/* Copyright (C) 2013 Nikos Chantziaras.
 *
 * This file is part of the QTads program.  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
 * 2, 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; see the file COPYING.  If not, write to the Free Software
 * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */
#include <QDebug>
#include <QFileInfo>
#include <QTimer>

#ifndef Q_OS_ANDROID
#include <SDL_mixer.h>
#include <SDL_sound.h>
#endif

#include "qtadssound.h"
#include "globals.h"
#include "sysframe.h"
#include "settings.h"
#include "syssoundwav.h"
#include "syssoundogg.h"
#include "syssoundmpeg.h"


#ifndef Q_OS_ANDROID
QList<QTadsSound*> QTadsSound::fObjList;


QTadsSound::QTadsSound( QObject* parent, Mix_Chunk* chunk, SoundType type )
    : QObject(parent),
      fChunk(chunk),
      fChannel(-1),
      fType(type),
      fPlaying(false),
      fFadeOut(0),
      fCrossFade(false),
      fFadeOutTimer(new QTimer(0)),
      fDone_func(0),
      fDone_func_ctx(0),
      fRepeats(0),
      fRepeatsWanted(1)
{
    // FIXME: Calculate sound length in a safer way.
    this->fLength = (this->fChunk->alen * 8) / (2 * 16 * 44.1);
    // Pretend that the sound is 30ms shorter than it really is in order to
    // compensate for wacky OS timers (Windows and low-Hz systems).
    if (this->fLength > 30) {
        this->fLength -= 30;
    } else {
        this->fLength = 0;
    }
    //qDebug() << "Sound length:" << this->fLength;
    connect(this, SIGNAL(readyToLoop()), SLOT(fDoLoop()));
    connect(this, SIGNAL(readyToFadeOut()), SLOT(fPrepareFadeOut()));
    connect(this->fFadeOutTimer, SIGNAL(timeout()), this, SLOT(fDoFadeOut()));
    connect(this, SIGNAL(destroyed()), SLOT(fDeleteTimer()));

    // Make sure the timer only calls our fade-out slot *once* and then stops.
    this->fFadeOutTimer->setSingleShot(true);
}


QTadsSound::~QTadsSound()
{
    //qDebug() << Q_FUNC_INFO;
    this->fRepeatsWanted = -1;
    // If our chunk is still playing, halt it.
    if (Mix_GetChunk(this->fChannel) == this->fChunk and Mix_Playing(this->fChannel) == 1) {
        Mix_HaltChannel(this->fChannel);
    }
    // Wait till it finished before deleting it.
    if (Mix_GetChunk(this->fChannel) == this->fChunk) {
        while (Mix_Playing(this->fChannel) != 0) {
            SDL_Delay(10);
        }
    }
    // Free the raw audio data buffer if SDL_mixer didn't allocate it itself.
    if (not this->fChunk->allocated) {
        free(this->fChunk->abuf);
    }
    Mix_FreeChunk(this->fChunk);
}


void
QTadsSound::fDoFadeOut()
{
    Q_ASSERT(Mix_GetChunk(this->fChannel) == this->fChunk and Mix_Playing(this->fChannel) == 1);

    // If we need to do a crossfade, call the TADS callback now.
    if (this->fCrossFade and this->fDone_func) {
        this->fDone_func(this->fDone_func_ctx, this->fRepeats);
        // Make sure our SDL callback won't call the TADS callback a second
        // time.
        this->fDone_func = 0;
        this->fDone_func_ctx = 0;
    }
    Mix_FadeOutChannel(this->fChannel, this->fFadeOut);
}


void
QTadsSound::fDoLoop()
{
    // When playing again, we can't assume that we can use the same channel.
    this->fChannel = Mix_PlayChannel(-1, this->fChunk, 0);
    this->fTimePos.start();
    ++this->fRepeats;

    // If this is the last iteration and we have a fade-out, set the fade-out
    // timer.
    if (this->fFadeOut > 0 and (this->fRepeatsWanted == -1 or this->fRepeats == this->fRepeatsWanted)) {
        this->fFadeOutTimer->start(this->fLength - this->fFadeOut);
    }
}


void
QTadsSound::fPrepareFadeOut()
{
    this->fFadeOutTimer->start(this->fLength - this->fFadeOut);
}


void
QTadsSound::fDeleteTimer()
{
    delete this->fFadeOutTimer;
}


void
QTadsSound::callback( int channel )
{
    QTadsSound* mObj = 0;
    int index = 0;
    // Find the object that uses the specified channel.
    for (int i = 0; i < fObjList.size() and mObj == 0; ++i) {
        if (fObjList.at(i)->fChannel == channel) {
            mObj = fObjList.at(i);
            index = i;
        }
    }

    if (mObj == 0) {
        return;
    }

    // If it's an infinite loop sound, or it has not reached the wanted repeat
    // count yet, play again.
    if ((mObj->fRepeatsWanted == 0) or (mObj->fRepeats < mObj->fRepeatsWanted)) {
        mObj->emitReadyToLoop();
        return;
    }

    // Remove the object from the list.  Since it can be included several
    // times, only remove the instance we associated to the channel we're
    // handling.
    fObjList.removeAt(index);

    // Sound has repeated enough times, or it has been halted.  In either case,
    // we need to invoke the TADS callback, if there is one.
    mObj->fPlaying = false;
    if (mObj->fDone_func) {
        mObj->fDone_func(mObj->fDone_func_ctx, mObj->fRepeats);
    }
}


int
QTadsSound::startPlaying( void (*done_func)(void*, int repeat_count), void* done_func_ctx, int repeat, int vol,
                          int fadeIn, int fadeOut, bool crossFade )
{
    // Check if user disabled digital sound.
    if (not qFrame->settings()->enableSoundEffects) {
        return 1;
    }

    Q_ASSERT(not this->fPlaying);

    // Adjust volume if it exceeds min/max levels.
    if (vol < 0) {
        vol = 0;
    } else if (vol > 100) {
        vol = 100;
    }

    // Convert the TADS volume level semantics [0..100] to SDL volume
    // semantics [0..MIX_MAX_VOLUME].
    vol = (vol * MIX_MAX_VOLUME) / 100;

    // Set the volume level.
    Mix_VolumeChunk(this->fChunk, vol);

    this->fRepeatsWanted = repeat;
    if (fadeIn > 0) {
        this->fChannel = Mix_FadeInChannel(-1, this->fChunk, 0, fadeIn);
    } else {
        this->fChannel = Mix_PlayChannel(-1, this->fChunk, 0);
    }
    if (this->fChannel == -1) {
        qWarning() << "ERROR:" << Mix_GetError();
        Mix_SetError("");
        return 1;
    } else {
        this->fTimePos.start();
        this->fPlaying = true;
        this->fCrossFade = crossFade;
        this->fRepeats = 1;
        QTadsSound::fObjList.append(this);
        this->fDone_func = done_func;
        this->fDone_func_ctx = done_func_ctx;
        if (fadeOut > 0) {
            this->fFadeOut = fadeOut;
            if (repeat == 1) {
                // The sound should only be played once.  We need to set the
                // fade-out timer here since otherwise the sound won't get a
                // chance to fade-out.
                emit readyToFadeOut();
            }
        }
    }
    return 0;
}


void
QTadsSound::cancelPlaying( bool sync, int fadeOut, bool fadeOutInBg )
{
    if (not this->fPlaying) {
        return;
    }

    this->fRepeatsWanted = -1;

    if (not sync and fadeOut > 0) {
        if (fadeOutInBg and this->fDone_func) {
            // We need to do fade-out in the background; call the TADS callback
            // now.
            this->fDone_func(this->fDone_func_ctx, this->fRepeats);
            // Make sure our SDL callback won't call the TADS callback a second
            // time.
            this->fDone_func = 0;
            this->fDone_func_ctx = 0;
        }
        Mix_FadeOutChannel(this->fChannel, fadeOut);
    } else {
        Mix_HaltChannel(this->fChannel);
    }

    if (sync and Mix_GetChunk(this->fChannel) == this->fChunk) {
        // The operation needs to be synchronous; wait for the sound to finish.
        while (Mix_Playing(this->fChannel) != 0) {
            SDL_Delay(10);
        }
    }
}


void
QTadsSound::addCrossFade( int ms )
{
    this->fCrossFade = true;
    this->fFadeOut = ms;

    if (this->fPlaying) {
        this->fRepeatsWanted = -1;
        int timeFromNow = this->fLength - this->fFadeOut - this->fTimePos.elapsed();
        if (timeFromNow < 1) {
            timeFromNow = 1;
            this->fFadeOut = this->fLength - this->fTimePos.elapsed();
        }
        this->fFadeOutTimer->start(timeFromNow);
    }
}
#endif


CHtmlSysSound*
QTadsSound::createSound( const CHtmlUrl* /*url*/, const textchar_t* filename, unsigned long seekpos,
                         unsigned long filesize, CHtmlSysWin*, SoundType type )
#ifndef Q_OS_ANDROID
{
    //qDebug() << "Loading sound from" << filename << "offset:" << seekpos << "size:" << filesize
    //      << "url:" << url->get_url();

    // Check if the file exists and is readable.
    QFileInfo inf(fnameToQStr(filename));
    if (not inf.exists() or not inf.isReadable()) {
        qWarning() << "ERROR:" << inf.filePath() << "doesn't exist or is unreadable";
        return 0;
    }

    // Open the file and seek to the specified position.
    QFile file(inf.filePath());
    if (not file.open(QIODevice::ReadOnly)) {
        qWarning() << "ERROR: Can't open file" << inf.filePath();
        return 0;
    }
    if (not file.seek(seekpos)) {
        qWarning() << "ERROR: Can't seek in file" << inf.filePath();
        file.close();
        return 0;
    }
    QByteArray data(file.read(filesize));
    file.close();
    if (data.isEmpty() or static_cast<unsigned long>(data.size()) < filesize) {
        qWarning() << "ERROR: Could not read" << filesize << "bytes from file" << inf.filePath();
        return 0;
    }

    // Create the RWops through which the data will be read later.
    SDL_RWops* rw = SDL_RWFromConstMem(data.constData(), data.size());
    if (rw == 0) {
        qWarning() << "ERROR:" << SDL_GetError();
        SDL_ClearError();
        return 0;
    }

    // The chunk that will hold the final, decoded sound.
    Mix_Chunk* chunk;

    // If it's an MP3 or WAV, we'll decode it with SDL_sound.  For Ogg Vorbis
    // we use SDL_mixer.  The reason is that SDL_mixer plays WAV at wrong
    // speeds if they're not 11, 22 or 44kHz (like 48kHz or 32kHz) and crashes
    // sometimes with MP3s.  SDL_sound can't cope well with Ogg Vorbis that
    // have more then two channels.
    if (type == MPEG or type == WAV) {
        if (rw == 0) {
            qWarning() << "ERROR:" << SDL_GetError();
            SDL_ClearError();
            return 0;
        }
        Sound_AudioInfo wantedFormat;
        wantedFormat.channels = 2;
        wantedFormat.rate = 44100;
        wantedFormat.format = MIX_DEFAULT_FORMAT;
        // Note that we use a large buffer size to speed-up decoding of large
        // MP3s on Windows; the decoding will take extremely long with small
        // buffer sizes.
        Sound_Sample* sample = Sound_NewSample(rw, type == WAV ? "WAV" : "MP3", &wantedFormat,
#ifdef Q_OS_WIN32
                                               6291456
#else
                                               131072
#endif
                                               );
        if (sample == 0) {
            qWarning() << "ERROR:" << Sound_GetError();
            Sound_ClearError();
            return 0;
        }
        Sound_DecodeAll(sample);
        if (sample->flags & SOUND_SAMPLEFLAG_ERROR) {
            // We don't abort since some of these errors can be non-fatal.
            // Unfortunately, there's no way to tell :-/
            qWarning() << "WARNING:" << Sound_GetError();
            Sound_ClearError();
        }
        Uint8* buf = static_cast<Uint8*>(malloc(sample->buffer_size));
        memcpy(buf, sample->buffer, sample->buffer_size);
        Sound_FreeSample(sample);
        chunk = Mix_QuickLoad_RAW(buf, sample->buffer_size);
        if (chunk == 0) {
            qWarning() << "ERROR:" << Mix_GetError();
            Mix_SetError("");
            free(buf);
            return 0;
        }
    } else {
        Q_ASSERT(type == OGG);
        chunk = Mix_LoadWAV_RW(rw, true);
        if (chunk == 0) {
            qWarning() << "ERROR:" << Mix_GetError();
            Mix_SetError("");
            return 0;
        }
    }

    // Alternative way of decoding MPEG, utilizing SMPEG directly.  It sucks,
    // since SMPEG, for the piece of crap it is, tends to play MP3s at double
    // speed (chipmunks ahoy...)
#if 0
    if (type == MPEG) {
        // The sound is an mp3.  We'll decode it into an SDL_Mixer chunk using
        // SMPEG.
        SMPEG* smpeg = SMPEG_new_data(data.data(), data.size(), 0, 0);

        // Set the format we want the decoded raw data to have.
        SDL_AudioSpec spec;
        SMPEG_wantedSpec(smpeg, &spec);
        spec.channels = 2;
        spec.format = MIX_DEFAULT_FORMAT;
        spec.freq = 44100;
        SMPEG_actualSpec(smpeg, &spec);

        // We decode the mpeg stream in steps of 8192kB each and increase the
        // size of the output buffer after each step.
        size_t bufSize = 8192;
        Uint8* buf = static_cast<Uint8*>(malloc(bufSize));
        // Needs to be set to digital silence because SMPEG is mixing source
        // and destination.
        memset(buf, 0, bufSize);
        // Prepare for decoding and decode the first bunch of data.
        SMPEG_play(smpeg);
        int bytesWritten = SMPEG_playAudio(smpeg, buf, 8192);
        // Decode the rest.  Increase buffer as needed.
        while (bytesWritten > 0 and bytesWritten <= 8192) {
            bufSize += 8192;
            buf = static_cast<Uint8*>(realloc(buf, bufSize));
            memset(buf + (bufSize - 8192), 0, 8192);
            bytesWritten = SMPEG_playAudio(smpeg, buf + (bufSize - 8192), 8192);
        }
        // Done with decoding.
        SMPEG_stop(smpeg);
        if (SMPEG_error(smpeg) != 0) {
            qWarning() << "ERROR: cannot decode sound data:" << SMPEG_error(smpeg);
            free(buf);
            SMPEG_delete(smpeg);
            return 0;
        }
        SMPEG_delete(smpeg);
        // Adjust final buffer size to fit the decoded data exactly.
        buf = static_cast<Uint8*>(realloc(buf, (bufSize - 8192) + bytesWritten));
        chunk = Mix_QuickLoad_RAW(buf, (bufSize - 8192) + bytesWritten);
    }
#endif

    // We have all the data we need; create the sound object.  It is
    // *important* not to pass the CHtmlSysWin object as the parent in the
    // constructor; doing so would result in Qt deleting the sound object when
    // the parent object gets destroyed.  Therefore, we simply pass 0 to make
    // the sound object parentless.
    CHtmlSysSound* sound = NULL;
    switch (type) {
      case WAV:
        //qDebug() << "Sound type: WAV";
        sound = new CHtmlSysSoundWavQt(0, chunk, WAV);
        break;

      case OGG:
        //qDebug() << "Sound type: OGG";
        sound = new CHtmlSysSoundOggQt(0, chunk, OGG);
        break;

      case MPEG:
        //qDebug() << "Sound type: MPEG";
        sound = new CHtmlSysSoundMpegQt(0, chunk, MPEG);
        break;
    }
    return sound;
}
#else
{
    return 0;
}
#endif