#include "Demuxer.h"
#include "BoostLog.h"
extern "C" {
#include "libavformat/avformat.h"
}

static_assert(AVMEDIA_TYPE_VIDEO == Stream::Video, "enum value must same...");

Demuxer::Demuxer() {
    m_context = avformat_alloc_context();
}

Demuxer::~Demuxer() {
    m_exit = true;
    if (m_thread.joinable()) m_thread.join();
}

void Demuxer::open(const std::string &path) {
    avformat_open_input(&m_context, path.c_str(), nullptr, nullptr);
    av_dump_format(m_context, 0, path.c_str(), 0);
    const AVCodec *videoCodec = nullptr, *audioCodec = nullptr;
    m_streams[Stream::Video] = av_find_best_stream(m_context, AVMEDIA_TYPE_VIDEO, -1, -1, &videoCodec, 0);
    m_streams[Stream::Audio] = av_find_best_stream(m_context, AVMEDIA_TYPE_AUDIO, -1, -1, &audioCodec, 0);
    LOG(info) << "video stream index: " << m_streams[Stream::Video]
              << ", audio stream index: " << m_streams[Stream::Audio];

    m_codecInformations[Stream::Video] = {videoCodec, m_context->streams[Stream::Video]->codecpar};
    m_codecInformations[Stream::Audio] =
        std::pair<const AVCodec *, const AVCodecParameters *>(audioCodec, m_context->streams[Stream::Audio]->codecpar);
}

Demuxer::CodecInformation Demuxer::codecInformation(Stream type) const {
    return m_codecInformations[type];
}

void Demuxer::setStreamPacketCallback(Stream type, const Callback &callback) {
    m_callback[type] = callback;
}

void Demuxer::start() {
    m_exit = false;
    m_thread = std::thread(&Demuxer::run, this);
}

void Demuxer::run() {
    auto packet = av_packet_alloc();
    while (!m_exit) {
        int ret = av_read_frame(m_context, packet);
        if (ret == AVERROR_EOF) {
            LOG(info) << "end of file.";
            break;
        } else if (ret < 0) {
            char buffer[AV_ERROR_MAX_STRING_SIZE] = {0};
            av_strerror(ret, buffer, sizeof(buffer));
            LOG(error) << "read failed: " << ret << ", " << buffer;
            break;
        }

        std::shared_ptr<AVPacket> out(av_packet_alloc(), [](AVPacket *packet) { av_packet_free(&packet); });
        av_packet_ref(out.get(), packet);
        if (m_callback[packet->stream_index]) m_callback[packet->stream_index](out);
        // LOG(info) << ". " << packet->stream_index;
        av_packet_unref(packet);
    }
    av_packet_free(&packet);
}