/*
 * Copyright (C) 2020, KylinSoft Co., Ltd.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
#include "BaseEncoder.h"
#include "Logger.h"
#include "Global.h"

#include <unistd.h>

int ParseCodecOptionInt(const QString& key, const QString& value, int min, int max, int multiply) {
    bool parsed;
    int value_int = value.toInt(&parsed);
    if(!parsed) {
        Logger::LogError("[ParseCodecOptionInt] " + Logger::tr("Error: Option '%1' could not be parsed!").arg(key));
        throw LibavException();
    }
    return clamp(value_int, min, max) * multiply;
}
double ParseCodecOptionDouble(const QString& key, const QString& value, double min, double max, double multiply) {
    bool parsed;
    double value_double = value.toDouble(&parsed);
    if(!parsed) {
        Logger::LogError("[ParseCodecOptionDouble] " + Logger::tr("Error: Option '%1' could not be parsed!").arg(key));
        throw LibavException();
    }
    return clamp(value_double, min, max) * multiply;
}

BaseEncoder::BaseEncoder(Muxer *muxer, AVStream *stream, AVCodecContext *codec_context, AVCodec *codec, AVDictionary **options)
{
    m_muxer = muxer;
    m_stream = stream;
    m_codec_context = codec_context;
    m_codec_opened = false;

    //initialize shared data
    {
        SharedLock lock(&m_shared_data);
        lock->m_total_frames = 0;
        lock->m_total_packets = 0;
        lock->m_stats_actual_frame_rate = 0.0;
        lock->m_stats_previous_pts = AV_NOPTS_VALUE;
        lock->m_stats_previous_frames = 0;
    }

    //initialize thread sinals
    m_should_stop = false;
    m_should_finish = false;
    m_is_done = false;
    m_error_occurred = false;

    try {
        Init(codec, options);
    } catch (...) {
        Free();
        throw;
    }
}

BaseEncoder::~BaseEncoder()
{
    Free();
}

void BaseEncoder::StartThread()
{
    m_thread = std::thread(&BaseEncoder::EncoderThread, this);
}

void BaseEncoder::StopThread()
{
    //tell the thread to stop
    if (m_thread.joinable()) {
        Logger::LogInfo("[BaseEncoder::~BaseEncoder]" + Logger::tr("Stopping encoder thread ..."));
        m_should_stop = true;
        m_thread.join();
    }
    //free everything
    Free();
}

double BaseEncoder::GetActualFrameRate()
{
    SharedLock lock(&m_shared_data);
    return lock->m_stats_actual_frame_rate;
}

uint64_t BaseEncoder::GetTotalFrames()
{
    SharedLock lock(&m_shared_data);
    return lock->m_total_frames;
}

unsigned int BaseEncoder::GetFrameLatency()
{
    SharedLock lock(&m_shared_data);
    return (lock->m_total_frames > lock->m_total_packets) ? lock->m_total_frames - lock->m_total_packets : 0;
}

unsigned int BaseEncoder::GetQueuedFrameCount()
{
    SharedLock lock(&m_shared_data);
    return lock->m_frame_queue.size();
}

unsigned int BaseEncoder::GetQueuedPacketCount()
{
    return GetMuxer()->GetQueuedPacketCount(GetStream()->index);
}

void BaseEncoder::AddFrame(std::unique_ptr<AVFrameWrapper> frame)
{
    assert(frame->GetFrame()->pts != (int64_t) AV_NOPTS_VALUE);
    SharedLock lock(&m_shared_data);
    ++lock->m_total_frames;
    if(lock->m_stats_previous_pts == (int64_t) AV_NOPTS_VALUE) {
        lock->m_stats_previous_pts = frame->GetFrame()->pts;
        lock->m_stats_previous_frames = lock->m_total_frames;
    }
    double timedelta = (double) (frame->GetFrame()->pts - lock->m_stats_previous_pts) * ToDouble(m_codec_context->time_base);
    if(timedelta > 0.999999) {
        lock->m_stats_actual_frame_rate = (double) (lock->m_total_frames - lock->m_stats_previous_frames) / timedelta;
        lock->m_stats_previous_pts = frame->GetFrame()->pts;
        lock->m_stats_previous_frames = lock->m_total_frames;
    }
    lock->m_frame_queue.push_back(std::move(frame));
}

void BaseEncoder::Finish()
{
    m_should_finish = true;
}

void BaseEncoder::Stop()
{
    m_should_stop = true;
}

void BaseEncoder::IncrementPacketCounter()
{
    SharedLock lock(&m_shared_data);
    ++lock->m_total_packets;
}

void BaseEncoder::Init(AVCodec* codec, AVDictionary** options)
{
    // open codec
    if(avcodec_open2(m_codec_context, codec, options) < 0) {
        Logger::LogError("[BaseEncoder::Init] " + Logger::tr("Error: Can't open codec!"));
        throw LibavException();
    }
    m_codec_opened = true;

    // show a warning for every option that wasn't recognized
    AVDictionaryEntry *t = NULL;
    while((t = av_dict_get(*options, "", t, AV_DICT_IGNORE_SUFFIX)) != NULL) {
        Logger::LogWarning("[BaseEncoder::Init] " + Logger::tr("Warning: Codec option '%1' was not recognised!").arg(t->key));
    }
}

void BaseEncoder::Free()
{
    if(m_codec_opened) {
        avcodec_close(m_codec_context);
        m_codec_opened = false;
    }
}

void BaseEncoder::EncoderThread()
{
    try {
        Logger::LogInfo("[BaseEncoder::EncoderThread]" + Logger::tr("Encoder thread started."));

        //normal encoding
        while (!m_should_stop) {
            //get a frame
            std::unique_ptr<AVFrameWrapper> frame;
            {
                SharedLock lock(&m_shared_data);
                if (!lock->m_frame_queue.empty()) {
                    frame = std::move(lock->m_frame_queue.front());
                    lock->m_frame_queue.pop_front();
                }
            }
            if (frame == NULL) {
                if (m_should_finish) {
                    break;
                }
                usleep(20000);
                continue;
            }
            //encode the frame
            EncodeFrame(frame.get());
        }

        //flush the encoder
        if (!m_should_stop && (m_codec_context->codec->capabilities & AV_CODEC_CAP_DELAY)) {
            Logger::LogInfo("[BaseEncoder::EncoderThread] " + Logger::tr("Flushing encoder ..."));
            while (!m_should_stop) {
                if (!EncodeFrame(NULL)) {
                    break;
                }
            }
        }

        //tell the others that we're done
        m_is_done = true;

        Logger::LogInfo("[BaseEncoder::EncoderThread] " + Logger::tr("Encoder thread stopped."));

    } catch (const std::exception& e) {
        m_error_occurred = true;
        Logger::LogError("[BaseEncoder::EncoderThread] " + Logger::tr("Exception '%1' in encoder thread.").arg(e.what()));
    } catch (...) {
        m_error_occurred = true;
        Logger::LogError("[BaseEncoder::EncoderThread] " + Logger::tr("Unknown exception in encoder thread."));
    }

    // always end the stream, even if there was an error, otherwise the muxer will wait forever
    m_muxer->EndStream(m_stream->index);
}


























