PrismLauncher/api/logic/minecraft/ComponentList.cpp

/* Copyright 2013-2017 MultiMC Contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <QFile>
#include <QCryptographicHash>
#include <Version.h>
#include <QDir>
#include <QJsonDocument>
#include <QJsonArray>
#include <QDebug>

#include "minecraft/ComponentList.h"
#include "Exception.h"
#include <minecraft/OneSixVersionFormat.h>
#include <FileSystem.h>
#include <QSaveFile>
#include <Env.h>
#include <meta/Index.h>
#include <minecraft/MinecraftInstance.h>
#include <QUuid>

ComponentList::ComponentList(MinecraftInstance * instance)
	: QAbstractListModel()
{
	m_instance = instance;
	clear();
}

ComponentList::~ComponentList()
{
}

void ComponentList::reload()
{
	beginResetModel();
	load_internal();
	reapplyPatches();
	endResetModel();
}

void ComponentList::clear()
{
	m_minecraftVersion.clear();
	m_minecraftVersionType.clear();
	m_minecraftAssets.reset();
	m_minecraftArguments.clear();
	m_tweakers.clear();
	m_mainClass.clear();
	m_appletClass.clear();
	m_libraries.clear();
	m_traits.clear();
	m_jarMods.clear();
	m_mainJar.reset();
	m_problemSeverity = ProblemSeverity::None;
}

void ComponentList::clearPatches()
{
	beginResetModel();
	m_patches.clear();
	endResetModel();
}

void ComponentList::appendPatch(ProfilePatchPtr patch)
{
	int index = m_patches.size();
	beginInsertRows(QModelIndex(), index, index);
	m_patches.append(patch);
	endInsertRows();
}

bool ComponentList::remove(const int index)
{
	auto patch = versionPatch(index);
	if (!patch->isRemovable())
	{
		qDebug() << "Patch" << patch->getID() << "is non-removable";
		return false;
	}

	if(!removePatch_internal(patch))
	{
		qCritical() << "Patch" << patch->getID() << "could not be removed";
		return false;
	}

	beginRemoveRows(QModelIndex(), index, index);
	m_patches.removeAt(index);
	endRemoveRows();
	reapplyPatches();
	saveCurrentOrder();
	return true;
}

bool ComponentList::remove(const QString id)
{
	int i = 0;
	for (auto patch : m_patches)
	{
		if (patch->getID() == id)
		{
			return remove(i);
		}
		i++;
	}
	return false;
}

bool ComponentList::customize(int index)
{
	auto patch = versionPatch(index);
	if (!patch->isCustomizable())
	{
		qDebug() << "Patch" << patch->getID() << "is not customizable";
		return false;
	}
	if(!customizePatch_internal(patch))
	{
		qCritical() << "Patch" << patch->getID() << "could not be customized";
		return false;
	}
	reapplyPatches();
	saveCurrentOrder();
	// FIXME: maybe later in unstable
	// emit dataChanged(createIndex(index, 0), createIndex(index, columnCount(QModelIndex()) - 1));
	return true;
}

bool ComponentList::revertToBase(int index)
{
	auto patch = versionPatch(index);
	if (!patch->isRevertible())
	{
		qDebug() << "Patch" << patch->getID() << "is not revertible";
		return false;
	}
	if(!revertPatch_internal(patch))
	{
		qCritical() << "Patch" << patch->getID() << "could not be reverted";
		return false;
	}
	reapplyPatches();
	saveCurrentOrder();
	// FIXME: maybe later in unstable
	// emit dataChanged(createIndex(index, 0), createIndex(index, columnCount(QModelIndex()) - 1));
	return true;
}

ProfilePatchPtr ComponentList::versionPatch(const QString &id)
{
	for (auto patch : m_patches)
	{
		if (patch->getID() == id)
		{
			return patch;
		}
	}
	return nullptr;
}

ProfilePatchPtr ComponentList::versionPatch(int index)
{
	if(index < 0 || index >= m_patches.size())
		return nullptr;
	return m_patches[index];
}

bool ComponentList::isVanilla()
{
	for(auto patchptr: m_patches)
	{
		if(patchptr->isCustom())
			return false;
	}
	return true;
}

bool ComponentList::revertToVanilla()
{
	// remove patches, if present
	auto VersionPatchesCopy = m_patches;
	for(auto & it: VersionPatchesCopy)
	{
		if (!it->isCustom())
		{
			continue;
		}
		if(it->isRevertible() || it->isRemovable())
		{
			if(!remove(it->getID()))
			{
				qWarning() << "Couldn't remove" << it->getID() << "from profile!";
				reapplyPatches();
				saveCurrentOrder();
				return false;
			}
		}
	}
	reapplyPatches();
	saveCurrentOrder();
	return true;
}

QVariant ComponentList::data(const QModelIndex &index, int role) const
{
	if (!index.isValid())
		return QVariant();

	int row = index.row();
	int column = index.column();

	if (row < 0 || row >= m_patches.size())
		return QVariant();

	auto patch = m_patches.at(row);

	if (role == Qt::DisplayRole)
	{
		switch (column)
		{
		case 0:
			return m_patches.at(row)->getName();
		case 1:
		{
			if(patch->isCustom())
			{
				return QString("%1 (Custom)").arg(patch->getVersion());
			}
			else
			{
				return patch->getVersion();
			}
		}
		default:
			return QVariant();
		}
	}
	if(role == Qt::DecorationRole)
	{
		switch(column)
		{
		case 0:
		{
			auto severity = patch->getProblemSeverity();
			switch (severity)
			{
				case ProblemSeverity::Warning:
					return "warning";
				case ProblemSeverity::Error:
					return "error";
				default:
					return QVariant();
			}
		}
		default:
		{
			return QVariant();
		}
		}
	}
	return QVariant();
}
QVariant ComponentList::headerData(int section, Qt::Orientation orientation, int role) const
{
	if (orientation == Qt::Horizontal)
	{
		if (role == Qt::DisplayRole)
		{
			switch (section)
			{
			case 0:
				return tr("Name");
			case 1:
				return tr("Version");
			default:
				return QVariant();
			}
		}
	}
	return QVariant();
}
Qt::ItemFlags ComponentList::flags(const QModelIndex &index) const
{
	if (!index.isValid())
		return Qt::NoItemFlags;
	return Qt::ItemIsSelectable | Qt::ItemIsEnabled;
}

int ComponentList::rowCount(const QModelIndex &parent) const
{
	return m_patches.size();
}

int ComponentList::columnCount(const QModelIndex &parent) const
{
	return 2;
}

void ComponentList::saveCurrentOrder() const
{
	ProfileUtils::PatchOrder order;
	for(auto item: m_patches)
	{
		if(!item->isMoveable())
			continue;
		order.append(item->getID());
	}
	saveOrder_internal(order);
}

void ComponentList::move(const int index, const MoveDirection direction)
{
	int theirIndex;
	if (direction == MoveUp)
	{
		theirIndex = index - 1;
	}
	else
	{
		theirIndex = index + 1;
	}

	if (index < 0 || index >= m_patches.size())
		return;
	if (theirIndex >= rowCount())
		theirIndex = rowCount() - 1;
	if (theirIndex == -1)
		theirIndex = rowCount() - 1;
	if (index == theirIndex)
		return;
	int togap = theirIndex > index ? theirIndex + 1 : theirIndex;

	auto from = versionPatch(index);
	auto to = versionPatch(theirIndex);

	if (!from || !to || !to->isMoveable() || !from->isMoveable())
	{
		return;
	}
	beginMoveRows(QModelIndex(), index, index, QModelIndex(), togap);
	m_patches.swap(index, theirIndex);
	endMoveRows();
	reapplyPatches();
	saveCurrentOrder();
}
void ComponentList::resetOrder()
{
	resetOrder_internal();
	reload();
}

bool ComponentList::reapplyPatches()
{
	try
	{
		clear();
		for(auto file: m_patches)
		{
			qDebug() << "Applying" << file->getID() << (file->getProblemSeverity() == ProblemSeverity::Error ? "ERROR" : "GOOD");
			file->applyTo(this);
		}
	}
	catch (Exception & error)
	{
		clear();
		qWarning() << "Couldn't apply profile patches because: " << error.cause();
		return false;
	}
	return true;
}

static void applyString(const QString & from, QString & to)
{
	if(from.isEmpty())
		return;
	to = from;
}

void ComponentList::applyMinecraftVersion(const QString& id)
{
	applyString(id, this->m_minecraftVersion);
}

void ComponentList::applyAppletClass(const QString& appletClass)
{
	applyString(appletClass, this->m_appletClass);
}

void ComponentList::applyMainClass(const QString& mainClass)
{
	applyString(mainClass, this->m_mainClass);
}

void ComponentList::applyMinecraftArguments(const QString& minecraftArguments)
{
	applyString(minecraftArguments, this->m_minecraftArguments);
}

void ComponentList::applyMinecraftVersionType(const QString& type)
{
	applyString(type, this->m_minecraftVersionType);
}

void ComponentList::applyMinecraftAssets(MojangAssetIndexInfo::Ptr assets)
{
	if(assets)
	{
		m_minecraftAssets = assets;
	}
}

void ComponentList::applyTraits(const QSet<QString>& traits)
{
	this->m_traits.unite(traits);
}

void ComponentList::applyTweakers(const QStringList& tweakers)
{
	// if the applied tweakers override an existing one, skip it. this effectively moves it later in the sequence
	QStringList newTweakers;
	for(auto & tweaker: m_tweakers)
	{
		if (tweakers.contains(tweaker))
		{
			continue;
		}
		newTweakers.append(tweaker);
	}
	// then just append the new tweakers (or moved original ones)
	newTweakers += tweakers;
	m_tweakers = newTweakers;
}

void ComponentList::applyJarMods(const QList<LibraryPtr>& jarMods)
{
	this->m_jarMods.append(jarMods);
}

static int findLibraryByName(QList<LibraryPtr> *haystack, const GradleSpecifier &needle)
{
	int retval = -1;
	for (int i = 0; i < haystack->size(); ++i)
	{
		if (haystack->at(i)->rawName().matchName(needle))
		{
			// only one is allowed.
			if (retval != -1)
				return -1;
			retval = i;
		}
	}
	return retval;
}

void ComponentList::applyMods(const QList<LibraryPtr>& mods)
{
	QList<LibraryPtr> * list = &m_mods;
	for(auto & mod: mods)
	{
		auto modCopy = Library::limitedCopy(mod);

		// find the mod by name.
		const int index = findLibraryByName(list, mod->rawName());
		// mod not found? just add it.
		if (index < 0)
		{
			list->append(modCopy);
			return;
		}

		auto existingLibrary = list->at(index);
		// if we are higher it means we should update
		if (Version(mod->version()) > Version(existingLibrary->version()))
		{
			list->replace(index, modCopy);
		}
	}
}

void ComponentList::applyLibrary(LibraryPtr library)
{
	if(!library->isActive())
	{
		return;
	}

	QList<LibraryPtr> * list = &m_libraries;
	if(library->isNative())
	{
		list = &m_nativeLibraries;
	}

	auto libraryCopy = Library::limitedCopy(library);

	// find the library by name.
	const int index = findLibraryByName(list, library->rawName());
	// library not found? just add it.
	if (index < 0)
	{
		list->append(libraryCopy);
		return;
	}

	auto existingLibrary = list->at(index);
	// if we are higher it means we should update
	if (Version(library->version()) > Version(existingLibrary->version()))
	{
		list->replace(index, libraryCopy);
	}
}

const LibraryPtr ComponentList::getMainJar() const
{
	return m_mainJar;
}

void ComponentList::applyMainJar(LibraryPtr jar)
{
	if(jar)
	{
		m_mainJar = jar;
	}
}

void ComponentList::applyProblemSeverity(ProblemSeverity severity)
{
	if (m_problemSeverity < severity)
	{
		m_problemSeverity = severity;
	}
}


QString ComponentList::getMinecraftVersion() const
{
	return m_minecraftVersion;
}

QString ComponentList::getAppletClass() const
{
	return m_appletClass;
}

QString ComponentList::getMainClass() const
{
	return m_mainClass;
}

const QSet<QString> &ComponentList::getTraits() const
{
	return m_traits;
}

const QStringList & ComponentList::getTweakers() const
{
	return m_tweakers;
}

bool ComponentList::hasTrait(const QString& trait) const
{
	return m_traits.contains(trait);
}

ProblemSeverity ComponentList::getProblemSeverity() const
{
	return m_problemSeverity;
}

QString ComponentList::getMinecraftVersionType() const
{
	return m_minecraftVersionType;
}

std::shared_ptr<MojangAssetIndexInfo> ComponentList::getMinecraftAssets() const
{
	if(!m_minecraftAssets)
	{
		return std::make_shared<MojangAssetIndexInfo>("legacy");
	}
	return m_minecraftAssets;
}

QString ComponentList::getMinecraftArguments() const
{
	return m_minecraftArguments;
}

const QList<LibraryPtr> & ComponentList::getJarMods() const
{
	return m_jarMods;
}

const QList<LibraryPtr> & ComponentList::getLibraries() const
{
	return m_libraries;
}

const QList<LibraryPtr> & ComponentList::getNativeLibraries() const
{
	return m_nativeLibraries;
}

void ComponentList::getLibraryFiles(const QString& architecture, QStringList& jars, QStringList& nativeJars, const QString& overridePath, const QString& tempPath) const
{
	QStringList native32, native64;
	jars.clear();
	nativeJars.clear();
	for (auto lib : getLibraries())
	{
		lib->getApplicableFiles(currentSystem, jars, nativeJars, native32, native64, overridePath);
	}
	// NOTE: order is important here, add main jar last to the lists
	if(m_mainJar)
	{
		// FIXME: HACK!! jar modding is weird and unsystematic!
		if(m_jarMods.size())
		{
			QDir tempDir(tempPath);
			jars.append(tempDir.absoluteFilePath("minecraft.jar"));
		}
		else
		{
			m_mainJar->getApplicableFiles(currentSystem, jars, nativeJars, native32, native64, overridePath);
		}
	}
	for (auto lib : getNativeLibraries())
	{
		lib->getApplicableFiles(currentSystem, jars, nativeJars, native32, native64, overridePath);
	}
	if(architecture == "32")
	{
		nativeJars.append(native32);
	}
	else if(architecture == "64")
	{
		nativeJars.append(native64);
	}
}

void ComponentList::installJarMods(QStringList selectedFiles)
{
	installJarMods_internal(selectedFiles);
}

void ComponentList::installCustomJar(QString selectedFile)
{
	installCustomJar_internal(selectedFile);
}


/*
 * TODO: get rid of this. Get rid of all order numbers.
 */
int ComponentList::getFreeOrderNumber()
{
	int largest = 100;
	// yes, I do realize this is dumb. The order thing itself is dumb. and to be removed next.
	for(auto thing: m_patches)
	{
		int order = thing->getOrder();
		if(order > largest)
			largest = order;
	}
	return largest + 1;
}

void ComponentList::upgradeDeprecatedFiles_internal()
{
	auto versionJsonPath = FS::PathCombine(m_instance->instanceRoot(), "version.json");
	auto customJsonPath = FS::PathCombine(m_instance->instanceRoot(), "custom.json");
	auto mcJson = FS::PathCombine(m_instance->instanceRoot(), "patches" , "net.minecraft.json");

	QString sourceFile;
	QString renameFile;

	// convert old crap.
	if(QFile::exists(customJsonPath))
	{
		sourceFile = customJsonPath;
		renameFile = versionJsonPath;
	}
	else if(QFile::exists(versionJsonPath))
	{
		sourceFile = versionJsonPath;
	}
	if(!sourceFile.isEmpty() && !QFile::exists(mcJson))
	{
		if(!FS::ensureFilePathExists(mcJson))
		{
			qWarning() << "Couldn't create patches folder for" << m_instance->name();
			return;
		}
		if(!renameFile.isEmpty() && QFile::exists(renameFile))
		{
			if(!QFile::rename(renameFile, renameFile + ".old"))
			{
				qWarning() << "Couldn't rename" << renameFile << "to" << renameFile + ".old" << "in" << m_instance->name();
				return;
			}
		}
		auto file = ProfileUtils::parseJsonFile(QFileInfo(sourceFile), false);
		ProfileUtils::removeLwjglFromPatch(file);
		file->uid = "net.minecraft";
		file->version = file->minecraftVersion;
		file->name = "Minecraft";
		auto data = OneSixVersionFormat::versionFileToJson(file, false).toJson();
		QSaveFile newPatchFile(mcJson);
		if(!newPatchFile.open(QIODevice::WriteOnly))
		{
			newPatchFile.cancelWriting();
			qWarning() << "Couldn't open main patch for writing in" << m_instance->name();
			return;
		}
		newPatchFile.write(data);
		if(!newPatchFile.commit())
		{
			qWarning() << "Couldn't save main patch in" << m_instance->name();
			return;
		}
		if(!QFile::rename(sourceFile, sourceFile + ".old"))
		{
			qWarning() << "Couldn't rename" << sourceFile << "to" << sourceFile + ".old" << "in" << m_instance->name();
			return;
		}
	}
}

void ComponentList::loadDefaultBuiltinPatches_internal()
{
	auto addBuiltinPatch = [&](const QString &uid, const QString intendedVersion, int order)
	{
		auto jsonFilePath = FS::PathCombine(m_instance->instanceRoot(), "patches" , uid + ".json");
		// load up the base minecraft patch
		ProfilePatchPtr profilePatch;
		if(QFile::exists(jsonFilePath))
		{
			auto file = ProfileUtils::parseJsonFile(QFileInfo(jsonFilePath), false);
			if(file->version.isEmpty())
			{
				file->version = intendedVersion;
			}
			profilePatch = std::make_shared<ProfilePatch>(file, jsonFilePath);
			profilePatch->setVanilla(false);
			profilePatch->setRevertible(true);
		}
		else
		{
			auto metaVersion = ENV.metadataIndex()->get(uid, intendedVersion);
			profilePatch = std::make_shared<ProfilePatch>(metaVersion);
			profilePatch->setVanilla(true);
		}
		profilePatch->setOrder(order);
		appendPatch(profilePatch);
	};
	addBuiltinPatch("net.minecraft", m_instance->getComponentVersion("net.minecraft"), -2);
	addBuiltinPatch("org.lwjgl", m_instance->getComponentVersion("org.lwjgl"), -1);
}

void ComponentList::loadUserPatches_internal()
{
	// first, collect all patches (that are not builtins of OneSix) and load them
	QMap<QString, ProfilePatchPtr> loadedPatches;
	QDir patchesDir(FS::PathCombine(m_instance->instanceRoot(),"patches"));
	for (auto info : patchesDir.entryInfoList(QStringList() << "*.json", QDir::Files))
	{
		// parse the file
		qDebug() << "Reading" << info.fileName();
		auto file = ProfileUtils::parseJsonFile(info, true);
		// ignore builtins
		if (file->uid == "net.minecraft")
			continue;
		if (file->uid == "org.lwjgl")
			continue;
		auto patch = std::make_shared<ProfilePatch>(file, info.filePath());
		patch->setRemovable(true);
		patch->setMovable(true);
		if(ENV.metadataIndex()->hasUid(file->uid))
		{
			// FIXME: requesting a uid/list creates it in the index... this allows reverting to possibly invalid versions...
			patch->setRevertible(true);
		}
		loadedPatches[file->uid] = patch;
	}
	// these are 'special'... if not already loaded from instance files, grab them from the metadata repo.
	auto loadSpecial = [&](const QString & uid, int order)
	{
		auto patchVersion = m_instance->getComponentVersion(uid);
		if(!patchVersion.isEmpty() && !loadedPatches.contains(uid))
		{
			auto patch = std::make_shared<ProfilePatch>(ENV.metadataIndex()->get(uid, patchVersion));
			patch->setOrder(order);
			patch->setVanilla(true);
			patch->setRemovable(true);
			patch->setMovable(true);
			loadedPatches[uid] = patch;
		}
	};
	loadSpecial("net.minecraftforge", 5);
	loadSpecial("com.mumfrey.liteloader", 10);

	// now add all the patches by user sort order
	ProfileUtils::PatchOrder userOrder;
	ProfileUtils::readOverrideOrders(FS::PathCombine(m_instance->instanceRoot(), "order.json"), userOrder);
	for (auto uid : userOrder)
	{
		// ignore builtins
		if (uid == "net.minecraft")
			continue;
		if (uid == "org.lwjgl")
			continue;
		// ordering has a patch that is gone?
		if(!loadedPatches.contains(uid))
		{
			continue;
		}
		appendPatch(loadedPatches.take(uid));
	}

	// is there anything left to sort?
	if(loadedPatches.isEmpty())
	{
		// TODO: save the order here?
		return;
	}

	// inserting into multimap by order number as key sorts the patches and detects duplicates
	QMultiMap<int, ProfilePatchPtr> files;
	auto iter = loadedPatches.begin();
	while(iter != loadedPatches.end())
	{
		files.insert((*iter)->getOrder(), *iter);
		iter++;
	}

	// then just extract the patches and put them in the list
	for (auto order : files.keys())
	{
		const auto &values = files.values(order);
		for(auto &value: values)
		{
			// TODO: put back the insertion of problem messages here, so the user knows about the id duplication
			appendPatch(value);
		}
	}
	// TODO: save the order here?
}


void ComponentList::load_internal()
{
	clearPatches();
	upgradeDeprecatedFiles_internal();
	loadDefaultBuiltinPatches_internal();
	loadUserPatches_internal();
}

bool ComponentList::saveOrder_internal(ProfileUtils::PatchOrder order) const
{
	return ProfileUtils::writeOverrideOrders(FS::PathCombine(m_instance->instanceRoot(), "order.json"), order);
}

bool ComponentList::resetOrder_internal()
{
	return QDir(m_instance->instanceRoot()).remove("order.json");
}

bool ComponentList::removePatch_internal(ProfilePatchPtr patch)
{
	bool ok = true;
	// first, remove the patch file. this ensures it's not used anymore
	auto fileName = patch->getFilename();
	if(fileName.size())
	{
		QFile patchFile(fileName);
		if(patchFile.exists() && !patchFile.remove())
		{
			qCritical() << "File" << fileName << "could not be removed because:" << patchFile.errorString();
			return false;
		}
	}
	if(!m_instance->getComponentVersion(patch->getID()).isEmpty())
	{
		m_instance->setComponentVersion(patch->getID(), QString());
	}

	// FIXME: we need a generic way of removing local resources, not just jar mods...
	auto preRemoveJarMod = [&](LibraryPtr jarMod) -> bool
	{
		if (!jarMod->isLocal())
		{
			return true;
		}
		QStringList jar, temp1, temp2, temp3;
		jarMod->getApplicableFiles(currentSystem, jar, temp1, temp2, temp3, m_instance->jarmodsPath().absolutePath());
		QFileInfo finfo (jar[0]);
		if(finfo.exists())
		{
			QFile jarModFile(jar[0]);
			if(!jarModFile.remove())
			{
				qCritical() << "File" << jar[0] << "could not be removed because:" << jarModFile.errorString();
				return false;
			}
			return true;
		}
		return true;
	};

	auto &jarMods = patch->getVersionFile()->jarMods;
	for(auto &jarmod: jarMods)
	{
		ok &= preRemoveJarMod(jarmod);
	}
	return ok;
}

bool ComponentList::customizePatch_internal(ProfilePatchPtr patch)
{
	if(patch->isCustom())
	{
		return false;
	}

	auto filename = FS::PathCombine(m_instance->instanceRoot(), "patches" , patch->getID() + ".json");
	if(!FS::ensureFilePathExists(filename))
	{
		return false;
	}
	// FIXME: get rid of this try-catch.
	try
	{
		QSaveFile jsonFile(filename);
		if(!jsonFile.open(QIODevice::WriteOnly))
		{
			return false;
		}
		auto vfile = patch->getVersionFile();
		if(!vfile)
		{
			return false;
		}
		auto document = OneSixVersionFormat::versionFileToJson(vfile, true);
		jsonFile.write(document.toJson());
		if(!jsonFile.commit())
		{
			return false;
		}
		load_internal();
	}
	catch (Exception &error)
	{
		qWarning() << "Version could not be loaded:" << error.cause();
	}
	return true;
}

bool ComponentList::revertPatch_internal(ProfilePatchPtr patch)
{
	if(!patch->isCustom())
	{
		// already not custom
		return true;
	}
	auto filename = patch->getFilename();
	if(!QFile::exists(filename))
	{
		// already gone / not custom
		return true;
	}
	// just kill the file and reload
	bool result = QFile::remove(filename);
	// FIXME: get rid of this try-catch.
	try
	{
		load_internal();
	}
	catch (Exception &error)
	{
		qWarning() << "Version could not be loaded:" << error.cause();
	}
	return result;
}

bool ComponentList::installJarMods_internal(QStringList filepaths)
{
	QString patchDir = FS::PathCombine(m_instance->instanceRoot(), "patches");
	if(!FS::ensureFolderPathExists(patchDir))
	{
		return false;
	}

	if (!FS::ensureFolderPathExists(m_instance->jarModsDir()))
	{
		return false;
	}

	for(auto filepath:filepaths)
	{
		QFileInfo sourceInfo(filepath);
		auto uuid = QUuid::createUuid();
		QString id = uuid.toString().remove('{').remove('}');
		QString target_filename = id + ".jar";
		QString target_id = "org.multimc.jarmod." + id;
		QString target_name = sourceInfo.completeBaseName() + " (jar mod)";
		QString finalPath = FS::PathCombine(m_instance->jarModsDir(), target_filename);

		QFileInfo targetInfo(finalPath);
		if(targetInfo.exists())
		{
			return false;
		}

		if (!QFile::copy(sourceInfo.absoluteFilePath(),QFileInfo(finalPath).absoluteFilePath()))
		{
			return false;
		}

		auto f = std::make_shared<VersionFile>();
		auto jarMod = std::make_shared<Library>();
		jarMod->setRawName(GradleSpecifier("org.multimc.jarmods:" + id + ":1"));
		jarMod->setFilename(target_filename);
		jarMod->setDisplayName(sourceInfo.completeBaseName());
		jarMod->setHint("local");
		f->jarMods.append(jarMod);
		f->name = target_name;
		f->uid = target_id;
		f->order = getFreeOrderNumber();
		QString patchFileName = FS::PathCombine(patchDir, target_id + ".json");

		QFile file(patchFileName);
		if (!file.open(QFile::WriteOnly))
		{
			qCritical() << "Error opening" << file.fileName()
						<< "for reading:" << file.errorString();
			return false;
		}
		file.write(OneSixVersionFormat::versionFileToJson(f, true).toJson());
		file.close();

		auto patch = std::make_shared<ProfilePatch>(f, patchFileName);
		patch->setMovable(true);
		patch->setRemovable(true);
		appendPatch(patch);
	}
	saveCurrentOrder();
	reapplyPatches();
	return true;
}

bool ComponentList::installCustomJar_internal(QString filepath)
{
	QString patchDir = FS::PathCombine(m_instance->instanceRoot(), "patches");
	if(!FS::ensureFolderPathExists(patchDir))
	{
		return false;
	}

	QString libDir = m_instance->getLocalLibraryPath();
	if (!FS::ensureFolderPathExists(libDir))
	{
		return false;
	}

	auto specifier = GradleSpecifier("org.multimc:customjar:1");
	QFileInfo sourceInfo(filepath);
	QString target_filename = specifier.getFileName();
	QString target_id = specifier.artifactId();
	QString target_name = sourceInfo.completeBaseName() + " (custom jar)";
	QString finalPath = FS::PathCombine(libDir, target_filename);

	QFileInfo jarInfo(finalPath);
	if (jarInfo.exists())
	{
		if(!QFile::remove(finalPath))
		{
			return false;
		}
	}
	if (!QFile::copy(filepath, finalPath))
	{
		return false;
	}

	auto f = std::make_shared<VersionFile>();
	auto jarMod = std::make_shared<Library>();
	jarMod->setRawName(specifier);
	jarMod->setDisplayName(sourceInfo.completeBaseName());
	jarMod->setHint("local");
	f->mainJar = jarMod;
	f->name = target_name;
	f->uid = target_id;
	f->order = getFreeOrderNumber();
	QString patchFileName = FS::PathCombine(patchDir, target_id + ".json");

	QFile file(patchFileName);
	if (!file.open(QFile::WriteOnly))
	{
		qCritical() << "Error opening" << file.fileName()
					<< "for reading:" << file.errorString();
		return false;
	}
	file.write(OneSixVersionFormat::versionFileToJson(f, true).toJson());
	file.close();

	auto patch = std::make_shared<ProfilePatch>(f, patchFileName);
	patch->setMovable(true);
	patch->setRemovable(true);
	appendPatch(patch);

	saveCurrentOrder();
	reapplyPatches();
	return true;
}