#include "Codec.h"
#include "ffcpp.h"
#include <stdexcept>

namespace ffcpp {

	Codec::Codec(): _codecCtx(nullptr), _codec(nullptr) {

	}

	Codec::Codec(AVCodecContext *ctx, CodecType type): _codecCtx(ctx) {
		if(type == CodecType::Encoder) {
			_codec = avcodec_find_encoder(ctx->codec_id);
		} else {
			_codec = avcodec_find_decoder(ctx->codec_id);
		}

		if(!_codec) throw std::runtime_error("cannot find codec");

		int res = avcodec_open2(_codecCtx, _codec, nullptr);
		throwIfError(res, "cannot open codec");
	}

	Codec::Codec(AVCodecContext *ctx, AVCodec *codec) {
		_codecCtx = ctx;
		_codec = codec;

		int res = avcodec_open2(_codecCtx, _codec, nullptr);
		throwIfError(res, "cannot open codec");
	}

	Codec::~Codec() {
		if(_codecCtx) {
			avcodec_close(_codecCtx);
		}
	}

	Codec::operator AVCodecContext*() const {
		return _codecCtx;
	}

	int Codec::width() const {
		return _codecCtx->width;
	}

	int Codec::height() const {
		return _codecCtx->height;
	}

	AVRational Codec::timeBase() const {
		return _codecCtx->time_base;
	}

	int Codec::capabilities() const {
		return _codec->capabilities;
	}

	AVPixelFormat Codec::pixelFormat() const {
		return _codecCtx->pix_fmt;
	}

	AVSampleFormat Codec::sampleFormat() const {
		return _codecCtx->codec->sample_fmts[0];
	}

	int Codec::frameSize() const {
		return _codecCtx->frame_size;
	}

	int Codec::channels() const {
		return _codecCtx->channels;
	}

	int Codec::sampleRate() const {
		return _codecCtx->sample_rate;
	}

	void Codec::setWidth(int width) {
		_codecCtx->width = width;
	}

	void Codec::setHeight(int height) {
		_codecCtx->height = height;
	}

	void Codec::setPixelFormat(AVPixelFormat pixelFormat) {
		_codecCtx->pix_fmt = pixelFormat;
	}

	Codec::Codec(Codec&& c) noexcept {
		*this = std::move(c);
	}

	Codec& Codec::operator=(Codec&& c) noexcept {
		_codec = c._codec;
		_codecCtx = c._codecCtx;
		c._codec = nullptr;
		c._codecCtx = nullptr;
		return *this;
	}

	Frame Codec::decode(Packet &packet) {
		Frame frame;
		int gotPicture = 0;
		auto decFunc = (_codecCtx->codec_type == AVMEDIA_TYPE_VIDEO ? avcodec_decode_video2 : avcodec_decode_audio4);

		while(!gotPicture) {
			int res = decFunc(_codecCtx, frame, &gotPicture, packet);
			if(res < 0) throw std::runtime_error("cannot decode packet");
		}

		if(_codecCtx->codec_type == AVMEDIA_TYPE_VIDEO) {
			frame.guessPts();
		}

		return frame;
	}

	Packet Codec::encode(AVFrame* frame) {
		Packet packet;
		int gotPacket = 0;
		auto encFunc = (_codecCtx->codec_type == AVMEDIA_TYPE_VIDEO ? avcodec_encode_video2 : avcodec_encode_audio2);

		int res = encFunc(_codecCtx, packet, frame, &gotPacket);
		if(res < 0) throw std::runtime_error("cannot encode frame");

		return packet;
	}

	Frame Codec::createAudioFrame() const {
		return Frame(_codecCtx->frame_size, _codecCtx->channels, _codecCtx->codec->sample_fmts[0], _codecCtx->sample_rate);
	}

}