//    This file is part of Motion Watch.

//    Motion Watch 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.

//    Motion Watch 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.

#include "camera.h"

Camera::Camera(QObject *parent) : QObject(parent) {}

int Camera::start(const QStringList &args)
{
    if (rdConf(getParam("-c", args), &shared))
    {   
        auto thr1 = new QThread(nullptr);
        auto thr2 = new QThread(nullptr);
        auto thr3 = new QThread(nullptr);

        new Upkeep(&shared, thr1, nullptr);
        new EventLoop(&shared, thr2, nullptr);
        new DetectLoop(&shared, thr3, nullptr);
        
        thr1->start();
        thr2->start();
        thr3->start();
    }

    return shared.retCode;
}

Loop::Loop(shared_t *sharedRes, QThread *thr, QObject *parent) : QObject(parent)
{
    shared    = sharedRes;
    heartBeat = 10;
    loopTimer = 0;

    connect(thr, &QThread::started, this, &Loop::init);

    moveToThread(thr);
}

void Loop::init()
{
    loopTimer = new QTimer(this);

    connect(loopTimer, &QTimer::timeout, this, &Loop::loopSlot);

    loopTimer->setSingleShot(false);
    loopTimer->start(heartBeat * 1000);

    loopSlot();
}

void Loop::loopSlot()
{
    if (!exec())
    {
        loopTimer->stop(); QCoreApplication::exit(shared->retCode);
    }
}

bool Loop::exec()
{
    if (loopTimer->interval() != heartBeat * 1000)
    {
        loopTimer->start(heartBeat * 1000);
    }

    return shared->retCode == 0;
}

Upkeep::Upkeep(shared_t *sharedRes, QThread *thr, QObject *parent) : Loop(sharedRes, thr, parent) {}

bool Upkeep::exec()
{
    enforceMaxEvents(shared);
    enforceMaxImages(shared);
    enforceMaxVids(shared);

    return Loop::exec();
}

EventLoop::EventLoop(shared_t *sharedRes, QThread *thr, QObject *parent) : Loop(sharedRes, thr, parent)
{
    heartBeat = 2;
    highScore = 0;
    cycles    = 0;
}

bool EventLoop::exec()
{
    if (!vidList.isEmpty())
    {
        vidList.removeDuplicates();

        if (vidList.size() > 1)
        {
            QTextStream(stdout) << "attempting write out of event: " << name << Qt::endl;

            if (wrOutVod())
            {
                QProcess    proc;
                QStringList args;

                args << "convert";
                args << imgPath;
                args << shared->recPath + "/" + name + shared->thumbExt;

                proc.start("magick", args);
                proc.waitForFinished();
            }
        }

        cycles    = 0;
        highScore = 0;

        vidList.clear();
    }

    QList<int> rmIndx;

    for (auto i = 0; i < shared->recList.size(); ++i)
    {
        auto event = &shared->recList[i];

        if (highScore < event->score)
        {
            name      = event->timeStamp.toString(DATETIME_FMT);
            imgPath   = event->imgPath;
            highScore = event->score;
        }

        if (event->queAge >= (shared->evMaxSecs / heartBeat))
        {
            auto maxSecs = shared->evMaxSecs / 2;
            // half the maxsecs value to get front-back half secs

            auto backFiles  = backwardFacingFiles(shared->buffPath + "/live", shared->streamExt, event->timeStamp, maxSecs);
            auto frontFiles = forwardFacingFiles(shared->buffPath + "/live", shared->streamExt, event->timeStamp, maxSecs);

            vidList.append(backFiles + frontFiles);
            rmIndx.append(i);
        }
        else
        {
            event->queAge += heartBeat;
        }
    }

    for (auto i : rmIndx)
    {
        shared->recList.removeAt(i);
    }
    
    return Loop::exec();
}

bool EventLoop::wrOutVod()
{
    auto cnt    = 0;
    auto concat = name + ".tmp";
    auto ret    = false;

    QFile file(concat);

    file.open(QFile::WriteOnly);

    for (auto &&vid : vidList)
    {
        QTextStream(stdout) << "event_src: " << vid << Qt::endl;

        if (QFile::exists(vid))
        {
            file.write(QString("file '" + vid + "'\n").toUtf8()); cnt++;
        }
        else
        {
            QTextStream(stdout) << "warning: the event hls clip does not exists." << Qt::endl;
        }
    }

    file.close();

    if (cnt == 0)
    {
        QTextStream(stderr) << "err: none of the event hls clips exists, canceling write out." << Qt::endl;

        QFile::remove(concat);
    }
    else
    {
        QStringList args;

        args << "-f";
        args << "concat";
        args << "-safe" << "0";
        args << "-i" << concat;
        args << "-c" << "copy";
        args << shared->recPath + "/" + name + shared->recExt;
        
        QProcess::execute("ffmpeg", args);
        QFile::remove(concat);
    }

    return ret;
}

DetectLoop::DetectLoop(shared_t *sharedRes, QThread *thr, QObject *parent) : Loop(sharedRes, thr, parent)
{
    seed        = 0;
    pcTimer     = 0;
    heartBeat   = 2;
    delayCycles = 12; // this will be used to delay the
                      // actual start of DetectLoop by
                      // 24secs.
}

void DetectLoop::init()
{
    pcTimer = new QTimer(this);
    mod     = false;

    connect(pcTimer, &QTimer::timeout, this, &DetectLoop::pcBreak);

    resetTimers();

    Loop::init();
}

void DetectLoop::resetTimers()
{
    pcTimer->start(shared->postSecs * 1000);
}

void DetectLoop::pcBreak()
{
    if (!shared->postCmd.isEmpty())
    {
        QTextStream(stdout) << "---POST_BREAK---" << Qt::endl;

        if (mod)
        {
            QTextStream(stdout) << "motion detected, skipping the post command." << Qt::endl;
        }
        else
        {
            if (delayCycles == 0) delayCycles  = 5;
            else                  delayCycles += 5;

            QTextStream(stdout) << "no motion detected, running post command: " << shared->postCmd << Qt::endl;

            auto args = parseArgs(shared->postCmd.toUtf8(), -1);

            if (args.isEmpty())
            {
                QTextStream(stderr) << "err: did not parse an executable from the post command line." << Qt::endl;
            }
            else
            {
                QProcess::execute(args[0], args.mid(1));
            }
        }
    }

    mod = false;
}

float DetectLoop::getFloatFromExe(const QByteArray &line)
{
    QString strLine(line);
    QString strNum;

    for (auto chr : strLine)
    {
        if (chr.isDigit() || (chr == '.'))
        {
            strNum.append(chr);
        }
        else
        {
            break;
        }
    }

    return strNum.toFloat();
}

QStringList DetectLoop::buildArgs(const QString &prev, const QString &next)
{
    auto args = parseArgs(shared->compCmd.toUtf8(), -1);

    for (auto i = 0; i < args.size(); ++i)
    {
        if (args[i] == PREV_IMG) args[i] = prev;
        if (args[i] == NEXT_IMG) args[i] = next;
    }

    return args;
}

QStringList DetectLoop::buildSnapArgs(const QString &vidSrc, const QString &imgPath)
{
    QStringList ret;

    ret.append("-y");
    ret.append("-i");
    ret.append(vidSrc);
    ret.append("-frames:v");
    ret.append("1");
    ret.append(imgPath);
    
    return ret;
}

bool DetectLoop::exec()
{
    if (delayCycles > 0)
    {
        delayCycles -= 1;

        QTextStream(stdout) << "delay: detection cycle skipped. cycles left to be skipped: " << QString::number(delayCycles) << Qt::endl;
    }
    else
    {
        auto imgAPath = "img/" + QString::number(seed++) + ".bmp";
        auto imgBPath = "img/" + QString::number(seed++) + ".bmp";
        auto curDT    = QDateTime::currentDateTime();
        auto clips    = backwardFacingFiles("live", shared->streamExt, curDT, 16);

        if (clips.size() < 2)
        {
            QTextStream(stdout) << "warning: didn't pick up enough clips files from the video stream. number of files: " << QString::number(clips.size()) << Qt::endl;
            QTextStream(stdout) << "         will try again on the next loop." << Qt::endl;
        }
        else
        {
            auto snapArgsA = buildSnapArgs(clips[clips.size() - 2], imgAPath);
            auto snapArgsB = buildSnapArgs(clips[clips.size() - 1], imgAPath);
            auto compArgs  = buildArgs(imgAPath, imgBPath);

            if (compArgs.isEmpty())
            {
                QTextStream(stderr) << "err: could not parse a executable name from img_comp_cmd: " << shared->compCmd << Qt::endl;
            }
            else
            {
                QProcess snapFromVidA;
                QProcess snapFromVidB;
                QProcess extComp;

                snapFromVidA.start("ffmpeg", snapArgsA);
                snapFromVidA.waitForFinished();
            
                snapFromVidB.start("ffmpeg", snapArgsB);
                snapFromVidB.waitForFinished();

                extComp.start(compArgs[0], compArgs.mid(1));
                extComp.waitForFinished();

                float score = 0;
                auto  ok    = true;

                if (shared->outputType == "stdout")
                {
                    score = getFloatFromExe(extComp.readAllStandardOutput());
                }
                else if (shared->outputType == "stderr")
                {
                    score = getFloatFromExe(extComp.readAllStandardError());
                }
                else
                {
                    ok = false;
                }

                if (!ok)
                {
                    QTextStream(stderr) << "err: img_comp_out: " << shared->outputType << " is not valid. it must be 'stdout' or 'stderr'" << Qt::endl;
                }
                else
                {
                    QTextStream(stdout) << compArgs.join(" ") << " --result: " << QString::number(score) << Qt::endl;

                    if (score >= shared->imgThresh)
                    {
                        QTextStream(stdout) << "--threshold_breached: " << QString::number(shared->imgThresh) << Qt::endl;

                        evt_t event;

                        event.timeStamp = curDT;
                        event.score     = score;
                        event.imgPath   = imgBPath;
                        event.queAge    = 0;
                        
                        mod = true;
                        
                        shared->recList.append(event); 
                    }
                }
            }
        }
    }

    return Loop::exec();
}