text: /* Copyright (c) 2012, Bastien Dejean
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
   * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <sys/stat.h>
  #include <sys/types.h>
  #include <sys/time.h>
  #include <sys/wait.h>
  #include <sys/socket.h>
  #include <sys/un.h>
  #include <signal.h>
  #include <unistd.h>
  #include <stdbool.h>
  #include <xcb/xinerama.h>
  #include "types.h"
  #include "desktop.h"
  #include "monitor.h"
  #include "settings.h"
  #include "messages.h"
  #include "pointer.h"
  #include "events.h"
  #include "common.h"
  #include "window.h"
  #include "history.h"
  #include "ewmh.h"
  #include "rule.h"
  #include "bspwm.h"
  
  int main(int argc, char *argv[])
  {
  	fd_set descriptors;
  	char socket_path[MAXLEN];
  	config_path[0] = '\0';
  	int sock_fd, cli_fd, dpy_fd, max_fd, n;
  	struct sockaddr_un sock_address;
  	char msg[BUFSIZ] = {0};
  	xcb_generic_event_t *event;
  	int opt;
  
  	while ((opt = getopt(argc, argv, "hvc:")) != -1) {
  		switch (opt) {
  			case 'h':
  				printf(WM_NAME " [-h|-v|-c CONFIG_PATH]\n");
  				exit(EXIT_SUCCESS);
  				break;
  			case 'v':
  				printf("%s\n", VERSION);
  				exit(EXIT_SUCCESS);
  				break;
  			case 'c':
  				snprintf(config_path, sizeof(config_path), "%s", optarg);
  				break;
  		}
  	}
  
  	if (config_path[0] == '\0') {
  		char *config_home = getenv(CONFIG_HOME_ENV);
  		if (config_home != NULL) {
  			snprintf(config_path, sizeof(config_path), "%s/%s/%s", config_home, WM_NAME, CONFIG_NAME);
  		} else {
  			snprintf(config_path, sizeof(config_path), "%s/%s/%s/%s", getenv("HOME"), ".config", WM_NAME, CONFIG_NAME);
  		}
  	}
  
  	dpy = xcb_connect(NULL, &default_screen);
  
  	if (!check_connection(dpy)) {
  		exit(EXIT_FAILURE);
  	}
  
  	load_settings();
  	setup();
  
  	dpy_fd = xcb_get_file_descriptor(dpy);
  
  	char *sp = getenv(SOCKET_ENV_VAR);
  	if (sp != NULL) {
  		snprintf(socket_path, sizeof(socket_path), "%s", sp);
  	} else {
  		char *host = NULL;
  		int dn = 0, sn = 0;
  		if (xcb_parse_display(NULL, &host, &dn, &sn) != 0) {
  			snprintf(socket_path, sizeof(socket_path), SOCKET_PATH_TPL, host, dn, sn);
  		}
  		free(host);
  	}
  
  	sock_address.sun_family = AF_UNIX;
  	snprintf(sock_address.sun_path, sizeof(sock_address.sun_path), "%s", socket_path);
  
  	sock_fd = socket(AF_UNIX, SOCK_STREAM, 0);
  
  	if (sock_fd == -1) {
  		err("Couldn't create the socket.\n");
  	}
  
  	unlink(socket_path);
  	if (bind(sock_fd, (struct sockaddr *) &sock_address, sizeof(sock_address)) == -1) {
  		err("Couldn't bind a name to the socket.\n");
  	}
  
  	if (listen(sock_fd, SOMAXCONN) == -1) {
  		err("Couldn't listen to the socket.\n");
  	}
  
  	signal(SIGINT, sig_handler);
  	signal(SIGHUP, sig_handler);
  	signal(SIGTERM, sig_handler);
  	signal(SIGCHLD, sig_handler);
  	signal(SIGPIPE, SIG_IGN);
  	run_config();
  	running = true;
  
  	while (running) {
  
  		xcb_flush(dpy);
  
  		FD_ZERO(&descriptors);
  		FD_SET(sock_fd, &descriptors);
  		FD_SET(dpy_fd, &descriptors);
  		max_fd = MAX(sock_fd, dpy_fd);
  
  		for (pending_rule_t *pr = pending_rule_head; pr != NULL; pr = pr->next) {
  			FD_SET(pr->fd, &descriptors);
  			if (pr->fd > max_fd) {
  				max_fd = pr->fd;
  			}
  		}
  
  		if (select(max_fd + 1, &descriptors, NULL, NULL, NULL) > 0) {
  
  			pending_rule_t *pr = pending_rule_head;
  			while (pr != NULL) {
  				pending_rule_t *next = pr->next;
  				if (FD_ISSET(pr->fd, &descriptors)) {
  					manage_window(pr->win, pr->csq, pr->fd);
  					remove_pending_rule(pr);
  				}
  				pr = next;
  			}
  
  			if (FD_ISSET(sock_fd, &descriptors)) {
  				cli_fd = accept(sock_fd, NULL, 0);
  				if (cli_fd > 0 && (n = recv(cli_fd, msg, sizeof(msg), 0)) > 0) {
  					msg[n] = '\0';
  					FILE *rsp = fdopen(cli_fd, "w");
  					if (rsp != NULL) {
  						handle_message(msg, n, rsp);
  					} else {
  						warn("Can't open the client socket as file.\n");
  						close(cli_fd);
  					}
  				}
  			}
  
  			if (FD_ISSET(dpy_fd, &descriptors)) {
  				while ((event = xcb_poll_for_event(dpy)) != NULL) {
  					handle_event(event);
  					free(event);
  				}
  			}
  
  		}
  
  		if (!check_connection(dpy)) {
  			running = false;
  		}
  	}
  
  	cleanup();
  	close(sock_fd);
  	unlink(socket_path);
  	ungrab_buttons();
  	xcb_ewmh_connection_wipe(ewmh);
  	xcb_destroy_window(dpy, meta_window);
  	xcb_destroy_window(dpy, motion_recorder.id);
  	free(ewmh);
  	xcb_flush(dpy);
  	xcb_disconnect(dpy);
  	return exit_status;
  }
  
  void init(void)
  {
  	clients_count = 0;
  	mon = mon_head = mon_tail = pri_mon = NULL;
  	history_head = history_tail = history_needle = NULL;
  	rule_head = rule_tail = NULL;
  	stack_head = stack_tail = NULL;
  	subscribe_head = subscribe_tail = NULL;
  	pending_rule_head = pending_rule_tail = NULL;
  	auto_raise = sticky_still = record_history = true;
  	randr_base = 0;
  	exit_status = 0;
  }
  
  void setup(void)
  {
  	init();
  	ewmh_init();
  	pointer_init();
  
  	screen = xcb_setup_roots_iterator(xcb_get_setup(dpy)).data;
  
  	if (screen == NULL) {
  		err("Can't acquire the default screen.\n");
  	}
  
  	root = screen->root;
  	register_events();
  
  	screen_width = screen->width_in_pixels;
  	screen_height = screen->height_in_pixels;
  
  	meta_window = xcb_generate_id(dpy);
  	xcb_create_window(dpy, XCB_COPY_FROM_PARENT, meta_window, root, -1, -1, 1, 1, 0, XCB_WINDOW_CLASS_INPUT_ONLY, XCB_COPY_FROM_PARENT, XCB_NONE, NULL);
  	xcb_icccm_set_wm_class(dpy, meta_window, sizeof(META_WINDOW_IC), META_WINDOW_IC);
  
  	motion_recorder.id = xcb_generate_id(dpy);
  	motion_recorder.sequence = 0;
  	motion_recorder.enabled = false;
  	uint32_t values[] = {XCB_EVENT_MASK_STRUCTURE_NOTIFY | XCB_EVENT_MASK_POINTER_MOTION};
  	xcb_create_window(dpy, XCB_COPY_FROM_PARENT, motion_recorder.id, root, 0, 0, 1, 1, 0,
  	                  XCB_WINDOW_CLASS_INPUT_ONLY, XCB_COPY_FROM_PARENT, XCB_CW_EVENT_MASK, values);
  	xcb_icccm_set_wm_class(dpy, motion_recorder.id, sizeof(MOTION_RECORDER_IC), MOTION_RECORDER_IC);
  
  	xcb_atom_t net_atoms[] = {ewmh->_NET_SUPPORTED,
  	                          ewmh->_NET_SUPPORTING_WM_CHECK,
  	                          ewmh->_NET_DESKTOP_NAMES,
  	                          ewmh->_NET_DESKTOP_VIEWPORT,
  	                          ewmh->_NET_NUMBER_OF_DESKTOPS,
  	                          ewmh->_NET_CURRENT_DESKTOP,
  	                          ewmh->_NET_CLIENT_LIST,
  	                          ewmh->_NET_ACTIVE_WINDOW,
  	                          ewmh->_NET_CLOSE_WINDOW,
  	                          ewmh->_NET_WM_STRUT_PARTIAL,
  	                          ewmh->_NET_WM_DESKTOP,
  	                          ewmh->_NET_WM_STATE,
  	                          ewmh->_NET_WM_STATE_HIDDEN,
  	                          ewmh->_NET_WM_STATE_FULLSCREEN,
  	                          ewmh->_NET_WM_STATE_BELOW,
  	                          ewmh->_NET_WM_STATE_ABOVE,
  	                          ewmh->_NET_WM_STATE_STICKY,
  	                          ewmh->_NET_WM_STATE_DEMANDS_ATTENTION,
  	                          ewmh->_NET_WM_WINDOW_TYPE,
  	                          ewmh->_NET_WM_WINDOW_TYPE_DOCK,
  	                          ewmh->_NET_WM_WINDOW_TYPE_DESKTOP,
  	                          ewmh->_NET_WM_WINDOW_TYPE_NOTIFICATION,
  	                          ewmh->_NET_WM_WINDOW_TYPE_DIALOG,
  	                          ewmh->_NET_WM_WINDOW_TYPE_UTILITY,
  	                          ewmh->_NET_WM_WINDOW_TYPE_TOOLBAR};
  
  	xcb_ewmh_set_supported(ewmh, default_screen, LENGTH(net_atoms), net_atoms);
  	ewmh_set_supporting(meta_window);
  
  #define GETATOM(a) \
  	get_atom(#a, &a);
  	GETATOM(WM_STATE)
  	GETATOM(WM_DELETE_WINDOW)
  	GETATOM(WM_TAKE_FOCUS)
  #undef GETATOM
  
  	const xcb_query_extension_reply_t *qep = xcb_get_extension_data(dpy, &xcb_randr_id);
  	if (qep->present && update_monitors()) {
  		randr = true;
  		randr_base = qep->first_event;
  		xcb_randr_select_input(dpy, root, XCB_RANDR_NOTIFY_MASK_SCREEN_CHANGE);
  	} else {
  		randr = false;
  		warn("Couldn't retrieve monitors via RandR.\n");
  		bool xinerama_is_active = false;
  
  		if (xcb_get_extension_data(dpy, &xcb_xinerama_id)->present) {
  			xcb_xinerama_is_active_reply_t *xia = xcb_xinerama_is_active_reply(dpy, xcb_xinerama_is_active(dpy), NULL);
  			if (xia != NULL) {
  				xinerama_is_active = xia->state;
  				free(xia);
  			}
  		}
  
  		if (xinerama_is_active) {
  			xcb_xinerama_query_screens_reply_t *xsq = xcb_xinerama_query_screens_reply(dpy, xcb_xinerama_query_screens(dpy), NULL);
  			xcb_xinerama_screen_info_t *xsi = xcb_xinerama_query_screens_screen_info(xsq);
  			int n = xcb_xinerama_query_screens_screen_info_length(xsq);
  			for (int i = 0; i < n; i++) {
  				xcb_xinerama_screen_info_t info = xsi[i];
  				xcb_rectangle_t rect = (xcb_rectangle_t) {info.x_org, info.y_org, info.width, info.height};
  				monitor_t *m = make_monitor(NULL, &rect, XCB_NONE);
  				add_monitor(m);
  				add_desktop(m, make_desktop(NULL, XCB_NONE));
  			}
  			free(xsq);
  		} else {
  			warn("Xinerama is inactive.\n");
  			xcb_rectangle_t rect = (xcb_rectangle_t) {0, 0, screen_width, screen_height};
  			monitor_t *m = make_monitor(NULL, &rect, XCB_NONE);
  			add_monitor(m);
  			add_desktop(m, make_desktop(NULL, XCB_NONE));
  		}
  	}
  
  	ewmh_update_number_of_desktops();
  	ewmh_update_desktop_names();
  	ewmh_update_desktop_viewport();
  	ewmh_update_current_desktop();
  	xcb_get_input_focus_reply_t *ifo = xcb_get_input_focus_reply(dpy, xcb_get_input_focus(dpy), NULL);
  	if (ifo != NULL && (ifo->focus == XCB_INPUT_FOCUS_POINTER_ROOT || ifo->focus == XCB_NONE)) {
  		clear_input_focus();
  	}
  	free(ifo);
  }
  
  void register_events(void)
  {
  	uint32_t values[] = {ROOT_EVENT_MASK};
  	xcb_generic_error_t *e = xcb_request_check(dpy, xcb_change_window_attributes_checked(dpy, root, XCB_CW_EVENT_MASK, values));
  	if (e != NULL) {
  		xcb_disconnect(dpy);
  		err("Another window manager is already running.\n");
  	}
  }
  
  void cleanup(void)
  {
  	mon = NULL;
  
  	while (mon_head != NULL) {
  		remove_monitor(mon_head);
  	}
  	while (rule_head != NULL) {
  		remove_rule(rule_head);
  	}
  	while (subscribe_head != NULL) {
  		remove_subscriber(subscribe_head);
  	}
  	while (pending_rule_head != NULL) {
  		remove_pending_rule(pending_rule_head);
  	}
  
  	empty_history();
  }
  
  bool check_connection (xcb_connection_t *dpy)
  {
  	int xerr;
  	if ((xerr = xcb_connection_has_error(dpy)) != 0) {
  		warn("The server closed the connection: ");
  		switch (xerr) {
  			case XCB_CONN_ERROR:
  				warn("socket, pipe or stream error.\n");
  				break;
  			case XCB_CONN_CLOSED_EXT_NOTSUPPORTED:
  				warn("unsupported extension.\n");
  				break;
  			case XCB_CONN_CLOSED_MEM_INSUFFICIENT:
  				warn("not enough memory.\n");
  				break;
  			case XCB_CONN_CLOSED_REQ_LEN_EXCEED:
  				warn("request length exceeded.\n");
  				break;
  			case XCB_CONN_CLOSED_PARSE_ERR:
  				warn("can't parse display string.\n");
  				break;
  			case XCB_CONN_CLOSED_INVALID_SCREEN:
  				warn("invalid screen.\n");
  				break;
  			case XCB_CONN_CLOSED_FDPASSING_FAILED:
  				warn("failed to pass FD.\n");
  				break;
  			default:
  				warn("unknown error.\n");
  				break;
  		}
  		return false;
  	} else {
  		return true;
  	}
  }
  
  void sig_handler(int sig)
  {
  	if (sig == SIGCHLD) {
  		signal(sig, sig_handler);
  		while (waitpid(-1, 0, WNOHANG) > 0)
  			;
  	} else if (sig == SIGINT || sig == SIGHUP || sig == SIGTERM) {
  		running = false;
  	}
  }
  