/*
 * Copyright (c) 2016 The ZLMediaKit project authors. All Rights Reserved.
 *
 * This file is part of ZLMediaKit(https://github.com/ZLMediaKit/ZLMediaKit).
 *
 * Use of this source code is governed by MIT license that can be found in the
 * LICENSE file in the root of the source tree. All contributing project authors
 * may be found in the AUTHORS file in the root of the source tree.
 */

#if defined(ENABLE_FFMPEG)
#if !defined(_WIN32)
#include <dlfcn.h>
#endif
#include "Util/File.h"
#include "Util/uv_errno.h"
#include "Transcode.h"
#include "Extension/AAC.h"

#define MAX_DELAY_SECOND 3

using namespace std;
using namespace toolkit;

namespace mediakit {

static string ffmpeg_err(int errnum) {
    char errbuf[AV_ERROR_MAX_STRING_SIZE];
    av_strerror(errnum, errbuf, AV_ERROR_MAX_STRING_SIZE);
    return errbuf;
}

std::shared_ptr<AVPacket> alloc_av_packet() {
    auto pkt = std::shared_ptr<AVPacket>(av_packet_alloc(), [](AVPacket *pkt) {
        av_packet_free(&pkt);
    });
    pkt->data = NULL;    // packet data will be allocated by the encoder
    pkt->size = 0;
    return pkt;
}

//////////////////////////////////////////////////////////////////////////////////////////
static void on_ffmpeg_log(void *ctx, int level, const char *fmt, va_list args) {
    GET_CONFIG(bool, enable_ffmpeg_log, General::kEnableFFmpegLog);
    if (!enable_ffmpeg_log) {
        return;
    }
    LogLevel lev;
    switch (level) {
        case AV_LOG_FATAL:
        case AV_LOG_ERROR: lev = LError; break;
        case AV_LOG_WARNING: lev = LWarn; break;
        case AV_LOG_INFO: lev = LInfo; break;
        case AV_LOG_VERBOSE:
        case AV_LOG_DEBUG: lev = LDebug; break;
        case AV_LOG_TRACE:
        default: lev = LTrace; break;
    }
    LoggerWrapper::printLogV(::toolkit::getLogger(), lev, __FILE__, ctx ? av_default_item_name(ctx) : "NULL", level, fmt, args);
}

static bool setupFFmpeg_l() {
    av_log_set_level(AV_LOG_TRACE);
    av_log_set_flags(AV_LOG_PRINT_LEVEL);
    av_log_set_callback(on_ffmpeg_log);
#if (LIBAVCODEC_VERSION_MAJOR < 58)
    avcodec_register_all();
#endif
    return true;
}

static void setupFFmpeg() {
    static auto flag = setupFFmpeg_l();
}

static bool checkIfSupportedNvidia_l() {
#if !defined(_WIN32)
    GET_CONFIG(bool, check_nvidia_dev, General::kCheckNvidiaDev);
    if (!check_nvidia_dev) {
        return false;
    }
    auto so = dlopen("libnvcuvid.so.1", RTLD_LAZY);
    if (!so) {
        WarnL << "libnvcuvid.so.1加载失败:" << get_uv_errmsg();
        return false;
    }
    dlclose(so);

    bool find_driver = false;
    File::scanDir("/dev", [&](const string &path, bool is_dir) {
        if (!is_dir && start_with(path, "/dev/nvidia")) {
            //找到nvidia的驱动
            find_driver = true;
            return false;
        }
        return true;
    }, false);

    if (!find_driver) {
        WarnL << "英伟达硬件编解码器驱动文件 /dev/nvidia* 不存在";
    }
    return find_driver;
#else
    return false;
#endif
}

static bool checkIfSupportedNvidia() {
    static auto ret = checkIfSupportedNvidia_l();
    return ret;
}

//////////////////////////////////////////////////////////////////////////////////////////

bool TaskManager::addEncodeTask(function<void()> task) {
    {
        lock_guard<mutex> lck(_task_mtx);
        _task.emplace_back(std::move(task));
        if (_task.size() > _max_task) {
            WarnL << "encoder thread task is too more, now drop frame!";
            _task.pop_front();
        }
    }
    _sem.post();
    return true;
}

bool TaskManager::addDecodeTask(bool key_frame, function<void()> task) {
    {
        lock_guard<mutex> lck(_task_mtx);
        if (_decode_drop_start) {
            if (!key_frame) {
                TraceL << "decode thread drop frame";
                return false;
            }
            _decode_drop_start = false;
            InfoL << "decode thread stop drop frame";
        }

        _task.emplace_back(std::move(task));
        if (_task.size() > _max_task) {
            _decode_drop_start = true;
            WarnL << "decode thread start drop frame";
        }
    }
    _sem.post();
    return true;
}

void TaskManager::setMaxTaskSize(size_t size) {
    CHECK(size >= 3 && size <= 1000, "async task size limited to 3 ~ 1000, now size is:", size);
    _max_task = size;
}

void TaskManager::startThread(const string &name) {
    _thread.reset(new thread([this, name]() {
        onThreadRun(name);
    }), [](thread *ptr) {
        ptr->join();
        delete ptr;
    });
}

void TaskManager::stopThread(bool drop_task) {
    TimeTicker();
    if (!_thread) {
        return;
    }
    {
        lock_guard<mutex> lck(_task_mtx);
        if (drop_task) {
            _exit = true;
            _task.clear();
        }
        _task.emplace_back([]() {
            throw ThreadExitException();
        });
    }
    _sem.post(10);
    _thread = nullptr;
}

TaskManager::~TaskManager() {
    stopThread(true);
}

bool TaskManager::isEnabled() const {
    return _thread.operator bool();
}

void TaskManager::onThreadRun(const string &name) {
    setThreadName(name.data());
    function<void()> task;
    _exit = false;
    while (!_exit) {
        _sem.wait();
        {
            unique_lock<mutex> lck(_task_mtx);
            if (_task.empty()) {
                continue;
            }
            task = _task.front();
            _task.pop_front();
        }

        try {
            TimeTicker2(50, TraceL);
            task();
            task = nullptr;
        } catch (ThreadExitException &ex) {
            break;
        } catch (std::exception &ex) {
            WarnL << ex.what();
            continue;
        } catch (...) {
            WarnL << "catch one unknown exception";
            throw;
        }
    }
    InfoL << name << " exited!";
}

//////////////////////////////////////////////////////////////////////////////////////////

FFmpegFrame::FFmpegFrame(std::shared_ptr<AVFrame> frame) {
    if (frame) {
        _frame = std::move(frame);
    } else {
        _frame.reset(av_frame_alloc(), [](AVFrame *ptr) {
            av_frame_free(&ptr);
        });
    }
}

FFmpegFrame::~FFmpegFrame() {
    if (_data) {
        delete[] _data;
        _data = nullptr;
    }
}

AVFrame *FFmpegFrame::get() const {
    return _frame.get();
}

void FFmpegFrame::fillPicture(AVPixelFormat target_format, int target_width, int target_height) {
    assert(_data == nullptr);
    _data = new char[av_image_get_buffer_size(target_format, target_width, target_height, 1)];
    av_image_fill_arrays(_frame->data, _frame->linesize, (uint8_t *) _data,  target_format, target_width, target_height,1);
}

///////////////////////////////////////////////////////////////////////////

template<bool decoder = true>
static inline const AVCodec *getCodec_l(const char *name) {
    auto codec = decoder ? avcodec_find_decoder_by_name(name) : avcodec_find_encoder_by_name(name);
    if (codec) {
        InfoL << (decoder ? "got decoder:" : "got encoder:") << name;
    } else {
        TraceL << (decoder ? "decoder:" : "encoder:") << name << " not found";
    }
    return codec;
}

template<bool decoder = true>
static inline const AVCodec *getCodec_l(enum AVCodecID id) {
    auto codec = decoder ? avcodec_find_decoder(id) : avcodec_find_encoder(id);
    if (codec) {
        InfoL << (decoder ? "got decoder:" : "got encoder:") << avcodec_get_name(id);
    } else {
        TraceL << (decoder ? "decoder:" : "encoder:") << avcodec_get_name(id) << " not found";
    }
    return codec;
}

class CodecName {
public:
    CodecName(string name) : _codec_name(std::move(name)) {}
    CodecName(enum AVCodecID id) : _id(id) {}

    template <bool decoder>
    const AVCodec *getCodec() const {
        if (!_codec_name.empty()) {
            return getCodec_l<decoder>(_codec_name.data());
        }
        return getCodec_l<decoder>(_id);
    }

private:
    string _codec_name;
    enum AVCodecID _id;
};

template <bool decoder = true>
static inline const AVCodec *getCodec(const std::initializer_list<CodecName> &codec_list) {
    const AVCodec *ret = nullptr;
    for (int i = codec_list.size(); i >= 1; --i) {
        ret = codec_list.begin()[i - 1].getCodec<decoder>();
        if (ret) {
            return ret;
        }
    }
    return ret;
}

FFmpegDecoder::FFmpegDecoder(const Track::Ptr &track, int thread_num) {
    setupFFmpeg();
    const AVCodec *codec = nullptr;
    const AVCodec *codec_default = nullptr;
    switch (track->getCodecId()) {
        case CodecH264:
            codec_default = getCodec({AV_CODEC_ID_H264});
            if (checkIfSupportedNvidia()) {
                codec = getCodec({{"libopenh264"}, {AV_CODEC_ID_H264}, {"h264_qsv"}, {"h264_videotoolbox"}, {"h264_cuvid"}, {"h264_nvmpi"}});
            } else {
                codec = getCodec({{"libopenh264"}, {AV_CODEC_ID_H264}, {"h264_qsv"}, {"h264_videotoolbox"}, {"h264_nvmpi"}});
            }
            break;
        case CodecH265:
            codec_default = getCodec({AV_CODEC_ID_HEVC});
            if (checkIfSupportedNvidia()) {
                codec = getCodec({{AV_CODEC_ID_HEVC}, {"hevc_qsv"}, {"hevc_videotoolbox"}, {"hevc_cuvid"}, {"hevc_nvmpi"}});
            } else {
                codec = getCodec({{AV_CODEC_ID_HEVC}, {"hevc_qsv"}, {"hevc_videotoolbox"}, {"hevc_nvmpi"}});
            }
            break;
        case CodecAAC:
            codec = getCodec({AV_CODEC_ID_AAC});
            break;
        case CodecG711A:
            codec = getCodec({AV_CODEC_ID_PCM_ALAW});
            break;
        case CodecG711U:
            codec = getCodec({AV_CODEC_ID_PCM_MULAW});
            break;
        case CodecOpus:
            codec = getCodec({AV_CODEC_ID_OPUS});
            break;
        case CodecVP8:
            codec = getCodec({AV_CODEC_ID_VP8});
            break;
        case CodecVP9:
            codec = getCodec({AV_CODEC_ID_VP9});
            break;
        default:
            break;
    }

    if (!codec) {
        throw std::runtime_error("未找到解码器");
    }

    while (true) {
        _context.reset(avcodec_alloc_context3(codec), [](AVCodecContext *ctx) {
            avcodec_free_context(&ctx);
        });

        if (!_context) {
            throw std::runtime_error("创建解码器失败");
        }

        //保存AVFrame的引用
#ifdef FF_API_OLD_ENCDEC
        _context->refcounted_frames = 1;
#endif
        _context->flags |= AV_CODEC_FLAG_LOW_DELAY;
        _context->flags2 |= AV_CODEC_FLAG2_FAST;
        if (track->getTrackType() == TrackVideo) {
            _context->width = static_pointer_cast<VideoTrack>(track)->getVideoWidth();
            _context->height = static_pointer_cast<VideoTrack>(track)->getVideoHeight();
        }

        switch (track->getCodecId()) {
            case CodecG711A:
            case CodecG711U: {
                AudioTrack::Ptr audio = static_pointer_cast<AudioTrack>(track);
                _context->channels = audio->getAudioChannel();
                _context->sample_rate = audio->getAudioSampleRate();
                _context->channel_layout = av_get_default_channel_layout(_context->channels);
                break;
            }
            default:
                break;
        }
        AVDictionary *dict = nullptr;
        if (thread_num <= 0) {
            av_dict_set(&dict, "threads", "auto", 0);
        } else {
            av_dict_set(&dict, "threads", to_string(MIN(thread_num, thread::hardware_concurrency())).data(), 0);
        }
        av_dict_set(&dict, "zerolatency", "1", 0);
        av_dict_set(&dict, "strict", "-2", 0);

        if (codec->capabilities & AV_CODEC_CAP_TRUNCATED) {
            /* we do not send complete frames */
            _context->flags |= AV_CODEC_FLAG_TRUNCATED;
        } else {
            // 此时业务层应该需要合帧
            _do_merger = true;
        }

        int ret = avcodec_open2(_context.get(), codec, &dict);
        av_dict_free(&dict);
        if (ret >= 0) {
            //成功
            InfoL << "打开解码器成功:" << codec->name;
            break;
        }

        if (codec_default && codec_default != codec) {
            //硬件编解码器打开失败，尝试软件的
            WarnL << "打开解码器" << codec->name << "失败，原因是:" << ffmpeg_err(ret) << ", 再尝试打开解码器" << codec_default->name;
            codec = codec_default;
            continue;
        }
        throw std::runtime_error(StrPrinter << "打开解码器" << codec->name << "失败:" << ffmpeg_err(ret));
    }
}

FFmpegDecoder::~FFmpegDecoder() {
    stopThread(true);
    if (_do_merger) {
        _merger.inputFrame(nullptr, [&](uint32_t dts, uint32_t pts, const Buffer::Ptr &buffer, bool have_idr) {
            decodeFrame(buffer->data(), buffer->size(), dts, pts, false);
        });
    }
    flush();
}

void FFmpegDecoder::flush() {
    while (true) {
        auto out_frame = std::make_shared<FFmpegFrame>();
        auto ret = avcodec_receive_frame(_context.get(), out_frame->get());
        if (ret == AVERROR(EAGAIN)) {
            avcodec_send_packet(_context.get(), nullptr);
            continue;
        }
        if (ret == AVERROR_EOF) {
            break;
        }
        if (ret < 0) {
            WarnL << "avcodec_receive_frame failed:" << ffmpeg_err(ret);
            break;
        }
        onDecode(out_frame);
    }
}

const AVCodecContext *FFmpegDecoder::getContext() const {
    return _context.get();
}

bool FFmpegDecoder::inputFrame_l(const Frame::Ptr &frame, bool live, bool enable_merge) {
    if (_do_merger && enable_merge) {
        return _merger.inputFrame(frame, [&](uint32_t dts, uint32_t pts, const Buffer::Ptr &buffer, bool have_idr) {
            decodeFrame(buffer->data(), buffer->size(), dts, pts, live);
        });
    }

    return decodeFrame(frame->data(), frame->size(), frame->dts(), frame->pts(), live);
}

bool FFmpegDecoder::inputFrame(const Frame::Ptr &frame, bool live, bool async, bool enable_merge) {
    if (async && !TaskManager::isEnabled() && getContext()->codec_type == AVMEDIA_TYPE_VIDEO) {
        //开启异步编码，且为视频，尝试启动异步解码线程
        startThread("decoder thread");
    }

    if (!async || !TaskManager::isEnabled()) {
        return inputFrame_l(frame, live, enable_merge);
    }

    auto frame_cache = Frame::getCacheAbleFrame(frame);
    return addDecodeTask(frame->keyFrame(), [this, live, frame_cache, enable_merge]() {
        inputFrame_l(frame_cache, live, enable_merge);
        //此处模拟解码太慢导致的主动丢帧
        //usleep(100 * 1000);
    });
}

bool FFmpegDecoder::decodeFrame(const char *data, size_t size, uint32_t dts, uint32_t pts, bool live) {
    TimeTicker2(30, TraceL);

    auto pkt = alloc_av_packet();
    pkt->data = (uint8_t *) data;
    pkt->size = size;
    pkt->dts = dts;
    pkt->pts = pts;

    auto ret = avcodec_send_packet(_context.get(), pkt.get());
    if (ret < 0) {
        if (ret != AVERROR_INVALIDDATA) {
            WarnL << "avcodec_send_packet failed:" << ffmpeg_err(ret);
        }
        return false;
    }

    while (true) {
        auto out_frame = std::make_shared<FFmpegFrame>();
        ret = avcodec_receive_frame(_context.get(), out_frame->get());
        if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
            break;
        }
        if (ret < 0) {
            WarnL << "avcodec_receive_frame failed:" << ffmpeg_err(ret);
            break;
        }
        if (live && pts - out_frame->get()->pts > MAX_DELAY_SECOND * 1000 && _ticker.createdTime() > 10 * 1000) {
            //后面的帧才忽略,防止Track无法ready
            WarnL << "解码时，忽略" << MAX_DELAY_SECOND << "秒前的数据:" << pts << " " << out_frame->get()->pts;
            continue;
        }
        onDecode(out_frame);
    }
    return true;
}

void FFmpegDecoder::setOnDecode(FFmpegDecoder::onDec cb) {
    _cb = std::move(cb);
}

void FFmpegDecoder::onDecode(const FFmpegFrame::Ptr &frame) {
    if (_cb) {
        _cb(frame);
    }
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////

FFmpegSwr::FFmpegSwr(AVSampleFormat output, int channel, int channel_layout, int samplerate) {
    _target_format = output;
    _target_channels = channel;
    _target_channel_layout = channel_layout;
    _target_samplerate = samplerate;
}

FFmpegSwr::~FFmpegSwr() {
    if (_ctx) {
        swr_free(&_ctx);
    }
}

FFmpegFrame::Ptr FFmpegSwr::inputFrame(const FFmpegFrame::Ptr &frame) {
    if (frame->get()->format == _target_format &&
        frame->get()->channels == _target_channels &&
        frame->get()->channel_layout == (uint64_t)_target_channel_layout &&
        frame->get()->sample_rate == _target_samplerate) {
        //不转格式
        return frame;
    }
    if (!_ctx) {
        _ctx = swr_alloc_set_opts(nullptr, _target_channel_layout, _target_format, _target_samplerate,
                                  frame->get()->channel_layout, (AVSampleFormat) frame->get()->format,
                                  frame->get()->sample_rate, 0, nullptr);
        InfoL << "swr_alloc_set_opts:" << av_get_sample_fmt_name((enum AVSampleFormat) frame->get()->format) << " -> "
              << av_get_sample_fmt_name(_target_format);
    }
    if (_ctx) {
        auto out = std::make_shared<FFmpegFrame>();
        out->get()->format = _target_format;
        out->get()->channel_layout = _target_channel_layout;
        out->get()->channels = _target_channels;
        out->get()->sample_rate = _target_samplerate;
        out->get()->pkt_dts = frame->get()->pkt_dts;
        out->get()->pts = frame->get()->pts;

        int ret = 0;
        if (0 != (ret = swr_convert_frame(_ctx, out->get(), frame->get()))) {
            WarnL << "swr_convert_frame failed:" << ffmpeg_err(ret);
            return nullptr;
        }
        return out;
    }

    return nullptr;
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////

FFmpegSws::FFmpegSws(AVPixelFormat output, int width, int height) {
    _target_format = output;
    _target_width = width;
    _target_height = height;
}

FFmpegSws::~FFmpegSws() {
    if (_ctx) {
        sws_freeContext(_ctx);
        _ctx = nullptr;
    }
}

int FFmpegSws::inputFrame(const FFmpegFrame::Ptr &frame, uint8_t *data) {
    TimeTicker2(30, TraceL);
    if (!_target_width) {
        _target_width = frame->get()->width;
    }
    if (!_target_height) {
        _target_height = frame->get()->height;
    }
    AVFrame dst;
    memset(&dst, 0, sizeof(dst));
    av_image_fill_arrays(dst.data, dst.linesize, data,  _target_format, _target_width, _target_height,1);

    if (!_ctx) {
        _ctx = sws_getContext(frame->get()->width, frame->get()->height, (enum AVPixelFormat) frame->get()->format,
                              _target_width, _target_height, _target_format, SWS_FAST_BILINEAR, NULL, NULL, NULL);
        InfoL << "sws_getContext:" << av_get_pix_fmt_name((enum AVPixelFormat) frame->get()->format) << " -> "
              << av_get_pix_fmt_name(_target_format);
    }
    assert(_ctx);
    int ret = 0;
    if (0 >= (ret = sws_scale(_ctx, frame->get()->data, frame->get()->linesize, 0, frame->get()->height, dst.data,
                              dst.linesize))) {
        WarnL << "sws_scale failed:" << ffmpeg_err(ret);
    }
    return ret;
}

FFmpegFrame::Ptr FFmpegSws::inputFrame(const FFmpegFrame::Ptr &frame) {
    TimeTicker2(30, TraceL);

    if (!_target_width) {
        _target_width = frame->get()->width;
    }
    if (!_target_height) {
        _target_height = frame->get()->height;
    }
    if (frame->get()->format == _target_format && frame->get()->width == _target_width
        && frame->get()->height == _target_height) {
        //不转格式
        return frame;
    }
    if (!_ctx) {
        _ctx = sws_getContext(frame->get()->width, frame->get()->height, (enum AVPixelFormat) frame->get()->format,
                              _target_width, _target_height, _target_format,
                              SWS_FAST_BILINEAR, NULL, NULL, NULL);
        InfoL << "sws_getContext:" << av_get_pix_fmt_name((enum AVPixelFormat) frame->get()->format) << " -> "
              << av_get_pix_fmt_name(_target_format);
    }
    if (_ctx) {
        auto out = std::make_shared<FFmpegFrame>();
        if (!out->get()->data[0]) {
            out->fillPicture(_target_format, _target_width, _target_height);
        }
        int ret = 0;
        if (0 == (ret = sws_scale(_ctx, frame->get()->data, frame->get()->linesize, 0, frame->get()->height,
                                  out->get()->data, out->get()->linesize))) {
            WarnL << "sws_scale failed:" << ffmpeg_err(ret);
            return nullptr;
        }

        out->get()->format = _target_format;
        out->get()->width = _target_width;
        out->get()->height = _target_height;
        out->get()->pkt_dts = frame->get()->pkt_dts;
        out->get()->pts = frame->get()->pts;
        return out;
    }
    return nullptr;
}

} //namespace mediakit
#endif//ENABLE_FFMPEG
