#include <image_io.hpp>
#include <utilities.hpp>

extern "C" {
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libswscale/swscale.h>
}

using namespace std;


static void save_as_jpg(av::frame const & frame, std::string const & filename){
	const auto pix_fmt = AV_PIX_FMT_YUVJ444P;
	const auto codec_id= AV_CODEC_ID_MJPEG;

	// Convert
	int tile_width = 800;
	int tile_height = 600;

	int h_tiles = 8;
	int v_tiles = 6;

	std::vector<uint8_t, av::allocator<uint8_t>> data(make_u(avpicture_get_size(pix_fmt, h_tiles * tile_width, v_tiles * tile_height)), 0);
	av::frame converted_frame = av::frame_alloc();
	avpicture_fill(reinterpret_cast<AVPicture*>(converted_frame.get()), data.data(), pix_fmt, h_tiles * tile_width, v_tiles * tile_height);
	converted_frame->width = h_tiles * tile_width;
	converted_frame->height = v_tiles * tile_height;
	converted_frame->format = pix_fmt;

	auto sws_context = sws_getContext(frame->width, frame->height, av::get_format(frame), tile_width, tile_height, av::get_format(converted_frame), 0, nullptr, nullptr, nullptr);
	if(!sws_context) throw std::runtime_error("boem sws context");

	av::frame cropped_frame = av::frame_clone(converted_frame);
	for(int r = 0; r < v_tiles; ++r) {
		for(int c = 0; c < h_tiles; ++c){
			av_picture_crop(reinterpret_cast<AVPicture*>(cropped_frame.get()), reinterpret_cast<AVPicture*>(converted_frame.get()), av::get_format(converted_frame), r * tile_height, c * tile_width);
			sws_scale (sws_context, {frame->data}, {frame->linesize}, 0, frame->height, {cropped_frame->data}, {cropped_frame->linesize});
		}
	}

	sws_freeContext(sws_context);

	// Encode
	auto codec = avcodec_find_encoder(codec_id);
	if(!codec) throw av::error("Could not find codec");

	auto codec_ctx = std::unique_ptr<AVCodecContext, av::deleter<AVCodecContext>>(avcodec_alloc_context3(codec), [](auto x){ avcodec_free_context(&x); });
	if(!codec_ctx) throw av::error("Could not allocate codec context");

	codec_ctx->pix_fmt = pix_fmt;
	codec_ctx->width = converted_frame->width;
	codec_ctx->height = converted_frame->height;
	codec_ctx->time_base = av_make_q(1, 1);
	auto opened_codec = av::codec_open(codec_ctx.get(), codec, nullptr);

	const auto buffer_size = avpicture_get_size(pix_fmt, codec_ctx->width, codec_ctx->height);
	std::vector<uint8_t> buffer(make_u(buffer_size), 0);
	auto output_size = avcodec_encode_video(codec_ctx.get(), buffer.data(), buffer_size, converted_frame.get());
	assert(output_size <= buffer_size);
	cout << "output size" << output_size << endl;

	auto file = fopen(filename.c_str(), "wb");
	fwrite(buffer.data(), 1, make_u(output_size), file);
	fclose(file);
}

int main(){
	av_register_all();

	while(true){
		auto image = open_image("needle.png");
		save_as_jpg(image, "output.jpg");
	}
}