/**
 * vgmstream for Audacious
 */

#include <cstdlib>
#include <algorithm>
#include <string.h>

#if DEBUG
#include <ctime>
#include <sys/time.h>
#endif

#include <libaudcore/audio.h>


extern "C" {
#include "../src/vgmstream.h"
#include "../src/plugins.h"
}
#include "plugin.h"
#include "vfs.h"


#ifndef VERSION
#include "version.h"
#endif
#ifndef VERSION
#define VERSION "(unknown version)"
#endif

#define CFG_ID "vgmstream" // ID for storing in audacious
#define MIN_BUFFER_SIZE 576

/* global state */
/*EXPORT*/ VgmstreamPlugin aud_plugin_instance;
audacious_settings_t settings;

/* Audacious will first send the file to a plugin based on this static extension list. If none
 * accepts it'll try again all plugins, ordered by priority, until one accepts the file. Problem is,
 * mpg123 plugin has higher priority and tendency to accept files that aren't even MP3. To fix this
 * we declare a few conflicting formats so we have a better chance.
 * The extension affects only this priority and in all cases file must accepted during "is_our_file".
 */
const char *const VgmstreamPlugin::exts[] = {
        "ahx","asf","awc","ckd","fsb","genh","msf","p3d","rak","scd","str","txth","xvag", nullptr
};


const char *const VgmstreamPlugin::defaults[] = {
    "loop_forever",     "FALSE",
    "ignore_loop",      "FALSE",
    "loop_count",       "2.0",
    "fade_length",      "10.0",
    "fade_delay",       "0.0",
    "downmix_channels", "2",
    "exts_unknown_on",  "FALSE",
    "exts_common_on",   "FALSE",
    NULL
};

// N_(...) for i18n but not much point here
const char VgmstreamPlugin::about[] =
    "vgmstream plugin " VERSION " " __DATE__ "\n"
    "by hcs, FastElbja, manakoAT, bxaimc, snakemeat, soneek, kode54, bnnm and many others\n"
    "\n"
    "Audacious plugin:\n"
    "ported to Audacious 3.6 by Brandon Whitehead\n"
    "adopted from Audacious 3 port by Thomas Eppers\n"
    "originally written by Todd Jeffreys (http://voidpointer.org/)\n"
    "\n"
    "https://github.com/kode54/vgmstream/\n"
    "https://sourceforge.net/projects/vgmstream/ (original)";

/* widget config: {min, max, step} */
const PreferencesWidget VgmstreamPlugin::widgets[] = {
    WidgetLabel(N_("<b>vgmstream config</b>")),
    WidgetCheck(N_("Loop forever:"), WidgetBool(settings.loop_forever)),
    WidgetCheck(N_("Ignore loop:"), WidgetBool(settings.ignore_loop)),
    WidgetSpin(N_("Loop count:"), WidgetFloat(settings.loop_count), {1, 100, 1.0}),
    WidgetSpin(N_("Fade length:"), WidgetFloat(settings.fade_time), {0, 60, 0.1}),
    WidgetSpin(N_("Fade delay:"), WidgetFloat(settings.fade_delay), {0, 60, 0.1}),
    WidgetSpin(N_("Downmix:"), WidgetInt(settings.downmix_channels), {0, 8, 1}),
    WidgetCheck(N_("Enable unknown exts"), WidgetBool(settings.exts_unknown_on)),
    // Audacious 3.6 will only match one plugin so this option has no actual use
    // (ex. a fake .flac only gets to the FLAC plugin and never to vgmstream, even on error)
    //WidgetCheck(N_("Enable common exts"), WidgetBool(settings.exts_common_on)),
};

void vgmstream_settings_load() {
    AUDINFO("load settings\n");
    aud_config_set_defaults(CFG_ID, VgmstreamPlugin::defaults);
    settings.loop_forever = aud_get_bool(CFG_ID, "loop_forever");
    settings.ignore_loop = aud_get_bool(CFG_ID, "ignore_loop");
    settings.loop_count = aud_get_double(CFG_ID, "loop_count");
    settings.fade_time = aud_get_double(CFG_ID, "fade_length");
    settings.fade_delay = aud_get_double(CFG_ID, "fade_delay");
    settings.downmix_channels = aud_get_int(CFG_ID, "downmix_channels");
    settings.exts_unknown_on = aud_get_bool(CFG_ID, "exts_unknown_on");
    settings.exts_common_on = aud_get_bool(CFG_ID, "exts_common_on");
}

void vgmstream_settings_save() {
    AUDINFO("save settings\n");
    aud_set_bool(CFG_ID, "loop_forever", settings.loop_forever);
    aud_set_bool(CFG_ID, "ignore_loop", settings.ignore_loop);
    aud_set_double(CFG_ID, "loop_count", settings.loop_count);
    aud_set_double(CFG_ID, "fade_length", settings.fade_time);
    aud_set_double(CFG_ID, "fade_delay", settings.fade_delay);
    aud_set_int(CFG_ID, "downmix_channels", settings.downmix_channels);
    aud_set_bool(CFG_ID, "exts_unknown_on", settings.exts_unknown_on);
    aud_set_bool(CFG_ID, "exts_common_on", settings.exts_common_on);
}

const PluginPreferences VgmstreamPlugin::prefs = {
    {widgets}, vgmstream_settings_load, vgmstream_settings_save
};

// validate extension (thread safe)
bool VgmstreamPlugin::is_our_file(const char * filename, VFSFile & file) {
    AUDDBG("test file=%s\n", filename);

    vgmstream_ctx_valid_cfg cfg = {0};

    cfg.accept_unknown = settings.exts_unknown_on;
    cfg.accept_common = settings.exts_common_on;
    return vgmstream_ctx_is_valid(filename, &cfg) > 0 ? true : false;
}

// called on startup (main thread)
bool VgmstreamPlugin::init() {
    AUDINFO("plugin start\n");

    vgmstream_settings_load();

    return true;
}

// called on stop (main thread)
void VgmstreamPlugin::cleanup() {
    AUDINFO("plugin end\n");

    vgmstream_settings_save();
}

#if 0
static int get_filename_subtune(const char* filename) {
    int subtune;

    int pos = strstr("?"))
    if (pos <= 0)
        return -1;
    if (sscanf(filename + pos, "%i", &subtune) != 1)
        return -1;
    return subtune;
}
#endif

static void apply_config(VGMSTREAM* vgmstream, audacious_settings_t* settings) {
    vgmstream_cfg_t vcfg = {0};

    vcfg.allow_play_forever = 1;
    vcfg.play_forever = settings->loop_forever;
    vcfg.loop_count = settings->loop_count;
    vcfg.fade_time = settings->fade_time;
    vcfg.fade_delay = settings->fade_delay;
    vcfg.ignore_loop = settings->ignore_loop;

    vgmstream_apply_config(vgmstream, &vcfg);
}

// internal helper, called every time user adds a new file to playlist
static bool read_info(const char* filename, Tuple & tuple) {
    AUDINFO("read file=%s\n", filename);

#if 0
    //todo subsongs:
    // in theory just set FlagSubtunes in plugin.h, and set_subtunes below
    // Audacious will call "play" and this(?) with filename?N where N=subtune
    // and you just load subtune N, but I can't get it working
    int subtune;
    string basename;
    int subtune = get_filename_subtune(basename, &subtune);
    //must use basename to open streamfile
#endif

    STREAMFILE* sf = open_vfs(filename);
    if (!sf) return false;

    VGMSTREAM* infostream = init_vgmstream_from_STREAMFILE(sf);
    if (!infostream) {
        close_streamfile(sf);
        return false;
    }

#if 0
    int total_subtunes = infostream->num_streams;

    //somehow max was changed to short in recent versions, though
    // some formats can exceed this
    if (total_subtunes > 32767)
        total_subtunes = 32767;
    if (infostream->num_streams > 1 && subtune <= 0) {
        //set nullptr to leave subsong index linear (must add +1 to subtune)
        tuple.set_subtunes(total_subtunes, nullptr);
        return true; //must return?
    }

    sf->stream_index = (subtune + 1);
#endif


    apply_config(infostream, &settings);

    int output_channels = infostream->channels;
    vgmstream_mixing_autodownmix(infostream, settings.downmix_channels);
    vgmstream_mixing_enable(infostream, 0, NULL, &output_channels);

    int bitrate = get_vgmstream_average_bitrate(infostream);
    int length_samples = vgmstream_get_samples(infostream);
    int length_ms = length_samples * 1000LL / infostream->sample_rate;

    //todo: set_format may throw std::bad_alloc if output_channels isn't supported (only 2?)
    // short form, not sure if better way
    tuple.set_format("vgmstream codec", output_channels, infostream->sample_rate, bitrate);
    tuple.set_filename(filename); //used?
    tuple.set_int(Tuple::Bitrate, bitrate); //in kb/s
    tuple.set_int(Tuple::Length, length_ms);

    //todo here we could call describe_vgmstream() and get substring to add tags and stuff
    tuple.set_str(Tuple::Codec, "vgmstream codec");
    //tuple.set_int(Tuple::Subtune, subtune);
    //tuple.set_int(Tuple::NumSubtunes, subtune); //done un set_subtunes

    //todo tags (see tuple.h)
    //tuple.set_int (Tuple::Track, ...);
    //tuple.set_str (Tuple::Artist, ...);
    //tuple.set_str (Tuple::Album, ...);

    close_streamfile(sf);
    close_vgmstream(infostream);

    return true;
}

// thread safe (for Audacious <= 3.7, unused otherwise)
Tuple VgmstreamPlugin::read_tuple(const char * filename, VFSFile & file) {
    Tuple tuple;
    read_info(filename, tuple);
    return tuple;
}

// thread safe (for Audacious >= 3.8, unused otherwise)
bool VgmstreamPlugin::read_tag(const char * filename, VFSFile & file, Tuple & tuple, Index<char> * image) {
    return read_info(filename, tuple);
}

// internal util to seek during play
static void do_seek(VGMSTREAM* vgmstream, int seek_ms, int& current_sample_pos) {
    AUDINFO("seeking\n");

    // compute from ms to samples
    int seek_sample = (long long)seek_ms * vgmstream->sample_rate / 1000L;

    seek_vgmstream(vgmstream, seek_sample);

    current_sample_pos = seek_sample;
}

// called on play (play thread)
bool VgmstreamPlugin::play(const char * filename, VFSFile & file) {
    AUDINFO("play file=%s\n", filename);

    STREAMFILE* sf = open_vfs(filename);
    if (!sf) {
        AUDERR("failed opening file %s\n", filename);
        return false;
    }

    VGMSTREAM* vgmstream = init_vgmstream_from_STREAMFILE(sf);
    close_streamfile(sf);

    if (!vgmstream) {
        AUDINFO("filename %s is not a valid format\n", filename);
        close_vgmstream(vgmstream);
        return false;
    }

    int bitrate = get_vgmstream_average_bitrate(vgmstream);
    set_stream_bitrate(bitrate);

    //todo apply config


    apply_config(vgmstream, &settings);

    int input_channels = vgmstream->channels;
    int output_channels = vgmstream->channels;
    /* enable after all config but before outbuf */
    vgmstream_mixing_autodownmix(vgmstream, settings.downmix_channels);
    vgmstream_mixing_enable(vgmstream, MIN_BUFFER_SIZE, &input_channels, &output_channels);

    //FMT_S8 / FMT_S16_NE / FMT_S24_NE / FMT_S32_NE / FMT_FLOAT
    open_audio(FMT_S16_LE, vgmstream->sample_rate, output_channels);

    // play
    short buffer[MIN_BUFFER_SIZE * input_channels];
    int max_buffer_samples = MIN_BUFFER_SIZE;

    int play_forever = vgmstream_get_play_forever(vgmstream);
    int length_samples = vgmstream_get_samples(vgmstream);
    int decode_pos_samples = 0;

    while (!check_stop()) {
        int to_do = max_buffer_samples;

        // handle seek request
        int seek_value = check_seek();
        if (seek_value >= 0) {
            do_seek(vgmstream, seek_value, decode_pos_samples);
            continue;
        }

        // check stream finished
        if (!play_forever) {
            if (decode_pos_samples >= length_samples)
                break;

            if (decode_pos_samples + to_do > length_samples)
                to_do = length_samples - decode_pos_samples;
        }

        render_vgmstream(buffer, to_do, vgmstream);

        write_audio(buffer, to_do * sizeof(short) * output_channels);
        decode_pos_samples += to_do;
    }

    AUDINFO("play finished\n");

    close_vgmstream(vgmstream);
    return true;
}