/* update.c

   Copyright (c) 2003-2016 HandBrake Team
   This file is part of the HandBrake source code
   Homepage: <http://handbrake.fr/>.
   It may be used under the terms of the GNU General Public License v2.
   For full terms see the file COPYING file or visit http://www.gnu.org/licenses/gpl-2.0.html
 */

#include "hb.h"

static void UpdateFunc( void * );

typedef struct
{
    int  * build;
    char * version;

} hb_update_t;

hb_thread_t * hb_update_init( int * build, char * version )
{
    hb_update_t * data = calloc( sizeof( hb_update_t ), 1 );
    data->build   = build;
    data->version = version;

    return hb_thread_init( "update", UpdateFunc, data,
                           HB_NORMAL_PRIORITY );
}


static void UpdateFunc( void * _data )
{

    hb_update_t * data = (hb_update_t *) _data;

    char* const url  = HB_PROJECT_URL_APPCAST;
    char* const urlz = url + strlen( HB_PROJECT_URL_APPCAST ); /* marks null-term */
    char        url_host[64];
    char        url_path[128];
    char        query[256];

	hb_net_t * net;
    int        ret;
    char       buf[4096];
    char     * cur, * end;
    int        size;
    int        i_vers;
    char       s_vers[32]; /* must be no larger than hb_handle_s.version */
    int        i;

    /* Setup hb_query and hb_query_two with the correct appcast file */
    hb_log( "Using %s", url );

    /* extract host part */
    cur = strstr( HB_PROJECT_URL_APPCAST, "//" );
    if( !cur || cur+2 > urlz )
        goto error;
    cur += 2;

    end = strstr( cur, "/" );
    if( !end || end > urlz )
        goto error;

    memset( url_host, 0, sizeof(url_host) );
    strncpy( url_host, cur, (end-cur) );

    /* extract path part */
    memset( url_path, 0, sizeof(url_path) );
    strncpy( url_path, end, (urlz-end) );

    if( !strlen( url_path ))
        goto error;

    memset( query, 0, sizeof(query) );
    snprintf( query, sizeof(query), "GET %s HTTP/1.0\r\nHost: %s\r\n\r\n", url_path, url_host );

    /* Grab the data from the web server */
    if( !( net = hb_net_open( url_host, 80 ) ) )
    {
        goto error;
    }

    if( hb_net_send( net, query ) < 0 )
    {
        hb_log("Error: Unable to connect to server");
        hb_net_close( &net );
        goto error;
    }

    size = 0;
    memset( buf, 0, 4096 );
    for( ;; )
    {
        ret = hb_net_recv( net, &buf[size], sizeof( buf ) - size );
        if( ret < 1 )
        {
            hb_net_close( &net );
            break;
        }
        size += ret;
    }

    cur = buf;
    end = &buf[sizeof( buf )];
	
    /* Make sure we got it */
    cur += 9;
    if( size < 15 || strncmp( cur, "200 OK", 6 ) )
    {
        hb_log("Error: We did not get a 200 OK from the server. \n");
        goto error;
    }
    cur += 6;

    /* Find the end of the headers and the beginning of the content */
    for( ; &cur[3] < end; cur++ )
    {
        if( cur[0] == '\r' && cur[1] == '\n' &&
            cur[2] == '\r' && cur[3] == '\n' )
        {
            cur += 4;
            break;
        }
    }

    if( cur >= end )
    {
        hb_log("Error: Found the end of the buffer before the end of the HTTP header information! \n");
        goto error;
    }
	
    /*
     * Find the <cli> tag
     * Scan though each character of the buffer until we find that the first 4 characters of "cur" are "<cli"
     */
    for(i=0 ; &cur[3] < end; i++, cur++ )
    {
        if( cur[0] == 'c' && cur[1] == 'l' && cur[2] == 'i' && cur[3] == '>' )
        {
            cur += 1;
            break;
        }
		 
        /* If the CLI tag has not been found in the first 768 characters, or the end is reached, something bad happened.*/
        if (( i > 768) || ( cur >= end ))
		{
            hb_log("Error: Did not find the <cli> tag in the expected maximum amount of characters into the file. \n");
            goto error;
		}
    }
	 
    if( cur >= end )
    {
        goto error;
    }
	
    /*
     * Ok, The above code didn't position cur, it only found <cli so we need to shift cur along 3 places.
     * After which, the next 10 characters are the build number
     */
    cur += 3;
	
    if( cur >= end )
    {
        hb_log("Error: Unexpected end of buffer! Could not find the build information. \n");
        goto error;
    }
	
    /* Stable HB_PROJECT_BUILD */
    i_vers = strtol( cur, &cur, 10 );

    if( cur >= end )
    {
        hb_log("Error: Unexpected end of buffer! \n");
        goto error;
    }
	
    /*
     * The Version number is 2 places after the build, so shift cur, 2 places.
     * Get all the characters in cur until the point where " is found.
     */
    cur += 2;
	
    if( cur >= end )
    {
        hb_log("Error: Unexpected end of buffer! Could not get version number. \n");
        goto error;
    }
    memset( s_vers, 0, sizeof( s_vers ) );
    for( i = 0;   i < sizeof( s_vers ) - 1 && cur < end && *cur != '"'; i++, cur++ )
    {
        s_vers[i] = *cur;
		
        /* If the CLI tag has not been found in the first 768 characters, or the end is reached, something bad happened.*/
        if (( cur >= end ))
        {
            hb_log("Error: Version number too long, or end of buffer reached. \n");
            goto error;
        }
    }

    if( cur >= end )
    {
        goto error;
    }

    /* Print the version information */
    hb_log( "latest: %s, build %d", s_vers, i_vers );

    /* Return the build information */
    if( i_vers > HB_PROJECT_BUILD )
    {
        memcpy( data->version, s_vers, sizeof(s_vers) );
        *(data->build) = i_vers;
    }

error:
    free( data );
    return;
}