#include "gui/pages/torrents.h"
#include "core/strings.h"
#include "core/http.h"
#include "core/session.h"
#include "gui/widgets/text.h"
#include "track/media.h"
#include "pugixml.hpp"
#include <QVBoxLayout>
#include <QToolBar>
#include <QTreeView>
#include <QMainWindow>
#include <QByteArray>
#include <QDataStream>
#include <QThreadPool>
#include <QDebug>
#include <iostream>
#include <sstream>
#include <algorithm>

TorrentsPageListSortFilter::TorrentsPageListSortFilter(QObject* parent) : QSortFilterProxyModel(parent) {
}

bool TorrentsPageListSortFilter::lessThan(const QModelIndex& l, const QModelIndex& r) const {
	QVariant left = sourceModel()->data(l, sortRole());
	QVariant right = sourceModel()->data(r, sortRole());

	switch (left.userType()) {
		case QMetaType::Int:
		case QMetaType::UInt:
		case QMetaType::LongLong:
		case QMetaType::ULongLong: return left.toInt() < right.toInt();
		case QMetaType::QDate: return left.toDate() < right.toDate();
		case QMetaType::QString:
		default: return QString::compare(left.toString(), right.toString(), Qt::CaseInsensitive) < 0;
	}
}

/* -------------------------------------------- */

TorrentsPageListModel::TorrentsPageListModel(QObject* parent) : QAbstractListModel(parent) {
}

QByteArray TorrentsPageListModel::DownloadTorrentList() {
	return HTTP::Get(session.config.torrents.feed_link);
}

void TorrentsPageListModel::ParseTorrentList(const QByteArray& ba) {
	std::istringstream stdstream(Strings::ToUtf8String(ba));

	pugi::xml_document doc;
	if (!doc.load(stdstream))
		return; // peace out

	/* my extra special dumb hack. */
	if (!rowCount(index(0))) {
		beginInsertRows(QModelIndex(), 0, 0);
		endInsertRows();
	}

	beginResetModel();

	list.clear();
	/* this is just an rss parser; it should be in a separate class... */
	for (pugi::xml_node item : doc.child("rss").child("channel").children("item")) {
		TorrentModelItem torrent;
		torrent.SetFilename(item.child_value("title")); /* "title" == filename */
		{
			/* Use Anitomy to parse the file's elements (we should *really* not be doing this this way!) */
			std::unordered_map<std::string, std::string> elements = Track::Media::GetFileElements(torrent.GetFilename());
			torrent.SetTitle(elements["title"]);
			torrent.SetEpisode(Strings::RemoveLeadingChars(elements["episode"], '0'));
			torrent.SetGroup(elements["group"]);
			torrent.SetResolution(elements["resolution"]);
		}
		torrent.SetDescription(Strings::TextifySynopsis(item.child_value("description")));
		{
			/* Parse size from description */
			std::istringstream descstream(torrent.GetDescription());

			for (std::string line; std::getline(descstream, line);) {
				const std::string match = "Size: ";
				size_t pos = line.find(match);

				if (!pos) {
					const std::string size = line.substr(pos + match.length());
					torrent.SetSize(Strings::HumanReadableSizeToBytes(size));
				}
			}
		}
		torrent.SetLink(item.child_value("link"));
		torrent.SetGuid(item.child_value("guid"));
		{
			const QString date_str = Strings::ToQString(item.child_value("pubDate"));
			torrent.SetDate(QDateTime::fromString(date_str, "ddd, dd MMM yyyy HH:mm:ss t"));
		}
		list.push_back(torrent);
	}

	endResetModel();
}

void TorrentsPageListModel::RefreshTorrentList() {
	ParseTorrentList(DownloadTorrentList());
}

int TorrentsPageListModel::rowCount(const QModelIndex& parent) const {
	return list.size();
	(void)(parent);
}

int TorrentsPageListModel::columnCount(const QModelIndex& parent) const {
	return NB_COLUMNS;
	(void)(parent);
}

QVariant TorrentsPageListModel::headerData(const int section, const Qt::Orientation orientation, const int role) const {
	switch (role) {
		case Qt::DisplayRole: {
			switch (section) {
				case TL_TITLE: return tr("Anime title");
				case TL_EPISODE: return tr("Episode");
				case TL_GROUP: return tr("Group");
				case TL_SIZE: return tr("Size");
				case TL_RESOLUTION: return tr("Resolution"); /* this is named "Video" in Taiga */
				case TL_SEEDERS: return tr("Seeding"); /* named "S" in Taiga */
				case TL_LEECHERS: return tr("Leeching"); /* named "L" in Taiga */
				case TL_DOWNLOADERS: return tr("Downloading"); /* named "D" in Taiga */
				case TL_DESCRIPTION: return tr("Description");
				case TL_FILENAME: return tr("Filename");
				case TL_RELEASEDATE: return tr("Release date");
				default: return {};
			}
			break;
		}
		case Qt::TextAlignmentRole: {
			switch (section) {
				case TL_FILENAME:
				case TL_GROUP:
				case TL_DESCRIPTION:
				case TL_RESOLUTION:
				case TL_TITLE: return QVariant(Qt::AlignLeft | Qt::AlignVCenter);
				case TL_SEEDERS:
				case TL_LEECHERS:
				case TL_DOWNLOADERS:
				case TL_SIZE:
				case TL_EPISODE:
				case TL_RELEASEDATE: return QVariant(Qt::AlignRight | Qt::AlignVCenter);
				default: return {};
			}
			break;
		}
	}
	return QAbstractListModel::headerData(section, orientation, role);
}

bool TorrentsPageListModel::setData(const QModelIndex& index, const QVariant& value, int role) {
	TorrentModelItem& item = list.at(index.row());

	if (index.column() == 0) {
		switch (role) {
			case Qt::EditRole:
				return false;
			case Qt::CheckStateRole:
				item.SetChecked(value.toBool());
				emit dataChanged(index, index);
				return true;
		}
	}

	return QAbstractItemModel::setData(index, value, role);
}

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

	const TorrentModelItem& item = list.at(index.row());

	switch (role) {
		case Qt::DisplayRole:
			switch (index.column()) {
				case TL_TITLE: return Strings::ToQString(item.GetTitle());
				case TL_EPISODE: return Strings::ToQString(item.GetEpisode());
				case TL_GROUP: return Strings::ToQString(item.GetGroup());
				case TL_SIZE: return session.config.locale.GetLocale().formattedDataSize(item.GetSize());
				case TL_RESOLUTION: return Strings::ToQString(item.GetResolution());
				case TL_SEEDERS: return item.GetSeeders();
				case TL_LEECHERS: return item.GetLeechers();
				case TL_DOWNLOADERS: return item.GetDownloaders();
				case TL_DESCRIPTION: return Strings::ToQString(item.GetDescription());
				case TL_FILENAME: return Strings::ToQString(item.GetFilename());
				case TL_RELEASEDATE: return item.GetDate();
				default: return "";
			}
			break;
		case Qt::UserRole:
			switch (index.column()) {
				case TL_EPISODE: return Strings::ToInt(item.GetEpisode(), -1);
				case TL_SIZE: return item.GetSize();
				default: return data(index, Qt::DisplayRole);
			}
			break;
		case Qt::CheckStateRole:
			switch (index.column()) {
				case 0: return item.GetChecked() ? Qt::Checked : Qt::Unchecked;
				default: return {};
			}
		case Qt::SizeHintRole: {
			switch (index.column()) {
				default: {
					/* max horizontal size of 100, height size = size of current font */
					const QString d = data(index, Qt::DisplayRole).toString();
					const QFontMetrics metric = QFontMetrics(QFont());

					return QSize(std::max(metric.horizontalAdvance(d), 100), metric.height());
				}
			}
			break;
		}
		case Qt::TextAlignmentRole:
			switch (index.column()) {
				case TL_FILENAME:
				case TL_GROUP:
				case TL_DESCRIPTION:
				case TL_RESOLUTION:
				case TL_TITLE: return QVariant(Qt::AlignLeft | Qt::AlignVCenter);
				case TL_SEEDERS:
				case TL_LEECHERS:
				case TL_DOWNLOADERS:
				case TL_SIZE:
				case TL_EPISODE:
				case TL_RELEASEDATE: return QVariant(Qt::AlignRight | Qt::AlignVCenter);
				default: return {};
			}
			break;
	}
	return QVariant();
}

Qt::ItemFlags TorrentsPageListModel::flags(const QModelIndex& index) const {
	if (!index.isValid())
		return Qt::NoItemFlags;

	const TorrentModelItem& item = list.at(index.row());

	if (item.GetChecked() || index.column() == 0)
		return Qt::ItemIsEnabled | Qt::ItemIsSelectable | Qt::ItemIsUserCheckable;
	else
		return Qt::ItemIsSelectable | Qt::ItemIsUserCheckable;
}

TorrentsPage::TorrentsPage(QWidget* parent) : QFrame(parent) {
	setFrameShape(QFrame::Box);
	setFrameShadow(QFrame::Sunken);

	QVBoxLayout* layout = new QVBoxLayout(this);
	layout->setContentsMargins(0, 0, 0, 0);
	layout->setSpacing(0);

	{
		/* Toolbar */
		QToolBar* toolbar = new QToolBar(this);
		toolbar->setToolButtonStyle(Qt::ToolButtonTextBesideIcon);
		toolbar->setIconSize(QSize(16, 16));
		toolbar->setMovable(false);

		{
			/* this needs to be stored somewhere to replicate Taiga's
			   "timer" feature */
			toolbar->addAction(QIcon(":/icons/16x16/arrow-circle-315.png"), tr("&Check new torrents"), [this]{
				QThreadPool::globalInstance()->start([this] {
					Refresh();
				});
			});
		}

		toolbar->addSeparator();

		{
			toolbar->addAction(QIcon(":/icons/16x16/navigation-270-button.png"), tr("Download &marked torrents"));
		}

		{
			toolbar->addAction(QIcon(":/icons/16x16/cross-button.png"), tr("&Discard all"));
		}

		toolbar->addSeparator();

		{
			toolbar->addAction(QIcon(":/icons/16x16/gear.png"), tr("&Settings"));
		}

		layout->addWidget(toolbar);
	}

	{
		QFrame* line = new QFrame(this);
		line->setFrameShape(QFrame::HLine);
		line->setFrameShadow(QFrame::Sunken);
		line->setLineWidth(1);
		layout->addWidget(line);
	}

	{
		QTreeView* treeview = new QTreeView(this);
		treeview->setUniformRowHeights(true);
		treeview->setAllColumnsShowFocus(false);
		treeview->setAlternatingRowColors(true);
		treeview->setSortingEnabled(true);
		treeview->setSelectionMode(QAbstractItemView::ExtendedSelection);
		treeview->setItemsExpandable(false);
		treeview->setRootIsDecorated(false);
		treeview->setContextMenuPolicy(Qt::CustomContextMenu);
		treeview->setFrameShape(QFrame::NoFrame);

		{
			sort_model = new TorrentsPageListSortFilter(treeview);
			model = new TorrentsPageListModel(treeview);
			sort_model->setSourceModel(model);
			sort_model->setSortRole(Qt::UserRole);
			sort_model->setSortCaseSensitivity(Qt::CaseInsensitive);
			treeview->setModel(sort_model);
		}

		layout->addWidget(treeview);
	}
}

void TorrentsPage::Refresh() {
	if (!model)
		return;
	model->RefreshTorrentList();
}

#include "gui/pages/moc_torrents.cpp"