#include <database.hpp>
#include <fingerprints.hpp>
#include <image_io.hpp>
#include <mozaic.hpp>
#include <read_database.hpp>
#include <utilities.hpp>
#include <av/sws.hpp>

#include <boost/filesystem.hpp>

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

#include <algorithm>
#include <iostream>
#include <utility>

static const int tile_width = 500;
static const int tile_height = 500;

using namespace std;

using Metric = downscale;
using Database = image_database<Metric>;

static auto calculate_all_distances(Database const & db, string const & filename, int h_tiles, int v_tiles){
	using return_type = decltype(db.distances_for_image(std::declval<av::frame const &>()));
	Mozaic<return_type> mozaic(h_tiles, v_tiles);

	apply_to_tiles(filename, h_tiles, v_tiles, [&](int c, int r, av::frame const & frame){
		mozaic[r][c] = db.distances_for_image(frame);
	});

	return mozaic;
}

template <typename Mozaiq>
static void save_mozaic(Mozaiq const & mozaic, string filename){
	auto const pix_fmt = AV_PIX_FMT_YUVJ444P;
	auto const codec_id= AV_CODEC_ID_MJPEG;

	auto const total_width = mozaic.h_tiles * tile_width;
	auto const total_height = mozaic.v_tiles * tile_height;

	// Create output frame
	std::vector<uint8_t, av::allocator<uint8_t>> data(make_u(avpicture_get_size(pix_fmt, total_width, total_height)), 0);
	const av::frame frame = av::frame_alloc();
	avpicture_fill(reinterpret_cast<AVPicture*>(frame.get()), data.data(), pix_fmt, total_width, total_height);
	frame->width = total_width;
	frame->height = total_height;
	frame->format = pix_fmt;

	// For each tile: get the part, copy input to it
	for(int r = 0; r < mozaic.v_tiles; ++r) {
		for(int c = 0; c < mozaic.h_tiles; ++c){
			auto frame_part = av::crop(frame, c * tile_width, r * tile_height, tile_width, tile_height);
			auto input = crop_to_square(open_image(mozaic[r][c]));

			auto context = sws::create_context(input, frame_part);
			sws::scale(context, input, frame_part);
		}
	}

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

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

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

int main(){
	av_register_all();
	av_log_set_level(AV_LOG_QUIET);

	// TODO: use boost::program_options
	string const database_directory = "vakantie";
	string const filename = "vakantie.jpg";
	string const output = "output/vakantie.jpg";
	int const h_tiles = 4*4;
	int const v_tiles = 3*4;

	auto const db = read_database<Metric>(database_directory);
	cout << colors::green("Read database: ") << db.size() << endl;

	auto const distances = calculate_all_distances(db, filename, h_tiles, v_tiles);
	cout << colors::green("Calculated distances for ") << filename << endl;

	auto const best_indices = optimize_unique(distances);
	cout << colors::green("Picked best distances") << endl;

	auto const mozaic = mozaic_fmap(best_indices, [&](auto i){ return db.filename(i); });
	cout << colors::green("Picked filenames") << endl;

	save_mozaic(mozaic, output);
	cout << colors::green("Saved Mozaic to ") << output << endl;
}