/*****************************************************************************
 * livehttp.c: Live HTTP Streaming
 *****************************************************************************
 * Copyright © 2001, 2002 VLC authors and VideoLAN
 * Copyright © 2009-2010 by Keary Griffin
 *
 * Authors: Keary Griffin <kearygriffin at gmail.com>
 *
 * 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 <sys/types.h>
#include <time.h>
#include <fcntl.h>
#include <errno.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif

#include <vlc_common.h>
#include <vlc_plugin.h>
#include <vlc_sout.h>
#include <vlc_block.h>
#include <vlc_fs.h>
#include <vlc_strings.h>
#include <vlc_charset.h>

#ifndef O_LARGEFILE
#   define O_LARGEFILE 0
#endif

#define STR_ENDLIST "#EXT-X-ENDLIST\n"

#define MAX_RENAME_RETRIES        10

/*****************************************************************************
 * Module descriptor
 *****************************************************************************/
static int  Open ( vlc_object_t * );
static void Close( vlc_object_t * );

#define SOUT_CFG_PREFIX "sout-livehttp-"
#define SEGLEN_TEXT N_("Segment length")
#define SEGLEN_LONGTEXT N_("Length of TS stream segments")

#define SPLITANYWHERE_TEXT N_("Split segments anywhere")
#define SPLITANYWHERE_LONGTEXT N_("Don't require a keyframe before splitting "\
                                "a segment. Needed for audio only.")

#define NUMSEGS_TEXT N_("Number of segments")
#define NUMSEGS_LONGTEXT N_("Number of segments to include in index")

#define INDEX_TEXT N_("Index file")
#define INDEX_LONGTEXT N_("Path to the index file to create")

#define INDEXURL_TEXT N_("Full URL to put in index file")
#define INDEXURL_LONGTEXT N_("Full URL to put in index file. "\
                          "Use #'s to represent segment number")

#define DELSEGS_TEXT N_("Delete segments")
#define DELSEGS_LONGTEXT N_("Delete segments when they are no longer needed")

#define RATECONTROL_TEXT N_("Use muxers rate control mechanism")

vlc_module_begin ()
    set_description( N_("HTTP Live streaming output") )
    set_shortname( N_("LiveHTTP" ))
    add_shortcut( "livehttp" )
    set_capability( "sout access", 0 )
    set_category( CAT_SOUT )
    set_subcategory( SUBCAT_SOUT_ACO )
    add_integer( SOUT_CFG_PREFIX "seglen", 10, SEGLEN_TEXT, SEGLEN_LONGTEXT, true )
    add_integer( SOUT_CFG_PREFIX "numsegs", 0, NUMSEGS_TEXT, NUMSEGS_LONGTEXT, true )
    add_bool( SOUT_CFG_PREFIX "splitanywhere", false,
              SPLITANYWHERE_TEXT, SPLITANYWHERE_LONGTEXT, true )
    add_bool( SOUT_CFG_PREFIX "delsegs", true,
              DELSEGS_TEXT, DELSEGS_LONGTEXT, true )
    add_bool( SOUT_CFG_PREFIX "ratecontrol", false,
              RATECONTROL_TEXT, RATECONTROL_TEXT, true )
    add_string( SOUT_CFG_PREFIX "index", NULL,
                INDEX_TEXT, INDEX_LONGTEXT, true )
    add_string( SOUT_CFG_PREFIX "index-url", NULL,
                INDEXURL_TEXT, INDEXURL_LONGTEXT, true )
    set_callbacks( Open, Close )
vlc_module_end ()


/*****************************************************************************
 * Exported prototypes
 *****************************************************************************/
static const char *const ppsz_sout_options[] = {
    "seglen",
    "splitanywhere",
    "numsegs",
    "delsegs",
    "index",
    "index-url",
    "ratecontrol",
    NULL
};

static ssize_t Write( sout_access_out_t *, block_t * );
static int Seek ( sout_access_out_t *, off_t  );
static int Control( sout_access_out_t *, int, va_list );

struct sout_access_out_sys_t
{
    char *psz_cursegPath;
    char *psz_indexPath;
    char *psz_indexUrl;
    mtime_t i_opendts;
    mtime_t  i_seglenm;
    uint32_t i_segment;
    size_t  i_seglen;
    int i_handle;
    unsigned i_numsegs;
    bool b_delsegs;
    bool b_ratecontrol;
    bool b_splitanywhere;
};

/*****************************************************************************
 * Open: open the file
 *****************************************************************************/
static int Open( vlc_object_t *p_this )
{
    sout_access_out_t   *p_access = (sout_access_out_t*)p_this;
    sout_access_out_sys_t *p_sys;
    char *psz_idx;

    config_ChainParse( p_access, SOUT_CFG_PREFIX, ppsz_sout_options, p_access->p_cfg );

    if( !p_access->psz_path )
    {
        msg_Err( p_access, "no file name specified" );
        return VLC_EGENERIC;
    }

    if( !( p_sys = malloc ( sizeof( *p_sys ) ) ) )
        return VLC_ENOMEM;

    p_sys->i_seglen = var_GetInteger( p_access, SOUT_CFG_PREFIX "seglen" );
    /* Try to get within +-10% of asked segment length, so lower limit is 90% of segment length*/
    p_sys->i_seglenm = CLOCK_FREQ * p_sys->i_seglen * 0.9;

    p_sys->i_numsegs = var_GetInteger( p_access, SOUT_CFG_PREFIX "numsegs" );
    p_sys->b_splitanywhere = var_GetBool( p_access, SOUT_CFG_PREFIX "splitanywhere" );
    p_sys->b_delsegs = var_GetBool( p_access, SOUT_CFG_PREFIX "delsegs" );
    p_sys->b_ratecontrol = var_GetBool( p_access, SOUT_CFG_PREFIX "ratecontrol") ;

    p_sys->psz_indexPath = NULL;
    psz_idx = var_GetNonEmptyString( p_access, SOUT_CFG_PREFIX "index" );
    if ( psz_idx )
    {
        char *psz_tmp;
        psz_tmp = str_format( p_access, psz_idx );
        free( psz_idx );
        if ( !psz_tmp )
        {
            free( p_sys );
            return VLC_ENOMEM;
        }
        path_sanitize( psz_tmp );
        p_sys->psz_indexPath = psz_tmp;
        vlc_unlink( p_sys->psz_indexPath );
    }

    p_sys->psz_indexUrl = var_GetNonEmptyString( p_access, SOUT_CFG_PREFIX "index-url" );

    p_access->p_sys = p_sys;
    p_sys->i_handle = -1;
    p_sys->i_segment = 0;
    p_sys->psz_cursegPath = NULL;

    p_access->pf_write = Write;
    p_access->pf_seek  = Seek;
    p_access->pf_control = Control;

    return VLC_SUCCESS;
}

#define SEG_NUMBER_PLACEHOLDER "#"
/*****************************************************************************
 * formatSegmentPath: create segment path name based on seg #
 *****************************************************************************/
static char *formatSegmentPath( sout_access_out_t *p_access, char *psz_path, uint32_t i_seg, bool b_sanitize )
{
    char *psz_result;
    char *psz_firstNumSign;

    if ( ! ( psz_result  = str_format( p_access, psz_path ) ) )
        return NULL;

    psz_firstNumSign = psz_result + strcspn( psz_result, SEG_NUMBER_PLACEHOLDER );
    if ( *psz_firstNumSign ) {
        char *psz_newResult;
        int i_cnt = strspn( psz_firstNumSign, SEG_NUMBER_PLACEHOLDER );
        int ret;

        *psz_firstNumSign = '\0';
        ret = asprintf( &psz_newResult, "%s%0*d%s", psz_result, i_cnt, i_seg, psz_firstNumSign + i_cnt );
        free ( psz_result );
        if ( ret < 0 )
            return NULL;
        psz_result = psz_newResult;
    }

    if ( b_sanitize )
        path_sanitize( psz_result );

    return psz_result;
}

/************************************************************************
 * updateIndexAndDel: If necessary, update index file & delete old segments
 ************************************************************************/
static int updateIndexAndDel( sout_access_out_t *p_access, sout_access_out_sys_t *p_sys, bool b_isend )
{

    uint32_t i_firstseg;

    if ( p_sys->i_numsegs == 0 || p_sys->i_segment < p_sys->i_numsegs )
        i_firstseg = 1;
    else
        i_firstseg = ( p_sys->i_segment - p_sys->i_numsegs ) + 1;

    // First update index
    if ( p_sys->psz_indexPath )
    {
        int val;
        FILE *fp;
        char *psz_idxTmp;
        if ( asprintf( &psz_idxTmp, "%s.tmp", p_sys->psz_indexPath ) < 0)
            return -1;

        fp = vlc_fopen( psz_idxTmp, "wt");
        if ( !fp )
        {
            msg_Err( p_access, "cannot open index file `%s'", psz_idxTmp );
            free( psz_idxTmp );
            return -1;
        }

        if ( fprintf( fp, "#EXTM3U\n#EXT-X-TARGETDURATION:%zu\n#EXT-X-MEDIA-SEQUENCE:%"PRIu32"\n", p_sys->i_seglen, i_firstseg ) < 0 )
        {
            free( psz_idxTmp );
            fclose( fp );
            return -1;
        }

        char *psz_idxFormat = p_sys->psz_indexUrl ? p_sys->psz_indexUrl : p_access->psz_path;
        for ( uint32_t i = i_firstseg; i <= p_sys->i_segment; i++ )
        {
            char *psz_name;
            if ( ! ( psz_name = formatSegmentPath( p_access, psz_idxFormat, i, false ) ) )
            {
                free( psz_idxTmp );
                fclose( fp );
                return -1;
            }
            val = fprintf( fp, "#EXTINF:%zu,\n%s\n", p_sys->i_seglen, psz_name );
            free( psz_name );
            if ( val < 0 )
            {
                free( psz_idxTmp );
                fclose( fp );
                return -1;
            }
        }

        if ( b_isend )
        {
            if ( fputs ( STR_ENDLIST, fp ) < 0)
            {
                free( psz_idxTmp );
                fclose( fp ) ;
                return -1;
            }

        }
        fclose( fp );

        val = vlc_rename ( psz_idxTmp, p_sys->psz_indexPath);

        if ( val < 0 )
        {
            vlc_unlink( psz_idxTmp );
            msg_Err( p_access, "Error moving LiveHttp index file" );
        }
        else
            msg_Info( p_access, "LiveHttpIndexComplete: %s" , p_sys->psz_indexPath );

        free( psz_idxTmp );
    }

    // Then take care of deletion
    if ( p_sys->b_delsegs && i_firstseg > 1 )
    {
        char *psz_name = formatSegmentPath( p_access, p_access->psz_path, i_firstseg-1, true );
         if ( psz_name )
         {
             vlc_unlink( psz_name );
             free( psz_name );
         }
    }
    return 0;
}

/*****************************************************************************
 * closeCurrentSegment: Close the segment file
 *****************************************************************************/
static void closeCurrentSegment( sout_access_out_t *p_access, sout_access_out_sys_t *p_sys, bool b_isend )
{
    if ( p_sys->i_handle >= 0 )
    {
        close( p_sys->i_handle );
        p_sys->i_handle = -1;
        if ( p_sys->psz_cursegPath )
        {
            msg_Info( p_access, "LiveHttpSegmentComplete: %s (%"PRIu32")" , p_sys->psz_cursegPath, p_sys->i_segment );
            free( p_sys->psz_cursegPath );
            p_sys->psz_cursegPath = 0;
            updateIndexAndDel( p_access, p_sys, b_isend );
        }
    }
}

/*****************************************************************************
 * Close: close the target
 *****************************************************************************/
static void Close( vlc_object_t * p_this )
{
    sout_access_out_t *p_access = (sout_access_out_t*)p_this;
    sout_access_out_sys_t *p_sys = p_access->p_sys;


    closeCurrentSegment( p_access, p_sys, true );
    free( p_sys->psz_indexUrl );
    free( p_sys->psz_indexPath );
    free( p_sys );

    msg_Dbg( p_access, "livehttp access output closed" );
}

static int Control( sout_access_out_t *p_access, int i_query, va_list args )
{
    sout_access_out_sys_t *p_sys = p_access->p_sys;

    switch( i_query )
    {
        case ACCESS_OUT_CONTROLS_PACE:
        {
            bool *pb = va_arg( args, bool * );
            *pb = !p_sys->b_ratecontrol;
            //*pb = true;
            break;
        }

        default:
            return VLC_EGENERIC;
    }
    return VLC_SUCCESS;
}

/*****************************************************************************
 * openNextFile: Open the segment file
 *****************************************************************************/
static ssize_t openNextFile( sout_access_out_t *p_access, sout_access_out_sys_t *p_sys )
{
    int fd;

    uint32_t i_newseg = p_sys->i_segment + 1;

    char *psz_seg = formatSegmentPath( p_access, p_access->psz_path, i_newseg, true );
    if ( !psz_seg )
        return -1;

    fd = vlc_open( psz_seg, O_WRONLY | O_CREAT | O_LARGEFILE |
                     O_TRUNC, 0666 );
    if ( fd == -1 )
    {
        msg_Err( p_access, "cannot open `%s' (%m)", psz_seg );
        free( psz_seg );
        return -1;
    }

    msg_Dbg( p_access, "Successfully opened livehttp file: %s (%"PRIu32")" , psz_seg, i_newseg );

    //free( psz_seg );
    p_sys->psz_cursegPath = psz_seg;
    p_sys->i_handle = fd;
    p_sys->i_segment = i_newseg;
    return fd;
}

/*****************************************************************************
 * Write: standard write on a file descriptor.
 *****************************************************************************/
static ssize_t Write( sout_access_out_t *p_access, block_t *p_buffer )
{
    size_t i_write = 0;
    sout_access_out_sys_t *p_sys = p_access->p_sys;

    while( p_buffer )
    {
        if ( p_sys->i_handle >= 0 && ( p_sys->b_splitanywhere || ( p_buffer->i_flags & BLOCK_FLAG_TYPE_I ) ) && ( p_buffer->i_dts-p_sys->i_opendts ) > p_sys->i_seglenm )
        {
            closeCurrentSegment( p_access, p_sys, false );
        }
        if ( p_buffer->i_buffer > 0 && p_sys->i_handle < 0 )
        {
            p_sys->i_opendts = p_buffer->i_dts;
            if ( openNextFile( p_access, p_sys ) < 0 )
                return -1;
        }
        ssize_t val = write ( p_sys->i_handle,
                             p_buffer->p_buffer, p_buffer->i_buffer );
        if ( val == -1 )
        {
            if ( errno == EINTR )
                continue;
            block_ChainRelease ( p_buffer );
            return -1;
        }

        if ( (size_t)val >= p_buffer->i_buffer )
        {
            block_t *p_next = p_buffer->p_next;
            block_Release (p_buffer);
            p_buffer = p_next;
        }
        else
        {
            p_buffer->p_buffer += val;
            p_buffer->i_buffer -= val;
        }
        i_write += val;
    }
    return i_write;
}

/*****************************************************************************
 * Seek: seek to a specific location in a file
 *****************************************************************************/
static int Seek( sout_access_out_t *p_access, off_t i_pos )
{
    (void) i_pos;
    msg_Err( p_access, "livehttp sout access cannot seek" );
    return -1;
}
