//
// This file is part of Kepka,
// an unofficial desktop version of Telegram messaging app,
// see https://github.com/procxx/kepka
//
// Kepka is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// It 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.
//
// In addition, as a special exception, the copyright holders give permission
// to link the code of portions of this program with the OpenSSL library.
//
// Full license: https://github.com/procxx/kepka/blob/master/LICENSE
// Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
// Copyright (c) 2017- Kepka Contributors, https://github.com/procxx
//
#pragma once

#include <QMouseEvent>

#include "structs.h"
#include "ui/animation.h"
#include "ui/twidget.h"

class BoxContent;

namespace Window {
class MainMenu;
class Controller;
} // namespace Window

class LayerWidget : public TWidget {
	Q_OBJECT

public:
	using TWidget::TWidget;

	virtual void parentResized() = 0;
	virtual void showFinished() {}
	void setInnerFocus();
	bool setClosing() {
		if (!_closing) {
			_closing = true;
			closeHook();
			return true;
		}
		return false;
	}

	bool overlaps(const QRect &globalRect);

	void setClosedCallback(Fn<void()> callback) {
		_closedCallback = std::move(callback);
	}
	void setResizedCallback(Fn<void()> callback) {
		_resizedCallback = std::move(callback);
	}

protected:
	void closeLayer() {
		if (_closedCallback) {
			_closedCallback();
		}
	}
	void mousePressEvent(QMouseEvent *e) override {
		e->accept();
	}
	void resizeEvent(QResizeEvent *e) override {
		if (_resizedCallback) {
			_resizedCallback();
		}
	}
	virtual void doSetInnerFocus() {
		setFocus();
	}
	virtual void closeHook() {}

private:
	bool _closing = false;
	Fn<void()> _closedCallback;
	Fn<void()> _resizedCallback;
};

class LayerStackWidget : public TWidget {
	Q_OBJECT

public:
	LayerStackWidget(QWidget *parent, Window::Controller *controller);

	Window::Controller *controller() const {
		return _controller;
	}
	void finishAnimation();

	void showBox(object_ptr<BoxContent> box);
	void showSpecialLayer(object_ptr<LayerWidget> layer);
	void showMainMenu();
	void appendBox(object_ptr<BoxContent> box);
	void prependBox(object_ptr<BoxContent> box);

	bool canSetFocus() const;
	void setInnerFocus();

	bool contentOverlapped(const QRect &globalRect);

	void hideLayers();
	void hideAll();
	void hideTopLayer();

	bool layerShown() const;

	~LayerStackWidget();

protected:
	void keyPressEvent(QKeyEvent *e) override;
	void mousePressEvent(QMouseEvent *e) override;
	void resizeEvent(QResizeEvent *e) override;

private slots:
	void onLayerDestroyed(QObject *obj);
	void onLayerClosed(LayerWidget *layer);
	void onLayerResized();

private:
	LayerWidget *pushBox(object_ptr<BoxContent> box);
	void showFinished();
	void hideCurrent();

	enum class Action {
		ShowMainMenu,
		ShowSpecialLayer,
		ShowLayer,
		HideLayer,
		HideAll,
	};
	template <typename SetupNew, typename ClearOld>
	void startAnimation(SetupNew setupNewWidgets, ClearOld clearOldWidgets, Action action);

	void prepareForAnimation();
	void animationDone();

	void setCacheImages();
	void clearLayers();
	void clearSpecialLayer();
	void initChildLayer(LayerWidget *layer);
	void updateLayerBoxes();
	void fixOrder();
	void sendFakeMouseEvent();

	LayerWidget *currentLayer() {
		return _layers.empty() ? nullptr : _layers.back();
	}
	const LayerWidget *currentLayer() const {
		return const_cast<LayerStackWidget *>(this)->currentLayer();
	}

	Window::Controller *_controller = nullptr;

	QList<LayerWidget *> _layers;

	object_ptr<LayerWidget> _specialLayer = {nullptr};
	object_ptr<Window::MainMenu> _mainMenu = {nullptr};

	class BackgroundWidget;
	object_ptr<BackgroundWidget> _background;
};

class MediaPreviewWidget : public TWidget, private base::Subscriber {
	Q_OBJECT

public:
	MediaPreviewWidget(QWidget *parent, not_null<Window::Controller *> controller);

	void showPreview(DocumentData *document);
	void showPreview(PhotoData *photo);
	void hidePreview();

	~MediaPreviewWidget();

protected:
	void paintEvent(QPaintEvent *e) override;
	void resizeEvent(QResizeEvent *e) override;

private:
	QSize currentDimensions() const;
	QPixmap currentImage() const;
	void startShow();
	void fillEmojiString();
	void resetGifAndCache();

	not_null<Window::Controller *> _controller;

	Animation _a_shown;
	bool _hiding = false;
	DocumentData *_document = nullptr;
	PhotoData *_photo = nullptr;
	Media::Clip::ReaderPointer _gif;

	int _emojiSize;
	std::vector<not_null<EmojiPtr>> _emojiList;

	void clipCallback(Media::Clip::Notification notification);

	enum CacheStatus {
		CacheNotLoaded,
		CacheThumbLoaded,
		CacheLoaded,
	};
	mutable CacheStatus _cacheStatus = CacheNotLoaded;
	mutable QPixmap _cache;
	mutable QSize _cachedSize;
};

template <typename BoxType, typename... Args> inline object_ptr<BoxType> Box(Args &&... args) {
	auto parent = static_cast<QWidget *>(nullptr);
	return object_ptr<BoxType>(parent, std::forward<Args>(args)...);
}