/*
 * lwm, a window manager for X11
 * Copyright (C) 1997-2016 Elliott Hughes, James Carter
 * 
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <pwd.h>
#include <unistd.h>
#include <sys/types.h>

#include <X11/X.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/SM/SMlib.h>

#include "lwm.h"

typedef struct {
	SmProp p;
	SmPropValue v;
} SmProperty;

int ice_fd=-1;
static IceConn ice_conn;
static void *smc_conn = NULL;
static int session_argc;
static char **session_argv;
static char *client_id = NULL;

static void
ice_error(IceConn c) {
	/* i only bother catching ice i/o errors because metacity claims the
 	* default handler calls exit. twm doesn't bother, so it might not
 	* be necessary.
 	*/
	fprintf(stderr,"%s: ICE I/O error\n",argv0);
}

static void
session_save_yourself(SmcConn smc_conn,
	SmPointer client_data,
	int save_type,
	Bool shutdown,
	int interact_style,
	Bool fast) {
	int i;
	SmProperty program;
	SmProperty user_id;
	SmProperty restart_style_hint;
	SmProperty pid;
	SmProperty gsm_priority;
	SmProp clone_command;
	SmProp restart_command;
	enum prop_nums {
		prop_program,
		prop_user_id,
		prop_restart_style_hint,
		prop_pid,
		prop_gsm_priority,
		prop_clone_command,
		prop_restart_command,
		prop_LAST
	};
	SmProp *props[prop_LAST];
	struct passwd *pw;
	char hint = SmRestartImmediately;
	char pid_s[32];
	char priority = 20;

	program.p.name = SmProgram;
	program.p.type = SmARRAY8;
	program.p.num_vals = 1;
	program.p.vals = &program.v;
	program.v.value = "lwm";
	program.v.length = 3;
	props[prop_program] = &program.p;


	pw = getpwuid(getuid());
	user_id.p.name = SmUserID;
	user_id.p.type = SmARRAY8;
	user_id.p.num_vals = 1;
	user_id.p.vals = &user_id.v;
	user_id.v.value = pw ? pw->pw_name : NULL ;
	user_id.v.length = pw ? strlen(pw->pw_name) : 0;
	props[prop_user_id] = &user_id.p;

	restart_style_hint.p.name = SmRestartStyleHint;
	restart_style_hint.p.type = SmCARD8;
	restart_style_hint.p.num_vals = 1;
	restart_style_hint.p.vals = &restart_style_hint.v;
	restart_style_hint.v.value = &hint;
	restart_style_hint.v.length = 1;
	props[prop_restart_style_hint] = &restart_style_hint.p;

	snprintf(pid_s, sizeof(pid_s), "%d", getpid());
	pid.p.name = SmProcessID;
	pid.p.type = SmARRAY8;
	pid.p.num_vals = 1;
	pid.p.vals = &pid.v;
	pid.v.value = pid_s;
	pid.v.length = strlen(pid_s);
	props[prop_pid] = &pid.p;

	gsm_priority.p.name = "_GSM_Priority";
	gsm_priority.p.type = SmCARD8;
	gsm_priority.p.num_vals = 1;
	gsm_priority.p.vals = &gsm_priority.v;
	gsm_priority.v.value = &priority;
	gsm_priority.v.length = 1;
	props[prop_gsm_priority] = &gsm_priority.p;

	clone_command.name = SmCloneCommand;
	clone_command.type = SmLISTofARRAY8;
	clone_command.num_vals = session_argc;
	clone_command.vals =
		(SmPropValue *) malloc(sizeof(SmPropValue) * session_argc);
	for (i=0; i < session_argc; i++) {
		clone_command.vals[i].value = session_argv[i];
		clone_command.vals[i].length = strlen(session_argv[i]);
	}
	props[prop_clone_command] = &clone_command;

	restart_command.name = SmRestartCommand;
	restart_command.type = SmLISTofARRAY8;
	restart_command.num_vals = session_argc + 2;
	restart_command.vals =
		(SmPropValue *) malloc(sizeof(SmPropValue) *
			(session_argc + 2));
	for (i=0; i < session_argc; i++) {
		restart_command.vals[i].value = session_argv[i];
		restart_command.vals[i].length = strlen(session_argv[i]);
	}
	restart_command.vals[i].value = "-s";
	restart_command.vals[i].length = 2;
	i++;
	restart_command.vals[i].value = client_id;
	restart_command.vals[i].length = strlen(client_id);
	props[prop_restart_command] = &restart_command;

	SmcSetProperties(smc_conn, prop_LAST, props);

	free(clone_command.vals);
	free(restart_command.vals);

	SmcSaveYourselfDone(smc_conn, True);
}

void
session_end(void) {
	if (smc_conn == NULL) return;
	SmcCloseConnection(smc_conn,0,NULL);
}

static void
session_die(SmcConn smc_conn, SmPointer client_data) {
	Terminate(0);
}

static void
session_save_complete(SmcConn smc_conn, SmPointer client_data) {
}

static void
session_shutdown_cancelled(SmcConn smc_conn, SmPointer client_data) {
}

void
session_init(int argc, char *argv[]) {
	int i;
	char *previd = NULL;
	char err[256];
	unsigned long mask;
	SmcCallbacks callbacks;

	session_argv = (char **) malloc(sizeof(char *) * (argc + 2));
	session_argc = 0;
	for (i = 0; i < argc; i++) {
		if (i != 0 && strcmp(argv[i], "-s") == 0) {
			if ((i + 1) < argc) {
				i++;
				previd = argv[i];
			}
		} else {
			session_argv[session_argc] = argv[i];
			session_argc++;
		}
	}

	mask = SmcSaveYourselfProcMask |
		SmcDieProcMask |
		SmcSaveCompleteProcMask |
		SmcShutdownCancelledProcMask;

	callbacks.save_yourself.callback=session_save_yourself;
	callbacks.save_yourself.client_data=NULL;
	callbacks.die.callback = session_die;
	callbacks.die.client_data = NULL;
	callbacks.save_complete.callback = session_save_complete;
	callbacks.save_complete.client_data = NULL;
	callbacks.shutdown_cancelled.callback = session_shutdown_cancelled;
	callbacks.shutdown_cancelled.client_data = NULL;

	smc_conn = SmcOpenConnection(NULL, NULL,
		SmProtoMajor, SmProtoMinor,
		mask, &callbacks,
		previd, &client_id,
		sizeof(err) - 1, err);

	if (smc_conn == NULL) {
		/*
		this isn't actually an error, and can cause confusion
		fprintf(stderr,
			"%s: could not connect to session manager - %s\n",
			argv0, err);
		*/
		return;
	}
	if (client_id == NULL) {
		fprintf(stderr,
			"%s: session manager returned NULL connection\n",
			argv0);
		return;
	}


	IceSetIOErrorHandler(ice_error);
	ice_conn = SmcGetIceConnection(smc_conn);
	ice_fd = IceConnectionNumber(ice_conn);
}

void
session_process(void) {
	IceProcessMessages(ice_conn, NULL, NULL);
}