/*
This file is part of Telegram Desktop,
the official desktop application for the Telegram messaging service.

For license and copyright information please follow this link:
https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
*/
#include "storage/storage_media_prepare.h"

#include "platform/platform_file_utilities.h"
#include "storage/localimageloader.h"
#include "core/mime_type.h"
#include "ui/image/image_prepare.h"
#include "ui/chat/attach/attach_extensions.h"
#include "ui/chat/attach/attach_prepare.h"
#include "app.h"

#include <QtCore/QSemaphore>
#include <QtCore/QMimeData>

namespace Storage {
namespace {

using Ui::PreparedFileInformation;
using Ui::PreparedFile;
using Ui::PreparedList;

bool HasExtensionFrom(const QString &file, const QStringList &extensions) {
	for (const auto &extension : extensions) {
		const auto ext = file.right(extension.size());
		if (ext.compare(extension, Qt::CaseInsensitive) == 0) {
			return true;
		}
	}
	return false;
}

bool ValidPhotoForAlbum(
		const PreparedFileInformation::Image &image,
		const QString &mime) {
	if (image.animated || Core::IsMimeSticker(mime)) {
		return false;
	}
	const auto width = image.data.width();
	const auto height = image.data.height();
	return Ui::ValidateThumbDimensions(width, height);
}

bool ValidVideoForAlbum(const PreparedFileInformation::Video &video) {
	const auto width = video.thumbnail.width();
	const auto height = video.thumbnail.height();
	return Ui::ValidateThumbDimensions(width, height);
}

QSize PrepareShownDimensions(const QImage &preview) {
	constexpr auto kMaxWidth = 1280;
	constexpr auto kMaxHeight = 1280;

	const auto result = preview.size();
	return (result.width() > kMaxWidth || result.height() > kMaxHeight)
		? result.scaled(kMaxWidth, kMaxHeight, Qt::KeepAspectRatio)
		: result;
}

bool PrepareDetailsIsWaiting(
		QSemaphore &semaphore,
		PreparedFile &file,
		int previewWidth) {
	crl::async([=, &semaphore, &file] {
		const auto guard = gsl::finally([&] { semaphore.release(); });
		if (!file.path.isEmpty()) {
			file.mime = Core::MimeTypeForFile(QFileInfo(file.path)).name();
			file.information = FileLoadTask::ReadMediaInformation(
				file.path,
				QByteArray(),
				file.mime);
		} else if (!file.content.isEmpty()) {
			file.mime = Core::MimeTypeForData(file.content).name();
			file.information = FileLoadTask::ReadMediaInformation(
				QString(),
				file.content,
				file.mime);
		} else {
			Assert(file.information != nullptr);
		}

		using Image = PreparedFileInformation::Image;
		using Video = PreparedFileInformation::Video;
		if (const auto image = std::get_if<Image>(
				&file.information->media)) {
			if (ValidPhotoForAlbum(*image, file.mime)) {
				file.shownDimensions = PrepareShownDimensions(image->data);
				file.preview = Images::prepareOpaque(image->data.scaledToWidth(
					std::min(previewWidth, style::ConvertScale(image->data.width()))
						* cIntRetinaFactor(),
					Qt::SmoothTransformation));
				Assert(!file.preview.isNull());
				file.preview.setDevicePixelRatio(cRetinaFactor());
				file.type = PreparedFile::AlbumType::Photo;
			} else if (Core::IsMimeSticker(file.mime)) {
				file.type = PreparedFile::AlbumType::None;
			}
		} else if (const auto video = std::get_if<Video>(
				&file.information->media)) {
			if (ValidVideoForAlbum(*video)) {
				auto blurred = Images::prepareBlur(Images::prepareOpaque(video->thumbnail));
				file.shownDimensions = PrepareShownDimensions(video->thumbnail);
				file.preview = std::move(blurred).scaledToWidth(
					previewWidth * cIntRetinaFactor(),
					Qt::SmoothTransformation);
				Assert(!file.preview.isNull());
				file.preview.setDevicePixelRatio(cRetinaFactor());
				file.type = PreparedFile::AlbumType::Video;
			}
		}
	});
	return true;
}

void PrepareDetailsInParallel(PreparedList &result, int previewWidth) {
	Expects(result.files.size() <= Ui::MaxAlbumItems());

	auto waiting = 0;
	QSemaphore semaphore;
	for (auto &file : result.files) {
		if (PrepareDetailsIsWaiting(
				semaphore,
				file,
				previewWidth)) {
			++waiting;
		}
	}
	if (waiting > 0) {
		semaphore.acquire(waiting);
	}
}

} // namespace

bool ValidateDragData(not_null<const QMimeData*> data, bool isAlbum) {
	if (data->urls().size() > 1) {
		return false;
	} else if (data->hasImage()) {
		return true;
	}

	if (isAlbum && data->hasUrls()) {
		const auto url = data->urls().front();
		if (url.isLocalFile()) {
			using namespace Core;
			const auto info = QFileInfo(Platform::File::UrlToLocal(url));
			return IsMimeAcceptedForAlbum(MimeTypeForFile(info).name());
		}
	}

	return true;
}

MimeDataState ComputeMimeDataState(const QMimeData *data) {
	if (!data || data->hasFormat(qsl("application/x-td-forward"))) {
		return MimeDataState::None;
	}

	if (data->hasImage()) {
		return MimeDataState::Image;
	}

	const auto uriListFormat = qsl("text/uri-list");
	if (!data->hasFormat(uriListFormat)) {
		return MimeDataState::None;
	}

	const auto &urls = data->urls();
	if (urls.isEmpty()) {
		return MimeDataState::None;
	}

	const auto imageExtensions = Ui::ImageExtensions();
	auto files = QStringList();
	auto allAreSmallImages = true;
	for (const auto &url : urls) {
		if (!url.isLocalFile()) {
			return MimeDataState::None;
		}
		const auto file = Platform::File::UrlToLocal(url);

		const auto info = QFileInfo(file);
		if (info.isDir()) {
			return MimeDataState::None;
		}

		const auto filesize = info.size();
		if (filesize > kFileSizeLimit) {
			return MimeDataState::None;
		} else if (allAreSmallImages) {
			if (filesize > App::kImageSizeLimit) {
				allAreSmallImages = false;
			} else if (!HasExtensionFrom(file, imageExtensions)) {
				allAreSmallImages = false;
			}
		}
	}
	return allAreSmallImages
		? MimeDataState::PhotoFiles
		: MimeDataState::Files;
}

PreparedList PrepareMediaList(const QList<QUrl> &files, int previewWidth) {
	auto locals = QStringList();
	locals.reserve(files.size());
	for (const auto &url : files) {
		if (!url.isLocalFile()) {
			return {
				PreparedList::Error::NonLocalUrl,
				url.toDisplayString()
			};
		}
		locals.push_back(Platform::File::UrlToLocal(url));
	}
	return PrepareMediaList(locals, previewWidth);
}

PreparedList PrepareMediaList(const QStringList &files, int previewWidth) {
	auto result = PreparedList();
	result.files.reserve(files.size());
	const auto extensionsToCompress = Ui::ExtensionsForCompression();
	for (const auto &file : files) {
		const auto fileinfo = QFileInfo(file);
		const auto filesize = fileinfo.size();
		if (fileinfo.isDir()) {
			return {
				PreparedList::Error::Directory,
				file
			};
		} else if (filesize <= 0) {
			return {
				PreparedList::Error::EmptyFile,
				file
			};
		} else if (filesize > kFileSizeLimit) {
			return {
				PreparedList::Error::TooLargeFile,
				file
			};
		}
		if (result.files.size() < Ui::MaxAlbumItems()) {
			result.files.emplace_back(file);
			result.files.back().size = filesize;
		} else {
			result.filesToProcess.emplace_back(file);
			result.files.back().size = filesize;
		}
	}
	PrepareDetailsInParallel(result, previewWidth);
	return result;
}

PreparedList PrepareMediaFromImage(
		QImage &&image,
		QByteArray &&content,
		int previewWidth) {
	auto result = PreparedList();
	auto file = PreparedFile(QString());
	file.content = content;
	if (file.content.isEmpty()) {
		file.information = std::make_unique<PreparedFileInformation>();
		const auto animated = false;
		FileLoadTask::FillImageInformation(
			std::move(image),
			animated,
			file.information);
	}
	result.files.push_back(std::move(file));
	PrepareDetailsInParallel(result, previewWidth);
	return result;
}

std::optional<PreparedList> PreparedFileFromFilesDialog(
		FileDialog::OpenResult &&result,
		bool isAlbum,
		Fn<void(tr::phrase<>)> errorCallback,
		int previewWidth) {
	if (result.paths.isEmpty() && result.remoteContent.isEmpty()) {
		return std::nullopt;
	}

	if (!result.remoteContent.isEmpty()) {
		auto list = PrepareMediaFromImage(
			QImage(),
			std::move(result.remoteContent),
			previewWidth);

		const auto mimeFile = list.files.front().mime;
		if (Core::IsMimeSticker(mimeFile)) {
			errorCallback(tr::lng_edit_media_invalid_file);
			return std::nullopt;
		}

		if (isAlbum) {
			const auto file = &list.files.front();
			if (!Core::IsMimeAcceptedForAlbum(mimeFile)
				|| file->type == PreparedFile::AlbumType::File
				|| file->type == PreparedFile::AlbumType::File) {
				errorCallback(tr::lng_edit_media_album_error);
				return std::nullopt;
			}
		}
		Expects(list.files.size() == 1);
		return list;
	} else if (!result.paths.isEmpty()) {
		const auto isSingleFile = (result.paths.size() == 1);
		auto temp = PrepareMediaList(result.paths, previewWidth);
		if (temp.error != PreparedList::Error::None) {
			errorCallback(tr::lng_send_media_invalid_files);
			return std::nullopt;
		}
		auto filteredFiles = ranges::view::all(
			temp.files
		) | ranges::view::filter([&](const auto &file) {
			const auto info = QFileInfo(file.path);
			if (Core::IsMimeSticker(Core::MimeTypeForFile(info).name())) {
				if (isSingleFile) {
					errorCallback(tr::lng_edit_media_invalid_file);
				}
				return false;
			}
			if (!isAlbum) {
				return true;
			}
			using Info = PreparedFileInformation;

			const auto media = &file.information->media;
			const auto valid = v::match(*media, [](const Info::Image &data) {
				return Ui::ValidateThumbDimensions(
					data.data.width(),
					data.data.height())
					&& !data.animated;
			}, [](Info::Video &data) {
				data.isGifv = false;
				return true;
			}, [](auto &&other) {
				return false;
			});
			if (!valid && isSingleFile) {
				errorCallback(tr::lng_edit_media_album_error);
			}
			return valid;
		}) | ranges::view::transform([](auto &file) {
			return std::move(file);
		}) | ranges::to_vector;

		if (!filteredFiles.size()) {
			if (!isSingleFile) {
				errorCallback(tr::lng_send_media_invalid_files);
			}
			return std::nullopt;
		}

		auto list = PreparedList(temp.error, temp.errorData);
		list.files = std::move(filteredFiles);

		return list;
	}
	return std::nullopt;
}

} // namespace Storage