/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2020, Laurent Pinchart
 * Copyright 2022 NXP
 *
 * Generic format converter interface
 */

#pragma once

#include <functional>
#include <initializer_list>
#include <map>
#include <memory>
#include <string>
#include <tuple>
#include <utility>
#include <vector>

#include <libcamera/base/class.h>
#include <libcamera/base/flags.h>
#include <libcamera/base/signal.h>

#include <libcamera/geometry.h>
#include "libcamera/internal/v4l2_request.h"

namespace libcamera {

class FrameBuffer;
class MediaDevice;
class PixelFormat;
class Stream;
struct StreamConfiguration;

class Converter
{
public:
	enum class Feature {
		None = 0,
		InputCrop = (1 << 0),
	};

	using Features = Flags<Feature>;

	enum class Alignment {
		Down = 0,
		Up,
	};

	Converter(std::shared_ptr<MediaDevice> media, Features features = Feature::None);
	virtual ~Converter();

	virtual int loadConfiguration(const std::string &filename) = 0;

	virtual bool isValid() const = 0;

	virtual std::vector<PixelFormat> formats(PixelFormat input) = 0;
	virtual SizeRange sizes(const Size &input) = 0;

	virtual Size adjustInputSize(const PixelFormat &pixFmt,
				     const Size &size,
				     Alignment align = Alignment::Down) = 0;
	virtual Size adjustOutputSize(const PixelFormat &pixFmt,
				      const Size &size,
				      Alignment align = Alignment::Down) = 0;

	virtual std::tuple<unsigned int, unsigned int>
	strideAndFrameSize(const PixelFormat &pixelFormat, const Size &size) = 0;

	virtual int validateOutput(StreamConfiguration *cfg, bool *adjusted,
				   Alignment align = Alignment::Down) = 0;

	virtual int configure(const StreamConfiguration &inputCfg,
			      const std::vector<std::reference_wrapper<const StreamConfiguration>> &outputCfgs) = 0;
	virtual bool isConfigured(const Stream *stream) const = 0;
	virtual int exportBuffers(const Stream *stream, unsigned int count,
				  std::vector<std::unique_ptr<FrameBuffer>> *buffers) = 0;

	virtual int start() = 0;
	virtual void stop() = 0;

	virtual int queueBuffers(FrameBuffer *input,
				 const std::map<const Stream *, FrameBuffer *> &outputs,
				 const V4L2Request *request = nullptr) = 0;

	virtual int setInputCrop(const Stream *stream, Rectangle *rect) = 0;
	virtual std::pair<Rectangle, Rectangle> inputCropBounds() = 0;
	virtual std::pair<Rectangle, Rectangle> inputCropBounds(const Stream *stream) = 0;

	Signal<FrameBuffer *> inputBufferReady;
	Signal<FrameBuffer *> outputBufferReady;

	const std::string &deviceNode() const { return deviceNode_; }

	Features features() const { return features_; }

protected:
	Features features_;

private:
	std::string deviceNode_;
};

class ConverterFactoryBase
{
public:
	ConverterFactoryBase(const std::string name, std::initializer_list<std::string> compatibles);
	virtual ~ConverterFactoryBase() = default;

	const std::vector<std::string> &compatibles() const { return compatibles_; }

	static std::unique_ptr<Converter> create(std::shared_ptr<MediaDevice> media);
	static std::vector<ConverterFactoryBase *> &factories();
	static std::vector<std::string> names();

private:
	LIBCAMERA_DISABLE_COPY_AND_MOVE(ConverterFactoryBase)

	static void registerType(ConverterFactoryBase *factory);

	virtual std::unique_ptr<Converter>
	createInstance(std::shared_ptr<MediaDevice> media) const = 0;

	std::string name_;
	std::vector<std::string> compatibles_;
};

template<typename _Converter>
class ConverterFactory : public ConverterFactoryBase
{
public:
	ConverterFactory(const char *name, std::initializer_list<std::string> compatibles)
		: ConverterFactoryBase(name, compatibles)
	{
	}

	std::unique_ptr<Converter> createInstance(std::shared_ptr<MediaDevice> media) const override
	{
		return std::make_unique<_Converter>(media);
	}
};

#define REGISTER_CONVERTER(name, converter, compatibles) \
	static ConverterFactory<converter> global_##converter##Factory(name, compatibles);

} /* namespace libcamera */