glwav

-module(glwav).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/glwav.gleam").
-export([from_bit_array/1, to_bit_array/1]).
-export_type([wave/0, bits/0, from_bit_array_error/0, format_code/0, chunk_data/0, read_chunk_error/0]).

-if(?OTP_RELEASE >= 27).
-define(MODULEDOC(Str), -moduledoc(Str)).
-define(DOC(Str), -doc(Str)).
-else.
-define(MODULEDOC(Str), -compile([])).
-define(DOC(Str), -compile([])).
-endif.

-type wave() :: {wave,
        format_code(),
        integer(),
        integer(),
        bits(),
        list(float())}.

-type bits() :: u8 | i16 | i24 | f32.

-type from_bit_array_error() :: {riff_format_error,
        glriff:from_bit_array_error()} |
    invalid_format.

-type format_code() :: p_c_m | ieee_float | alaw | mulaw | extensible.

-type chunk_data() :: {fmt, format_code(), integer(), integer(), bits()} |
    {data, bitstring()}.

-type read_chunk_error() :: not_supported |
    invalid_format_code |
    invalid_channels |
    invalid_sample_rate |
    invalid_bytes_per_second |
    invalid_block_align |
    invalid_bits.

-file("src/glwav.gleam", 185).
-spec convert_format_code(bitstring()) -> {ok, format_code()} |
    {error, read_chunk_error()}.
convert_format_code(Bits) ->
    case Bits of
        <<1:16/little>> ->
            {ok, p_c_m};

        _ ->
            {error, not_supported}
    end.

-file("src/glwav.gleam", 192).
-spec convert_channels(bitstring()) -> {ok, integer()} |
    {error, read_chunk_error()}.
convert_channels(Bits) ->
    case Bits of
        <<Val:16/little>> ->
            {ok, Val};

        _ ->
            {error, invalid_channels}
    end.

-file("src/glwav.gleam", 199).
-spec convert_sample_rate(bitstring()) -> {ok, integer()} |
    {error, read_chunk_error()}.
convert_sample_rate(Bits) ->
    case Bits of
        <<Val:32/little>> ->
            {ok, Val};

        _ ->
            {error, invalid_sample_rate}
    end.

-file("src/glwav.gleam", 206).
-spec convert_bits(bitstring()) -> {ok, bits()} | {error, read_chunk_error()}.
convert_bits(Bits) ->
    case Bits of
        <<Val:16/little>> ->
            case Val of
                8 ->
                    {ok, u8};

                16 ->
                    {ok, i16};

                24 ->
                    {ok, i24};

                32 ->
                    {ok, f32};

                _ ->
                    {error, invalid_bits}
            end;

        _ ->
            {error, invalid_bits}
    end.

-file("src/glwav.gleam", 155).
-spec read_fmt_chunk(bitstring()) -> {ok, chunk_data()} |
    {error, read_chunk_error()}.
read_fmt_chunk(Data) ->
    gleam@result:'try'(
        begin
            _pipe = Data,
            _pipe@1 = gleam_stdlib:bit_array_slice(_pipe, 0, 2),
            gleam@result:replace_error(_pipe@1, invalid_format_code)
        end,
        fun(Format_code_bits) ->
            gleam@result:'try'(
                begin
                    _pipe@2 = Data,
                    _pipe@3 = gleam_stdlib:bit_array_slice(_pipe@2, 2, 2),
                    gleam@result:replace_error(_pipe@3, invalid_channels)
                end,
                fun(Channels_bits) ->
                    gleam@result:'try'(
                        begin
                            _pipe@4 = Data,
                            _pipe@5 = gleam_stdlib:bit_array_slice(
                                _pipe@4,
                                4,
                                4
                            ),
                            gleam@result:replace_error(
                                _pipe@5,
                                invalid_sample_rate
                            )
                        end,
                        fun(Sample_rate_bits) ->
                            gleam@result:'try'(
                                begin
                                    _pipe@6 = Data,
                                    _pipe@7 = gleam_stdlib:bit_array_slice(
                                        _pipe@6,
                                        14,
                                        2
                                    ),
                                    gleam@result:replace_error(
                                        _pipe@7,
                                        invalid_bits
                                    )
                                end,
                                fun(Bits_bits) ->
                                    gleam@result:'try'(
                                        begin
                                            _pipe@8 = Format_code_bits,
                                            convert_format_code(_pipe@8)
                                        end,
                                        fun(Format_code) ->
                                            gleam@result:'try'(
                                                begin
                                                    _pipe@9 = Channels_bits,
                                                    convert_channels(_pipe@9)
                                                end,
                                                fun(Channels) ->
                                                    gleam@result:'try'(
                                                        begin
                                                            _pipe@10 = Sample_rate_bits,
                                                            convert_sample_rate(
                                                                _pipe@10
                                                            )
                                                        end,
                                                        fun(Sample_rate) ->
                                                            gleam@result:'try'(
                                                                begin
                                                                    _pipe@11 = Bits_bits,
                                                                    convert_bits(
                                                                        _pipe@11
                                                                    )
                                                                end,
                                                                fun(Bits) ->
                                                                    {ok,
                                                                        {fmt,
                                                                            Format_code,
                                                                            Sample_rate,
                                                                            Channels,
                                                                            Bits}}
                                                                end
                                                            )
                                                        end
                                                    )
                                                end
                                            )
                                        end
                                    )
                                end
                            )
                        end
                    )
                end
            )
        end
    ).

-file("src/glwav.gleam", 220).
-spec read_data_chunk(bitstring()) -> {ok, chunk_data()} |
    {error, read_chunk_error()}.
read_data_chunk(Data) ->
    {ok, {data, Data}}.

-file("src/glwav.gleam", 228).
-spec do_parse_u8_samples(bitstring(), list(float())) -> list(float()).
do_parse_u8_samples(Data, Acc) ->
    case Data of
        <<Val:8/unsigned, Rest/bitstring>> ->
            Normalized = (erlang:float(Val) - 128.0) / 128.0,
            do_parse_u8_samples(Rest, [Normalized | Acc]);

        _ ->
            lists:reverse(Acc)
    end.

-file("src/glwav.gleam", 224).
-spec parse_u8_samples(bitstring()) -> list(float()).
parse_u8_samples(Data) ->
    do_parse_u8_samples(Data, []).

-file("src/glwav.gleam", 242).
-spec do_parse_i16_samples(bitstring(), list(float())) -> list(float()).
do_parse_i16_samples(Data, Acc) ->
    case Data of
        <<Val:16/signed-little, Rest/bitstring>> ->
            Normalized = erlang:float(Val) / 32768.0,
            do_parse_i16_samples(Rest, [Normalized | Acc]);

        _ ->
            lists:reverse(Acc)
    end.

-file("src/glwav.gleam", 238).
-spec parse_i16_samples(bitstring()) -> list(float()).
parse_i16_samples(Data) ->
    do_parse_i16_samples(Data, []).

-file("src/glwav.gleam", 256).
-spec do_parse_i24_samples(bitstring(), list(float())) -> list(float()).
do_parse_i24_samples(Data, Acc) ->
    case Data of
        <<Val:24/signed-little, Rest/bitstring>> ->
            Normalized = erlang:float(Val) / 8388608.0,
            do_parse_i24_samples(Rest, [Normalized | Acc]);

        _ ->
            lists:reverse(Acc)
    end.

-file("src/glwav.gleam", 252).
-spec parse_i24_samples(bitstring()) -> list(float()).
parse_i24_samples(Data) ->
    do_parse_i24_samples(Data, []).

-file("src/glwav.gleam", 270).
-spec do_parse_f32_samples(bitstring(), list(float())) -> list(float()).
do_parse_f32_samples(Data, Acc) ->
    case Data of
        <<Val:32/float-little, Rest/bitstring>> ->
            do_parse_f32_samples(Rest, [Val | Acc]);

        _ ->
            lists:reverse(Acc)
    end.

-file("src/glwav.gleam", 266).
-spec parse_f32_samples(bitstring()) -> list(float()).
parse_f32_samples(Data) ->
    do_parse_f32_samples(Data, []).

-file("src/glwav.gleam", 98).
?DOC(
    " Parse a WAV file from a bit array.\n"
    "\n"
    " Reads a WAV file in RIFF format and extracts all audio properties\n"
    " and samples. Samples are normalized to floating point values in the\n"
    " range -1.0 to 1.0.\n"
    "\n"
    " ## Example\n"
    "\n"
    " ```gleam\n"
    " let assert Ok(bits) = simplifile.read_bits(\"audio.wav\")\n"
    " let assert Ok(wave) = glwav.from_bit_array(bits)\n"
    " // Access wave properties\n"
    " wave.sample_rate  // e.g., 44100\n"
    " wave.channels     // e.g., 2\n"
    " wave.samples      // List of normalized samples\n"
    " ```\n"
    "\n"
    " ## Returns\n"
    "\n"
    " - `Ok(Wave)` if parsing succeeds\n"
    " - `Error(FromBitArrayError)` if the file is invalid or unsupported\n"
).
-spec from_bit_array(bitstring()) -> {ok, wave()} |
    {error, from_bit_array_error()}.
from_bit_array(Bits) ->
    gleam@result:'try'(
        begin
            _pipe = Bits,
            _pipe@1 = glriff:from_bit_array(_pipe),
            gleam@result:map_error(
                _pipe@1,
                fun(Field@0) -> {riff_format_error, Field@0} end
            )
        end,
        fun(Riff_chunk) -> case Riff_chunk of
                {riff_chunk, _, Chunks} ->
                    Chunk_data = begin
                        _pipe@2 = Chunks,
                        gleam@list:map(_pipe@2, fun(Chunk) -> case Chunk of
                                    {chunk, <<"fmt "/utf8>>, Data} ->
                                        read_fmt_chunk(Data);

                                    {chunk, <<"data"/utf8>>, Data@1} ->
                                        read_data_chunk(Data@1);

                                    _ ->
                                        {error, not_supported}
                                end end)
                    end,
                    case Chunk_data of
                        [{ok, {fmt, Format_code, Sample_rate, Channels, Bits@1}},
                            {ok, {data, Data_bits}} |
                            _] ->
                            Samples = case Bits@1 of
                                u8 ->
                                    parse_u8_samples(Data_bits);

                                i16 ->
                                    parse_i16_samples(Data_bits);

                                i24 ->
                                    parse_i24_samples(Data_bits);

                                f32 ->
                                    parse_f32_samples(Data_bits)
                            end,
                            {ok,
                                {wave,
                                    Format_code,
                                    Sample_rate,
                                    Channels,
                                    Bits@1,
                                    Samples}};

                        _ ->
                            {error, invalid_format}
                    end;

                _ ->
                    {error, invalid_format}
            end end
    ).

-file("src/glwav.gleam", 409).
-spec samples_to_f32(list(float())) -> bitstring().
samples_to_f32(Samples) ->
    _pipe = Samples,
    gleam@list:fold(
        _pipe,
        <<>>,
        fun(Acc, Sample) -> <<Acc/bitstring, Sample:32/float-little>> end
    ).

-file("src/glwav.gleam", 416).
-spec float_to_int(float()) -> integer().
float_to_int(F) ->
    erlang:round(F).

-file("src/glwav.gleam", 369).
-spec samples_to_u8(list(float())) -> bitstring().
samples_to_u8(Samples) ->
    _pipe = Samples,
    gleam@list:fold(
        _pipe,
        <<>>,
        fun(Acc, Sample) ->
            Value = (Sample * 128.0) + 128.0,
            Int_value = case Value of
                V when V < +0.0 ->
                    0;

                V@1 when V@1 > 255.0 ->
                    255;

                V@2 ->
                    float_to_int(V@2)
            end,
            <<Acc/bitstring, Int_value:8>>
        end
    ).

-file("src/glwav.gleam", 383).
-spec samples_to_i16(list(float())) -> bitstring().
samples_to_i16(Samples) ->
    _pipe = Samples,
    gleam@list:fold(
        _pipe,
        <<>>,
        fun(Acc, Sample) ->
            Value = Sample * 32768.0,
            Int_value = case Value of
                V when V < -32768.0 ->
                    -32768;

                V@1 when V@1 > 32767.0 ->
                    32767;

                V@2 ->
                    float_to_int(V@2)
            end,
            <<Acc/bitstring, Int_value:16/little>>
        end
    ).

-file("src/glwav.gleam", 396).
-spec samples_to_i24(list(float())) -> bitstring().
samples_to_i24(Samples) ->
    _pipe = Samples,
    gleam@list:fold(
        _pipe,
        <<>>,
        fun(Acc, Sample) ->
            Value = Sample * 8388608.0,
            Int_value = case Value of
                V when V < -8388608.0 ->
                    -8388608;

                V@1 when V@1 > 8388607.0 ->
                    8388607;

                V@2 ->
                    float_to_int(V@2)
            end,
            <<Acc/bitstring, Int_value:24/little>>
        end
    ).

-file("src/glwav.gleam", 307).
?DOC(
    " Convert a Wave structure to a bit array in WAV format.\n"
    "\n"
    " Creates a complete WAV file including RIFF header, fmt chunk, and data chunk.\n"
    " Samples are converted from normalized floating point values (-1.0 to 1.0)\n"
    " to the appropriate bit depth specified in the Wave structure.\n"
    "\n"
    " The `bytes_per_second` and `block_align` values are calculated automatically:\n"
    " - `block_align` = `channels * (bits_per_sample / 8)`\n"
    " - `bytes_per_second` = `sample_rate * block_align`\n"
    "\n"
    " ## Example\n"
    "\n"
    " ```gleam\n"
    " let wave = glwav.Wave(\n"
    "   format_code: glwav.PCM,\n"
    "   sample_rate: 44_100,\n"
    "   channels: 1,\n"
    "   bits: glwav.I16,\n"
    "   samples: [0.0, 0.5, 1.0, 0.5, 0.0, -0.5, -1.0],\n"
    " )\n"
    " let bits = glwav.to_bit_array(wave)\n"
    " // Write to file\n"
    " simplifile.write_bits(bits, \"output.wav\")\n"
    " ```\n"
    "\n"
    " ## Returns\n"
    "\n"
    " A bit array containing the complete WAV file data\n"
).
-spec to_bit_array(wave()) -> bitstring().
to_bit_array(Wave) ->
    Bits_per_sample = case erlang:element(5, Wave) of
        u8 ->
            8;

        i16 ->
            16;

        i24 ->
            24;

        f32 ->
            32
    end,
    Block_align = (erlang:element(4, Wave) * Bits_per_sample) div 8,
    Bytes_per_second = erlang:element(3, Wave) * Block_align,
    Data_bits = case erlang:element(5, Wave) of
        u8 ->
            samples_to_u8(erlang:element(6, Wave));

        i16 ->
            samples_to_i16(erlang:element(6, Wave));

        i24 ->
            samples_to_i24(erlang:element(6, Wave));

        f32 ->
            samples_to_f32(erlang:element(6, Wave))
    end,
    Format_code_bits = case erlang:element(2, Wave) of
        p_c_m ->
            <<1:16/little>>;

        ieee_float ->
            <<3:16/little>>;

        alaw ->
            <<6:16/little>>;

        mulaw ->
            <<7:16/little>>;

        extensible ->
            <<65534:16/little>>
    end,
    Fmt_data = <<Format_code_bits/bitstring,
        (erlang:element(4, Wave)):16/little,
        (erlang:element(3, Wave)):32/little,
        Bytes_per_second:32/little,
        Block_align:16/little,
        Bits_per_sample:16/little>>,
    Fmt_chunk = <<"fmt "/utf8, 16:32/little, Fmt_data/bitstring>>,
    Data_size = erlang:byte_size(Data_bits),
    Data_chunk = <<"data"/utf8, Data_size:32/little, Data_bits/bitstring>>,
    Chunks = <<Fmt_chunk/bitstring, Data_chunk/bitstring>>,
    Riff_size = erlang:byte_size(Chunks) + 4,
    <<"RIFF"/utf8, Riff_size:32/little, "WAVE"/utf8, Chunks/bitstring>>.