/**
 * Desktop purge: Remove unnecessary translations from *.desktop files
 * 
 * Copyright (c) 2006.10.15 Hong Jen Yee (PCMan)   <pcman.tw( at )gmail.com>
 *
 * 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.
 *
 * NOTE: This program requires glib 2.4+.
 * To compile this program, type following command:
 * 
 * gcc `plg-config glib-2.0 --cflags --libs` -o desktop-purge desktop-purge.c
 * 
 */

#include <glib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>

const char desktop_ent[] = "Desktop Entry";
const char app_dir_name[] = "applications";

static gsize saved_size = 0;

static void do_purge( const char* dir_path, gpointer user_data )
{
    char* file_name;
    GDir *dir;
    GKeyFile* file = g_key_file_new();
    struct stat statbuf;

    if( ! (dir = g_dir_open( dir_path, 0, NULL )) )
        return;
    while( file_name = g_dir_read_name( dir ) )
    {
        char* file_path;

        file_path = g_build_filename( dir_path, file_name, NULL );
        if( stat( file_path, &statbuf ) == -1 )
        {
            g_free( file_path );
            continue;
        }

        if( S_ISDIR(statbuf.st_mode) )
            do_purge( file_path, user_data );
        else if( g_key_file_load_from_file( file, file_path, G_KEY_FILE_KEEP_COMMENTS, NULL ) )
        {
            gsize len;
            char* data;

            if( G_UNLIKELY( ! g_str_has_suffix(file_name, ".desktop") ) )
            {
                g_free(file_path);
                continue;
            }

            if( data = g_key_file_to_data( file, &len, NULL ) )
            {
                char* pdata = data;
                while( *pdata && *pdata == '\n' )
                {
                    ++pdata;
                    --len;
                }

                if( G_LIKELY( len < statbuf.st_size ) )
                {
                    int fd = open( file_path, O_CREAT|O_WRONLY|O_TRUNC );
                    if( G_LIKELY(fd != -1) )
                    {
                        if( write( fd, pdata, len ) != -1 )
                        {
                            statbuf.st_size -= len;
                            saved_size += statbuf.st_size;
                            g_print( "%s purged, save %d bytes\n", file_path, statbuf.st_size );
                        }
                        else
                            g_print( "Error: %s\n", g_strerror( errno ) );
                        close( fd );
                    }
                    else
                        g_print( "Error: %s\n", g_strerror( errno ) );
                }
                else
                    g_print( "Skip %s\n", file_path );

                g_free( data );
            }
        }
        else
        {
            g_print( "Error parsing: %s\n", file_path );
        }
        g_free( file_path );
    }
    g_key_file_free(file);
    g_dir_close( dir );
}

static void app_dirs_foreach( GFunc func, gpointer user_data )
{
    const char** sys_dirs = (const char**)g_get_system_data_dirs();
    char* path;
    int i, len;
    struct stat dir_stat;

    len = g_strv_length((gchar **) sys_dirs);

    for( i = 0; i < len; ++i )
    {
        path = g_build_filename( sys_dirs[i], app_dir_name, NULL );
        func( path, user_data );
        g_free( path );
    }
    path = g_build_filename( g_get_user_data_dir(), app_dir_name, NULL );
    func( path, user_data );
    g_free( path );
}

int main( int argc, char** argv )
{
    g_print("Desktop purge 0.1\nDeveloped by Hong Jen Yee (PCMan) <pcman.tw@gmail.com>\n\n");
    app_dirs_foreach( do_purge, NULL );
    g_print( "%d KB saved\n", saved_size/1024 );
    return 0;
}