/*****************************************************************************
 * taglib.cpp: Taglib tag parser/writer
 *****************************************************************************
 * Copyright (C) 2003-2006 the VideoLAN team
 * $Id$
 *
 * Authors: Clément Stenac <zorglub@videolan.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 *****************************************************************************/
#include <stdlib.h>

#include <vlc/vlc.h>
#include <vlc_playlist.h>
#include <vlc_meta.h>
#include <vlc_demux.h>

#include <fileref.h>
#include <tag.h>
#include <tstring.h>
#include <id3v2tag.h>
#include <mpegfile.h>
#include <flacfile.h>
#include <uniquefileidentifierframe.h>
#if 0 //for artist and album id
#include <textidentificationframe.h>
#endif

static int  ReadMeta    ( vlc_object_t * );
static int  DownloadArt ( vlc_object_t * );
static int  WriteMeta   ( vlc_object_t * );

vlc_module_begin();
    set_capability( "meta reader", 1000 );
    set_callbacks( ReadMeta, NULL );
    add_submodule();
        set_capability( "art downloader", 50 );
        set_callbacks( DownloadArt, NULL );
    add_submodule();
        set_capability( "meta writer", 50 );
        set_callbacks( WriteMeta, NULL );
vlc_module_end();

static bool checkID3Image( const TagLib::ID3v2::Tag *tag )
{
    TagLib::ID3v2::FrameList l = tag->frameListMap()[ "APIC" ];
    return !l.isEmpty();
}

/* Try detecting embedded art */
static void DetectImage( TagLib::FileRef f, vlc_meta_t *p_meta )
{
    if( TagLib::MPEG::File *mpeg =
               dynamic_cast<TagLib::MPEG::File *>(f.file() ) )
    {
        if( mpeg->ID3v2Tag() && checkID3Image( mpeg->ID3v2Tag() ) )
            vlc_meta_SetArtURL( p_meta, "APIC" );
    }
    else if( TagLib::FLAC::File *flac =
             dynamic_cast<TagLib::FLAC::File *>(f.file() ) )
    {
        if( flac->ID3v2Tag() && checkID3Image( flac->ID3v2Tag() ) )
            vlc_meta_SetArtURL( p_meta, "APIC" );
    }
#if 0
/* This needs special additions to taglib */
 * else if( TagLib::MP4::File *mp4 =
               dynamic_cast<TagLib::MP4::File *>( f.file() ) )
    {
        TagLib::MP4::Tag *mp4tag =
                dynamic_cast<TagLib::MP4::Tag *>( mp4->tag() );
        if( mp4tag && mp4tag->cover().size() )
            vlc_meta_SetArtURL( p_meta, "MP4C" );
    }
#endif
}

static int ReadMeta( vlc_object_t *p_this )
{
    demux_t *p_demux = (demux_t *)p_this;

    if( !strncmp( p_demux->psz_access, "file", 4 ) )
    {
        if( !p_demux->p_private )
            p_demux->p_private = (void*)vlc_meta_New();
        TagLib::FileRef f( p_demux->psz_path );
        if( !f.isNull() && f.tag() && !f.tag()->isEmpty() )
        {
            TagLib::Tag *tag = f.tag();
            vlc_meta_t *p_meta = (vlc_meta_t *)(p_demux->p_private );

#define SET( foo, bar ) vlc_meta_Set##foo( p_meta, tag->bar ().toCString(true))
            SET( Title, title );
            SET( Artist, artist );
            SET( Album, album );
//            SET( Comment, comment );
            SET( Genre, genre );
//            SET( Year, year ); Gra, this is an int, need to convert
//            SET( Tracknum , track ); Same
#undef SET

            if( TagLib::MPEG::File *p_mpeg =
                dynamic_cast<TagLib::MPEG::File *>(f.file() ) )
            {
                if( p_mpeg->ID3v2Tag() )
                {
                    TagLib::ID3v2::Tag *tag = p_mpeg->ID3v2Tag();
                    TagLib::ID3v2::FrameList list = tag->frameListMap()["UFID"];
                    TagLib::ID3v2::UniqueFileIdentifierFrame* p_ufid;
                    for( TagLib::ID3v2::FrameList::Iterator iter = list.begin();
                            iter != list.end(); iter++ )
                    {
                        p_ufid = dynamic_cast<TagLib::ID3v2::UniqueFileIdentifierFrame*>(*iter);
                        const char *owner = p_ufid->owner().toCString();
                        if (!strcmp( owner, "http://musicbrainz.org" ))
                        {
                            /* ID3v2 UFID contains up to 64 bytes binary data
                             * but in our case it will be a '\0' 
                             * terminated string */
                            char *psz_ufid = (char*) malloc( 64 );
                            int j = 0;
                            while( ( j < 63 ) &&
                                    ( j < p_ufid->identifier().size() ) )
                                psz_ufid[j] = p_ufid->identifier()[j++];
                            psz_ufid[j] = '\0';
                            vlc_meta_SetTrackID( p_meta, psz_ufid );
                            free( psz_ufid );
                        }
                    }
                    /* musicbrainz artist and album id: not useful yet */
#if 0
                    list = tag->frameListMap()["TXXX"];
                    TagLib::ID3v2::UserTextIdentificationFrame* p_txxx;
                    for( TagLib::ID3v2::FrameList::Iterator iter = list.begin();
                            iter != list.end(); iter++ )
                    {
                        p_txxx = dynamic_cast<TagLib::ID3v2::UserTextIdentificationFrame*>(*iter);
                        const char *psz_desc= p_txxx->description().toCString();
                        if( !strncmp( psz_desc, "MusicBrainz Artist Id", 21 ) )
                            vlc_meta_SetArtistID( p_meta,
                                    p_txxx->fieldList().toString().toCString());
                        if( !strncmp( psz_desc, "MusicBrainz Album Id", 20 ) )
                            vlc_meta_SetAlbumID( p_meta,
                                    p_txxx->fieldList().toString().toCString());
                    }
#endif
                }
            }

            DetectImage( f, p_meta );

            return VLC_SUCCESS;
        }
    }
    return VLC_EGENERIC;
}

#define SET(a,b) if(b) { \
        TagLib::String *psz_##a = new TagLib::String( b, \
            TagLib::String::UTF8 ); \
        tag->set##a( *psz_##a ); \
        delete psz_##a; \
    }

static int WriteMeta( vlc_object_t *p_this )
{
    playlist_t *p_playlist = (playlist_t *)p_this;
    meta_export_t *p_export = (meta_export_t *)p_playlist->p_private;
    input_item_t *p_item = p_export->p_item;
    
    if( p_item == NULL )
    {
        msg_Err( p_this, "Can't save meta data of an empty input" );
        return VLC_EGENERIC;
    }

    TagLib::FileRef f( p_export->psz_file );
    if( !f.isNull() && f.tag() )
    {
        msg_Dbg( p_this, "Updating metadata for %s", p_export->psz_file );

        TagLib::Tag *tag = f.tag();

        SET( Artist, p_item->p_meta->psz_artist );

        char *psz_titlec = ( p_item->p_meta->psz_title ?
            p_item->p_meta->psz_title : p_item->psz_name );
        TagLib::String *psz_title = new TagLib::String( psz_titlec,
            TagLib::String::UTF8 );
        tag->setTitle( *psz_title );
        delete psz_title;

        SET( Album, p_item->p_meta->psz_album );
        SET( Genre, p_item->p_meta->psz_genre );

        if( p_item->p_meta->psz_date )
            tag->setYear( atoi( p_item->p_meta->psz_date ) );
        if( p_item->p_meta->psz_tracknum )
            tag->setTrack( atoi( p_item->p_meta->psz_tracknum ) );

        f.save();
        return VLC_SUCCESS;
    }
    msg_Err( p_this, "File %s can't be opened for tag writing\n",
        p_export->psz_file );
    return VLC_EGENERIC;
}

static int DownloadArt( vlc_object_t *p_this )
{
    /* We need to be passed the file name
     * Fetch the thing from the file, save it to the cache folder
     */
    return VLC_EGENERIC;
}
