinecraftForge ( const QString& file ) : Mod ( file )
+{
+
+}
+bool MinecraftForge::FixVersionIfNeeded ( QString newVersion )
+{/*
+	wxString reportedVersion = GetModVersion();
+	if(reportedVersion == "..." || reportedVersion.empty())
+	{
+		std::auto_ptr<wxFFileInputStream> in(new wxFFileInputStream("forge.zip"));
+		wxTempFileOutputStream out("forge.zip");
+		wxTextOutputStream textout(out);
+		wxZipInputStream inzip(*in);
+		wxZipOutputStream outzip(out);
+		std::auto_ptr<wxZipEntry> entry;
+		// preserve metadata
+		outzip.CopyArchiveMetaData(inzip);
+		// copy all entries
+		while (entry.reset(inzip.GetNextEntry()), entry.get() != NULL)
+			if (!outzip.CopyEntry(entry.release(), inzip))
+				return false;
+		// release last entry
+		in.reset();
+		outzip.PutNextEntry("forgeversion.properties");
+		
+		wxStringTokenizer tokenizer(newVersion,".");
+		wxString verFile;
+		verFile << wxString("forge.major.number=") << tokenizer.GetNextToken() << "\n";
+		verFile << wxString("forge.minor.number=") << tokenizer.GetNextToken() << "\n";
+		verFile << wxString("forge.revision.number=") << tokenizer.GetNextToken() << "\n";
+		verFile << wxString("forge.build.number=") << tokenizer.GetNextToken() << "\n";
+		auto buf = verFile.ToUTF8();
+		outzip.Write(buf.data(), buf.length());
+		// check if we succeeded
+		return inzip.Eof() && outzip.Close() && out.Commit();
+	}
+	*/
+	return true;
+}
diff --git a/backend/LegacyForge.h b/backend/LegacyForge.h
new file mode 100644
index 00000000..00a054b8
--- /dev/null
+++ b/backend/LegacyForge.h
@@ -0,0 +1,25 @@
+// 
+//  Copyright 2012 MultiMC Contributors
+// 
+//    Licensed under the Apache License, Version 2.0 (the "License");
+//    you may not use this file except in compliance with the License.
+//    You may obtain a copy of the License at
+// 
+//        http://www.apache.org/licenses/LICENSE-2.0
+// 
+//    Unless required by applicable law or agreed to in writing, software
+//    distributed under the License is distributed on an "AS IS" BASIS,
+//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//    See the License for the specific language governing permissions and
+//    limitations under the License.
+//
+
+#pragma once
+#include "Mod.h"
+
+class MinecraftForge : public Mod
+{
+public:
+	MinecraftForge ( const QString& file );
+	bool FixVersionIfNeeded(QString newVersion);
+};
diff --git a/backend/LegacyUpdate.cpp b/backend/LegacyUpdate.cpp
index 8580a2f2..a748bad3 100644
--- a/backend/LegacyUpdate.cpp
+++ b/backend/LegacyUpdate.cpp
@@ -212,6 +212,13 @@ void LegacyUpdate::jarStart()
 		return;
 	}
 	
+	// nuke the backup file, we are replacing the base jar anyway
+	QFile mc_backup(inst->mcBackup());
+	if (mc_backup.exists())
+	{
+		mc_backup.remove();
+	}
+	
 	// Get a pointer to the version object that corresponds to the instance's version.
 	auto targetVersion = MinecraftVersionList::getMainList().findVersion(intended_version_id);
 	
@@ -260,3 +267,115 @@ void LegacyUpdate::jarFailed()
 	// bad, bad
 	emitFailed("Failed to download the minecraft jar. Try again later.");
 }
+
+void LegacyUpdate::ModTheJar()
+{
+	/*
+	LegacyInstance * inst = (LegacyInstance *) m_inst;
+	// Get the mod list
+	auto modList = inst->getJarModList();
+	
+	QFileInfo mcBin(inst->binDir());
+	QFileInfo mcJar(inst->mcJar());
+	QFileInfo mcBackup(inst->mcBackup());
+	
+	// Nothing to do if there are no jar mods to install, no backup and just the mc jar
+	if(mcJar.isFile() && !mcBackup.exists() && modList->empty())
+	{
+		inst->setShouldRebuild(false);
+		emitSucceeded();
+		return;
+	}
+	
+	setStatus("Installing mods - backing up minecraft.jar...");
+	if (!mcBackup.exists() && !QFile::copy(mcJar.absoluteFilePath(), mcBackup.absoluteFilePath()) )
+	{
+		emitFailed("Failed to back up minecraft.jar");
+		return;
+	}
+	
+	if (mcJar.isFile() && !QFile::remove(mcJar.absoluteFilePath()))
+	{
+		emitFailed("Failed to delete old minecraft.jar");
+		return;
+	}
+	
+	setStatus("Installing mods - Opening minecraft.jar");
+
+	wxFFileOutputStream jarStream(mcJar.absoluteFilePath());
+	wxZipOutputStream zipOut(jarStream);
+
+	// Files already added to the jar.
+	// These files will be skipped.
+	QSet<QString> addedFiles;
+
+	// Modify the jar
+	setStatus("Installing mods - Adding mod files...");
+	for (ModList::const_reverse_iterator iter = modList->rbegin(); iter != modList->rend(); iter++)
+	{
+		wxFileName modFileName = iter->GetFileName();
+		setStatus("Installing mods - Adding " + modFileName.GetFullName());
+		if (iter->GetModType() == Mod::ModType::MOD_ZIPFILE)
+		{
+			wxFFileInputStream modStream(modFileName.GetFullPath());
+			wxZipInputStream zipStream(modStream);
+			std::unique_ptr<wxZipEntry> entry;
+			while (entry.reset(zipStream.GetNextEntry()), entry.get() != NULL)
+			{
+				if (entry->IsDir())
+					continue;
+
+				wxString name = entry->GetName();
+				if (addedFiles.count(name) == 0)
+				{
+					if (!zipOut.CopyEntry(entry.release(), zipStream))
+						break;
+					addedFiles.insert(name);
+				}
+			}
+		}
+		else
+		{
+			wxFileName destFileName = modFileName;
+			destFileName.MakeRelativeTo(m_inst->GetInstModsDir().GetFullPath());
+			wxString destFile = destFileName.GetFullPath();
+
+			if (addedFiles.count(destFile) == 0)
+			{
+				wxFFileInputStream input(modFileName.GetFullPath());
+				zipOut.PutNextEntry(destFile);
+				zipOut.Write(input);
+
+				addedFiles.insert(destFile);
+			}
+		}
+	}
+
+	{
+		wxFFileInputStream inStream(mcBackup.GetFullPath());
+		wxZipInputStream zipIn(inStream);
+
+		std::auto_ptr<wxZipEntry> entry;
+		while (entry.reset(zipIn.GetNextEntry()), entry.get() != NULL)
+		{
+			wxString name = entry->GetName();
+
+			if (!name.Matches("META-INF*") &&
+				addedFiles.count(name) == 0)
+			{
+				if (!zipOut.CopyEntry(entry.release(), zipIn))
+					break;
+				addedFiles.insert(name);
+			}
+		}
+	}
+	
+	// Recompress the jar
+	TaskStep(); // STEP 3
+	SetStatus(_("Installing mods - Recompressing jar..."));
+
+	inst->SetNeedsRebuild(false);
+	inst->UpdateVersion(true);
+	return (ExitCode)1;
+	*/
+}
\ No newline at end of file
diff --git a/backend/LegacyUpdate.h b/backend/LegacyUpdate.h
index ad58fc85..a48189a6 100644
--- a/backend/LegacyUpdate.h
+++ b/backend/LegacyUpdate.h
@@ -44,6 +44,8 @@ private slots:
 	void jarFailed();
 	
 	void extractLwjgl();
+	
+	void ModTheJar();
 private:
 	
 	QSharedPointer<QNetworkReply> m_reply;
diff --git a/backend/Mod.cpp b/backend/Mod.cpp
new file mode 100644
index 00000000..652bbda7
--- /dev/null
+++ b/backend/Mod.cpp
@@ -0,0 +1,264 @@
+// 
+//  Copyright 2012 MultiMC Contributors
+// 
+//    Licensed under the Apache License, Version 2.0 (the "License");
+//    you may not use this file except in compliance with the License.
+//    You may obtain a copy of the License at
+// 
+//        http://www.apache.org/licenses/LICENSE-2.0
+// 
+//    Unless required by applicable law or agreed to in writing, software
+//    distributed under the License is distributed on an "AS IS" BASIS,
+//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//    See the License for the specific language governing permissions and
+//    limitations under the License.
+//
+
+#include "Mod.h"
+#include <pathutils.h>
+#include <QDir>
+
+Mod::Mod( const QFileInfo& file )
+{
+	repath(file);
+}
+
+void Mod::repath ( const QFileInfo& file )
+{
+	m_file = file;
+	m_name = file.baseName();
+	m_id = file.fileName();
+	
+	m_type = Mod::MOD_UNKNOWN;
+	if (m_file.isDir())
+		m_type = MOD_FOLDER;
+	else if (m_file.isFile())
+	{
+		QString ext = m_file.suffix().toLower();
+		if (ext == "zip" || ext == "jar")
+			m_type = MOD_ZIPFILE;
+		else
+			m_type = MOD_SINGLEFILE;
+	}
+
+	/*
+	switch (modType)
+	{
+	case MOD_ZIPFILE:
+		{
+			wxFFileInputStream fileIn(modFile.GetFullPath());
+			wxZipInputStream zipIn(fileIn);
+
+			std::auto_ptr<wxZipEntry> entry;
+
+			bool is_forge = false;
+			while(true)
+			{
+				entry.reset(zipIn.GetNextEntry());
+				if (entry.get() == nullptr)
+					break;
+				if(entry->GetInternalName().EndsWith("mcmod.info"))
+					break;
+				if(entry->GetInternalName().EndsWith("forgeversion.properties"))
+				{
+					is_forge = true;
+					break;
+				}
+			}
+
+			if (entry.get() != nullptr)
+			{
+				// Read the info file into text
+				wxString infoFileData;
+				wxStringOutputStream stringOut(&infoFileData);
+				zipIn.Read(stringOut);
+				if(!is_forge)
+					ReadModInfoData(infoFileData);
+				else
+					ReadForgeInfoData(infoFileData);
+			}
+		}
+		break;
+
+	case MOD_FOLDER:
+		{
+			wxString infoFile = Path::Combine(modFile, "mcmod.info");
+			if (!wxFileExists(infoFile))
+			{
+				infoFile = wxEmptyString;
+
+				wxDir modDir(modFile.GetFullPath());
+
+				if (!modDir.IsOpened())
+				{
+					wxLogError(_("Can't fine mod info file. Failed to open mod folder."));
+					break;
+				}
+
+				wxString currentFile;
+				if (modDir.GetFirst(&currentFile))
+				{
+					do 
+					{
+						if (currentFile.EndsWith("mcmod.info"))
+						{
+							infoFile = Path::Combine(modFile.GetFullPath(), currentFile);
+							break;
+						}
+					} while (modDir.GetNext(&currentFile));
+				}
+			}
+
+			if (infoFile != wxEmptyString && wxFileExists(infoFile))
+			{
+				wxString infoStr;
+				wxFFileInputStream fileIn(infoFile);
+				wxStringOutputStream strOut(&infoStr);
+				fileIn.Read(strOut);
+				ReadModInfoData(infoStr);
+			}
+		}
+		break;
+	}
+*/
+}
+
+
+/*
+void ReadModInfoData(QString info)
+{
+	using namespace boost::property_tree;
+
+	// Read the data
+	ptree ptRoot;
+
+	std::stringstream stringIn(cStr(info));
+	try
+	{
+		read_json(stringIn, ptRoot);
+
+		ptree pt = ptRoot.get_child(ptRoot.count("modlist") == 1 ? "modlist" : "").begin()->second;
+
+		modID = wxStr(pt.get<std::string>("modid"));
+		modName = wxStr(pt.get<std::string>("name"));
+		modVersion = wxStr(pt.get<std::string>("version"));
+	}
+	catch (json_parser_error e)
+	{
+		// Silently fail...
+	}
+	catch (ptree_error e)
+	{
+		// Silently fail...
+	}
+}
+*/
+
+// FIXME: abstraction violated.
+/*
+void Mod::ReadForgeInfoData(QString infoFileData)
+{
+		using namespace boost::property_tree;
+
+	// Read the data
+	ptree ptRoot;
+	modName = "Minecraft Forge";
+	modID = "Forge";
+	std::stringstream stringIn(cStr(infoFileData));
+	try
+	{
+		read_ini(stringIn, ptRoot);
+		wxString major, minor, revision, build;
+		// BUG: boost property tree is bad. won't let us get a key with dots in it
+		// Likely cause = treating the dots as path separators.
+		for (auto iter = ptRoot.begin(); iter != ptRoot.end(); iter++)
+		{
+			auto &item = *iter;
+			std::string key = item.first;
+			std::string value = item.second.get_value<std::string>();
+			if(key == "forge.major.number")
+				major = value;
+			if(key == "forge.minor.number")
+				minor = value;
+			if(key == "forge.revision.number")
+				revision = value;
+			if(key == "forge.build.number")
+				build = value;
+		}
+		modVersion.Empty();
+		modVersion << major << "." << minor << "." << revision << "." << build;
+	}
+	catch (json_parser_error e)
+	{
+		std::cerr << e.what();
+	}
+	catch (ptree_error e)
+	{
+		std::cerr << e.what();
+	}
+}
+*/
+
+bool Mod::replace ( Mod& with )
+{
+	if(!destroy())
+		return false;
+	bool success = false;
+	auto t = with.type();
+	if(t == MOD_ZIPFILE || t == MOD_SINGLEFILE)
+	{
+		success = QFile::copy(with.m_file.filePath(), m_file.path());
+	}
+	if(t == MOD_FOLDER)
+	{
+		success = copyPath(with.m_file.filePath(), m_file.path());
+	}
+	if(success)
+	{
+		m_id = with.m_id;
+		m_mcversion = with.m_mcversion;
+		m_type = with.m_type;
+		m_name = with.m_name;
+		m_version = with.m_version;
+	}
+	return success;
+}
+
+bool Mod::destroy()
+{
+	if(m_type == MOD_FOLDER)
+	{
+		QDir d(m_file.filePath());
+		if(d.removeRecursively())
+		{
+			m_type = MOD_UNKNOWN;
+			return true;
+		}
+		return false;
+	}
+	else if (m_type == MOD_SINGLEFILE || m_type == MOD_ZIPFILE)
+	{
+		QFile f(m_file.filePath());
+		if(f.remove())
+		{
+			m_type = MOD_UNKNOWN;
+			return true;
+		}
+		return false;
+	}
+	return true;
+}
+
+
+QString Mod::version() const
+{
+	switch(type())
+	{
+		case MOD_ZIPFILE:
+			return m_version;
+		case MOD_FOLDER:
+			return "Folder";
+		case MOD_SINGLEFILE:
+			return "File";
+	}
+}
diff --git a/backend/Mod.h b/backend/Mod.h
new file mode 100644
index 00000000..d9d90426
--- /dev/null
+++ b/backend/Mod.h
@@ -0,0 +1,69 @@
+// 
+//  Copyright 2012 MultiMC Contributors
+// 
+//    Licensed under the Apache License, Version 2.0 (the "License");
+//    you may not use this file except in compliance with the License.
+//    You may obtain a copy of the License at
+// 
+//        http://www.apache.org/licenses/LICENSE-2.0
+// 
+//    Unless required by applicable law or agreed to in writing, software
+//    distributed under the License is distributed on an "AS IS" BASIS,
+//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//    See the License for the specific language governing permissions and
+//    limitations under the License.
+//
+
+#pragma once
+#include <QFileInfo>
+
+class Mod
+{
+public:
+	enum ModType
+	{
+		MOD_UNKNOWN, //!< Indicates an unspecified mod type.
+		MOD_ZIPFILE, //!< The mod is a zip file containing the mod's class files.
+		MOD_SINGLEFILE, //!< The mod is a single file (not a zip file).
+		MOD_FOLDER, //!< The mod is in a folder on the filesystem.
+	};
+
+	Mod(const QFileInfo &file);
+	
+	QFileInfo filename() const { return m_file; }
+	QString id() const { return m_id; }
+	ModType type() const { return m_type; }
+	QString mcversion() const;
+	bool valid() {return m_type != MOD_UNKNOWN;}
+	
+	QString version() const;
+	
+	// delete all the files of this mod
+	bool destroy();
+	// replace this mod with a copy of the other
+	bool replace(Mod & with);
+	// change the mod's filesystem path (used by mod lists for *MAGIC* purposes)
+	void repath(const QFileInfo &file);
+
+	
+	bool operator ==(const Mod &other) const
+	{
+		return filename() == other.filename();
+	}
+
+protected:
+
+	//FIXME: what do do with those? HMM...
+	/*
+	void ReadModInfoData(QString info);
+	void ReadForgeInfoData(QString infoFileData);
+	*/
+
+	QFileInfo m_file;
+	QString m_id;
+	QString m_name;
+	QString m_version;
+	QString m_mcversion;
+
+	ModType m_type;
+};
diff --git a/backend/ModList.cpp b/backend/ModList.cpp
new file mode 100644
index 00000000..851eb940
--- /dev/null
+++ b/backend/ModList.cpp
@@ -0,0 +1,418 @@
+// 
+//  Copyright 2012 MultiMC Contributors
+// 
+//    Licensed under the Apache License, Version 2.0 (the "License");
+//    you may not use this file except in compliance with the License.
+//    You may obtain a copy of the License at
+// 
+//        http://www.apache.org/licenses/LICENSE-2.0
+// 
+//    Unless required by applicable law or agreed to in writing, software
+//    distributed under the License is distributed on an "AS IS" BASIS,
+//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//    See the License for the specific language governing permissions and
+//    limitations under the License.
+//
+
+#include "ModList.h"
+#include "LegacyInstance.h"
+#include <pathutils.h>
+
+ModList::ModList ( const QString& dir ) : QObject(), m_dir(dir)
+{
+	m_dir.setFilter(QDir::Readable | QDir::NoDotAndDotDot | QDir::Files | QDir::Dirs | QDir::NoSymLinks);
+	m_dir.setSorting(QDir::Name);
+	update();
+}
+
+bool ModList::update()
+{
+	if (!isValid())
+		return false;
+
+	bool initial = mods.empty();
+
+	bool listChanged = false;
+
+	auto list = m_dir.entryInfoList();
+	for(auto entry: list)
+	{
+		Mod mod(entry);
+		if (initial || !mods.contains(mod))
+		{
+			mods.push_back(mod);
+			listChanged = true;
+		}
+	}
+	return listChanged;
+}
+
+bool ModList::isValid()
+{
+	return m_dir.exists() && m_dir.isReadable();
+}
+
+bool ModList::installMod ( const QFileInfo& filename, size_t index )
+{
+	if(!filename.exists() || !filename.isReadable())
+	{
+		return false;
+	}
+	Mod m(filename);
+	if(!m.valid())
+		return false;
+	
+	// if it's already there, replace the original mod (in place)
+	int idx = mods.indexOf(m);
+	if(idx != -1)
+	{
+		if(mods[idx].replace(m))
+		{
+			emit changed();
+			return true;
+		}
+		return false;
+	}
+	
+	auto type = m.type();
+	if(type == Mod::MOD_UNKNOWN)
+		return false;
+	if(type == Mod::MOD_SINGLEFILE || type == Mod::MOD_ZIPFILE)
+	{
+		QString newpath = PathCombine(m_dir.path(), filename.fileName());
+		if(!QFile::copy(filename.filePath(), newpath))
+			return false;
+		m.repath(newpath);
+		mods.append(m);
+		emit changed();
+		return true;
+	}
+	else if(type == Mod::MOD_FOLDER)
+	{
+		QString newpath = PathCombine(m_dir.path(), filename.fileName());
+		if(!copyPath(filename.filePath(), newpath))
+			return false;
+		m.repath(newpath);
+		mods.append(m);
+		emit changed();
+		return true;
+	}
+	return false;
+}
+
+bool ModList::deleteMod ( size_t index )
+{
+	if(index >= mods.size())
+		return false;
+	Mod & m = mods[index];
+	if(m.destroy())
+	{
+		mods.erase(mods.begin() + index);
+		emit changed();
+		return true;
+	}
+	return false;
+}
+
+
+/*
+ModList::ModList(const QString &dir)
+	: modsFolder(dir)
+{
+	
+}
+
+bool ModList::update(bool quickLoad)
+{
+	bool listChanged = false;
+
+	// Check for mods in the list whose files do not exist and remove them from the list.
+	// If doing a quickLoad, erase the whole list.
+	for (size_t i = 0; i < size(); i++)
+	{
+		if (quickLoad || !at(i).GetFileName().FileExists())
+		{
+			erase(begin() + i);
+			i--;
+			listChanged = true;
+		}
+	}
+
+	// Add any mods in the mods folder that aren't already in the list.
+	if (LoadModListFromDir(QString(), quickLoad))
+		listChanged = true;
+
+	return listChanged;
+}
+
+bool ModList::LoadModListFromDir(const QString& loadFrom, bool quickLoad)
+{
+	QString dir(loadFrom.isEmpty() ? modsFolder : loadFrom);
+
+	QDir modDir(dir);
+	if (!modDir.exists())
+		return false;
+
+	bool listChanged = false;
+
+	auto list = modDir.entryInfoList(QDir::Readable|QDir::NoDotAndDotDot, QDir::Name);
+	for(auto currentFile: list)
+	{
+		if (currentFile.isFile())
+		{
+			if (quickLoad || FindByFilename(currentFile.absoluteFilePath()) == nullptr)
+			{
+				Mod mod(currentFile.absoluteFilePath());
+				push_back(mod);
+				listChanged = true;
+			}
+		}
+		else if (currentFile.isDir())
+		{
+			if (LoadModListFromDir(currentFile.absoluteFilePath()))
+				listChanged = true;
+		}
+	}
+
+	return listChanged;
+}
+
+Mod *ModList::FindByFilename(const QString& filename)
+{
+	// Search the list for a mod with the given filename.
+	for (auto iter = begin(); iter != end(); ++iter)
+	{
+		if (iter->GetFileName() == QFileInfo(filename))
+			return &(*iter);
+	}
+
+	// If nothing is found, return nullptr.
+	return nullptr;
+}
+
+int ModList::FindIndexByFilename(const QString& filename)
+{
+	// Search the list for a mod with the given filename.
+	int i = 0;
+	for (auto iter = begin(); iter != end(); ++iter, i++)
+	{
+		if (iter->GetFileName() == QFileInfo(filename))
+			return i;
+	}
+
+	// If nothing is found, return nullptr.
+	return -1;
+}
+
+Mod* ModList::FindByID(const QString& modID, const QString& modVersion)
+{
+	// Search the list for a mod that matches
+	for (auto iter = begin(); iter != end(); ++iter)
+	{
+		QString ID = iter->GetModID();
+		QString version = iter->GetModVersion();
+		if ( ID == modID && version == modVersion)
+			return &(*iter);
+	}
+
+	// If nothing is found, return nullptr.
+	return nullptr;
+}
+
+void ModList::LoadFromFile(const QString& file)
+{
+	if (!wxFileExists(file))
+		return;
+
+	wxFFileInputStream inputStream(file);
+	wxArrayString modListFile = ReadAllLines(inputStream);
+
+	for (wxArrayString::iterator iter = modListFile.begin(); iter != modListFile.end(); iter++)
+	{
+		// Normalize the path to the instMods dir.
+		wxFileName modFile(*iter);
+		modFile.Normalize(wxPATH_NORM_ALL, modsFolder);
+		modFile.MakeRelativeTo();
+		// if the file is gone, do not load it
+		if(!modFile.Exists())
+		{
+			continue;
+		}
+
+		if (FindByFilename(modFile.GetFullPath()) == nullptr)
+		{
+			push_back(Mod(modFile));
+		}
+	}
+}
+
+void ModList::SaveToFile(const QString& file)
+{
+	QString text;
+	for (iterator iter = begin(); iter != end(); ++iter)
+	{
+		wxFileName modFile = iter->GetFileName();
+		modFile.MakeRelativeTo(modsFolder);
+		text.append(modFile.GetFullPath());
+		text.append("\n");
+	}
+
+	wxTempFileOutputStream out(file);
+	WriteAllText(out, text);
+	out.Commit();
+}
+
+bool ModList::InsertMod(size_t index, const QString &filename, const QString& saveToFile)
+{
+	QFileInfo source(filename);
+	QFileInfo dest(PathCombine(modsFolder, source.fileName()));
+
+	if (source != dest)
+	{
+		QFile::copy(source.absoluteFilePath(), dest.absoluteFilePath());
+	}
+
+	int oldIndex = FindIndexByFilename(dest.absoluteFilePath());
+
+	if (oldIndex != -1)
+	{
+		erase(begin() + oldIndex);
+	}
+
+	if (index >= size())
+		push_back(Mod(dest));
+	else
+		insert(begin() + index, Mod(dest));
+
+	if (!saveToFile.isEmpty())
+		SaveToFile(saveToFile);
+
+	return true;
+}
+
+bool ModList::DeleteMod(size_t index, const QString& saveToFile)
+{
+	Mod *mod = &at(index);
+	if(mod->GetModType() == Mod::MOD_FOLDER)
+	{
+		QDir dir(mod->GetFileName().absoluteFilePath());
+		if(dir.removeRecursively())
+		{
+			erase(begin() + index);
+			
+			if (!saveToFile.isEmpty())
+				SaveToFile(saveToFile);
+			
+			return true;
+		}
+		else
+		{
+			// wxLogError(_("Failed to delete mod."));
+		}
+	}
+	else if (QFile(mod->GetFileName().absoluteFilePath()).remove())
+	{
+		erase(begin() + index);
+		
+		if (!saveToFile.isEmpty())
+			SaveToFile(saveToFile);
+
+		return true;
+	}
+	else
+	{
+		// wxLogError(_("Failed to delete mod."));
+	}
+	return false;
+}
+
+bool JarModList::InsertMod(size_t index, const QString &filename, const QString& saveToFile)
+{
+	QString saveFile = saveToFile;
+	if (saveToFile.isEmpty())
+		saveFile = m_inst->GetModListFile().GetFullPath();
+
+	if (ModList::InsertMod(index, filename, saveFile))
+	{
+		m_inst->setLWJGLVersion(true);
+		return true;
+	}
+	return false;
+}
+
+bool JarModList::DeleteMod(size_t index, const QString& saveToFile)
+{
+	QString saveFile = saveToFile;
+	if (saveToFile.IsEmpty())
+		saveFile = m_inst->GetModListFile().GetFullPath();
+
+	if (ModList::DeleteMod(index, saveFile))
+	{
+		m_inst->SetNeedsRebuild();
+		return true;
+	}
+	return false;
+}
+
+bool JarModList::UpdateModList(bool quickLoad)
+{
+	if (ModList::UpdateModList(quickLoad))
+	{
+		m_inst->SetNeedsRebuild();
+		return true;
+	}
+	return false;
+}
+
+bool FolderModList::LoadModListFromDir(const QString& loadFrom, bool quickLoad)
+{
+	QString dir(loadFrom.IsEmpty() ? modsFolder : loadFrom);
+
+	if (!wxDirExists(dir))
+		return false;
+
+	bool listChanged = false;
+	wxDir modDir(dir);
+
+	if (!modDir.IsOpened())
+	{
+		wxLogError(_("Failed to open directory: ") + dir);
+		return false;
+	}
+
+	QString currentFile;
+	if (modDir.GetFirst(&currentFile))
+	{
+		do
+		{
+			wxFileName modFile(Path::Combine(dir, currentFile));
+
+			if (wxFileExists(modFile.GetFullPath()) || wxDirExists(modFile.GetFullPath()))
+			{
+				if (quickLoad || FindByFilename(modFile.GetFullPath()) == nullptr)
+				{
+					Mod mod(modFile.GetFullPath());
+					push_back(mod);
+					listChanged = true;
+				}
+			}
+		} while (modDir.GetNext(&currentFile));
+	}
+
+	return listChanged;
+}
+
+bool ModNameSort (const Mod & i,const Mod & j)
+{
+	if(i.GetModType() == j.GetModType())
+		return (i.GetName().toLower() < j.GetName().toLower());
+	return (i.GetModType() < j.GetModType());
+}
+
+bool FolderModList::UpdateModList ( bool quickLoad )
+{
+	bool changed = ModList::UpdateModList(quickLoad);
+	std::sort(begin(),end(),ModNameSort);
+	return changed;
+}
+*/
diff --git a/backend/ModList.h b/backend/ModList.h
new file mode 100644
index 00000000..bf65a080
--- /dev/null
+++ b/backend/ModList.h
@@ -0,0 +1,75 @@
+// 
+//  Copyright 2012 MultiMC Contributors
+// 
+//    Licensed under the Apache License, Version 2.0 (the "License");
+//    you may not use this file except in compliance with the License.
+//    You may obtain a copy of the License at
+// 
+//        http://www.apache.org/licenses/LICENSE-2.0
+// 
+#pragma once
+
+class LegacyInstance;
+class BaseInstance;
+#include <QList>
+#include <QString>
+#include <QDir>
+
+#include "Mod.h"
+
+/**
+ * A basic mod list.
+ * Backed by a folder.
+ */
+class ModList : public QObject
+{
+	Q_OBJECT
+public:
+	ModList(const QString& dir = QString());
+
+	size_t size() { return mods.size(); };
+	Mod& operator[](size_t index) { return mods[index]; };
+	
+	/// Reloads the mod list and returns true if the list changed.
+	virtual bool update();
+
+	/// Adds the given mod to the list at the given index.
+	virtual bool installMod(const QFileInfo& filename, size_t index = 0);
+
+	/// Deletes the mod at the given index.
+	virtual bool deleteMod(size_t index);
+	
+	/**
+	 * move the mod at index to the position N
+	 * 0 is the beginning of the list, length() is the end of the list.
+	 */
+	virtual bool moveMod(size_t from, size_t to) { return false; };
+	
+	virtual bool isValid();
+	
+signals:
+	virtual void changed();
+protected:
+	QDir m_dir;
+	QList<Mod> mods;
+};
+
+/**
+ * A jar mod list.
+ * Backed by a folder and a file which specifies the load order.
+ */
+class JarModList : public ModList
+{
+	Q_OBJECT
+public:
+	JarModList(const QString& dir, const QString& list_file, LegacyInstance * inst)
+		: ModList(dir), m_listfile(list_file), m_inst(inst) {}
+
+	virtual bool update();
+	virtual bool installMod(const QString &filename, size_t index);
+	virtual bool deleteMod(size_t index);
+	virtual bool moveMod(size_t from, size_t to);
+protected:
+	QString m_listfile;
+	LegacyInstance * m_inst;
+};
diff --git a/backend/OneSixUpdate.cpp b/backend/OneSixUpdate.cpp
index 5cd2c78c..2bb2f496 100644
--- a/backend/OneSixUpdate.cpp
+++ b/backend/OneSixUpdate.cpp
@@ -92,12 +92,15 @@ void OneSixUpdate::versionFileFinished()
 	{
 		QString version1 =  PathCombine(inst_dir, "/version.json");
 		ensurePathExists(version1);
+		// FIXME: detect errors here, download to a temp file, swap
 		QFile  vfile1 (version1);
 		vfile1.open(QIODevice::Truncate | QIODevice::WriteOnly );
 		vfile1.write(DlJob->m_data);
 		vfile1.close();
 	}
 	
+	// the version is downloaded safely. update is 'done' at this point
+	m_inst->setShouldUpdate(false);
 	// save the version file in versions/$version/$version.json
 	/*
 		//QString version2 =  QString("versions/") + version_id + "/" + version_id + ".json";