/*
 *      fm-app-lookup.c
 *
 *      Copyright 2010 PCMan <pcman.tw@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.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include "fm-app-lookup.h"
#include <gio/gdesktopappinfo.h>

#ifndef G_IMPLEMENT_INTERFACE_DYNAMIC /* this macro is only provided in glib > 2.24 */
    #define G_IMPLEMENT_INTERFACE_DYNAMIC(TYPE_IFACE, iface_init)       { \
      const GInterfaceInfo g_implement_interface_info = { \
        (GInterfaceInitFunc) iface_init, NULL, NULL      \
      }; \
      g_type_module_add_interface (type_module, g_define_type_id, TYPE_IFACE, &g_implement_interface_info); \
    }
#endif

static void app_lookup_iface_init(GDesktopAppInfoLookupIface *iface);
static GObject* fm_app_lookup_constructor(GType type, guint n_props, GObjectConstructParam *props);
static void fm_app_lookup_finalize  			(GObject *object);
static GAppInfo *get_default_for_uri_scheme(GDesktopAppInfoLookup *lookup, const char *scheme);

G_DEFINE_DYNAMIC_TYPE_EXTENDED(FmAppLookup, fm_app_lookup, G_TYPE_OBJECT, 0,
    G_IMPLEMENT_INTERFACE_DYNAMIC(G_TYPE_DESKTOP_APP_INFO_LOOKUP, app_lookup_iface_init))


static void fm_app_lookup_class_init(FmAppLookupClass *klass)
{
	GObjectClass *g_object_class;
	g_object_class = G_OBJECT_CLASS(klass);
    g_object_class->constructor = fm_app_lookup_constructor;
	g_object_class->finalize = fm_app_lookup_finalize;
}

static void fm_app_lookup_class_finalize(FmAppLookupClass *klass)
{
}

GObject* fm_app_lookup_constructor(GType type, guint n_props, GObjectConstructParam *props)
{
    GObject* obj;
    /* call parent constructor. */
    obj = G_OBJECT_CLASS(fm_app_lookup_parent_class)->constructor(type, n_props, props);
    return obj;
}

static void fm_app_lookup_finalize(GObject *object)
{
	FmAppLookup *self;

	g_return_if_fail(object != NULL);
	g_return_if_fail(FM_IS_APP_LOOKUP(object));

	self = FM_APP_LOOKUP(object);
	G_OBJECT_CLASS(fm_app_lookup_parent_class)->finalize(object);
}


static void fm_app_lookup_init(FmAppLookup *self)
{

}

void fm_app_lookup_register(GIOModule *module)
{
    gint priority;
    fm_app_lookup_register_type(G_TYPE_MODULE (module));
    /* check if we're in gnome, if true, use lower priority.
     * otherwise, use a high priority to override gvfs gconf module.
     * priority of the gconf module of gvfs is 10. */
    if(G_UNLIKELY(g_getenv("GNOME_DESKTOP_SESSION_ID"))) /* we're in Gnome */
        priority = 9;
    else /* we're in other desktop envionments */
        priority = 90;

    g_io_extension_point_implement(G_DESKTOP_APP_INFO_LOOKUP_EXTENSION_POINT_NAME,
                                         FM_TYPE_APP_LOOKUP, "libfm-applookup", priority);

    /* TODO: implement our own G_NATIVE_VOLUME_MONITOR_EXTENSION_POINT_NAME */
}

static void app_lookup_iface_init(GDesktopAppInfoLookupIface *iface)
{
    iface->get_default_for_uri_scheme = get_default_for_uri_scheme;
}

/* FIXME: implement our own browser lookup method not depending on gconf. */
GAppInfo *get_default_for_uri_scheme(GDesktopAppInfoLookup *lookup, const char *scheme)
{
    GAppInfo* app;
    GKeyFile* kf;
    const char* key;
    char* fname;
    char* desktop_id = NULL;

    /* web browser */
    if(g_ascii_strcasecmp(scheme, "http")==0 || g_ascii_strcasecmp(scheme, "https")==0)
        key = "WebBrowser";
    else if(g_ascii_strcasecmp(scheme, "mailto")==0)
        key = "MailClient";
    else /* we don't know this */
        return NULL;

    kf = g_key_file_new();

    /* try user config first */
    fname = g_build_filename(g_get_user_config_dir(), "libfm/pref-apps.conf", NULL);
    if(g_key_file_load_from_file(kf, fname, 0, NULL))
    {
        desktop_id = g_key_file_get_string(kf, "Preferred Applications", key, NULL);
        if(desktop_id && !*desktop_id)
        {
            g_free(desktop_id);
            desktop_id = NULL;
        }
    }
    g_free(fname);

    if(!desktop_id) /* system-wide */
    {
        const gchar* const *dirs = g_get_system_config_dirs();
        int i, n;
        if(g_key_file_load_from_file(kf, fname, 0, NULL))
            desktop_id = g_key_file_get_string(kf, "Preferred Applications", key, NULL);
        n = g_strv_length(dirs);
        for( i = n - 1; i > 0; --i )
        {
            fname = g_build_filename(dirs[i], "libfm/pref-apps.conf", NULL);
            if( g_key_file_load_from_file(kf, fname, 0, NULL) )
                desktop_id = g_key_file_get_string(kf, "Preferred Applications", key, NULL);
            g_free(fname);
            if(desktop_id)
            {
                if(*desktop_id)
                    break;
                else
                {
                    g_free(desktop_id);
                    desktop_id = NULL;
                }
            }
        }
    }

    g_key_file_free(kf);

    if(!desktop_id)
        return NULL;

    app = g_desktop_app_info_new(desktop_id);

    g_free(desktop_id);

    return app;
}