USING: kernel audio.wav io io.files io.encodings.ascii io.encodings.binary io.encodings.string endian accessors math sequences ;
USING: flac.decoder flac.stream flac.metadata ;

USING: specialized-arrays alien.c-types prettyprint io.encodings.utf8 ;

IN: flac

:: wav-header ( stream-info -- byte-array )
    RIFF-MAGIC ascii encode
    stream-info samples>> stream-info channels>> stream-info bits-per-sample>> 8 /i * * 36 + 4 >le
    WAVE-MAGIC ascii encode
    FMT-MAGIC ascii encode
    16 4 >le
    1 2 >le
    stream-info channels>> 2 >le
    stream-info sample-rate>> 4 >le
    stream-info sample-rate>> stream-info channels>> stream-info bits-per-sample>> 8 /i * * 4 >le
    stream-info channels>> stream-info bits-per-sample>> 8 /i * 2 >le
    stream-info bits-per-sample>> 2 >le
    DATA-MAGIC ascii encode
    stream-info samples>> stream-info channels>> stream-info bits-per-sample>> 8 /i * * 4 >le
    '{ _ _ _ _ _ _ _ _ _ _ _ _ _ } B{ } concat-as ;

:: write-frame ( sample-depth channels blocksize samples -- )
    sample-depth 8 /i :> sample-bytes
    sample-depth 8 = [ 128 ] [ 0 ] if :> addend
    blocksize <iota> [| block |
        channels <iota> [| channel |
                         block channel samples nth nth addend + sample-bytes >le write
        ] each
    ] each ;

! TODO: actually write good code
: decode-file ( flac-file -- )
    [
        "/home/steve/FACTOR.wav" binary [
            read-stream-info/seek-data
            dup
            [ wav-header write ]
            [ samples>> ] bi
            swap <repetition>
            [
                [ [ bits-per-sample>> ] [ channels>> ] bi ]
                [ read-flac-frame ] bi
                [ header>> blocksize>> ] [ samples>> ] bi
                write-frame
            ] each
        ] with-file-writer
    ] with-flac-file-reader ;