/* Copyright 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 "WorldList.h"
#include <pathutils.h>
#include <QMimeData>
#include <QUrl>
#include <QUuid>
#include <QString>
#include <QFileSystemWatcher>
#include <QDebug>

WorldList::WorldList(const QString &dir)
	: QAbstractListModel(), m_dir(dir)
{
	ensureFolderPathExists(m_dir.absolutePath());
	m_dir.setFilter(QDir::Readable | QDir::NoDotAndDotDot | QDir::Files | QDir::Dirs |
					QDir::NoSymLinks);
	m_dir.setSorting(QDir::Name | QDir::IgnoreCase | QDir::LocaleAware);
	m_watcher = new QFileSystemWatcher(this);
	is_watching = false;
	connect(m_watcher, SIGNAL(directoryChanged(QString)), this,
			SLOT(directoryChanged(QString)));
}

void WorldList::startWatching()
{
	update();
	is_watching = m_watcher->addPath(m_dir.absolutePath());
	if (is_watching)
	{
		qDebug() << "Started watching " << m_dir.absolutePath();
	}
	else
	{
		qDebug() << "Failed to start watching " << m_dir.absolutePath();
	}
}

void WorldList::stopWatching()
{
	is_watching = !m_watcher->removePath(m_dir.absolutePath());
	if (!is_watching)
	{
		qDebug() << "Stopped watching " << m_dir.absolutePath();
	}
	else
	{
		qDebug() << "Failed to stop watching " << m_dir.absolutePath();
	}
}

void WorldList::internalSort(QList<World> &what)
{
	auto predicate = [](const World &left, const World &right)
	{
		return left.name().localeAwareCompare(right.name()) < 0;
	};
	std::sort(what.begin(), what.end(), predicate);
}

bool WorldList::update()
{
	if (!isValid())
		return false;

	QList<World> orderedWorlds;
	QList<World> newWorlds;
	m_dir.refresh();
	auto folderContents = m_dir.entryInfoList();
	// if there are any untracked files...
	if (folderContents.size())
	{
		// the order surely changed!
		for (auto entry : folderContents)
		{
			World w(entry);
			if(w.isValid()) {
				newWorlds.append(w);
			}
		}
		internalSort(newWorlds);
		orderedWorlds.append(newWorlds);
	}
	beginResetModel();
	worlds.swap(orderedWorlds);
	endResetModel();
	return true;
}

void WorldList::directoryChanged(QString path)
{
	update();
}

bool WorldList::isValid()
{
	return m_dir.exists() && m_dir.isReadable();
}

bool WorldList::deleteWorld(int index)
{
	if (index >= worlds.size() || index < 0)
		return false;
	World &m = worlds[index];
	if (m.destroy())
	{
		beginRemoveRows(QModelIndex(), index, index);
		worlds.removeAt(index);
		endRemoveRows();
		emit changed();
		return true;
	}
	return false;
}

bool WorldList::deleteWorlds(int first, int last)
{
	for (int i = first; i <= last; i++)
	{
		World &m = worlds[i];
		m.destroy();
	}
	beginRemoveRows(QModelIndex(), first, last);
	worlds.erase(worlds.begin() + first, worlds.begin() + last + 1);
	endRemoveRows();
	emit changed();
	return true;
}

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

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

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

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

	switch (role)
	{
	case Qt::DisplayRole:
		switch (column)
		{
		case NameColumn:
			return worlds[row].name();

		default:
			return QVariant();
		}

	case Qt::ToolTipRole:
		return worlds[row].name();
	default:
		return QVariant();
	}
}

QVariant WorldList::headerData(int section, Qt::Orientation orientation, int role) const
{
	switch (role)
	{
	case Qt::DisplayRole:
		switch (section)
		{
		case NameColumn:
			return tr("Name");
		default:
			return QVariant();
		}

	case Qt::ToolTipRole:
		switch (section)
		{
		case NameColumn:
			return tr("The name of the world.");
		default:
			return QVariant();
		}
	default:
		return QVariant();
	}
	return QVariant();
}

QStringList WorldList::mimeTypes() const
{
	QStringList types;
	types << "text/plain";
	return types;
}

QMimeData *WorldList::mimeData(const QModelIndexList &indexes) const
{
	QMimeData *data = new QMimeData();

	if (indexes.size() == 0)
		return data;

	auto idx = indexes[0];
	int row = idx.row();
	if (row < 0 || row >= worlds.size())
		return data;

	data->setText(QString::number(row));
	return data;
}