// FMOD Sample Bank (FSB) - Audio Container Format
// Firelight Technologies Pty, Ltd.
// Supports FSB3, FSB4, FSB5
//
// Reference: https://github.com/gdawg/fsbext

// Root FSB type - auto-detects version
type fmod_fsb [root, display="FMOD Sample Bank"] byteorder LE
{
  criteria {
    require ascii(bytesat(0, 4)) == "FSB3" ||
            ascii(bytesat(0, 4)) == "FSB4" ||
            ascii(bytesat(0, 4)) == "FSB5" ||
            _ext == "fsb";
  }

  magic = ascii(read(4));


  ui("magic", "Magic");

  if (magic == "FSB3") {
    i32 num_samples;

    ui("num_samples", "Sample Count");
    i32 sample_header_size;

    ui("sample_header_size", "Sample Headers Size");
    i32 data_size;

    ui("data_size", "Audio Data Size");
    u32 version;

    ui("version", "Version");
    u32 mode;

    ui("mode", "Mode Flags");

    _header_end = 24;
    _audio_data_start = _header_end + sample_header_size;
    _current_audio_offset = _audio_data_start;

    if (num_samples > 0 && num_samples < 10000) {
      repeat(num_samples) {
        _sample = parse_here("fsb3_sample_header");

        _compressed_size = get(_sample, "length_compressed");
        _sample_name = get(_sample, "name");
        _sample_mode = get(_sample, "mode");

        // Export and preview audio file
        if (_compressed_size > 0 && _compressed_size < 100000000) {
          _audio_bytes = bytesat(_current_audio_offset, _compressed_size);
          _export_name = _sample_name + ".raw";
          if ((_sample_mode & 0x200) != 0) {
            _export_name = _sample_name + ".mp3";
          }
          write_file(_export_name, _audio_bytes);
          set_preview(_export_name, _audio_bytes);
          set_viewer("audio");
        }

        _current_audio_offset = _current_audio_offset + _compressed_size;
        content = push("content", _sample);
      }
    }
  }

  if (magic == "FSB4") {
    content = parse_here("fsb4_content");
  }
  if (magic == "FSB5") {
    content = parse_here("fsb5_content");
  }
}

// FSB3 Sample Header
type fsb3_sample_header [display="Sample"] byteorder LE
{
  u16 header_size;

  ui("header_size", "Header Size");

  _name_bytes = read(30);
  name = clean(ascii(_name_bytes));

  ui("name", "Name");
  set_name(name);

  u32 length_samples;


  ui("length_samples", "Length (samples)");
  u32 length_compressed;

  ui("length_compressed", "Compressed Size");
  u32 loop_start;

  ui("loop_start", "Loop Start");
  u32 loop_end;

  ui("loop_end", "Loop End");
  u32 mode;

  ui("mode", "Mode Flags");
  i32 frequency;

  ui("frequency", "Frequency (Hz)");
  u16 volume;

  ui("volume", "Default Volume");
  i16 pan;

  ui("pan", "Default Pan");
  u16 priority;

  ui("priority", "Priority");
  u16 channels;

  ui("channels", "Channels");

  f32 min_distance;


  ui("min_distance", "Min Distance");
  f32 max_distance;

  ui("max_distance", "Max Distance");

  i32 var_freq;


  ui("var_freq", "Frequency Variance");
  u16 var_vol;

  ui("var_vol", "Volume Variance");
  i16 var_pan;

  ui("var_pan", "Pan Variance");

  _bytes_read = 80;
  _extra_bytes = header_size - _bytes_read;
  if (_extra_bytes > 0 && _extra_bytes < 10000) {
    skip(_extra_bytes);
  }

  // Decode format
  format = "Unknown";

  ui("format", "Format");
  if ((mode & 0x200) != 0) {
    format = "MPEG";

    ui("format", "Format");
  }
  if ((mode & 0x400000) != 0) {
    format = "IMA ADPCM";

    ui("format", "Format");
  }
  if ((mode & 0x1000000) != 0) {
    format = "XMA";

    ui("format", "Format");
  }
  if ((mode & 0x2000000) != 0) {
    format = "GC ADPCM";

    ui("format", "Format");
  }
  if ((mode & 0x800000) != 0) {
    format = "VAG";

    ui("format", "Format");
  }
  if ((mode & 0x10) != 0 && (mode & 0x200) == 0 &&
      (mode & 0x400000) == 0 && (mode & 0x1000000) == 0) {
    format = "PCM16";

    ui("format", "Format");
  }
  if ((mode & 0x8) != 0) {
    format = "PCM8";

    ui("format", "Format");
  }
}

// FSB4 Content
type fsb4_content [display="FSB4 Content"] byteorder LE
{
  i32 num_samples;

  ui("num_samples", "Sample Count");
  i32 sample_header_size;

  ui("sample_header_size", "Sample Headers Size");
  i32 data_size;

  ui("data_size", "Audio Data Size");
  u32 version;

  ui("version", "Version");
  u32 mode;

  ui("mode", "Mode Flags");

  skip(8);
  hash = read(16);

  ui("hash", "Hash");

  _header_end = 48;
  _audio_data_start = _header_end + sample_header_size;

  if (num_samples > 0 && num_samples < 10000) {
    _current_audio_offset = _audio_data_start;
    repeat(num_samples) {
      _sample = parse_here("fsb3_sample_header");

      _compressed_size = get(_sample, "length_compressed");
      _sample_name = get(_sample, "name");
      _sample_mode = get(_sample, "mode");

      // Export and preview audio file
      if (_compressed_size > 0 && _compressed_size < 100000000) {
        _audio_bytes = bytesat(_current_audio_offset, _compressed_size);
        _export_name = _sample_name + ".raw";
        if ((_sample_mode & 0x200) != 0) {
          _export_name = _sample_name + ".mp3";
        }
        write_file(_export_name, _audio_bytes);
        set_preview(_export_name, _audio_bytes);
        set_viewer("audio");
      }

      _current_audio_offset = _current_audio_offset + _compressed_size;
      content = push("content", _sample);
    }
  }
}

// FSB5 Content
type fsb5_content [display="FSB5 Content"] byteorder LE
{
  i32 version;

  ui("version", "Version");
  i32 num_samples;

  ui("num_samples", "Sample Count");
  i32 sample_header_size;

  ui("sample_header_size", "Sample Headers Size");
  i32 name_table_size;

  ui("name_table_size", "Name Table Size");
  i32 data_size;

  ui("data_size", "Audio Data Size");
  u32 mode;

  ui("mode", "Mode/Codec");

  skip(8);
  hash = read(16);

  ui("hash", "Hash");
  skip(8);

  _header_end = 60;
  _data_start = _header_end + sample_header_size + name_table_size;

  info = "FSB5 uses compact variable-length headers";


  ui("info", "Note");
}

// Embedded parser for PAK files
type fmod_fsb_embedded [display="FMOD Sample Bank"] byteorder LE
{
  magic = ascii(read(4));

  ui("magic", "Magic");

  if (magic == "FSB3") {
    i32 num_samples;

    ui("num_samples", "Sample Count");
    i32 sample_header_size;

    ui("sample_header_size", "Sample Headers Size");
    i32 data_size;

    ui("data_size", "Audio Data Size");
    u32 version;

    ui("version", "Version");
    u32 mode;

    ui("mode", "Mode Flags");

    _header_end = 24;
    _audio_data_start = _header_end + sample_header_size;
    _current_audio_offset = _audio_data_start;

    if (num_samples > 0 && num_samples < 10000) {
      repeat(num_samples) {
        _sample = parse_here("fsb3_sample_header");

        _compressed_size = get(_sample, "length_compressed");
        _sample_name = get(_sample, "name");
        _sample_mode = get(_sample, "mode");

        // Export and preview audio file
        if (_compressed_size > 0 && _compressed_size < 100000000) {
          _audio_bytes = bytesat(_current_audio_offset, _compressed_size);
          _export_name = _sample_name + ".raw";
          if ((_sample_mode & 0x200) != 0) {
            _export_name = _sample_name + ".mp3";
          }
          write_file(_export_name, _audio_bytes);
          set_preview(_export_name, _audio_bytes);
          set_viewer("audio");
        }

        _current_audio_offset = _current_audio_offset + _compressed_size;
        content = push("content", _sample);
      }
    }
  }

  if (magic == "FSB4") {
    content = parse_here("fsb4_content");
  }
  if (magic == "FSB5") {
    content = parse_here("fsb5_content");
  }
}