/*
 * Copyright (C) 2003-2011 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * 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 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, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h"
#include "decoder_api.h"
#include "audio_check.h"
#include "libav_metadata.h"
#include "tag_handler.h"

#include <glib.h>

#include <assert.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libavformat/avio.h>
#include <libavutil/avutil.h>
#include <libavutil/log.h>
#include <libavutil/mathematics.h>
#include <libavutil/dict.h>

#undef G_LOG_DOMAIN
#define G_LOG_DOMAIN "libav"

typedef struct LibavDecContext {
    struct decoder *decoder;
    struct input_stream *input;

    AVIOContext *io;
    AVFormatContext *fmt_ctx;
    AVStream *ast;
} LibavDecContext;

static GLogLevelFlags level_libav_to_glib(int level)
{
    if (level <= AV_LOG_FATAL)
        return G_LOG_LEVEL_CRITICAL;

    if (level <= AV_LOG_ERROR)
        return G_LOG_LEVEL_WARNING;

    if (level <= AV_LOG_INFO)
        return G_LOG_LEVEL_MESSAGE;

    return G_LOG_LEVEL_DEBUG;
}

static void mpd_libav_log_callback(void *ptr, int level,
                                   const char *fmt, va_list vl)
{
    const AVClass * cls = NULL;

    if (ptr != NULL)
        cls = *(const AVClass *const*)ptr;

    if (cls != NULL) {
        char *domain = g_strconcat(G_LOG_DOMAIN, "/", cls->item_name(ptr), NULL);
        g_logv(domain, level_libav_to_glib(level), fmt, vl);
        g_free(domain);
    }
}

static int mpd_libav_stream_read(void *opaque, uint8_t *buf, int size)
{
    LibavDecContext *stream = opaque;

    return decoder_read(stream->decoder, stream->input,
                (void *)buf, size);
}

static int64_t mpd_libav_stream_seek(void *opaque, int64_t pos, int whence)
{
    LibavDecContext *stream = opaque;

    if (whence == AVSEEK_SIZE)
        return stream->input->size;

    if (!input_stream_lock_seek(stream->input, pos, whence, NULL))
        return -1;

    return stream->input->offset;
}

static void libav_close(LibavDecContext *s)
{
    if (s->fmt_ctx)
        avformat_close_input(&s->fmt_ctx);
    if (s->io)
        av_freep(&s->io->buffer);
    av_freep(&s->io);
}


#define INPUT_BUFFER_SIZE 16384
static int libav_open(LibavDecContext *s, struct input_stream *input)
{
    const char *filename = input->uri;
    uint8_t *buf;
    int ret = 0;

    s->input = input;

    /* init IO context */
    buf = av_malloc(INPUT_BUFFER_SIZE);
    if (!buf)
        return AVERROR(ENOMEM);

    s->io = avio_alloc_context(buf, INPUT_BUFFER_SIZE, 0,
                               s, mpd_libav_stream_read, NULL,
                               input->seekable ? mpd_libav_stream_seek : NULL);
    if (!s->io) {
        av_freep(&buf);
        return AVERROR(ENOMEM);
    }

    /* open the input stream */
    s->fmt_ctx = avformat_alloc_context();
    if (!s->fmt_ctx) {
        ret = AVERROR(ENOMEM);
        goto fail;
    }
    s->fmt_ctx->pb = s->io;

    ret = avformat_open_input(&s->fmt_ctx, filename, NULL, NULL);
    if (ret < 0)
        goto fail;

    g_debug("Successfully opened input stream '%s', detected input format '%s' (%s)\n",
            filename, s->fmt_ctx->iformat->name, s->fmt_ctx->iformat->long_name);

    ret = avformat_find_stream_info(s->fmt_ctx, NULL);
    if (ret < 0) {
        g_warning("Couldn't find stream info\n");
        goto fail;
    }

    for (int i = 0; i < s->fmt_ctx->nb_streams; i++)
        if (s->fmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
            s->ast = s->fmt_ctx->streams[i];
            break;
        }
    if (!s->ast) {
        g_warning("No audio stream in the file.\n");
        ret = AVERROR(EINVAL);
        goto fail;
    }

    return 0;

fail:
    g_warning("Failed to open input stream '%s'.\n", filename);
    libav_close(s);
    return ret;
}

static bool
libav_init(const struct config_param *param)
{
    av_log_set_callback(mpd_libav_log_callback);

    av_register_all();
    return true;
}

static double time_from_libav(int64_t t, const AVRational time_base)
{
    assert(t != (int64_t)AV_NOPTS_VALUE);

    return (double)av_rescale_q(t, time_base, (AVRational){1, 1024}) / (double)1024;
}

static int64_t time_to_libav(double t, const AVRational time_base)
{
    return av_rescale_q((int64_t)(t * 1024), (AVRational){1, 1024}, time_base);
}

/**
 * Copy PCM data from a AVFrame to an interleaved buffer.
 */
static int copy_interleave_frame(const AVCodecContext *codec_context,
                                 const AVFrame *frame,
                                 uint8_t *buffer, size_t buffer_size)
{
    int plane_size;
    const int data_size =
        av_samples_get_buffer_size(&plane_size,
                       codec_context->channels,
                       frame->nb_samples,
                       codec_context->sample_fmt, 1);
    uint16_t *dst = (uint16_t*)buffer;

    if (buffer_size < (size_t)data_size)
        /* buffer is too small - shouldn't happen */
        return AVERROR(EINVAL);

    if (av_sample_fmt_is_planar(codec_context->sample_fmt) &&
        codec_context->channels > 1) {
        for (int i = 0; i < frame->nb_samples; i++) {
            for (int j = 0; j < codec_context->channels; j++)
                dst[i * codec_context->channels + j] = ((uint16_t*)frame->extended_data[j])[i];
        }
    } else {
        memcpy(buffer, frame->extended_data[0], data_size);
    }

    return data_size;
}

#define AVCODEC_MAX_AUDIO_FRAME_SIZE 50000

static enum decoder_command libav_send_packet(struct decoder *decoder,
                                              struct input_stream *is,
                                              const AVPacket *packet,
                                              AVCodecContext *codec_context,
                                              const AVRational *time_base)
{
    AVPacket packet2 = *packet;
    uint8_t aligned_buffer[(AVCODEC_MAX_AUDIO_FRAME_SIZE * 3) / 2 + 16];
    const size_t buffer_size = sizeof(aligned_buffer);

    enum decoder_command cmd = DECODE_COMMAND_NONE;

    if (packet->pts != (int64_t)AV_NOPTS_VALUE)
        decoder_timestamp(decoder, time_from_libav(packet->pts, *time_base));

    while (packet2.size > 0 &&
           cmd == DECODE_COMMAND_NONE) {
        int audio_size = buffer_size;
        AVFrame frame;
        int got_frame = 0;
        int len = avcodec_decode_audio4(codec_context,
                                        &frame, &got_frame,
                                        &packet2);
        if (len >= 0 && got_frame) {
            audio_size = copy_interleave_frame(codec_context,
                                               &frame,
                                               aligned_buffer,
                                               buffer_size);
            if (audio_size < 0)
                len = audio_size;
        } else if (len >= 0)
            len = -1;

        if (len < 0) {
            /* if error, we skip the frame */
            g_message("decoding failed, frame skipped\n");
            break;
        }

        packet2.data += len;
        packet2.size -= len;

        if (audio_size <= 0)
            continue;

        cmd = decoder_data(decoder, is,
                           aligned_buffer, audio_size,
                           codec_context->bit_rate / 1000);
    }
    return cmd;
}

static enum sample_format libav_sample_format(const AVCodecContext *codec_context)
{
    switch (codec_context->sample_fmt) {
    case AV_SAMPLE_FMT_S16:
    case AV_SAMPLE_FMT_S16P:
        return SAMPLE_FORMAT_S16;

    case AV_SAMPLE_FMT_S32:
        return SAMPLE_FORMAT_S32;

    default:
        g_warning("Unsupported libavcodec SampleFormat value: %d",
              codec_context->sample_fmt);
        return SAMPLE_FORMAT_UNDEFINED;
    }
}

static void libav_decode(struct decoder *decoder, struct input_stream *input)
{
    LibavDecContext s = { .decoder = decoder };
    AVCodecContext *dec = NULL;
    const AVCodec *codec;
    struct audio_format audio_format;
    enum decoder_command cmd;
    GError *error = NULL;
    int ret, total_time;

    ret = libav_open(&s, input);
    if (ret < 0)
        return;

    dec   = s.ast->codec;
    codec = avcodec_find_decoder(dec->codec_id);
    if (!codec) {
        g_warning("Unsupported audio codec\n");
        goto finish;
    }
    g_debug("Selected audio decoder %s\n", codec->name);

    if (!audio_format_init_checked(&audio_format,
                                   dec->sample_rate,
                                   libav_sample_format(dec),
                                   dec->channels, &error)) {
        g_warning("%s", error->message);
        g_error_free(error);
        goto finish;
    }

    /* the audio format must be read from AVCodecContext by now,
       because avcodec_open() has been demonstrated to fill bogus
       values into AVCodecContext.channels - a change that will be
       reverted later by avcodec_decode_audio3() */

    ret = avcodec_open2(dec, codec, NULL);
    if (ret < 0) {
        g_warning("Could not open codec\n");
        goto finish;
    }

    total_time = s.fmt_ctx->duration != (int64_t)AV_NOPTS_VALUE ?
                 s.fmt_ctx->duration / AV_TIME_BASE : 0;

    decoder_initialized(decoder, &audio_format,
                        input->seekable, total_time);

    do {
        AVPacket packet;
        if (av_read_frame(s.fmt_ctx, &packet) < 0)
            /* end of file */
            break;

        if (packet.stream_index == s.ast->index)
            cmd = libav_send_packet(decoder, input,
                                    &packet, dec,
                                    &s.ast->time_base);
        else
            cmd = decoder_get_command(decoder);

        av_free_packet(&packet);

        if (cmd == DECODE_COMMAND_SEEK) {
            int64_t where = time_to_libav(decoder_seek_where(decoder),
                                          s.ast->time_base);

            if (av_seek_frame(s.fmt_ctx, s.ast->index, where,
                              AV_TIME_BASE) < 0)
                decoder_seek_error(decoder);
            else {
                avcodec_flush_buffers(dec);
                decoder_command_finished(decoder);
            }
        }
    } while (cmd != DECODE_COMMAND_STOP);

finish:
    if (dec)
        avcodec_close(dec);
    libav_close(&s);
}

//no tag reading in ffmpeg, check if playable
static bool libav_scan_stream(struct input_stream *is,
                              const struct tag_handler *handler,
                              void *handler_ctx)
{
    LibavDecContext s = { NULL };
    int ret;

    ret = libav_open(&s, is);
    if (ret < 0)
        return 0;

    if (s.fmt_ctx->duration != (int64_t)AV_NOPTS_VALUE)
        tag_handler_invoke_duration(handler, handler_ctx,
                                    s.fmt_ctx->duration / AV_TIME_BASE);


    libav_scan_dictionary(s.fmt_ctx->metadata, handler, handler_ctx);
    libav_scan_dictionary(s.ast->metadata, handler, handler_ctx);

    libav_close(&s);

    return true;
}

/**
 * A list of extensions found for the formats supported by ffmpeg.
 * This list is current as of 02-23-09; To find out if there are more
 * supported formats, check the ffmpeg changelog since this date for
 * more formats.
 */
static const char *const libav_suffixes[] = {
    "16sv", "3g2", "3gp", "4xm", "8svx", "aa3", "aac", "ac3", "afc", "aif",
    "aifc", "aiff", "al", "alaw", "amr", "anim", "apc", "ape", "asf",
    "atrac", "au", "aud", "avi", "avm2", "avs", "bap", "bfi", "c93", "cak",
    "cin", "cmv", "cpk", "daud", "dct", "divx", "dts", "dv", "dvd", "dxa",
    "eac3", "film", "flac", "flc", "fli", "fll", "flx", "flv", "g726",
    "gsm", "gxf", "iss", "m1v", "m2v", "m2t", "m2ts",
    "m4a", "m4b", "m4v",
    "mad",
    "mj2", "mjpeg", "mjpg", "mka", "mkv", "mlp", "mm", "mmf", "mov", "mp+",
    "mp1", "mp2", "mp3", "mp4", "mpc", "mpeg", "mpg", "mpga", "mpp", "mpu",
    "mve", "mvi", "mxf", "nc", "nsv", "nut", "nuv", "oga", "ogm", "ogv",
    "ogx", "oma", "ogg", "omg", "psp", "pva", "qcp", "qt", "r3d", "ra",
    "ram", "rl2", "rm", "rmvb", "roq", "rpl", "rvc", "shn", "smk", "snd",
    "sol", "son", "spx", "str", "swf", "tgi", "tgq", "tgv", "thp", "ts",
    "tsp", "tta", "xa", "xvid", "uv", "uv2", "vb", "vid", "vob", "voc",
    "vp6", "vmd", "wav", "webm", "wma", "wmv", "wsaud", "wsvga", "wv",
    "wve",
    NULL
};

static const char *const libav_mime_types[] = {
    "application/m4a",
    "application/mp4",
    "application/octet-stream",
    "application/ogg",
    "application/x-ms-wmz",
    "application/x-ms-wmd",
    "application/x-ogg",
    "application/x-shockwave-flash",
    "application/x-shorten",
    "audio/8svx",
    "audio/16sv",
    "audio/aac",
    "audio/ac3",
    "audio/aiff"
    "audio/amr",
    "audio/basic",
    "audio/flac",
    "audio/m4a",
    "audio/mp4",
    "audio/mpeg",
    "audio/musepack",
    "audio/ogg",
    "audio/qcelp",
    "audio/vorbis",
    "audio/vorbis+ogg",
    "audio/x-8svx",
    "audio/x-16sv",
    "audio/x-aac",
    "audio/x-ac3",
    "audio/x-aiff"
    "audio/x-alaw",
    "audio/x-au",
    "audio/x-dca",
    "audio/x-eac3",
    "audio/x-flac",
    "audio/x-gsm",
    "audio/x-mace",
    "audio/x-matroska",
    "audio/x-monkeys-audio",
    "audio/x-mpeg",
    "audio/x-ms-wma",
    "audio/x-ms-wax",
    "audio/x-musepack",
    "audio/x-ogg",
    "audio/x-vorbis",
    "audio/x-vorbis+ogg",
    "audio/x-pn-realaudio",
    "audio/x-pn-multirate-realaudio",
    "audio/x-speex",
    "audio/x-tta"
    "audio/x-voc",
    "audio/x-wav",
    "audio/x-wma",
    "audio/x-wv",
    "video/anim",
    "video/quicktime",
    "video/msvideo",
    "video/ogg",
    "video/theora",
    "video/webm",
    "video/x-dv",
    "video/x-flv",
    "video/x-matroska",
    "video/x-mjpeg",
    "video/x-mpeg",
    "video/x-ms-asf",
    "video/x-msvideo",
    "video/x-ms-wmv",
    "video/x-ms-wvx",
    "video/x-ms-wm",
    "video/x-ms-wmx",
    "video/x-nut",
    "video/x-pva",
    "video/x-theora",
    "video/x-vid",
    "video/x-wmv",
    "video/x-xvid",

    /* special value for the "ffmpeg" input plugin: all streams by
       the "ffmpeg" input plugin shall be decoded by this
       plugin */
    "audio/x-mpd-libav",

    NULL
};

const struct decoder_plugin libav_decoder_plugin = {
    .name = "libav",
    .init = libav_init,
    .stream_decode = libav_decode,
    .scan_stream = libav_scan_stream,
    .suffixes = libav_suffixes,
    .mime_types = libav_mime_types
};