/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
 *
 * Copyright (C) 2004-2006 William Jon McCann <mccann@jhu.edu>
 *
 * 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 St, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 * Authors: William Jon McCann <mccann@jhu.edu>
 *
 */

#include "config.h"

#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <signal.h>

#include <glib/gi18n.h>
#include <gdk/gdkx.h>
#include <gtk/gtk.h>

#include "gs-lock-plug.h"

#include "gs-auth.h"
#include "setuid.h"

#include "gs-debug.h"

#define MAX_FAILURES 5

static gboolean verbose = FALSE;
static gboolean show_version = FALSE;
static gboolean enable_logout = FALSE;
static gboolean enable_switch = FALSE;
static char* logout_command = NULL;
static char* status_message = NULL;
static char* away_message = NULL;

static GOptionEntry entries[] = {
	{"verbose", 0, 0, G_OPTION_ARG_NONE, &verbose, N_("Show debugging output"), NULL},
	{"version", 0, 0, G_OPTION_ARG_NONE, &show_version, N_("Version of this application"), NULL},
	{"enable-logout", 0, 0, G_OPTION_ARG_NONE, &enable_logout, N_("Show the logout button"), NULL},
	{"logout-command", 0, 0, G_OPTION_ARG_STRING, &logout_command, N_("Command to invoke from the logout button"), NULL},
	{"enable-switch", 0, 0, G_OPTION_ARG_NONE, &enable_switch, N_("Show the switch user button"), NULL},
	{"status-message", 0, 0, G_OPTION_ARG_STRING, &status_message, N_("Message to show in the dialog"), N_("MESSAGE")},
	{"away-message", 0, 0, G_OPTION_ARG_STRING, &away_message, N_("Not used"), N_("MESSAGE")},
	{NULL}
};

static char* get_id_string(GtkWidget* widget)
{
	char* id = NULL;

	g_return_val_if_fail(widget != NULL, NULL);
	g_return_val_if_fail(GTK_IS_WIDGET(widget), NULL);

	id = g_strdup_printf("%" G_GUINT32_FORMAT, (guint32) GDK_WINDOW_XID(widget->window));
	return id;
}

static gboolean print_id(GtkWidget* widget)
{
	char* id;

	gs_profile_start(NULL);

	id = get_id_string(widget);
	printf("WINDOW ID=%s\n", id);
	fflush(stdout);

	gs_profile_end(NULL);

	g_free(id);

	return FALSE;
}

static void response_cancel(void)
{
	printf("RESPONSE=CANCEL\n");
	fflush(stdout);
}

static void response_ok(void)
{
	printf("RESPONSE=OK\n");
	fflush(stdout);
}

static gboolean quit_response_ok(void)
{
	response_ok();
	gtk_main_quit();
	return FALSE;
}

static gboolean quit_response_cancel(void)
{
	response_cancel();
	gtk_main_quit();
	return FALSE;
}

static void response_lock_init_failed(void)
{
	/* if we fail to lock then we should drop the dialog */
	response_ok();
}

static char* request_response(GSLockPlug* plug, const char* prompt, gboolean visible)
{
	int response;
	char* text;

	gs_lock_plug_set_sensitive(plug, TRUE);
	gs_lock_plug_enable_prompt(plug, prompt, visible);
	response = gs_lock_plug_run(plug);

	gs_debug ("got response: %d", response);

	text = NULL;

	if (response == GS_LOCK_PLUG_RESPONSE_OK)
	{
		gs_lock_plug_get_text(plug, &text);
	}

	gs_lock_plug_disable_prompt(plug);

	return text;
}

/* Adapted from MDM2 daemon/verify-pam.c on 2006-06-13 */
static const char* maybe_translate_message(const char* msg)
{
	char* s;
	const char* ret;
	static GHashTable* hash = NULL;

	if (hash == NULL)
	{
		/* Here we come with some fairly standard messages so that
		   we have as much as possible translated.  Should really be
		   translated in pam I suppose.  This way we can "change"
		   some of these messages to be more sane. */
		hash = g_hash_table_new (g_str_hash, g_str_equal);
		/* login: is whacked always translate to Username: */
		g_hash_table_insert(hash, "login:", _("Username:"));
		g_hash_table_insert(hash, "Username:", _("Username:"));
		g_hash_table_insert(hash, "username:", _("Username:"));
		g_hash_table_insert(hash, "Password:", _("Password:"));
		g_hash_table_insert(hash, "password:", _("Password:"));
		g_hash_table_insert(hash, "You are required to change your password immediately (password aged)", _("You are required to change your password immediately (password aged)"));
		g_hash_table_insert(hash, "You are required to change your password immediately (root enforced)", _("You are required to change your password immediately (root enforced)"));
		g_hash_table_insert(hash, "Your account has expired; please contact your system administrator", _("Your account has expired; please contact your system administrator"));
		g_hash_table_insert(hash, "No password supplied", _("No password supplied"));
		g_hash_table_insert(hash, "Password unchanged", _("Password unchanged"));
		g_hash_table_insert(hash, "Can not get username", _("Can not get username"));
		g_hash_table_insert(hash, "Retype new UNIX password:", _("Retype new UNIX password:"));
		g_hash_table_insert(hash, "Enter new UNIX password:", _("Enter new UNIX password:"));
		g_hash_table_insert(hash, "(current) UNIX password:", _("(current) UNIX password:"));
		g_hash_table_insert(hash, "Error while changing NIS password.", _("Error while changing NIS password."));
		g_hash_table_insert(hash, "You must choose a longer password", _("You must choose a longer password"));
		g_hash_table_insert(hash, "Password has been already used. Choose another.", _("Password has been already used. Choose another."));
		g_hash_table_insert(hash, "You must wait longer to change your password", _("You must wait longer to change your password"));
		g_hash_table_insert(hash, "Sorry, passwords do not match", _("Sorry, passwords do not match"));
		/* FIXME: what about messages which have some variables in them, perhaps try to do those as well */
	}

	s = g_strstrip(g_strdup(msg));
	ret = g_hash_table_lookup(hash, s);
	g_free(s);

	if (ret != NULL)
	{
		return ret;
	}
	else
	{
		return msg;
	}
}

static gboolean auth_message_handler(GSAuthMessageStyle style, const char* msg, char** response, gpointer data)
{
	gboolean ret;
	GSLockPlug* plug;
	const char* message;

	plug = GS_LOCK_PLUG(data);

	gs_profile_start(NULL);
	gs_debug("Got message style %d: '%s'", style, msg);

	gtk_widget_show(GTK_WIDGET(plug));
	gs_lock_plug_set_ready(plug);

	ret = TRUE;
	*response = NULL;
	message = maybe_translate_message(msg);

	switch (style)
	{
		case GS_AUTH_MESSAGE_PROMPT_ECHO_ON:
			if (msg != NULL)
			{
				char *resp;
				resp = request_response(plug, message, TRUE);
				*response = resp;
			}
			break;
		case GS_AUTH_MESSAGE_PROMPT_ECHO_OFF:
			if (msg != NULL)
			{
				char *resp;
				resp = request_response(plug, message, FALSE);
				*response = resp;
			}
			break;
		case GS_AUTH_MESSAGE_ERROR_MSG:
			gs_lock_plug_show_message(plug, message);
			break;
		case GS_AUTH_MESSAGE_TEXT_INFO:
			gs_lock_plug_show_message(plug, message);
			break;
		default:
			g_assert_not_reached();
	}

	if (*response == NULL)
	{
		gs_debug("Got no response");
		ret = FALSE;
	}
	else
	{
		gs_lock_plug_show_message(plug, _("Checking..."));
		gs_lock_plug_set_sensitive(plug, FALSE);
	}

	/* we may have pending events that should be processed before continuing back into PAM */
	while (gtk_events_pending())
	{
		gtk_main_iteration();
	}

	gs_lock_plug_set_busy(plug);
	gs_profile_end(NULL);

	return ret;
}

static gboolean reset_idle_cb(GSLockPlug* plug)
{
	gs_lock_plug_set_sensitive(plug, TRUE);
	gs_lock_plug_show_message(plug, NULL);

	return FALSE;
}

static gboolean do_auth_check(GSLockPlug* plug)
{
	GError* error;
	gboolean res;

	error = NULL;

	gs_lock_plug_disable_prompt(plug);
	gs_lock_plug_set_busy(plug);
	res = gs_auth_verify_user(g_get_user_name(), g_getenv("DISPLAY"), auth_message_handler, plug, &error);

	gs_debug("Verify user returned: %s", res ? "TRUE" : "FALSE");

	if (! res)
	{
		if (error != NULL)
		{
			gs_debug("Verify user returned error: %s", error->message);
			gs_lock_plug_show_message(plug, error->message);
		}
		else
		{
			gs_lock_plug_show_message(plug, _("Authentication failed."));
		}

		printf("NOTICE=AUTH FAILED\n");
		fflush(stdout);

		if (error != NULL)
		{
			g_error_free(error);
		}
	}

	return res;
}

static void response_cb(GSLockPlug* plug, gint response_id)
{
	if ((response_id == GS_LOCK_PLUG_RESPONSE_CANCEL) || (response_id == GTK_RESPONSE_DELETE_EVENT))
	{
		quit_response_cancel();
	}
}

static gboolean response_request_quit(void)
{
	printf("REQUEST QUIT\n");
	fflush(stdout);
	return FALSE;
}

static gboolean quit_timeout_cb(gpointer data)
{
	gtk_main_quit();
	return FALSE;
}

static gboolean auth_check_idle(GSLockPlug* plug)
{
	gboolean res;
	gboolean again;
	static guint loop_counter = 0;

	again = TRUE;
	res = do_auth_check(plug);

	if (res)
	{
		again = FALSE;
		g_idle_add((GSourceFunc) quit_response_ok, NULL);
	}
	else
	{
		loop_counter++;

		if (loop_counter < MAX_FAILURES)
		{
			gs_debug ("Authentication failed, retrying (%u)", loop_counter);
			g_timeout_add (3000, (GSourceFunc) reset_idle_cb, plug);
		}
		else
		{
			gs_debug ("Authentication failed, quitting (max failures)");
			again = FALSE;
			/* Don't quit immediately, but rather request that mate-screensaver
			 * terminates us after it has finished the dialog shake. Time out
			 * after 5 seconds and quit anyway if this doesn't happen though */
			g_idle_add((GSourceFunc) response_request_quit, NULL);
			g_timeout_add(5000, (GSourceFunc) quit_timeout_cb, NULL);
		}
	}

	return again;
}

static void show_cb(GtkWidget* widget, gpointer data)
{
	print_id(widget);
}

static gboolean popup_dialog_idle(void)
{
	GtkWidget* widget;

	gs_profile_start(NULL);

	widget = gs_lock_plug_new();

	if (enable_logout)
	{
		g_object_set(widget, "logout-enabled", TRUE, NULL);
	}

	if (logout_command)
	{
		g_object_set(widget, "logout-command", logout_command, NULL);
	}

	if (enable_switch)
	{
		g_object_set(widget, "switch-enabled", TRUE, NULL);
	}

	if (status_message)
	{
		g_object_set(widget, "status-message", status_message, NULL);
	}

	g_signal_connect(GS_LOCK_PLUG(widget), "response", G_CALLBACK(response_cb), NULL);
	g_signal_connect(widget, "show", G_CALLBACK(show_cb), NULL);

	gtk_widget_realize(widget);

	g_idle_add((GSourceFunc) auth_check_idle, widget);

	gs_profile_end(NULL);

	return FALSE;
}


/*
 * Copyright (c) 1991-2004 Jamie Zawinski <jwz@jwz.org>
 * Copyright (c) 2005 William Jon McCann <mccann@jhu.edu>
 *
 * Initializations that potentially take place as a priveleged user:
   If the executable is setuid root, then these initializations
   are run as root, before discarding privileges.
*/
static gboolean privileged_initialization(int* argc, char** argv, gboolean verbose)
{
	gboolean ret;
	char* nolock_reason;
	char* orig_uid;
	char* uid_message;

	gs_profile_start(NULL);

	#ifndef NO_LOCKING
		/* before hack_uid () for proper permissions */
		gs_auth_priv_init();
	#endif /* NO_LOCKING */

	ret = hack_uid(&nolock_reason, &orig_uid, &uid_message);

	if (nolock_reason)
	{
		g_debug("Locking disabled: %s", nolock_reason);
	}

	if (uid_message && verbose)
	{
		g_print("Modified UID: %s", uid_message);
	}

	g_free(nolock_reason);
	g_free(orig_uid);
	g_free(uid_message);

	gs_profile_end(NULL);

	return ret;
}


/*
 * Copyright (c) 1991-2004 Jamie Zawinski <jwz@jwz.org>
 * Copyright (c) 2005 William Jon McCann <mccann@jhu.edu>
 *
 * Figure out what locking mechanisms are supported.
 */
static gboolean lock_initialization (int* argc, char** argv, char** nolock_reason, gboolean verbose)
{
	if (nolock_reason != NULL)
	{
		*nolock_reason = NULL;
	}

	#ifdef NO_LOCKING

		if (nolock_reason != NULL)
		{
			*nolock_reason = g_strdup("not compiled with locking support");
		}

		return FALSE;
	#else /* !NO_LOCKING */

		/* Finish initializing locking, now that we're out of privileged code. */
		if (!gs_auth_init())
		{
			if (nolock_reason != NULL)
			{
				*nolock_reason = g_strdup("error getting password");
			}

			return FALSE;
		}

		/* If locking is currently enabled, but the environment indicates that
		 * we have been launched as MDM's "Background" program, then disable
		 * locking just in case.
		 */
		if (getenv("RUNNING_UNDER_MDM"))
		{
			if (nolock_reason != NULL)
			{
				*nolock_reason = g_strdup("running under MDM");
			}

			return FALSE;
		}

		/* If the server is XDarwin (MacOS X) then disable locking.
		 * (X grabs only affect X programs, so you can use Command-Tab
		 * to bring any other Mac program to the front, e.g., Terminal.)
		 */
		{
			gboolean macos = FALSE;

			#ifdef __APPLE__
				/* Disable locking if *running* on Apple hardware, since we have no
				 * reliable way to determine whether the server is running on MacOS.
				 * Hopefully __APPLE__ means "MacOS" and not "Linux on Mac hardware"
				 * but I'm not really sure about that.
				 */
				macos = TRUE;
			#endif /* __APPLE__ */

			if (macos)
			{
				if (nolock_reason != NULL)
				{
					*nolock_reason = g_strdup("Cannot lock securely on MacOS X");
				}

				return FALSE;
			}
		}

	#endif /* NO_LOCKING */

	return TRUE;
}

int main(int argc, char** argv)
{
	GError* error = NULL;
	char* nolock_reason = NULL;

	#ifdef ENABLE_NLS
		bindtextdomain(GETTEXT_PACKAGE, MATELOCALEDIR);
		#ifdef HAVE_BIND_TEXTDOMAIN_CODESET
			bind_textdomain_codeset(GETTEXT_PACKAGE, "UTF-8");
		#endif
		textdomain(GETTEXT_PACKAGE);
	#endif

	if (!g_thread_supported())
	{
		g_thread_init(NULL);
	}

	g_type_init();

	gs_profile_start(NULL);

	if (!privileged_initialization(&argc, argv, verbose))
	{
		response_lock_init_failed();
		exit(1);
	}

	error = NULL;

	if (!gtk_init_with_args(&argc, &argv, NULL, entries, NULL, &error))
	{
		if (error != NULL)
		{
			fprintf(stderr, "%s", error->message);
			g_error_free(error);
		}

		exit(1);
	}

	if (show_version)
	{
		g_print("%s %s\n", argv[0], VERSION);
		exit(1);
	}

	if (!lock_initialization(&argc, argv, &nolock_reason, verbose))
	{
		if (nolock_reason != NULL)
		{
			g_debug ("Screen locking disabled: %s", nolock_reason);
			g_free (nolock_reason);
		}

		response_lock_init_failed();
		exit (1);
	}

	gs_debug_init(verbose, FALSE);

	g_idle_add((GSourceFunc) popup_dialog_idle, NULL);

	gtk_main();

	gs_profile_end(NULL);
	gs_debug_shutdown();

	return 0;
}