/*****************************************************************************
 * m3u.c : M3U playlist format import
 *****************************************************************************
 * Copyright (C) 2004 VLC authors and VideoLAN
 * $Id$
 *
 * Authors: Clément Stenac <zorglub@videolan.org>
 *          Sigmund Augdal Helberg <dnumgis@videolan.org>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser 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.
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <vlc_common.h>
#include <vlc_access.h>
#include <vlc_charset.h>
#include <vlc_strings.h>

#include "playlist.h"

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
static int ReadDir( stream_t *, input_item_node_t * );
static void parseEXTINF( char *psz_string, char **ppsz_artist, char **ppsz_name, int *pi_duration );
static bool ContainsURL(const uint8_t *, size_t);

static char *GuessEncoding (const char *str)
{
    return IsUTF8 (str) ? strdup (str) : FromLatin1 (str);
}

static char *CheckUnicode (const char *str)
{
    return IsUTF8 (str) ? strdup (str): NULL;
}

static bool IsHLS(const unsigned char *buf, size_t length)
{
    static const char *const hlsexts[] =
    {
        "#EXT-X-MEDIA:",
        "#EXT-X-VERSION:",
        "#EXT-X-TARGETDURATION:",
        "#EXT-X-MEDIA-SEQUENCE:",
        "#EXT-X-STREAM-INF:",
    };

    for (size_t i = 0; i < ARRAY_SIZE(hlsexts); i++)
        if (strnstr((const char *)buf, hlsexts[i], length) != NULL)
            return true;

    return false;
}

/*****************************************************************************
 * Import_M3U: main import function
 *****************************************************************************/
int Import_M3U( vlc_object_t *p_this )
{
    stream_t *p_stream = (stream_t *)p_this;
    const uint8_t *p_peek;
    ssize_t i_peek;
    int offset = 0;

    CHECK_FILE(p_stream);
    i_peek = vlc_stream_Peek( p_stream->p_source, &p_peek, 1024 );
    if( i_peek < 8 )
        return VLC_EGENERIC;

    /* Encoding: UTF-8 or unspecified */
    char *(*pf_dup) (const char *) = GuessEncoding;

    if (stream_HasExtension(p_stream, ".m3u8")
     || strncasecmp((const char *)p_peek, "RTSPtext", 8) == 0) /* QuickTime */
        pf_dup = CheckUnicode;
    else
    if (memcmp( p_peek, "\xef\xbb\xbf", 3) == 0) /* UTF-8 Byte Order Mark */
    {
        if( i_peek < 12 )
            return VLC_EGENERIC;
        pf_dup = CheckUnicode;
        offset = 3;
        p_peek += offset;
        i_peek -= offset;
    }

    /* File type: playlist, or not (HLS manifest or whatever else) */
    char *type = stream_MimeType(p_stream->p_source);
    bool match;

    if (p_stream->obj.force)
        match = true;
    else
    if (type != NULL
     && !vlc_ascii_strcasecmp(type, "application/vnd.apple.mpegurl")) /* HLS */
        match = false;
    else
    if (memcmp(p_peek, "#EXTM3U", 7 ) == 0
     || (type != NULL
      && (vlc_ascii_strcasecmp(type, "application/mpegurl") == 0
       || vlc_ascii_strcasecmp(type, "application/x-mpegurl") == 0
       || vlc_ascii_strcasecmp(type, "audio/mpegurl") == 0
       || vlc_ascii_strcasecmp(type, "vnd.apple.mpegURL") == 0
       || vlc_ascii_strcasecmp(type, "audio/x-mpegurl") == 0))
     || stream_HasExtension(p_stream, ".m3u8")
     || stream_HasExtension(p_stream, ".m3u"))
        match = !IsHLS(p_peek, i_peek);
    else
    if (stream_HasExtension(p_stream, ".vlc")
     || strncasecmp((const char *)p_peek, "RTSPtext", 8) == 0
     || ContainsURL(p_peek, i_peek))
        match = true;
    else
        match = false;

    free(type);

    if (!match)
        return VLC_EGENERIC;

    if (offset != 0 && vlc_stream_Seek(p_stream->p_source, offset))
        return VLC_EGENERIC;

    msg_Dbg( p_stream, "found valid M3U playlist" );
    p_stream->p_sys = pf_dup;
    p_stream->pf_readdir = ReadDir;
    p_stream->pf_control = access_vaDirectoryControlHelper;

    return VLC_SUCCESS;
}

static bool ContainsURL(const uint8_t *p_peek, size_t i_peek)
{
    const char *ps = (const char *)p_peek;
    const char *ps_end = (const char *) p_peek + i_peek;
    const size_t i_max = sizeof( "https://" );
    if( i_peek < i_max + 1 )
        return false;

    bool b_newline = true;
    while( ps + i_max + 1 < ps_end )
    {
        if( *ps <= 0 )
            return false;

        /* Goto next line */
        if( *ps == '\n' )
        {
            ps++;
            b_newline = true;
            continue;
        }

        /* One line starting with a URL is enough */
        if( b_newline )
        {
            const char *ps_match = strnstr( ps, "://", i_max );
            if(ps_match)
            {
                switch(ps_match - ps)
                {
                    case 3:
                        if( !strncasecmp( ps, "mms", 3 ) ||
                            !strncasecmp( ps, "ftp", 3 ) )
                            return true;
                        break;
                    case 4:
                        if( !strncasecmp( ps, "http", 4 ) ||
                            !strncasecmp( ps, "rtsp", 4 ) ||
                            !strncasecmp( ps, "ftps", 4 ) )
                            return true;
                        break;
                    case 5:
                        if( !strncasecmp( ps, "https", 5 ) ||
                            !strncasecmp( ps, "ftpes", 5 ) )
                            return true;
                    default:
                        break;
                }
            }

            /* Comments and blank lines are ignored */
            if( *ps != '#' && *ps != '\n' && *ps != '\r')
                return false;

            b_newline = false;
        }

        ps++;
    }
    return false;
}

static int ReadDir( stream_t *p_demux, input_item_node_t *p_subitems )
{
    char       *psz_line;
    char       *psz_name = NULL;
    char       *psz_artist = NULL;
    char       *psz_album_art = NULL;
    int        i_parsed_duration = 0;
    vlc_tick_t i_duration = -1;
    const char**ppsz_options = NULL;
    char *    (*pf_dup) (const char *) = p_demux->p_sys;
    int        i_options = 0;
    bool b_cleanup = false;
    input_item_t *p_input;

    input_item_t *p_current_input = p_demux->p_input ? GetCurrentItem(p_demux) : NULL;

    psz_line = vlc_stream_ReadLine( p_demux->p_source );
    while( psz_line )
    {
        char *psz_parse = psz_line;

        /* Skip leading tabs and spaces */
        while( *psz_parse == ' ' || *psz_parse == '\t' ||
               *psz_parse == '\n' || *psz_parse == '\r' ) psz_parse++;

        if( *psz_parse == '#' )
        {
            /* Parse extra info */

            /* Skip leading tabs and spaces */
            while( *psz_parse == ' ' || *psz_parse == '\t' ||
                   *psz_parse == '\n' || *psz_parse == '\r' ||
                   *psz_parse == '#' ) psz_parse++;

            if( !*psz_parse ) goto error;

            if( !strncasecmp( psz_parse, "EXTINF:", sizeof("EXTINF:") -1 ) )
            {
                /* Extended info */
                psz_parse += sizeof("EXTINF:") - 1;
                FREENULL( psz_name );
                FREENULL( psz_artist );
                parseEXTINF( psz_parse, &psz_artist, &psz_name, &i_parsed_duration );
                if( i_parsed_duration >= 0 )
                    i_duration = i_parsed_duration * INT64_C(1000000);
                if( psz_name )
                    psz_name = pf_dup( psz_name );
                if( psz_artist )
                    psz_artist = pf_dup( psz_artist );
            }
            else if( !strncasecmp( psz_parse, "EXTVLCOPT:",
                                   sizeof("EXTVLCOPT:") -1 ) )
            {
                /* VLC Option */
                char *psz_option;
                psz_parse += sizeof("EXTVLCOPT:") -1;
                if( !*psz_parse ) goto error;

                psz_option = pf_dup( psz_parse );
                if( psz_option )
                    TAB_APPEND( i_options, ppsz_options, psz_option );
            }
            /* Special case for jamendo which provide the albumart */
            else if( !strncasecmp( psz_parse, "EXTALBUMARTURL:",
                     sizeof( "EXTALBUMARTURL:" ) -1 ) )
            {
                psz_parse += sizeof( "EXTALBUMARTURL:" ) - 1;
                free( psz_album_art );
                psz_album_art = pf_dup( psz_parse );
            }
            else if ( !strncasecmp( psz_parse, "PLAYLIST:",
                      sizeof( "PLAYLIST:" ) - 1 ) )
            {
                psz_parse += sizeof( "PLAYLIST:" ) - 1;
                input_item_SetTitle( p_current_input, psz_parse );
            }
        }
        else if( !strncasecmp( psz_parse, "RTSPtext", sizeof("RTSPtext") -1 ) )
        {
            ;/* special case to handle QuickTime RTSPtext redirect files */
        }
        else if( *psz_parse )
        {
            char *psz_mrl;

            psz_parse = pf_dup( psz_parse );
            if( !psz_name && psz_parse )
                /* Use filename as name for relative entries */
                psz_name = strdup( psz_parse );

            psz_mrl = ProcessMRL( psz_parse, p_demux->psz_url );

            b_cleanup = true;
            if( !psz_mrl )
            {
                free( psz_parse );
                goto error;
            }

            p_input = input_item_NewExt( psz_mrl, psz_name, i_duration,
                                         ITEM_TYPE_UNKNOWN, ITEM_NET_UNKNOWN );
            free( psz_parse );
            free( psz_mrl );

            if( !p_input )
                goto error;
            input_item_AddOptions( p_input, i_options, ppsz_options, 0 );
            if ( p_current_input )
                input_item_CopyOptions( p_input, p_current_input );

            if( !EMPTY_STR(psz_artist) )
                input_item_SetArtist( p_input, psz_artist );
            if( psz_name ) input_item_SetTitle( p_input, psz_name );
            if( !EMPTY_STR(psz_album_art) )
                input_item_SetArtURL( p_input, psz_album_art );

            input_item_node_AppendItem( p_subitems, p_input );
            input_item_Release( p_input );
        }

 error:

        /* Fetch another line */
        free( psz_line );
        psz_line = vlc_stream_ReadLine( p_demux->p_source );
        if( !psz_line ) b_cleanup = true;

        if( b_cleanup )
        {
            /* Cleanup state */
            while( i_options-- ) free( (char*)ppsz_options[i_options] );
            FREENULL( ppsz_options );
            i_options = 0;
            FREENULL( psz_name );
            FREENULL( psz_artist );
            FREENULL( psz_album_art );
            i_parsed_duration = 0;
            i_duration = -1;

            b_cleanup = false;
        }
    }
    return VLC_SUCCESS; /* Needed for correct operation of go back */
}

static void parseEXTINF(char *psz_string, char **ppsz_artist,
                        char **ppsz_name, int *pi_duration)
{
    char *end = NULL;
    char *psz_item = NULL;

    end = psz_string + strlen( psz_string );

    /* ignore whitespaces */
    for (; psz_string < end && ( *psz_string == '\t' || *psz_string == ' ' );
         psz_string++ );

    /* duration: read to next comma */
    psz_item = psz_string;
    psz_string = strchr( psz_string, ',' );
    if ( psz_string )
    {
        *psz_string = '\0';
        *pi_duration = atoi( psz_item );
    }
    else
    {
        return;
    }

    if ( psz_string < end )               /* continue parsing if possible */
        psz_string++;

    /* analyse the remaining string */
    psz_item = strstr( psz_string, " - " );

    /* here we have the 0.8.2+ format with artist */
    if ( psz_item )
    {
        /* *** "EXTINF:time,artist - name" */
        *psz_item = '\0';
        *ppsz_artist = psz_string;
        *ppsz_name = psz_item + 3;          /* points directly after ' - ' */
        return;
    }

    /* reaching this point means: 0.8.1- with artist or something without artist */
    if ( *psz_string == ',' )
    {
        /* *** "EXTINF:time,,name" */
        psz_string++;
        *ppsz_name = psz_string;
        return;
    }

    psz_item = psz_string;
    psz_string = strchr( psz_string, ',' );
    if ( psz_string )
    {
        /* *** "EXTINF:time,artist,name" */
        *psz_string = '\0';
        *ppsz_artist = psz_item;
        *ppsz_name = psz_string+1;
    }
    else
    {
        /* *** "EXTINF:time,name" */
        *ppsz_name = psz_item;
    }
    return;
}