#include "LegacyUpgradeTask.h"
#include "BaseInstanceProvider.h"
#include "settings/INISettingsObject.h"
#include "FileSystem.h"
#include "NullInstance.h"
#include "pathmatcher/RegexpMatcher.h"
#include <QtConcurrentRun>
#include "LegacyInstance.h"
#include "minecraft/MinecraftInstance.h"
#include "minecraft/ComponentList.h"
#include "classparser.h"

LegacyUpgradeTask::LegacyUpgradeTask(InstancePtr origInstance)
{
	m_origInstance = origInstance;
}

void LegacyUpgradeTask::executeTask()
{
	setStatus(tr("Copying instance %1").arg(m_origInstance->name()));

	FS::copy folderCopy(m_origInstance->instanceRoot(), m_stagingPath);
	folderCopy.followSymlinks(true);

	m_copyFuture = QtConcurrent::run(QThreadPool::globalInstance(), folderCopy);
	connect(&m_copyFutureWatcher, &QFutureWatcher<bool>::finished, this, &LegacyUpgradeTask::copyFinished);
	connect(&m_copyFutureWatcher, &QFutureWatcher<bool>::canceled, this, &LegacyUpgradeTask::copyAborted);
	m_copyFutureWatcher.setFuture(m_copyFuture);
}

static QString decideVersion(const QString& currentVersion, const QString& intendedVersion)
{
	if(intendedVersion != currentVersion)
	{
		if(!intendedVersion.isEmpty())
		{
			return intendedVersion;
		}
		else if(!currentVersion.isEmpty())
		{
			return currentVersion;
		}
	}
	else
	{
		if(!intendedVersion.isEmpty())
		{
			return intendedVersion;
		}
	}
	return QString();
}

void LegacyUpgradeTask::copyFinished()
{
	auto successful = m_copyFuture.result();
	if(!successful)
	{
		emitFailed(tr("Instance folder copy failed."));
		return;
	}
	auto legacyInst = std::dynamic_pointer_cast<LegacyInstance>(m_origInstance);

	auto instanceSettings = std::make_shared<INISettingsObject>(FS::PathCombine(m_stagingPath, "instance.cfg"));
	instanceSettings->registerSetting("InstanceType", "Legacy");
	instanceSettings->set("InstanceType", "OneSix");
	// NOTE: this scope ensures the instance is fully saved before we emitSucceeded
	{
		MinecraftInstance inst(m_globalSettings, instanceSettings, m_stagingPath);
		inst.setName(m_instName);
		inst.init();

		QString preferredVersionNumber = decideVersion(legacyInst->currentVersionId(), legacyInst->intendedVersionId());
		if(preferredVersionNumber.isNull())
		{
			// try to decide version based on the jar(s?)
			preferredVersionNumber = classparser::GetMinecraftJarVersion(legacyInst->baseJar());
			if(preferredVersionNumber.isNull())
			{
				preferredVersionNumber = classparser::GetMinecraftJarVersion(legacyInst->runnableJar());
				if(preferredVersionNumber.isNull())
				{
					emitFailed(tr("Could not decide Minecraft version."));
					return;
				}
			}
		}
		auto components = inst.getComponentList();
		components->buildingFromScratch();
		components->setComponentVersion("net.minecraft", preferredVersionNumber, true);

		QString jarPath = legacyInst->mainJarToPreserve();
		if(!jarPath.isNull())
		{
			qDebug() << "Preserving base jar! : " << jarPath;
			// FIXME: handle case when the jar is unreadable?
			// TODO: check the hash, if it's the same as the upstream jar, do not do this
			components->installCustomJar(jarPath);
		}

		auto jarMods = legacyInst->getJarMods();
		for(auto & jarMod: jarMods)
		{
			QString modPath = jarMod.filename().absoluteFilePath();
			qDebug() << "jarMod: " << modPath;
			components->installJarMods({modPath});
		}

		// remove all the extra garbage we no longer need
		auto removeAll = [&](const QString &root, const QStringList &things)
		{
			for(auto &thing : things)
			{
				auto removePath = FS::PathCombine(root, thing);
				QFileInfo stat(removePath);
				if(stat.isDir())
				{
					FS::deletePath(removePath);
				}
				else
				{
					QFile::remove(removePath);
				}
			}
		};
		QStringList rootRemovables = {"modlist", "version", "instMods"};
		QStringList mcRemovables = {"bin", "MultiMCLauncher.jar", "icon.png"};
		removeAll(inst.instanceRoot(), rootRemovables);
		removeAll(inst.minecraftRoot(), mcRemovables);
	}
	emitSucceeded();
}

void LegacyUpgradeTask::copyAborted()
{
	emitFailed(tr("Instance folder copy has been aborted."));
	return;
}