/* 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 "LwjglVersionList.h"
#include "Env.h"

#include <QtNetwork>
#include <QtXml>
#include <QRegExp>

#include <QDebug>

#define RSS_URL "https://sourceforge.net/projects/java-game-lib/rss"

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

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

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

	const PtrLWJGLVersion version = m_vlist.at(index.row());

	switch (role)
	{
	case Qt::DisplayRole:
		return version->name();

	case Qt::ToolTipRole:
		return version->url();

	default:
		return QVariant();
	}
}

QVariant LWJGLVersionList::headerData(int section, Qt::Orientation orientation, int role) const
{
	switch (role)
	{
	case Qt::DisplayRole:
		return tr("Version");

	case Qt::ToolTipRole:
		return tr("LWJGL version name.");

	default:
		return QVariant();
	}
}

int LWJGLVersionList::columnCount(const QModelIndex &parent) const
{
	return 1;
}

void LWJGLVersionList::loadList()
{
	if(m_loading)
	{
		return;
	}
	m_loading = true;

	qDebug() << "Downloading LWJGL RSS...";
	m_rssDLJob.reset(new NetJob("LWJGL RSS"));
	m_rssDL = Net::Download::makeByteArray(QUrl(RSS_URL), &m_rssData);
	m_rssDLJob->addNetAction(m_rssDL);
	connect(m_rssDLJob.get(), &NetJob::failed, this, &LWJGLVersionList::rssFailed);
	connect(m_rssDLJob.get(), &NetJob::succeeded, this, &LWJGLVersionList::rssSucceeded);
	m_rssDLJob->start();
}

inline QDomElement getDomElementByTagName(QDomElement parent, QString tagname)
{
	QDomNodeList elementList = parent.elementsByTagName(tagname);
	if (elementList.count())
		return elementList.at(0).toElement();
	else
		return QDomElement();
}

void LWJGLVersionList::rssFailed(const QString& reason)
{
	m_rssDLJob.reset();
	m_loading = false;
	qWarning() << "Failed to load LWJGL list. Network error: " + reason;
}

void LWJGLVersionList::rssSucceeded()
{
	QRegExp lwjglRegex("lwjgl-(([0-9]\\.?)+)\\.zip");
	Q_ASSERT_X(lwjglRegex.isValid(), "load LWJGL list", "LWJGL regex is invalid");

	QDomDocument doc;

	QString xmlErrorMsg;
	int errorLine;

	if (!doc.setContent(m_rssData, false, &xmlErrorMsg, &errorLine))
	{
		qWarning() << "Failed to load LWJGL list. XML error: " + xmlErrorMsg + " at line " + QString::number(errorLine);
		m_rssDLJob.reset();
		m_rssData.clear();
		m_loading = false;
		return;
	}
	m_rssData.clear();

	QDomNodeList items = doc.elementsByTagName("item");

	QList<PtrLWJGLVersion> tempList;

	for (int i = 0; i < items.length(); i++)
	{
		Q_ASSERT_X(items.at(i).isElement(), "load LWJGL list", "XML element isn't an element... wat?");

		QDomElement linkElement = getDomElementByTagName(items.at(i).toElement(), "link");
		if (linkElement.isNull())
		{
			qDebug() << "Link element" << i << "in RSS feed doesn't exist! Skipping.";
			continue;
		}

		QString link = linkElement.text();

		// Make sure it's a download link.
		if (link.endsWith("/download") && link.contains(lwjglRegex))
		{
			QString name = link.mid(lwjglRegex.indexIn(link) + 6);
			// Subtract 4 here to remove the .zip file extension.
			name = name.left(lwjglRegex.matchedLength() - 10);

			QUrl url(link);
			if (!url.isValid())
			{
				qWarning() << "LWJGL version URL isn't valid:" << link << "Skipping.";
				continue;
			}
			qDebug() << "Discovered LWGL version" << name << "at" << link;
			tempList.append(std::make_shared<LWJGLVersion>(name, link));
		}
	}

	beginResetModel();
	m_vlist.swap(tempList);
	endResetModel();

	qDebug() << "Loaded LWJGL list.";
	m_rssDLJob.reset();
	m_loading = false;
}