/*  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 "GameListModel.h"
#include "common/FileSystem.h"
#include "common/StringUtil.h"
#include <QtCore/QDate>
#include <QtCore/QDateTime>
#include <QtGui/QGuiApplication>
#include <QtGui/QIcon>
#include <QtGui/QPainter>

static constexpr std::array<const char*, GameListModel::Column_Count> s_column_names = {
	{"Type", "Code", "Title", "File Title", "CRC", "Size", "Region", "Compatibility", "Cover"}};

static constexpr int COVER_ART_WIDTH = 350;
static constexpr int COVER_ART_HEIGHT = 512;
static constexpr int COVER_ART_SPACING = 32;

static int DPRScale(int size, float dpr)
{
	return static_cast<int>(static_cast<float>(size) * dpr);
}

static int DPRUnscale(int size, float dpr)
{
	return static_cast<int>(static_cast<float>(size) / dpr);
}

static void resizeAndPadPixmap(QPixmap* pm, int expected_width, int expected_height, float dpr)
{
	const int dpr_expected_width = DPRScale(expected_width, dpr);
	const int dpr_expected_height = DPRScale(expected_height, dpr);
	if (pm->width() == dpr_expected_width && pm->height() == dpr_expected_height)
		return;

	*pm = pm->scaled(dpr_expected_width, dpr_expected_height, Qt::KeepAspectRatio, Qt::SmoothTransformation);
	if (pm->width() == dpr_expected_width && pm->height() == dpr_expected_height)
		return;

	// QPainter works in unscaled coordinates.
	int xoffs = 0;
	int yoffs = 0;
	if (pm->width() < dpr_expected_width)
		xoffs = DPRUnscale((dpr_expected_width - pm->width()) / 2, dpr);
	if (pm->height() < dpr_expected_height)
		yoffs = DPRUnscale((dpr_expected_height - pm->height()) / 2, dpr);

	QPixmap padded_image(dpr_expected_width, dpr_expected_height);
	padded_image.setDevicePixelRatio(dpr);
	padded_image.fill(Qt::transparent);
	QPainter painter;
	if (painter.begin(&padded_image))
	{
		painter.setCompositionMode(QPainter::CompositionMode_Source);
		painter.drawPixmap(xoffs, yoffs, *pm);
		painter.setCompositionMode(QPainter::CompositionMode_Destination);
		painter.fillRect(padded_image.rect(), QColor(0, 0, 0, 0));
		painter.end();
	}

	*pm = padded_image;
}

static QPixmap createPlaceholderImage(const QPixmap& placeholder_pixmap, int width, int height, float scale,
	const std::string& title)
{
	const float dpr = qApp->devicePixelRatio();
	QPixmap pm(placeholder_pixmap.copy());
	pm.setDevicePixelRatio(dpr);
	if (pm.isNull())
		return QPixmap();

	resizeAndPadPixmap(&pm, width, height, dpr);
	QPainter painter;
	if (painter.begin(&pm))
	{
		QFont font;
		font.setPointSize(std::max(static_cast<int>(32.0f * scale), 1));
		painter.setFont(font);
		painter.setPen(Qt::white);

		const QRect text_rc(0, 0, static_cast<int>(static_cast<float>(width)),
			static_cast<int>(static_cast<float>(height)));
		painter.drawText(text_rc, Qt::AlignCenter | Qt::TextWordWrap, QString::fromStdString(title));
		painter.end();
	}

	return pm;
}

std::optional<GameListModel::Column> GameListModel::getColumnIdForName(std::string_view name)
{
	for (int column = 0; column < Column_Count; column++)
	{
		if (name == s_column_names[column])
			return static_cast<Column>(column);
	}

	return std::nullopt;
}

const char* GameListModel::getColumnName(Column col)
{
	return s_column_names[static_cast<int>(col)];
}

GameListModel::GameListModel(QObject* parent /* = nullptr */)
	: QAbstractTableModel(parent)
{
	loadCommonImages();
	setColumnDisplayNames();
}
GameListModel::~GameListModel() = default;

void GameListModel::setCoverScale(float scale)
{
	if (m_cover_scale == scale)
		return;

	m_cover_pixmap_cache.clear();
	m_cover_scale = scale;
}

void GameListModel::refreshCovers()
{
	m_cover_pixmap_cache.clear();
	refresh();
}

int GameListModel::getCoverArtWidth() const
{
	return std::max(static_cast<int>(static_cast<float>(COVER_ART_WIDTH) * m_cover_scale), 1);
}

int GameListModel::getCoverArtHeight() const
{
	return std::max(static_cast<int>(static_cast<float>(COVER_ART_HEIGHT) * m_cover_scale), 1);
}

int GameListModel::getCoverArtSpacing() const
{
	return std::max(static_cast<int>(static_cast<float>(COVER_ART_SPACING) * m_cover_scale), 1);
}

int GameListModel::rowCount(const QModelIndex& parent) const
{
	if (parent.isValid())
		return 0;

	return static_cast<int>(GameList::GetEntryCount());
}

int GameListModel::columnCount(const QModelIndex& parent) const
{
	if (parent.isValid())
		return 0;

	return Column_Count;
}

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

	const int row = index.row();
	if (row < 0 || row >= static_cast<int>(GameList::GetEntryCount()))
		return {};

	const auto lock = GameList::GetLock();
	const GameList::Entry* ge = GameList::GetEntryByIndex(row);
	if (!ge)
		return {};

	switch (role)
	{
		case Qt::DisplayRole:
		{
			switch (index.column())
			{
				case Column_Serial:
					return QString::fromStdString(ge->serial);

				case Column_Title:
					return QString::fromStdString(ge->title);

				case Column_FileTitle:
				{
					const std::string_view file_title(FileSystem::GetFileTitleFromPath(ge->path));
					return QString::fromUtf8(file_title.data(), static_cast<int>(file_title.length()));
				}

				case Column_CRC:
					return QStringLiteral("%1").arg(ge->crc, 8, 16, QChar('0'));

				case Column_Size:
					return QString("%1 MB").arg(static_cast<double>(ge->total_size) / 1048576.0, 0, 'f', 2);

				case Column_Cover:
				{
					if (m_show_titles_for_covers)
						return QString::fromStdString(ge->title);
					else
						return {};
				}

				default:
					return {};
			}
		}

		case Qt::InitialSortOrderRole:
		{
			switch (index.column())
			{
				case Column_Type:
					return static_cast<int>(ge->type);

				case Column_Serial:
					return QString::fromStdString(ge->serial);

				case Column_Title:
				case Column_Cover:
					return QString::fromStdString(ge->title);

				case Column_FileTitle:
				{
					const std::string_view file_title(FileSystem::GetFileTitleFromPath(ge->path));
					return QString::fromUtf8(file_title.data(), static_cast<int>(file_title.length()));
				}

				case Column_CRC:
					return static_cast<int>(ge->crc);

				case Column_Region:
					return static_cast<int>(ge->region);

				case Column_Compatibility:
					return static_cast<int>(ge->compatibility_rating);

				case Column_Size:
					return static_cast<qulonglong>(ge->total_size);

				default:
					return {};
			}
		}

		case Qt::DecorationRole:
		{
			switch (index.column())
			{
				case Column_Type:
				{
					switch (ge->type)
					{
						case GameList::EntryType::PS1Disc:
						case GameList::EntryType::PS2Disc:
							// return ((ge->settings.GetUserSettingsCount() > 0) ? m_type_disc_with_settings_pixmap : // m_type_disc_pixmap);
							return m_type_disc_pixmap;
						case GameList::EntryType::Playlist:
							return m_type_playlist_pixmap;
						case GameList::EntryType::ELF:
						default:
							return m_type_exe_pixmap;
					}
				}

				case Column_Region:
				{
					switch (ge->region)
					{
						case GameList::Region::NTSC_J:
							return m_region_jp_pixmap;
						case GameList::Region::NTSC_UC:
							return m_region_us_pixmap;
						case GameList::Region::PAL:
							return m_region_eu_pixmap;
						case GameList::Region::Other:
						default:
							return m_region_other_pixmap;
					}
				}

				case Column_Compatibility:
				{
					return m_compatibiliy_pixmaps[static_cast<int>(
						(static_cast<u32>(ge->compatibility_rating) >= GameList::CompatibilityRatingCount) ?
                            GameList::CompatibilityRating::Unknown :
                            ge->compatibility_rating)];
				}

				case Column_Cover:
				{
					auto it = m_cover_pixmap_cache.find(ge->path);
					if (it != m_cover_pixmap_cache.end())
						return it->second;

					QPixmap image;
					std::string path = GameList::GetCoverImagePathForEntry(ge);
					if (!path.empty())
					{
						const float dpr = qApp->devicePixelRatio();
						image = QPixmap(QString::fromStdString(path));
						if (!image.isNull())
						{
							image.setDevicePixelRatio(dpr);
							resizeAndPadPixmap(&image, getCoverArtWidth(), getCoverArtHeight(), dpr);
						}
					}

					if (image.isNull())
					{
						image = createPlaceholderImage(m_placeholder_pixmap, getCoverArtWidth(), getCoverArtHeight(), m_cover_scale,
							ge->title);
					}

					m_cover_pixmap_cache.emplace(ge->path, image);
					return image;
				}
				break;

				default:
					return {};
			}

			default:
				return {};
		}
	}
}

QVariant GameListModel::headerData(int section, Qt::Orientation orientation, int role) const
{
	if (orientation != Qt::Horizontal || role != Qt::DisplayRole || section < 0 || section >= Column_Count)
		return {};

	return m_column_display_names[section];
}

void GameListModel::refresh()
{
	beginResetModel();
	endResetModel();
}

bool GameListModel::titlesLessThan(int left_row, int right_row) const
{
	if (left_row < 0 || left_row >= static_cast<int>(GameList::GetEntryCount()) || right_row < 0 ||
		right_row >= static_cast<int>(GameList::GetEntryCount()))
	{
		return false;
	}

	const GameList::Entry* left = GameList::GetEntryByIndex(left_row);
	const GameList::Entry* right = GameList::GetEntryByIndex(right_row);
	return (StringUtil::Strcasecmp(left->title.c_str(), right->title.c_str()) < 0);
}

bool GameListModel::lessThan(const QModelIndex& left_index, const QModelIndex& right_index, int column) const
{
	if (!left_index.isValid() || !right_index.isValid())
		return false;

	const int left_row = left_index.row();
	const int right_row = right_index.row();
	if (left_row < 0 || left_row >= static_cast<int>(GameList::GetEntryCount()) || right_row < 0 ||
		right_row >= static_cast<int>(GameList::GetEntryCount()))
	{
		return false;
	}

	const auto lock = GameList::GetLock();
	const GameList::Entry* left = GameList::GetEntryByIndex(left_row);
	const GameList::Entry* right = GameList::GetEntryByIndex(right_row);
	if (!left || !right)
		return false;

	switch (column)
	{
		case Column_Type:
		{
			if (left->type == right->type)
				return titlesLessThan(left_row, right_row);

			return static_cast<int>(left->type) < static_cast<int>(right->type);
		}

		case Column_Serial:
		{
			if (left->serial == right->serial)
				return titlesLessThan(left_row, right_row);
			return (StringUtil::Strcasecmp(left->serial.c_str(), right->serial.c_str()) < 0);
		}

		case Column_Title:
		{
			return titlesLessThan(left_row, right_row);
		}

		case Column_FileTitle:
		{
			const std::string_view file_title_left(FileSystem::GetFileTitleFromPath(left->path));
			const std::string_view file_title_right(FileSystem::GetFileTitleFromPath(right->path));
			if (file_title_left == file_title_right)
				return titlesLessThan(left_row, right_row);

			const std::size_t smallest = std::min(file_title_left.size(), file_title_right.size());
			return (StringUtil::Strncasecmp(file_title_left.data(), file_title_right.data(), smallest) < 0);
		}

		case Column_Region:
		{
			if (left->region == right->region)
				return titlesLessThan(left_row, right_row);
			return (static_cast<int>(left->region) < static_cast<int>(right->region));
		}

		case Column_Compatibility:
		{
			if (left->compatibility_rating == right->compatibility_rating)
				return titlesLessThan(left_row, right_row);

			return (static_cast<int>(left->compatibility_rating) < static_cast<int>(right->compatibility_rating));
		}

		case Column_Size:
		{
			if (left->total_size == right->total_size)
				return titlesLessThan(left_row, right_row);

			return (left->total_size < right->total_size);
		}

		case Column_CRC:
		{
			if (left->crc == right->crc)
				return titlesLessThan(left_row, right_row);

			return (left->crc < right->crc);
		}

		default:
			return false;
	}
}

void GameListModel::loadCommonImages()
{
	m_type_disc_pixmap = QIcon(QStringLiteral(":/icons/media-optical-24.png")).pixmap(QSize(24, 24));
	m_type_disc_with_settings_pixmap = QIcon(QStringLiteral(":/icons/media-optical-gear-24.png")).pixmap(QSize(24, 24));
	m_type_exe_pixmap = QIcon(QStringLiteral(":/icons/applications-system-24.png")).pixmap(QSize(24, 24));
	m_type_playlist_pixmap = QIcon(QStringLiteral(":/icons/address-book-new-22.png")).pixmap(QSize(22, 22));
	m_region_eu_pixmap = QIcon(QStringLiteral(":/icons/flag-eu.png")).pixmap(QSize(42, 30));
	m_region_jp_pixmap = QIcon(QStringLiteral(":/icons/flag-jp.png")).pixmap(QSize(42, 30));
	m_region_us_pixmap = QIcon(QStringLiteral(":/icons/flag-us.png")).pixmap(QSize(42, 30));
	m_region_other_pixmap = QIcon(QStringLiteral(":/icons/flag-other.png")).pixmap(QSize(42, 30));

	for (u32 i = 1; i < GameList::CompatibilityRatingCount; i++)
		m_compatibiliy_pixmaps[i].load(QStringLiteral(":/icons/star-%1.png").arg(i - 1));

	m_placeholder_pixmap.load(QString::fromStdString(Path::CombineStdString(EmuFolders::Resources, "cover-placeholder.png")));
}

void GameListModel::setColumnDisplayNames()
{
	m_column_display_names[Column_Type] = tr("Type");
	m_column_display_names[Column_Serial] = tr("Code");
	m_column_display_names[Column_Title] = tr("Title");
	m_column_display_names[Column_FileTitle] = tr("File Title");
	m_column_display_names[Column_CRC] = tr("CRC");
	m_column_display_names[Column_Size] = tr("Size");
	m_column_display_names[Column_Region] = tr("Region");
	m_column_display_names[Column_Compatibility] = tr("Compatibility");
}