! Copyright (C) 2009 Tim Wawrzynczak, Doug Coleman.
! See http://factorcode.org/license.txt for BSD license.
USING: sequences io io.encodings.binary io.files io.pathnames
strings kernel math io.mmap io.mmap.uchar accessors syntax
combinators math.ranges unicode.categories byte-arrays
io.encodings.string io.encodings.utf16 assocs math.parser
combinators.short-circuit fry namespaces combinators.smart
splitting io.encodings.ascii arrays io.files.info unicode.case
io.directories.search ;
IN: id3

<PRIVATE

CONSTANT: genres
    {
        "Blues" "Classic Rock" "Country" "Dance" "Disco" "Funk" 
        "Grunge" "Hip-Hop" "Jazz" "Metal" "New Age" "Oldies" "Other" 
        "Pop" "R&B" "Rap" "Reggae" "Rock" "Techno" "Industrial" 
        "Alternative" "Ska" "Death Metal" "Pranks" "Soundtrack" 
        "Euro-Techno" "Ambient" "Trip-Hop" "Vocal" "Jazz+Funk" 
        "Fusion" "Trance" "Classical" "Instrumental" "Acid" "House" 
        "Game" "Sound Clip" "Gospel" "Noise" "AlternRock" "Bass" 
        "Soul" "Punk" "Space" "Meditative" "Instrumental Pop" 
        "Instrumental Rock" "Ethnic" "Gothic" "Darkwave" 
        "Techno-Industrial" "Electronic" "Pop-Folk" "Eurodance" 
        "Dream" "Southern Rock" "Comedy" "Cult" "Gangsta" "Top 40" 
        "Christian Rap" "Pop/Funk" "Jungle" "Native American" 
        "Cabaret" "New Wave" "Psychedelic" "Rave" "Showtunes" 
        "Trailer" "Lo-Fi" "Tribal" "Acid Punk" "Acid Jazz" "Polka" 
        "Retro" "Musical" "Rock & Roll" "Hard Rock" "Folk" 
        "Folk-Rock" "National Folk" "Swing" "Fast Fusion" "Bebop" 
        "Latin" "Revival" "Celtic" "Bluegrass" "Avantgarde" 
        "Gothic Rock" "Progressive Rock" "Psychedelic Rock" 
        "Symphonic Rock" "Slow Rock" "Big Band" "Chorus" 
        "Easy Listening" "Acoustic" "Humour" "Speech" "Chanson" 
        "Opera" "Chamber Music" "Sonata" "Symphony" "Booty Bass" 
        "Primus" "Porn Groove" "Satire" "Slow Jam" "Club" "Tango" 
        "Samba" "Folklore" "Ballad" "Power Ballad" "Rhythmic Soul" 
        "Freestyle" "Duet" "Punk Rock" "Drum Solo" "A capella" 
        "Euro-House" "Dance Hall"
    }

TUPLE: header version flags size ;

TUPLE: frame frame-id flags size data ;

TUPLE: id3v2-info header frames ;

TUPLE: id3v1-info title artist album year comment genre ;

: <id3v1-info> ( -- object ) id3v1-info new ;

: <id3v2-info> ( header frames -- object )
    [ [ frame-id>> ] keep ] H{ } map>assoc
    id3v2-info boa ;

: <header> ( -- object ) header new ;

: <frame> ( -- object ) frame new ;

: id3v2? ( mmap -- ? ) "ID3" head? ; inline

: id3v1? ( mmap -- ? )
    { [ length 128 >= ] [ 128 tail-slice* "TAG" head? ] } 1&& ; inline

: id3v1-frame ( string key -- frame )
    <frame>
        swap >>frame-id
        swap >>data ;

: id3v1>id3v2 ( id3v1 -- id3v2 )
    [
        {
            [ title>> "TIT2" id3v1-frame ]
            [ artist>> "TPE1" id3v1-frame ]
            [ album>> "TALB" id3v1-frame ]
            [ year>> "TYER" id3v1-frame ]
            [ comment>> "COMM" id3v1-frame ]
            [ genre>> "TCON" id3v1-frame ]
        } cleave
    ] output>array f swap <id3v2-info> ;

: >28bitword ( seq -- int )
    0 [ [ 7 shift ] dip bitor ] reduce ; inline

: filter-text-data ( data -- filtered )
    [ printable? ] filter ; inline

: valid-frame-id? ( id -- ? )
    [ { [ digit? ] [ LETTER? ] } 1|| ] all? ; inline

: read-frame-data ( frame mmap -- frame data )
    [ 10 over size>> 10 + ] dip <slice> filter-text-data ; inline

: decode-text ( string -- string' )
    dup 2 short head
    { { HEX: ff HEX: fe } { HEX: fe HEX: ff } } member?
    utf16 ascii ? decode ; inline

: (read-frame) ( mmap -- frame )
    [ <frame> ] dip
    {
        [ 4 head-slice decode-text >>frame-id ]
        [ [ 4 8 ] dip subseq >28bitword >>size ]
        [ [ 8 10 ] dip subseq >byte-array >>flags ]
        [ read-frame-data decode-text >>data ]
    } cleave ;

: read-frame ( mmap -- frame/f )
    dup 4 head-slice valid-frame-id?
    [ (read-frame) ] [ drop f ] if ;

: remove-frame ( mmap frame -- mmap )
    size>> 10 + tail-slice ; inline

: read-frames ( mmap -- frames )
    [ dup read-frame dup ]
    [ [ remove-frame ] keep ]
    produce 2nip ;
    
! header stuff

: read-v2-header ( seq -- id3header )
    [ <header> ] dip
    {
        [ [ 3 5 ] dip <slice> >array >>version ]
        [ [ 5 ] dip nth >>flags ]
        [ [ 6 10 ] dip <slice> >28bitword >>size ]
    } cleave ; inline

: read-v2-tag-data ( seq -- id3v2-info )
    10 cut-slice
    [ read-v2-header ]
    [ read-frames ] bi* <id3v2-info> ; inline
    
! v1 information

: skip-to-v1-data ( seq -- seq ) 125 tail-slice* ; inline

: (read-v1-tag-data) ( seq -- mp3-file )
    [ <id3v1-info> ] dip
    {
        [ 30 head-slice decode-text filter-text-data >>title ]
        [ [ 30 60 ] dip subseq decode-text filter-text-data >>artist ]
        [ [ 60 90 ] dip subseq decode-text filter-text-data >>album ]
        [ [ 90 94 ] dip subseq decode-text filter-text-data >>year ]
        [ [ 94 124 ] dip subseq decode-text filter-text-data >>comment ]
        [ [ 124 ] dip nth number>string >>genre ]
    } cleave ; inline

: read-v1-tag-data ( seq -- mp3-file )
    skip-to-v1-data (read-v1-tag-data) ; inline

: parse-genre ( string -- n/f )
    dup "(" ?head-slice drop ")" ?tail-slice drop
    string>number dup number? [
        genres ?nth swap or
    ] [
        drop
    ] if ; inline

PRIVATE>

: frame-named ( id3 name quot -- obj )
    [ swap frames>> at* ] dip
    [ data>> ] prepose [ drop f ] if ; inline

: id3-title ( id3 -- title/f ) "TIT2" [ ] frame-named ; inline

: id3-artist ( id3 -- artist/f ) "TPE1" [ ] frame-named ; inline

: id3-album ( id3 -- album/f ) "TALB" [ ] frame-named ; inline

: id3-year ( id3 -- year/f ) "TYER" [ ] frame-named ; inline

: id3-comment ( id3 -- comment/f ) "COMM" [ ] frame-named ; inline

: id3-genre ( id3 -- genre/f )
    "TCON" [ parse-genre ] frame-named ; inline

: id3-frame ( id3 key -- value/f ) [ ] frame-named ; inline

: (file-id3-tags) ( path -- id3v2-info/f )
    [
        {
            { [ dup id3v2? ] [ read-v2-tag-data ] }
            { [ dup id3v1? ] [ read-v1-tag-data id3v1>id3v2 ] }
            [ drop f ]
        } cond
    ] with-mapped-uchar-file ;

: file-id3-tags ( path -- id3v2-info/f )
    dup file-info size>> 0 <= [ drop f ] [ (file-id3-tags) ] if ;

: parse-id3s ( path -- seq )
    [ >lower ".mp3" tail? ] find-all-files
    [ dup file-id3-tags ] { } map>assoc ;