/*  PCSX2 - PS2 Emulator for PCs
 *  Copyright (C) 2002-2022  PCSX2 Dev Team
 *
 *  PCSX2 is free software: you can redistribute it and/or modify it under the terms
 *  of the GNU Lesser General Public License as published by the Free Software Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  PCSX2 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 *  PURPOSE.  See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with PCSX2.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

#include "PrecompiledHeader.h"

#include "common/Assertions.h"
#include "common/StringUtil.h"

#include "pcsx2/Frontend/GameList.h"
#include "pcsx2/HostSettings.h"

#include <QtCore/QSortFilterProxyModel>
#include <QtGui/QPixmap>
#include <QtGui/QWheelEvent>
#include <QtWidgets/QApplication>
#include <QtWidgets/QHeaderView>
#include <QtWidgets/QMenu>
#include <QtWidgets/QScrollBar>

#include "GameListModel.h"
#include "GameListRefreshThread.h"
#include "GameListWidget.h"
#include "QtHost.h"
#include "QtUtils.h"

#include "fmt/format.h"

static const char* SUPPORTED_FORMATS_STRING = QT_TRANSLATE_NOOP(GameListWidget,
	".bin/.iso (ISO Disc Images)\n"
	".chd (Compressed Hunks of Data)\n"
	".cso (Compressed ISO)\n"
	".gz (Gzip Compressed ISO)");

static constexpr float MIN_SCALE = 0.1f;
static constexpr float MAX_SCALE = 2.0f;

class GameListSortModel final : public QSortFilterProxyModel
{
public:
	explicit GameListSortModel(GameListModel* parent)
		: QSortFilterProxyModel(parent)
		, m_model(parent)
	{
	}

	void setFilterType(GameList::EntryType type)
	{
		m_filter_type = type;
		invalidateRowsFilter();
	}
	void setFilterRegion(GameList::Region region)
	{
		m_filter_region = region;
		invalidateRowsFilter();
	}
	void setFilterName(const QString& name)
	{
		m_filter_name = name;
		invalidateRowsFilter();
	}

	bool filterAcceptsRow(int source_row, const QModelIndex& source_parent) const override
	{
		if (m_filter_type != GameList::EntryType::Count ||
			m_filter_region != GameList::Region::Count ||
			!m_filter_name.isEmpty())
		{
			const auto lock = GameList::GetLock();
			const GameList::Entry* entry = GameList::GetEntryByIndex(source_row);
			if (m_filter_type != GameList::EntryType::Count && entry->type != m_filter_type)
				return false;
			if (m_filter_region != GameList::Region::Count && entry->region != m_filter_region)
				return false;
			if (!m_filter_name.isEmpty() &&
				!QString::fromStdString(entry->path).contains(m_filter_name, Qt::CaseInsensitive) &&
				!QString::fromStdString(entry->serial).contains(m_filter_name, Qt::CaseInsensitive) &&
				!QString::fromStdString(entry->title).contains(m_filter_name, Qt::CaseInsensitive))
				return false;
		}

		return QSortFilterProxyModel::filterAcceptsRow(source_row, source_parent);
	}

	bool lessThan(const QModelIndex& source_left, const QModelIndex& source_right) const override
	{
		return m_model->lessThan(source_left, source_right, source_left.column());
	}

private:
	GameListModel* m_model;
	GameList::EntryType m_filter_type = GameList::EntryType::Count;
	GameList::Region m_filter_region = GameList::Region::Count;
	QString m_filter_name;
};

GameListWidget::GameListWidget(QWidget* parent /* = nullptr */)
	: QWidget(parent)
{
}

GameListWidget::~GameListWidget() = default;

void GameListWidget::initialize()
{
	m_model = new GameListModel(this);
	m_model->setCoverScale(Host::GetBaseFloatSettingValue("UI", "GameListCoverArtScale", 0.45f));
	m_model->setShowCoverTitles(Host::GetBaseBoolSettingValue("UI", "GameListShowCoverTitles", true));
	m_model->updateCacheSize(width(), height());

	m_sort_model = new GameListSortModel(m_model);
	m_sort_model->setSourceModel(m_model);

	m_ui.setupUi(this);
	for (u32 type = 0; type < static_cast<u32>(GameList::EntryType::Count); type++)
	{
		m_ui.filterType->addItem(GameListModel::getIconForType(static_cast<GameList::EntryType>(type)),
			qApp->translate("GameList", GameList::EntryTypeToDisplayString(static_cast<GameList::EntryType>(type))));
	}
	for (u32 region = 0; region < static_cast<u32>(GameList::Region::Count); region++)
	{
		m_ui.filterRegion->addItem(GameListModel::getIconForRegion(static_cast<GameList::Region>(region)),
			qApp->translate("GameList", GameList::RegionToString(static_cast<GameList::Region>(region))));
	}

	connect(m_ui.viewGameList, &QPushButton::clicked, this, &GameListWidget::showGameList);
	connect(m_ui.viewGameGrid, &QPushButton::clicked, this, &GameListWidget::showGameGrid);
	connect(m_ui.gridScale, &QSlider::valueChanged, this, &GameListWidget::gridIntScale);
	connect(m_ui.viewGridTitles, &QPushButton::toggled, this, &GameListWidget::setShowCoverTitles);
	connect(m_ui.filterType, &QComboBox::currentIndexChanged, this, [this](int index) {
		m_sort_model->setFilterType((index == 0) ? GameList::EntryType::Count : static_cast<GameList::EntryType>(index - 1));
	});
	connect(m_ui.filterRegion, &QComboBox::currentIndexChanged, this, [this](int index) {
		m_sort_model->setFilterRegion((index == 0) ? GameList::Region::Count : static_cast<GameList::Region>(index - 1));
	});
	connect(m_ui.searchText, &QLineEdit::textChanged, this, [this](const QString& text) {
		m_sort_model->setFilterName(text);
	});

	m_table_view = new QTableView(m_ui.stack);
	m_table_view->setModel(m_sort_model);
	m_table_view->setSortingEnabled(true);
	m_table_view->setSelectionMode(QAbstractItemView::SingleSelection);
	m_table_view->setSelectionBehavior(QAbstractItemView::SelectRows);
	m_table_view->setContextMenuPolicy(Qt::CustomContextMenu);
	m_table_view->setAlternatingRowColors(true);
	m_table_view->setShowGrid(false);
	m_table_view->setCurrentIndex({});
	m_table_view->horizontalHeader()->setHighlightSections(false);
	m_table_view->horizontalHeader()->setContextMenuPolicy(Qt::CustomContextMenu);
	m_table_view->verticalHeader()->hide();
	m_table_view->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOn);
	m_table_view->setVerticalScrollMode(QAbstractItemView::ScrollMode::ScrollPerPixel);

	loadTableViewColumnVisibilitySettings();
	loadTableViewColumnSortSettings();

	connect(m_table_view->selectionModel(), &QItemSelectionModel::currentChanged, this,
		&GameListWidget::onSelectionModelCurrentChanged);
	connect(m_table_view, &QTableView::activated, this, &GameListWidget::onTableViewItemActivated);
	connect(m_table_view, &QTableView::customContextMenuRequested, this,
		&GameListWidget::onTableViewContextMenuRequested);
	connect(m_table_view->horizontalHeader(), &QHeaderView::customContextMenuRequested, this,
		&GameListWidget::onTableViewHeaderContextMenuRequested);
	connect(m_table_view->horizontalHeader(), &QHeaderView::sortIndicatorChanged, this,
		&GameListWidget::onTableViewHeaderSortIndicatorChanged);

	m_ui.stack->insertWidget(0, m_table_view);

	m_list_view = new GameListGridListView(m_ui.stack);
	m_list_view->setModel(m_sort_model);
	m_list_view->setModelColumn(GameListModel::Column_Cover);
	m_list_view->setSelectionMode(QAbstractItemView::SingleSelection);
	m_list_view->setViewMode(QListView::IconMode);
	m_list_view->setResizeMode(QListView::Adjust);
	m_list_view->setUniformItemSizes(true);
	m_list_view->setItemAlignment(Qt::AlignHCenter);
	m_list_view->setContextMenuPolicy(Qt::CustomContextMenu);
	m_list_view->setFrameStyle(QFrame::NoFrame);
	m_list_view->setSpacing(m_model->getCoverArtSpacing());
	m_list_view->setVerticalScrollMode(QAbstractItemView::ScrollMode::ScrollPerPixel);
	m_list_view->verticalScrollBar()->setSingleStep(15);

	updateListFont();

	connect(m_list_view->selectionModel(), &QItemSelectionModel::currentChanged, this,
		&GameListWidget::onSelectionModelCurrentChanged);
	connect(m_list_view, &GameListGridListView::zoomIn, this, &GameListWidget::gridZoomIn);
	connect(m_list_view, &GameListGridListView::zoomOut, this, &GameListWidget::gridZoomOut);
	connect(m_list_view, &QListView::activated, this, &GameListWidget::onListViewItemActivated);
	connect(m_list_view, &QListView::customContextMenuRequested, this, &GameListWidget::onListViewContextMenuRequested);

	m_ui.stack->insertWidget(1, m_list_view);

	m_empty_widget = new QWidget(m_ui.stack);
	m_empty_ui.setupUi(m_empty_widget);
	m_empty_ui.supportedFormats->setText(qApp->translate("GameListWidget", SUPPORTED_FORMATS_STRING));
	connect(m_empty_ui.addGameDirectory, &QPushButton::clicked, this, [this]() { emit addGameDirectoryRequested(); });
	connect(m_empty_ui.scanForNewGames, &QPushButton::clicked, this, [this]() { refresh(false); });
	m_ui.stack->insertWidget(2, m_empty_widget);

	if (Host::GetBaseBoolSettingValue("UI", "GameListGridView", false))
		m_ui.stack->setCurrentIndex(1);
	else
		m_ui.stack->setCurrentIndex(0);

	updateToolbar();
	resizeTableViewColumnsToFit();
}

bool GameListWidget::isShowingGameList() const
{
	return m_ui.stack->currentIndex() == 0;
}

bool GameListWidget::isShowingGameGrid() const
{
	return m_ui.stack->currentIndex() == 1;
}

bool GameListWidget::getShowGridCoverTitles() const
{
	return m_model->getShowCoverTitles();
}

void GameListWidget::refresh(bool invalidate_cache)
{
	cancelRefresh();

	m_refresh_thread = new GameListRefreshThread(invalidate_cache);
	connect(m_refresh_thread, &GameListRefreshThread::refreshProgress, this, &GameListWidget::onRefreshProgress,
		Qt::QueuedConnection);
	connect(m_refresh_thread, &GameListRefreshThread::refreshComplete, this, &GameListWidget::onRefreshComplete,
		Qt::QueuedConnection);
	m_refresh_thread->start();
}

void GameListWidget::cancelRefresh()
{
	if (!m_refresh_thread)
		return;

	m_refresh_thread->cancel();
	m_refresh_thread->wait();

	// Cancelling might not be instant if we're say, scanning a gzip dump. Wait until it's done.
	while (m_refresh_thread)
		QApplication::processEvents(QEventLoop::ExcludeUserInputEvents, 1);
}

void GameListWidget::refreshImages()
{
	m_model->refreshImages();
}

void GameListWidget::onRefreshProgress(const QString& status, int current, int total)
{
	// switch away from the placeholder while we scan, in case we find anything
	if (m_ui.stack->currentIndex() == 2)
		m_ui.stack->setCurrentIndex(Host::GetBaseBoolSettingValue("UI", "GameListGridView", false) ? 1 : 0);

	m_model->refresh();
	emit refreshProgress(status, current, total);
}

void GameListWidget::onRefreshComplete()
{
	m_model->refresh();
	emit refreshComplete();

	pxAssertRel(m_refresh_thread, "Has a refresh thread");
	m_refresh_thread->wait();
	delete m_refresh_thread;
	m_refresh_thread = nullptr;

	// if we still had no games, switch to the helper widget
	if (m_model->rowCount() == 0)
		m_ui.stack->setCurrentIndex(2);
}

void GameListWidget::onSelectionModelCurrentChanged(const QModelIndex& current, const QModelIndex& previous)
{
	const QModelIndex source_index = m_sort_model->mapToSource(current);
	if (!source_index.isValid() || source_index.row() >= static_cast<int>(GameList::GetEntryCount()))
		return;

	emit selectionChanged();
}

void GameListWidget::onTableViewItemActivated(const QModelIndex& index)
{
	const QModelIndex source_index = m_sort_model->mapToSource(index);
	if (!source_index.isValid() || source_index.row() >= static_cast<int>(GameList::GetEntryCount()))
		return;

	emit entryActivated();
}

void GameListWidget::onTableViewContextMenuRequested(const QPoint& point)
{
	emit entryContextMenuRequested(m_table_view->mapToGlobal(point));
}

void GameListWidget::onListViewItemActivated(const QModelIndex& index)
{
	const QModelIndex source_index = m_sort_model->mapToSource(index);
	if (!source_index.isValid() || source_index.row() >= static_cast<int>(GameList::GetEntryCount()))
		return;

	emit entryActivated();
}

void GameListWidget::onListViewContextMenuRequested(const QPoint& point)
{
	emit entryContextMenuRequested(m_list_view->mapToGlobal(point));
}

void GameListWidget::onTableViewHeaderContextMenuRequested(const QPoint& point)
{
	QMenu menu;

	for (int column = 0; column < GameListModel::Column_Count; column++)
	{
		if (column == GameListModel::Column_Cover)
			continue;

		QAction* action = menu.addAction(m_model->getColumnDisplayName(column));
		action->setCheckable(true);
		action->setChecked(!m_table_view->isColumnHidden(column));
		connect(action, &QAction::toggled, [this, column](bool enabled) {
			m_table_view->setColumnHidden(column, !enabled);
			saveTableViewColumnVisibilitySettings(column);
			resizeTableViewColumnsToFit();
		});
	}

	menu.exec(m_table_view->mapToGlobal(point));
}

void GameListWidget::onTableViewHeaderSortIndicatorChanged(int, Qt::SortOrder)
{
	saveTableViewColumnSortSettings();
}

void GameListWidget::listZoom(float delta)
{
	const float new_scale = std::clamp(m_model->getCoverScale() + delta, MIN_SCALE, MAX_SCALE);
	Host::SetBaseFloatSettingValue("UI", "GameListCoverArtScale", new_scale);
	Host::CommitBaseSettingChanges();
	m_model->setCoverScale(new_scale);
	m_model->updateCacheSize(width(), height());
	updateListFont();
	updateToolbar();
}

void GameListWidget::gridZoomIn()
{
	listZoom(0.05f);
}

void GameListWidget::gridZoomOut()
{
	listZoom(-0.05f);
}

void GameListWidget::gridIntScale(int int_scale)
{
	const float new_scale = std::clamp(static_cast<float>(int_scale) / 100.0f, MIN_SCALE, MAX_SCALE);

	Host::SetBaseFloatSettingValue("UI", "GameListCoverArtScale", new_scale);
	Host::CommitBaseSettingChanges();
	m_model->setCoverScale(new_scale);
	m_model->updateCacheSize(width(), height());
	updateListFont();
	updateToolbar();
}

void GameListWidget::refreshGridCovers()
{
	m_model->refreshCovers();
}

void GameListWidget::showGameList()
{
	if (m_ui.stack->currentIndex() == 0 || m_model->rowCount() == 0)
	{
		// We can click the toolbar multiple times, so keep it correct.
		updateToolbar();
		return;
	}

	Host::SetBaseBoolSettingValue("UI", "GameListGridView", false);
	Host::CommitBaseSettingChanges();
	m_ui.stack->setCurrentIndex(0);
	resizeTableViewColumnsToFit();
	updateToolbar();
	emit layoutChange();
}

void GameListWidget::showGameGrid()
{
	if (m_ui.stack->currentIndex() == 1 || m_model->rowCount() == 0)
	{
		// We can click the toolbar multiple times, so keep it correct.
		updateToolbar();
		return;
	}

	Host::SetBaseBoolSettingValue("UI", "GameListGridView", true);
	Host::CommitBaseSettingChanges();
	m_ui.stack->setCurrentIndex(1);
	updateToolbar();
	emit layoutChange();
}

void GameListWidget::setShowCoverTitles(bool enabled)
{
	if (m_model->getShowCoverTitles() == enabled)
		return;

	Host::SetBaseBoolSettingValue("UI", "GameListShowCoverTitles", enabled);
	Host::CommitBaseSettingChanges();
	m_model->setShowCoverTitles(enabled);
	if (isShowingGameGrid())
		m_model->refresh();
	updateToolbar();
	emit layoutChange();
}

void GameListWidget::updateListFont()
{
	QFont font;
	font.setPointSizeF(16.0f * m_model->getCoverScale());
	m_list_view->setFont(font);
}

void GameListWidget::updateToolbar()
{
	const bool grid_view = isShowingGameGrid();
	{
		QSignalBlocker sb(m_ui.viewGameGrid);
		m_ui.viewGameGrid->setChecked(grid_view);
	}
	{
		QSignalBlocker sb(m_ui.viewGameList);
		m_ui.viewGameList->setChecked(!grid_view);
	}
	{
		QSignalBlocker sb(m_ui.viewGridTitles);
		m_ui.viewGridTitles->setChecked(m_model->getShowCoverTitles());
	}
	{
		QSignalBlocker sb(m_ui.gridScale);
		m_ui.gridScale->setValue(static_cast<int>(m_model->getCoverScale() * 100.0f));
	}

	m_ui.viewGridTitles->setEnabled(grid_view);
	m_ui.gridScale->setEnabled(grid_view);
}

void GameListWidget::resizeEvent(QResizeEvent* event)
{
	QWidget::resizeEvent(event);
	resizeTableViewColumnsToFit();
	m_model->updateCacheSize(width(), height());
}

void GameListWidget::resizeTableViewColumnsToFit()
{
	QtUtils::ResizeColumnsForTableView(m_table_view, {
														 45, // type
														 80, // code
														 -1, // title
														 -1, // file title
														 65, // crc
														 80, // time played
														 80, // last played
														 80, // size
														 60, // region
														 120 // compatibility
													 });
}

static std::string getColumnVisibilitySettingsKeyName(int column)
{
	return StringUtil::StdStringFromFormat("Show%s",
		GameListModel::getColumnName(static_cast<GameListModel::Column>(column)));
}

void GameListWidget::loadTableViewColumnVisibilitySettings()
{
	static constexpr std::array<bool, GameListModel::Column_Count> DEFAULT_VISIBILITY = {{
		true, // type
		true, // code
		true, // title
		false, // file title
		false, // crc
		true, // time played
		true, // last played
		true, // size
		true, // region
		true // compatibility
	}};

	for (int column = 0; column < GameListModel::Column_Count; column++)
	{
		const bool visible = Host::GetBaseBoolSettingValue(
			"GameListTableView", getColumnVisibilitySettingsKeyName(column).c_str(), DEFAULT_VISIBILITY[column]);
		m_table_view->setColumnHidden(column, !visible);
	}
}

void GameListWidget::saveTableViewColumnVisibilitySettings()
{
	for (int column = 0; column < GameListModel::Column_Count; column++)
	{
		const bool visible = !m_table_view->isColumnHidden(column);
		Host::SetBaseBoolSettingValue("GameListTableView", getColumnVisibilitySettingsKeyName(column).c_str(), visible);
		Host::CommitBaseSettingChanges();
	}
}

void GameListWidget::saveTableViewColumnVisibilitySettings(int column)
{
	const bool visible = !m_table_view->isColumnHidden(column);
	Host::SetBaseBoolSettingValue("GameListTableView", getColumnVisibilitySettingsKeyName(column).c_str(), visible);
	Host::CommitBaseSettingChanges();
}

void GameListWidget::loadTableViewColumnSortSettings()
{
	const GameListModel::Column DEFAULT_SORT_COLUMN = GameListModel::Column_Type;
	const bool DEFAULT_SORT_DESCENDING = false;

	const GameListModel::Column sort_column =
		GameListModel::getColumnIdForName(Host::GetBaseStringSettingValue("GameListTableView", "SortColumn"))
			.value_or(DEFAULT_SORT_COLUMN);
	const bool sort_descending =
		Host::GetBaseBoolSettingValue("GameListTableView", "SortDescending", DEFAULT_SORT_DESCENDING);
	m_table_view->sortByColumn(sort_column, sort_descending ? Qt::DescendingOrder : Qt::AscendingOrder);
}

void GameListWidget::saveTableViewColumnSortSettings()
{
	const int sort_column = m_table_view->horizontalHeader()->sortIndicatorSection();
	const bool sort_descending = (m_table_view->horizontalHeader()->sortIndicatorOrder() == Qt::DescendingOrder);

	if (sort_column >= 0 && sort_column < GameListModel::Column_Count)
	{
		Host::SetBaseStringSettingValue(
			"GameListTableView", "SortColumn", GameListModel::getColumnName(static_cast<GameListModel::Column>(sort_column)));
	}

	Host::SetBaseBoolSettingValue("GameListTableView", "SortDescending", sort_descending);
	Host::CommitBaseSettingChanges();
}

const GameList::Entry* GameListWidget::getSelectedEntry() const
{
	if (m_ui.stack->currentIndex() == 0)
	{
		const QItemSelectionModel* selection_model = m_table_view->selectionModel();
		if (!selection_model->hasSelection())
			return nullptr;

		const QModelIndexList selected_rows = selection_model->selectedRows();
		if (selected_rows.empty())
			return nullptr;

		const QModelIndex source_index = m_sort_model->mapToSource(selected_rows[0]);
		if (!source_index.isValid())
			return nullptr;

		return GameList::GetEntryByIndex(source_index.row());
	}
	else
	{
		const QItemSelectionModel* selection_model = m_list_view->selectionModel();
		if (!selection_model->hasSelection())
			return nullptr;

		const QModelIndex source_index = m_sort_model->mapToSource(selection_model->currentIndex());
		if (!source_index.isValid())
			return nullptr;

		return GameList::GetEntryByIndex(source_index.row());
	}
}

void GameListWidget::rescanFile(const std::string& path)
{
	// We can't do this while there's a VM running, because of CDVD state... ugh.
	if (QtHost::IsVMValid())
	{
		Console.Error(fmt::format("Can't re-scan ELF at '{}' because we have a VM running.", path));
		return;
	}

	GameList::RescanPath(path);
	m_model->refresh();
}

GameListGridListView::GameListGridListView(QWidget* parent /*= nullptr*/)
	: QListView(parent)
{
}

void GameListGridListView::wheelEvent(QWheelEvent* e)
{
	if (e->modifiers() & Qt::ControlModifier)
	{
		int dy = e->angleDelta().y();
		if (dy != 0)
		{
			if (dy < 0)
				zoomOut();
			else
				zoomIn();

			return;
		}
	}

	QListView::wheelEvent(e);
}