/* Copyright 2013-2015 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 "LiteLoaderVersionList.h"
#include "Env.h"
#include "net/URLConstants.h"
#include "MMCError.h"

#include <QtXml>

#include <QJsonDocument>
#include <QJsonObject>
#include <QJsonArray>
#include <QJsonValue>
#include <QJsonParseError>

#include <QtAlgorithms>

#include <QtNetwork>

LiteLoaderVersionList::LiteLoaderVersionList(QObject *parent) : BaseVersionList(parent)
{
}

Task *LiteLoaderVersionList::getLoadTask()
{
	return new LLListLoadTask(this);
}

bool LiteLoaderVersionList::isLoaded()
{
	return m_loaded;
}

const BaseVersionPtr LiteLoaderVersionList::at(int i) const
{
	return m_vlist.at(i);
}

int LiteLoaderVersionList::count() const
{
	return m_vlist.count();
}

static bool cmpVersions(BaseVersionPtr first, BaseVersionPtr second)
{
	auto left = std::dynamic_pointer_cast<LiteLoaderVersion>(first);
	auto right = std::dynamic_pointer_cast<LiteLoaderVersion>(second);
	return left->timestamp > right->timestamp;
}

void LiteLoaderVersionList::sort()
{
	beginResetModel();
	std::sort(m_vlist.begin(), m_vlist.end(), cmpVersions);
	endResetModel();
}

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

	if (index.row() > count())
		return QVariant();

	auto version = std::dynamic_pointer_cast<LiteLoaderVersion>(m_vlist[index.row()]);
	switch (role)
	{
	case VersionPointerRole:
		return qVariantFromValue(m_vlist[index.row()]);

	case VersionRole:
		return version->name();

	case VersionIdRole:
		return version->descriptor();

	case ParentGameVersionRole:
		return version->mcVersion;

	case RecommendedRole:
		return version->isLatest;

	default:
		return QVariant();
	}
}

QList<BaseVersionList::ModelRoles> LiteLoaderVersionList::providesRoles()
{
	return {VersionPointerRole, VersionRole, VersionIdRole, ParentGameVersionRole, RecommendedRole};
}

BaseVersionPtr LiteLoaderVersionList::getLatestStable() const
{
	for (int i = 0; i < m_vlist.length(); i++)
	{
		auto ver = std::dynamic_pointer_cast<LiteLoaderVersion>(m_vlist.at(i));
		if (ver->isLatest)
		{
			return m_vlist.at(i);
		}
	}
	return BaseVersionPtr();
}

void LiteLoaderVersionList::updateListData(QList<BaseVersionPtr> versions)
{
	beginResetModel();
	m_vlist = versions;
	m_loaded = true;
	std::sort(m_vlist.begin(), m_vlist.end(), cmpVersions);
	endResetModel();
}

LLListLoadTask::LLListLoadTask(LiteLoaderVersionList *vlist)
{
	m_list = vlist;
}

LLListLoadTask::~LLListLoadTask()
{
}

void LLListLoadTask::executeTask()
{
	setStatus(tr("Loading LiteLoader version list..."));
	auto job = new NetJob("Version index");
	// we do not care if the version is stale or not.
	auto liteloaderEntry = ENV.metacache()->resolveEntry("liteloader", "versions.json");

	// verify by poking the server.
	liteloaderEntry->stale = true;

	job->addNetAction(listDownload = CacheDownload::make(QUrl(URLConstants::LITELOADER_URL),
														 liteloaderEntry));

	connect(listDownload.get(), SIGNAL(failed(int)), SLOT(listFailed()));

	listJob.reset(job);
	connect(listJob.get(), SIGNAL(succeeded()), SLOT(listDownloaded()));
	connect(listJob.get(), SIGNAL(progress(qint64, qint64)), SIGNAL(progress(qint64, qint64)));
	listJob->start();
}

void LLListLoadTask::listFailed()
{
	emitFailed("Failed to load LiteLoader version list.");
	return;
}

void LLListLoadTask::listDownloaded()
{
	QByteArray data;
	{
		auto dlJob = listDownload;
		auto filename = std::dynamic_pointer_cast<CacheDownload>(dlJob)->getTargetFilepath();
		QFile listFile(filename);
		if (!listFile.open(QIODevice::ReadOnly))
		{
			emitFailed("Failed to open the LiteLoader version list.");
			return;
		}
		data = listFile.readAll();
		listFile.close();
		dlJob.reset();
	}

	QJsonParseError jsonError;
	QJsonDocument jsonDoc = QJsonDocument::fromJson(data, &jsonError);

	if (jsonError.error != QJsonParseError::NoError)
	{
		emitFailed("Error parsing version list JSON:" + jsonError.errorString());
		return;
	}

	if (!jsonDoc.isObject())
	{
		emitFailed("Error parsing version list JSON: jsonDoc is not an object");
		return;
	}

	const QJsonObject root = jsonDoc.object();

	// Now, get the array of versions.
	if (!root.value("versions").isObject())
	{
		emitFailed("Error parsing version list JSON: missing 'versions' object");
		return;
	}

	auto meta = root.value("meta").toObject();
	QString description = meta.value("description").toString(tr("This is a lightweight loader for mods that don't change game mechanics."));
	QString defaultUrl = meta.value("url").toString("http://dl.liteloader.com");
	QString authors = meta.value("authors").toString("Mumfrey");
	auto versions = root.value("versions").toObject();

	QList<BaseVersionPtr> tempList;
	for (auto vIt = versions.begin(); vIt != versions.end(); ++vIt)
	{
		const QString mcVersion = vIt.key();
		QString latest;
		const QJsonObject artefacts = vIt.value()
										  .toObject()
										  .value("artefacts")
										  .toObject()
										  .value("com.mumfrey:liteloader")
										  .toObject();
		QList<BaseVersionPtr> perMcVersionList;
		for (auto aIt = artefacts.begin(); aIt != artefacts.end(); ++aIt)
		{
			const QString identifier = aIt.key();
			const QJsonObject artefact = aIt.value().toObject();
			if (identifier == "latest")
			{
				latest = artefact.value("version").toString();
				continue;
			}
			LiteLoaderVersionPtr version(new LiteLoaderVersion());
			version->version = artefact.value("version").toString();
			version->file = artefact.value("file").toString();
			version->mcVersion = mcVersion;
			version->md5 = artefact.value("md5").toString();
			version->timestamp = artefact.value("timestamp").toString().toInt();
			version->tweakClass = artefact.value("tweakClass").toString();
			version->authors = authors;
			version->description = description;
			version->defaultUrl = defaultUrl;
			const QJsonArray libs = artefact.value("libraries").toArray();
			for (auto lIt = libs.begin(); lIt != libs.end(); ++lIt)
			{
				auto libobject = (*lIt).toObject();
				try
				{
					auto lib = RawLibrary::fromJson(libobject, "versions.json");
					// hack to make liteloader 1.7.10_00 work
					if(lib->rawName() == GradleSpecifier("org.ow2.asm:asm-all:5.0.3"))
					{
						lib->m_base_url = "http://repo.maven.apache.org/maven2/";
					}
					version->libraries.append(lib);
				}
				catch (MMCError &e)
				{
					qCritical() << "Couldn't read JSON object:";
					continue;
				}
			}
			perMcVersionList.append(version);
		}
		for (auto version : perMcVersionList)
		{
			auto v = std::dynamic_pointer_cast<LiteLoaderVersion>(version);
			v->isLatest = v->version == latest;
		}
		tempList.append(perMcVersionList);
	}
	m_list->updateListData(tempList);

	emitSucceeded();
}
