/*
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
* @file
* ModPlug demuxer
* @todo metadata
*/

#include <libmodplug/modplug.h>
#include "libavutil/opt.h"
#include "avformat.h"

typedef struct ModPlugContext {
    const AVClass *class;
    ModPlugFile *f;
    uint8_t buf[5 * 1<<20]; ///< input file content, 5M max

    /* options */
    int noise_reduction;
    int reverb_depth;
    int reverb_delay;
    int bass_amount;
    int bass_range;
    int surround_depth;
    int surround_delay;
} ModPlugContext;

#define OFFSET(x) offsetof(ModPlugContext, x)
#define D AV_OPT_FLAG_DECODING_PARAM
static const AVOption options[] = {
    {"noise_reduction", "Enable noise reduction 0(off)-1(on)",  OFFSET(noise_reduction), FF_OPT_TYPE_INT, {.dbl = 0}, 0,       1, D},
    {"reverb_depth",    "Reverb level 0(quiet)-100(loud)",      OFFSET(reverb_depth),    FF_OPT_TYPE_INT, {.dbl = 0}, 0,     100, D},
    {"reverb_delay",    "Reverb delay in ms, usually 40-200ms", OFFSET(reverb_delay),    FF_OPT_TYPE_INT, {.dbl = 0}, 0, INT_MAX, D},
    {"bass_amount",     "XBass level 0(quiet)-100(loud)",       OFFSET(bass_amount),     FF_OPT_TYPE_INT, {.dbl = 0}, 0,     100, D},
    {"bass_range",      "XBass cutoff in Hz 10-100",            OFFSET(bass_range),      FF_OPT_TYPE_INT, {.dbl = 0}, 0,     100, D},
    {"surround_depth",  "Surround level 0(quiet)-100(heavy)",   OFFSET(surround_depth),  FF_OPT_TYPE_INT, {.dbl = 0}, 0,     100, D},
    {"surround_delay",  "Surround delay in ms, usually 5-40ms", OFFSET(surround_delay),  FF_OPT_TYPE_INT, {.dbl = 0}, 0, INT_MAX, D},
    {NULL},
};

#define SET_OPT_IF_REQUESTED(libopt, opt, flag) do {        \
    if (modplug->opt) {                                     \
        settings.libopt  = modplug->opt;                    \
        settings.mFlags |= flag;                            \
    }                                                       \
} while (0)

static int modplug_read_header(AVFormatContext *s, AVFormatParameters *ap)
{
    AVStream *st;
    AVIOContext *pb = s->pb;
    ModPlug_Settings settings;
    ModPlugContext *modplug = s->priv_data;

    int sz = avio_read(pb, modplug->buf, sizeof(modplug->buf));

    ModPlug_GetSettings(&settings);
    settings.mChannels       = 2;
    settings.mBits           = 16;
    settings.mFrequency      = 44100;
    settings.mResamplingMode = MODPLUG_RESAMPLE_FIR; // best quality
    settings.mLoopCount      = 0; // prevents looping forever

    if (modplug->noise_reduction) settings.mFlags     |= MODPLUG_ENABLE_NOISE_REDUCTION;
    SET_OPT_IF_REQUESTED(mReverbDepth,   reverb_depth,   MODPLUG_ENABLE_REVERB);
    SET_OPT_IF_REQUESTED(mReverbDelay,   reverb_delay,   MODPLUG_ENABLE_REVERB);
    SET_OPT_IF_REQUESTED(mBassAmount,    bass_amount,    MODPLUG_ENABLE_MEGABASS);
    SET_OPT_IF_REQUESTED(mBassRange,     bass_range,     MODPLUG_ENABLE_MEGABASS);
    SET_OPT_IF_REQUESTED(mSurroundDepth, surround_depth, MODPLUG_ENABLE_SURROUND);
    SET_OPT_IF_REQUESTED(mSurroundDelay, surround_delay, MODPLUG_ENABLE_SURROUND);

    if (modplug->reverb_depth)   settings.mReverbDepth   = modplug->reverb_depth;
    if (modplug->reverb_delay)   settings.mReverbDelay   = modplug->reverb_delay;
    if (modplug->bass_amount)    settings.mBassAmount    = modplug->bass_amount;
    if (modplug->bass_range)     settings.mBassRange     = modplug->bass_range;
    if (modplug->surround_depth) settings.mSurroundDepth = modplug->surround_depth;
    if (modplug->surround_delay) settings.mSurroundDelay = modplug->surround_delay;

    ModPlug_SetSettings(&settings);

    modplug->f = ModPlug_Load(modplug->buf, sz);
    if (!modplug->f)
        return AVERROR_INVALIDDATA;

    st = av_new_stream(s, 0);
    if (!st)
        return AVERROR(ENOMEM);
    av_set_pts_info(st, 64, 1, 1000);
    st->duration = ModPlug_GetLength(modplug->f);
    st->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
    st->codec->codec_id    = CODEC_ID_PCM_S16LE;
    st->codec->channels    = settings.mChannels;
    st->codec->sample_rate = settings.mFrequency;
    return 0;
}

static int modplug_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    ModPlugContext *modplug = s->priv_data;

    if (av_new_packet(pkt, 512) < 0)
        return AVERROR(ENOMEM);

    pkt->size = ModPlug_Read(modplug->f, pkt->data, 512);
    if (pkt->size <= 0) {
        av_free_packet(pkt);
        return pkt->size == 0 ? AVERROR_EOF : AVERROR(EIO);
    }
    return 0;
}

static int modplug_read_close(AVFormatContext *s)
{
    ModPlugContext *modplug = s->priv_data;
    ModPlug_Unload(modplug->f);
    return 0;
}

static int modplug_read_seek(AVFormatContext *s, int stream_idx, int64_t ts, int flags)
{
    const ModPlugContext *modplug = s->priv_data;
    ModPlug_Seek(modplug->f, (int)ts);
    return 0;
}

static const AVClass modplug_class = {
    .class_name = "ModPlug demuxer",
    .item_name  = av_default_item_name,
    .option     = options,
    .version    = LIBAVUTIL_VERSION_INT,
};

AVInputFormat ff_libmodplug_demuxer = {
    .name           = "libmodplug",
    .long_name      = NULL_IF_CONFIG_SMALL("ModPlug demuxer"),
    .priv_data_size = sizeof(ModPlugContext),
    .read_header    = modplug_read_header,
    .read_packet    = modplug_read_packet,
    .read_close     = modplug_read_close,
    .read_seek      = modplug_read_seek,
    .extensions     = "669,abc,amf,ams,dbm,dmf,dsm,far,it,mdl,med,mid,mod,mt2,mtm,okt,psm,ptm,s3m,stm,ult,umx,xm"
                      ",itgz,itr,itz,mdgz,mdr,mdz,s3gz,s3r,s3z,xmgz,xmr,xmz", // compressed mods
    .priv_class     = &modplug_class,
};