#include "helper.h"
#include <iostream>

int open_input_context(AVFormatContext **in_ctx, const char *path)
{
	if (avformat_open_input(in_ctx, path, NULL, NULL))
	{
		std::cout << "Error: Can't open the file at " << path << std::endl;
		return 1;
	}
	if (avformat_find_stream_info(*in_ctx, NULL) < 0)
	{
		std::cout << "Error: Could't find streams informations for the file at " << path << std::endl;
		return 1;
	}
	av_dump_format(*in_ctx, 0, path, false);
	return 0;
}

AVStream *copy_stream_to_output(AVFormatContext *out_ctx, AVStream *in_stream)
{
	AVStream *out_stream = avformat_new_stream(out_ctx, NULL);

	if (out_stream == NULL)
	{
		std::cout << "Error: Couldn't create stream." << std::endl;
		return NULL;
	}
	if (avcodec_parameters_copy(out_stream->codecpar, in_stream->codecpar) < 0)
	{
		std::cout << "Error: Couldn't copy parameters to the output file." << std::endl;
		return NULL;
	}
	out_stream->codecpar->codec_tag = 0;
	avformat_transfer_internal_stream_timing_info(out_ctx->oformat, out_stream, in_stream, AVTimebaseSource::AVFMT_TBCF_AUTO);
	out_stream->time_base = av_add_q(av_stream_get_codec_timebase(out_stream), AVRational {0, 1});
	out_stream->duration = av_rescale_q(in_stream->duration, in_stream->time_base, out_stream->time_base);
	out_stream->disposition = in_stream->disposition;
	out_stream->avg_frame_rate = in_stream->avg_frame_rate;
	out_stream->r_frame_rate = in_stream->r_frame_rate;
	return out_stream;
}

constexpr enum AVRounding operator |(const enum AVRounding a, const enum AVRounding b)
{
	return (enum AVRounding)(uint32_t(a) | uint32_t(b));
}

int open_output_file_for_write(AVFormatContext *out_ctx, const char *out_path, AVDictionary **options)
{
	if (!(out_ctx->oformat->flags & AVFMT_NOFILE))
	{
		if (avio_open(&out_ctx->pb, out_path, AVIO_FLAG_WRITE) < 0)
		{
			std::cout << "Error: Couldn't open file at " << out_path << std::endl;
			return 1;
		}
	}
	else
		std::cout << "Output flag set to AVFMT_NOFILE." << std::endl;
	if (avformat_write_header(out_ctx, options) < 0)
	{
		std::cout << "Error: Couldn't write headers to file at " << out_path << std::endl;
		return 1;
	}
	return 0;
}

void process_packet(AVPacket &pkt, AVStream *in_stream, AVStream *out_stream)
{
	pkt.pts = av_rescale_q_rnd(pkt.pts, in_stream->time_base, out_stream->time_base, AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX);
	pkt.dts = av_rescale_q_rnd(pkt.dts, in_stream->time_base, out_stream->time_base, AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX);
	pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base, out_stream->time_base);
	pkt.pos = -1;
}