#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <libgnome/libgnome.h>
#include <stdlib.h>

#include "gm-external-view.h"
#include "gm-debug.h"
#include "gm-app.h"
#include "gm-options.h"

void on_gm_external_view_exited(GPid pid, gint status, GmExternalView *view);
void on_gm_external_view_file_changed(GnomeVFSMonitorHandle *handle, 
		const gchar *monitor_uri, const gchar *info_uri,
		GnomeVFSMonitorEventType event_type, GmExternalView *view);

void
gm_external_view_destroy(GmExternalView *view) {
	struct stat buf;

	if (view->monitor) {
		gnome_vfs_monitor_cancel(view->monitor);
	}

	g_source_remove(view->child_watch);
	g_spawn_close_pid(view->pid);

	if (GM_IS_EDITOR(view->editor)) {	
		if (stat(view->filename, &buf) != -1) {
			if (buf.st_mtime > view->last_modified) {
				gm_editor_save(view->editor);
			}
		}
	}
	
	if (view->filename) {
		unlink(view->filename);
		g_free(view->filename);
	}
}

void
gm_external_view_update_last_modified(GmExternalView *view) {
	struct stat buf;
	
	if (stat(view->filename, &buf) != -1) {
		view->last_modified = buf.st_mtime;
	}
}

gboolean
gm_external_view_spawn(GmExternalView *view, gchar **argv) {
	GError *err = NULL;

	g_spawn_async(NULL, argv, NULL, G_SPAWN_SEARCH_PATH | 
			G_SPAWN_DO_NOT_REAP_CHILD, NULL, NULL, &(view->pid), &err);

	if (err) {
		gm_debug_msg(DEBUG_DEFAULT, "GmExternalView.Spawn: couldn't spawn "
				"editor: %s", err->message);
		g_error_free(err);
		return FALSE;
	} else {
		return TRUE;
	}
}


GmExternalView *
gm_external_view_new(GmWorld *world, GmEditor *editor) {
	GmExternalView *obj = g_new0(GmExternalView, 1);
    gchar *spawn_command[4] = {NULL, NULL, NULL, NULL};
    gchar **av, *command;
    gint an;
	GmOptions *options = gm_app_options(gm_app_instance());

	obj->world = world;
	obj->editor = editor;
	obj->filename = gm_editor_write_lines(editor);
	
	gm_external_view_update_last_modified(obj);
	
	gnome_vfs_monitor_add(&(obj->monitor), obj->filename, 
			GNOME_VFS_MONITOR_FILE, 
			(GnomeVFSMonitorCallback)on_gm_external_view_file_changed, obj);

	command = g_strconcat(gm_options_get(options, "editor_alternative"), 
			" ", obj->filename, NULL);

    if (gm_options_get_int(options, "editor_needs_terminal")) {
		spawn_command[0] = getenv("TERM");
		
		if (spawn_command[0] == NULL) {
			spawn_command[0] = "xterm";
		}
		
		spawn_command[1] = "-e";
		spawn_command[2] = command;

		gm_external_view_spawn(obj, spawn_command);
	} else {
		g_shell_parse_argv(command, &an, &av, NULL);
		gm_external_view_spawn(obj, av);
    }

	g_free(command);
    obj->child_watch = g_child_watch_add(obj->pid, 
    		(GChildWatchFunc)on_gm_external_view_exited, obj);

    return obj;
}

/* Callbacks */

void
on_gm_external_view_exited(GPid pid, gint status, GmExternalView *view) {
	gm_editor_close(view->editor);
}

void
on_gm_external_view_file_changed(GnomeVFSMonitorHandle *handle, 
		const gchar *monitor_uri, const gchar *info_uri,
		GnomeVFSMonitorEventType event_type, GmExternalView *view) {
	switch (event_type) {
		case GNOME_VFS_MONITOR_EVENT_CHANGED:
		case GNOME_VFS_MONITOR_EVENT_CREATED:
			gm_debug_msg(DEBUG_DEFAULT, "GmExternalView.OnFileChanged: "
					"change event detected!");
			
			gm_editor_set_lines_from_file(view->editor, 
					view->filename);
			gm_editor_save(view->editor);
			gm_external_view_update_last_modified(view);
		break;
		default:
		break;
	}
}