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Add resize-pane -Z to temporary zoom the active pane to occupy the full
window or unzoom (restored to the normal layout) if it already zoomed,
bound to C-b z by default. The pane is unzoomed on pretty much any
excuse whatsoever.

We considered making this a new layout but the requirements are quite
different from layouts so decided it is better as a special case. Each
current layout cell is saved, a temporary one-cell layout generated and
all except the active pane set to NULL.

Prompted by suggestions and scripts from several. Thanks to Aaron Jensen
and Thiago Padilha for testing an earlier version.

/* $OpenBSD: window.c,v 1.93 2013/03/24 09:57:59 nicm Exp $ */

/*
 * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <sys/ioctl.h>

#include <errno.h>
#include <fcntl.h>
#include <fnmatch.h>
#include <paths.h>
#include <pwd.h>
#include <signal.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include <util.h>

#include "tmux.h"

/*
 * Each window is attached to a number of panes, each of which is a pty. This
 * file contains code to handle them.
 *
 * A pane has two buffers attached, these are filled and emptied by the main
 * server poll loop. Output data is received from pty's in screen format,
 * translated and returned as a series of escape sequences and strings via
 * input_parse (in input.c). Input data is received as key codes and written
 * directly via input_key.
 *
 * Each pane also has a "virtual" screen (screen.c) which contains the current
 * state and is redisplayed when the window is reattached to a client.
 *
 * Windows are stored directly on a global array and wrapped in any number of
 * winlink structs to be linked onto local session RB trees. A reference count
 * is maintained and a window removed from the global list and destroyed when
 * it reaches zero.
 */

/* Global window list. */
struct windows windows;

/* Global panes tree. */
struct window_pane_tree all_window_panes;
u_int	next_window_pane_id;
u_int	next_window_id;

void	window_pane_timer_callback(int, short, void *);
void	window_pane_read_callback(struct bufferevent *, void *);
void	window_pane_error_callback(struct bufferevent *, short, void *);

RB_GENERATE(winlinks, winlink, entry, winlink_cmp);

int
winlink_cmp(struct winlink *wl1, struct winlink *wl2)
{
	return (wl1->idx - wl2->idx);
}

RB_GENERATE(window_pane_tree, window_pane, tree_entry, window_pane_cmp);

int
window_pane_cmp(struct window_pane *wp1, struct window_pane *wp2)
{
	return (wp1->id - wp2->id);
}

struct winlink *
winlink_find_by_window(struct winlinks *wwl, struct window *w)
{
	struct winlink	*wl;

	RB_FOREACH(wl, winlinks, wwl) {
		if (wl->window == w)
			return (wl);
	}

	return (NULL);
}

struct winlink *
winlink_find_by_index(struct winlinks *wwl, int idx)
{
	struct winlink	wl;

	if (idx < 0)
		fatalx("bad index");

	wl.idx = idx;
	return (RB_FIND(winlinks, wwl, &wl));
}

struct winlink *
winlink_find_by_window_id(struct winlinks *wwl, u_int id)
{
	struct winlink *wl;

	RB_FOREACH(wl, winlinks, wwl) {
		if (wl->window->id == id)
			return (wl);
	}
	return (NULL);
}

int
winlink_next_index(struct winlinks *wwl, int idx)
{
	int	i;

	i = idx;
	do {
		if (winlink_find_by_index(wwl, i) == NULL)
			return (i);
		if (i == INT_MAX)
			i = 0;
		else
			i++;
	} while (i != idx);
	return (-1);
}

u_int
winlink_count(struct winlinks *wwl)
{
	struct winlink	*wl;
	u_int		 n;

	n = 0;
	RB_FOREACH(wl, winlinks, wwl)
		n++;

	return (n);
}

struct winlink *
winlink_add(struct winlinks *wwl, int idx)
{
	struct winlink	*wl;

	if (idx < 0) {
		if ((idx = winlink_next_index(wwl, -idx - 1)) == -1)
			return (NULL);
	} else if (winlink_find_by_index(wwl, idx) != NULL)
		return (NULL);

	wl = xcalloc(1, sizeof *wl);
	wl->idx = idx;
	RB_INSERT(winlinks, wwl, wl);

	return (wl);
}

void
winlink_set_window(struct winlink *wl, struct window *w)
{
	wl->window = w;
	w->references++;
}

void
winlink_remove(struct winlinks *wwl, struct winlink *wl)
{
	struct window	*w = wl->window;

	RB_REMOVE(winlinks, wwl, wl);
	free(wl->status_text);
	free(wl);

	if (w != NULL)
		window_remove_ref(w);
}

struct winlink *
winlink_next(struct winlink *wl)
{
	return (RB_NEXT(winlinks, wwl, wl));
}

struct winlink *
winlink_previous(struct winlink *wl)
{
	return (RB_PREV(winlinks, wwl, wl));
}

struct winlink *
winlink_next_by_number(struct winlink *wl, struct session *s, int n)
{
	for (; n > 0; n--) {
		if ((wl = RB_NEXT(winlinks, wwl, wl)) == NULL)
			wl = RB_MIN(winlinks, &s->windows);
	}

	return (wl);
}

struct winlink *
winlink_previous_by_number(struct winlink *wl, struct session *s, int n)
{
	for (; n > 0; n--) {
		if ((wl = RB_PREV(winlinks, wwl, wl)) == NULL)
			wl = RB_MAX(winlinks, &s->windows);
	}

	return (wl);
}

void
winlink_stack_push(struct winlink_stack *stack, struct winlink *wl)
{
	if (wl == NULL)
		return;

	winlink_stack_remove(stack, wl);
	TAILQ_INSERT_HEAD(stack, wl, sentry);
}

void
winlink_stack_remove(struct winlink_stack *stack, struct winlink *wl)
{
	struct winlink	*wl2;

	if (wl == NULL)
		return;

	TAILQ_FOREACH(wl2, stack, sentry) {
		if (wl2 == wl) {
			TAILQ_REMOVE(stack, wl, sentry);
			return;
		}
	}
}

int
window_index(struct window *s, u_int *i)
{
	for (*i = 0; *i < ARRAY_LENGTH(&windows); (*i)++) {
		if (s == ARRAY_ITEM(&windows, *i))
			return (0);
	}
	return (-1);
}

struct window *
window_find_by_id(u_int id)
{
	struct window	*w;
	u_int		 i;

	for (i = 0; i < ARRAY_LENGTH(&windows); i++) {
		w = ARRAY_ITEM(&windows, i);
		if (w->id == id)
			return (w);
	}
	return (NULL);
}

struct window *
window_create1(u_int sx, u_int sy)
{
	struct window	*w;
	u_int		 i;

	w = xcalloc(1, sizeof *w);
	w->id = next_window_id++;
	w->name = NULL;
	w->flags = 0;

	TAILQ_INIT(&w->panes);
	w->active = NULL;

	w->lastlayout = -1;
	w->layout_root = NULL;

	w->sx = sx;
	w->sy = sy;

	options_init(&w->options, &global_w_options);
	if (options_get_number(&w->options, "automatic-rename"))
		queue_window_name(w);

	for (i = 0; i < ARRAY_LENGTH(&windows); i++) {
		if (ARRAY_ITEM(&windows, i) == NULL) {
			ARRAY_SET(&windows, i, w);
			break;
		}
	}
	if (i == ARRAY_LENGTH(&windows))
		ARRAY_ADD(&windows, w);
	w->references = 0;

	return (w);
}

struct window *
window_create(const char *name, const char *cmd, const char *shell,
    const char *cwd, struct environ *env, struct termios *tio,
    u_int sx, u_int sy, u_int hlimit, char **cause)
{
	struct window		*w;
	struct window_pane	*wp;
	const char		*prefix;
	char			*cmd1;

	w = window_create1(sx, sy);
	wp = window_add_pane(w, hlimit);
	layout_init(w, wp);

	if (*cmd != '\0') {
		prefix = options_get_string(&w->options, "command-prefix");
		xasprintf(&cmd1, "%s%s", prefix, cmd);
	} else
		cmd1 = xstrdup("");
	if (window_pane_spawn(wp, cmd1, shell, cwd, env, tio, cause) != 0) {
		window_destroy(w);
		free(cmd1);
		return (NULL);
	}
	free(cmd1);

	w->active = TAILQ_FIRST(&w->panes);
	if (name != NULL) {
		w->name = xstrdup(name);
		options_set_number(&w->options, "automatic-rename", 0);
	} else
		w->name = default_window_name(w);

	return (w);
}

void
window_destroy(struct window *w)
{
	u_int	i;

	window_unzoom(w);

	if (window_index(w, &i) != 0)
		fatalx("index not found");
	ARRAY_SET(&windows, i, NULL);
	while (!ARRAY_EMPTY(&windows) && ARRAY_LAST(&windows) == NULL)
		ARRAY_TRUNC(&windows, 1);

	if (w->layout_root != NULL)
		layout_free(w);

	if (event_initialized(&w->name_timer))
		evtimer_del(&w->name_timer);

	options_free(&w->options);

	window_destroy_panes(w);

	free(w->name);
	free(w);
}

void
window_remove_ref(struct window *w)
{
	if (w->references == 0)
		fatal("bad reference count");
	w->references--;
	if (w->references == 0)
		window_destroy(w);
}

void
window_set_name(struct window *w, const char *new_name)
{
	free(w->name);
	w->name = xstrdup(new_name);
	notify_window_renamed(w);
}

void
window_resize(struct window *w, u_int sx, u_int sy)
{
	w->sx = sx;
	w->sy = sy;
}

void
window_set_active_pane(struct window *w, struct window_pane *wp)
{
	if (wp == w->active)
		return;
	w->last = w->active;
	w->active = wp;
	while (!window_pane_visible(w->active)) {
		w->active = TAILQ_PREV(w->active, window_panes, entry);
		if (w->active == NULL)
			w->active = TAILQ_LAST(&w->panes, window_panes);
		if (w->active == wp)
			return;
	}
}

struct window_pane *
window_get_active_at(struct window *w, u_int x, u_int y)
{
	struct window_pane	*wp;

	TAILQ_FOREACH(wp, &w->panes, entry) {
		if (!window_pane_visible(wp))
			continue;
		if (x < wp->xoff || x > wp->xoff + wp->sx)
			continue;
		if (y < wp->yoff || y > wp->yoff + wp->sy)
			continue;
		return (wp);
	}
	return (NULL);
}

void
window_set_active_at(struct window *w, u_int x, u_int y)
{
	struct window_pane	*wp;

	wp = window_get_active_at(w, x, y);
	if (wp != NULL && wp != w->active)
		window_set_active_pane(w, wp);
}

struct window_pane *
window_find_string(struct window *w, const char *s)
{
	u_int	x, y;

	x = w->sx / 2;
	y = w->sy / 2;

	if (strcasecmp(s, "top") == 0)
		y = 0;
	else if (strcasecmp(s, "bottom") == 0)
		y = w->sy - 1;
	else if (strcasecmp(s, "left") == 0)
		x = 0;
	else if (strcasecmp(s, "right") == 0)
		x = w->sx - 1;
	else if (strcasecmp(s, "top-left") == 0) {
		x = 0;
		y = 0;
	} else if (strcasecmp(s, "top-right") == 0) {
		x = w->sx - 1;
		y = 0;
	} else if (strcasecmp(s, "bottom-left") == 0) {
		x = 0;
		y = w->sy - 1;
	} else if (strcasecmp(s, "bottom-right") == 0) {
		x = w->sx - 1;
		y = w->sy - 1;
	} else
		return (NULL);

	return (window_get_active_at(w, x, y));
}

int
window_zoom(struct window_pane *wp)
{
	struct window		*w = wp->window;
	struct window_pane	*wp1;

	if (w->flags & WINDOW_ZOOMED)
		return (-1);

	if (!window_pane_visible(wp))
		return (-1);
	if (w->active != wp)
		window_set_active_pane(w, wp);

	TAILQ_FOREACH(wp1, &w->panes, entry) {
		wp1->saved_layout_cell = wp1->layout_cell;
		wp1->layout_cell = NULL;
	}

	w->saved_layout_root = w->layout_root;
	layout_init(w, wp);
	w->flags |= WINDOW_ZOOMED;

	return (0);
}

int
window_unzoom(struct window *w)
{
	struct window_pane	*wp, *wp1;

	if (!(w->flags & WINDOW_ZOOMED))
		return (-1);
	wp = w->active;

	w->flags &= ~WINDOW_ZOOMED;
	layout_free(w);
	w->layout_root = w->saved_layout_root;

	TAILQ_FOREACH(wp1, &w->panes, entry) {
		wp1->layout_cell = wp1->saved_layout_cell;
		wp1->saved_layout_cell = NULL;
	}
	layout_fix_panes(w, w->sx, w->sy);

	return (0);
}

struct window_pane *
window_add_pane(struct window *w, u_int hlimit)
{
	struct window_pane	*wp;

	wp = window_pane_create(w, w->sx, w->sy, hlimit);
	if (TAILQ_EMPTY(&w->panes))
		TAILQ_INSERT_HEAD(&w->panes, wp, entry);
	else
		TAILQ_INSERT_AFTER(&w->panes, w->active, wp, entry);
	return (wp);
}

void
window_remove_pane(struct window *w, struct window_pane *wp)
{
	if (wp == w->active) {
		w->active = w->last;
		w->last = NULL;
		if (w->active == NULL) {
			w->active = TAILQ_PREV(wp, window_panes, entry);
			if (w->active == NULL)
				w->active = TAILQ_NEXT(wp, entry);
		}
	} else if (wp == w->last)
		w->last = NULL;

	TAILQ_REMOVE(&w->panes, wp, entry);
	window_pane_destroy(wp);
}

struct window_pane *
window_pane_at_index(struct window *w, u_int idx)
{
	struct window_pane	*wp;
	u_int			 n;

	n = options_get_number(&w->options, "pane-base-index");
	TAILQ_FOREACH(wp, &w->panes, entry) {
		if (n == idx)
			return (wp);
		n++;
	}
	return (NULL);
}

struct window_pane *
window_pane_next_by_number(struct window *w, struct window_pane *wp, u_int n)
{
	for (; n > 0; n--) {
		if ((wp = TAILQ_NEXT(wp, entry)) == NULL)
			wp = TAILQ_FIRST(&w->panes);
	}

	return (wp);
}

struct window_pane *
window_pane_previous_by_number(struct window *w, struct window_pane *wp,
    u_int n)
{
	for (; n > 0; n--) {
		if ((wp = TAILQ_PREV(wp, window_panes, entry)) == NULL)
			wp = TAILQ_LAST(&w->panes, window_panes);
	}

	return (wp);
}

int
window_pane_index(struct window_pane *wp, u_int *i)
{
	struct window_pane	*wq;
	struct window		*w = wp->window;

	*i = options_get_number(&w->options, "pane-base-index");
	TAILQ_FOREACH(wq, &w->panes, entry) {
		if (wp == wq) {
			return (0);
		}
		(*i)++;
	}

	return (-1);
}

u_int
window_count_panes(struct window *w)
{
	struct window_pane	*wp;
	u_int			 n;

	n = 0;
	TAILQ_FOREACH(wp, &w->panes, entry)
		n++;
	return (n);
}

void
window_destroy_panes(struct window *w)
{
	struct window_pane	*wp;

	while (!TAILQ_EMPTY(&w->panes)) {
		wp = TAILQ_FIRST(&w->panes);
		TAILQ_REMOVE(&w->panes, wp, entry);
		window_pane_destroy(wp);
	}
}

/* Return list of printable window flag symbols. No flags is just a space. */
char *
window_printable_flags(struct session *s, struct winlink *wl)
{
	char	flags[BUFSIZ];
	int	pos;

	pos = 0;
	if (wl->flags & WINLINK_ACTIVITY)
		flags[pos++] = '#';
	if (wl->flags & WINLINK_BELL)
		flags[pos++] = '!';
	if (wl->flags & WINLINK_CONTENT)
		flags[pos++] = '+';
	if (wl->flags & WINLINK_SILENCE)
		flags[pos++] = '~';
	if (wl == s->curw)
		flags[pos++] = '*';
	if (wl == TAILQ_FIRST(&s->lastw))
		flags[pos++] = '-';
	if (wl->window->flags & WINDOW_ZOOMED)
		flags[pos++] = 'Z';
	if (pos == 0)
		flags[pos++] = ' ';
	flags[pos] = '\0';
	return (xstrdup(flags));
}

/* Find pane in global tree by id. */
struct window_pane *
window_pane_find_by_id(u_int id)
{
	struct window_pane	wp;

	wp.id = id;
	return (RB_FIND(window_pane_tree, &all_window_panes, &wp));
}

struct window_pane *
window_pane_create(struct window *w, u_int sx, u_int sy, u_int hlimit)
{
	struct window_pane	*wp;

	wp = xcalloc(1, sizeof *wp);
	wp->window = w;

	wp->id = next_window_pane_id++;
	RB_INSERT(window_pane_tree, &all_window_panes, wp);

	wp->cmd = NULL;
	wp->shell = NULL;
	wp->cwd = NULL;

	wp->fd = -1;
	wp->event = NULL;

	wp->mode = NULL;

	wp->layout_cell = NULL;

	wp->xoff = 0;
	wp->yoff = 0;

	wp->sx = sx;
	wp->sy = sy;

	wp->pipe_fd = -1;
	wp->pipe_off = 0;
	wp->pipe_event = NULL;

	wp->saved_grid = NULL;

	screen_init(&wp->base, sx, sy, hlimit);
	wp->screen = &wp->base;

	input_init(wp);

	return (wp);
}

void
window_pane_destroy(struct window_pane *wp)
{
	window_pane_reset_mode(wp);

	if (event_initialized(&wp->changes_timer))
		evtimer_del(&wp->changes_timer);

	if (wp->fd != -1) {
		bufferevent_free(wp->event);
		close(wp->fd);
	}

	input_free(wp);

	screen_free(&wp->base);
	if (wp->saved_grid != NULL)
		grid_destroy(wp->saved_grid);

	if (wp->pipe_fd != -1) {
		bufferevent_free(wp->pipe_event);
		close(wp->pipe_fd);
	}

	RB_REMOVE(window_pane_tree, &all_window_panes, wp);

	free(wp->cwd);
	free(wp->shell);
	free(wp->cmd);
	free(wp);
}

int
window_pane_spawn(struct window_pane *wp, const char *cmd, const char *shell,
    const char *cwd, struct environ *env, struct termios *tio, char **cause)
{
	struct winsize	 ws;
	char		*argv0, paneid[16];
	const char	*ptr;
	struct termios	 tio2;

	if (wp->fd != -1) {
		bufferevent_free(wp->event);
		close(wp->fd);
	}
	if (cmd != NULL) {
		free(wp->cmd);
		wp->cmd = xstrdup(cmd);
	}
	if (shell != NULL) {
		free(wp->shell);
		wp->shell = xstrdup(shell);
	}
	if (cwd != NULL) {
		free(wp->cwd);
		wp->cwd = xstrdup(cwd);
	}

	log_debug("spawn: %s -- %s", wp->shell, wp->cmd);

	memset(&ws, 0, sizeof ws);
	ws.ws_col = screen_size_x(&wp->base);
	ws.ws_row = screen_size_y(&wp->base);

	switch (wp->pid = forkpty(&wp->fd, wp->tty, NULL, &ws)) {
	case -1:
		wp->fd = -1;
		xasprintf(cause, "%s: %s", cmd, strerror(errno));
		return (-1);
	case 0:
		if (chdir(wp->cwd) != 0)
			chdir("/");

		if (tcgetattr(STDIN_FILENO, &tio2) != 0)
			fatal("tcgetattr failed");
		if (tio != NULL)
			memcpy(tio2.c_cc, tio->c_cc, sizeof tio2.c_cc);
		tio2.c_cc[VERASE] = '\177';
		if (tcsetattr(STDIN_FILENO, TCSANOW, &tio2) != 0)
			fatal("tcgetattr failed");

		closefrom(STDERR_FILENO + 1);

		xsnprintf(paneid, sizeof paneid, "%%%u", wp->id);
		environ_set(env, "TMUX_PANE", paneid);
		environ_push(env);

		clear_signals(1);
		log_close();

		setenv("SHELL", wp->shell, 1);
		ptr = strrchr(wp->shell, '/');

		if (*wp->cmd != '\0') {
			/* Use the command. */
			if (ptr != NULL && *(ptr + 1) != '\0')
				xasprintf(&argv0, "%s", ptr + 1);
			else
				xasprintf(&argv0, "%s", wp->shell);
			execl(wp->shell, argv0, "-c", wp->cmd, (char *) NULL);
			fatal("execl failed");
		}

		/* No command; fork a login shell. */
		if (ptr != NULL && *(ptr + 1) != '\0')
			xasprintf(&argv0, "-%s", ptr + 1);
		else
			xasprintf(&argv0, "-%s", wp->shell);
		execl(wp->shell, argv0, (char *) NULL);
		fatal("execl failed");
	}

	setblocking(wp->fd, 0);

	wp->event = bufferevent_new(wp->fd,
	    window_pane_read_callback, NULL, window_pane_error_callback, wp);
	bufferevent_enable(wp->event, EV_READ|EV_WRITE);

	return (0);
}

void
window_pane_timer_start(struct window_pane *wp)
{
	struct timeval	tv;

	tv.tv_sec = 0;
	tv.tv_usec = 1000;

	evtimer_del(&wp->changes_timer);
	evtimer_set(&wp->changes_timer, window_pane_timer_callback, wp);
	evtimer_add(&wp->changes_timer, &tv);
}

void
window_pane_timer_callback(unused int fd, unused short events, void *data)
{
	struct window_pane	*wp = data;
	struct window		*w = wp->window;
	u_int			 interval, trigger;

	interval = options_get_number(&w->options, "c0-change-interval");
	trigger = options_get_number(&w->options, "c0-change-trigger");

	if (wp->changes_redraw++ == interval) {
		wp->flags |= PANE_REDRAW;
		wp->changes_redraw = 0;

	}

	if (trigger == 0 || wp->changes < trigger) {
		wp->flags |= PANE_REDRAW;
		wp->flags &= ~PANE_DROP;
	} else
		window_pane_timer_start(wp);
	wp->changes = 0;
}

void
window_pane_read_callback(unused struct bufferevent *bufev, void *data)
{
	struct window_pane     *wp = data;
	char   		       *new_data;
	size_t			new_size;

	new_size = EVBUFFER_LENGTH(wp->event->input) - wp->pipe_off;
	if (wp->pipe_fd != -1 && new_size > 0) {
		new_data = EVBUFFER_DATA(wp->event->input);
		bufferevent_write(wp->pipe_event, new_data, new_size);
	}

	input_parse(wp);

	wp->pipe_off = EVBUFFER_LENGTH(wp->event->input);

	/*
	 * If we get here, we're not outputting anymore, so set the silence
	 * flag on the window.
	 */
	wp->window->flags |= WINDOW_SILENCE;
	if (gettimeofday(&wp->window->silence_timer, NULL) != 0)
		fatal("gettimeofday failed.");
}

void
window_pane_error_callback(
    unused struct bufferevent *bufev, unused short what, void *data)
{
	struct window_pane *wp = data;

	server_destroy_pane(wp);
}

void
window_pane_resize(struct window_pane *wp, u_int sx, u_int sy)
{
	if (sx == wp->sx && sy == wp->sy)
		return;
	wp->sx = sx;
	wp->sy = sy;

	screen_resize(&wp->base, sx, sy, wp->saved_grid == NULL);
	if (wp->mode != NULL)
		wp->mode->resize(wp, sx, sy);
}

/*
 * Enter alternative screen mode. A copy of the visible screen is saved and the
 * history is not updated
 */
void
window_pane_alternate_on(struct window_pane *wp, struct grid_cell *gc,
    int cursor)
{
	struct screen	*s = &wp->base;
	u_int		 sx, sy;

	if (wp->saved_grid != NULL)
		return;
	if (!options_get_number(&wp->window->options, "alternate-screen"))
		return;
	sx = screen_size_x(s);
	sy = screen_size_y(s);

	wp->saved_grid = grid_create(sx, sy, 0);
	grid_duplicate_lines(wp->saved_grid, 0, s->grid, screen_hsize(s), sy);
	if (cursor) {
		wp->saved_cx = s->cx;
		wp->saved_cy = s->cy;
	}
	memcpy(&wp->saved_cell, gc, sizeof wp->saved_cell);

	grid_view_clear(s->grid, 0, 0, sx, sy);

	wp->base.grid->flags &= ~GRID_HISTORY;

	wp->flags |= PANE_REDRAW;
}

/* Exit alternate screen mode and restore the copied grid. */
void
window_pane_alternate_off(struct window_pane *wp, struct grid_cell *gc,
    int cursor)
{
	struct screen	*s = &wp->base;
	u_int		 sx, sy;

	if (wp->saved_grid == NULL)
		return;
	if (!options_get_number(&wp->window->options, "alternate-screen"))
		return;
	sx = screen_size_x(s);
	sy = screen_size_y(s);

	/*
	 * If the current size is bigger, temporarily resize to the old size
	 * before copying back.
	 */
	if (sy > wp->saved_grid->sy)
		screen_resize(s, sx, wp->saved_grid->sy, 1);

	/* Restore the grid, cursor position and cell. */
	grid_duplicate_lines(s->grid, screen_hsize(s), wp->saved_grid, 0, sy);
	if (cursor)
		s->cx = wp->saved_cx;
	if (s->cx > screen_size_x(s) - 1)
		s->cx = screen_size_x(s) - 1;
	if (cursor)
		s->cy = wp->saved_cy;
	if (s->cy > screen_size_y(s) - 1)
		s->cy = screen_size_y(s) - 1;
	memcpy(gc, &wp->saved_cell, sizeof *gc);

	/*
	 * Turn history back on (so resize can use it) and then resize back to
	 * the current size.
	 */
	wp->base.grid->flags |= GRID_HISTORY;
	if (sy > wp->saved_grid->sy || sx != wp->saved_grid->sx)
		screen_resize(s, sx, sy, 1);

	grid_destroy(wp->saved_grid);
	wp->saved_grid = NULL;

	wp->flags |= PANE_REDRAW;
}

int
window_pane_set_mode(struct window_pane *wp, const struct window_mode *mode)
{
	struct screen	*s;

	if (wp->mode != NULL)
		return (1);
	wp->mode = mode;

	if ((s = wp->mode->init(wp)) != NULL)
		wp->screen = s;
	wp->flags |= PANE_REDRAW;
	return (0);
}

void
window_pane_reset_mode(struct window_pane *wp)
{
	if (wp->mode == NULL)
		return;

	wp->mode->free(wp);
	wp->mode = NULL;

	wp->screen = &wp->base;
	wp->flags |= PANE_REDRAW;
}

void
window_pane_key(struct window_pane *wp, struct session *sess, int key)
{
	struct window_pane	*wp2;

	if (!window_pane_visible(wp))
		return;

	if (wp->mode != NULL) {
		if (wp->mode->key != NULL)
			wp->mode->key(wp, sess, key);
		return;
	}

	if (wp->fd == -1)
		return;
	input_key(wp, key);
	if (options_get_number(&wp->window->options, "synchronize-panes")) {
		TAILQ_FOREACH(wp2, &wp->window->panes, entry) {
			if (wp2 == wp || wp2->mode != NULL)
				continue;
			if (wp2->fd != -1 && window_pane_visible(wp2))
				input_key(wp2, key);
		}
	}
}

void
window_pane_mouse(
    struct window_pane *wp, struct session *sess, struct mouse_event *m)
{
	if (!window_pane_visible(wp))
		return;

	if (m->x < wp->xoff || m->x >= wp->xoff + wp->sx)
		return;
	if (m->y < wp->yoff || m->y >= wp->yoff + wp->sy)
		return;
	m->x -= wp->xoff;
	m->y -= wp->yoff;

	if (wp->mode != NULL) {
		if (wp->mode->mouse != NULL &&
		    options_get_number(&wp->window->options, "mode-mouse"))
			wp->mode->mouse(wp, sess, m);
	} else if (wp->fd != -1)
		input_mouse(wp, sess, m);
}

int
window_pane_visible(struct window_pane *wp)
{
	struct window	*w = wp->window;

	if (wp->layout_cell == NULL)
		return (0);
	if (wp->xoff >= w->sx || wp->yoff >= w->sy)
		return (0);
	if (wp->xoff + wp->sx > w->sx || wp->yoff + wp->sy > w->sy)
		return (0);
	return (1);
}

char *
window_pane_search(struct window_pane *wp, const char *searchstr, u_int *lineno)
{
	struct screen	*s = &wp->base;
	char		*newsearchstr, *line, *msg;
	u_int	 	 i;

	msg = NULL;
	xasprintf(&newsearchstr, "*%s*", searchstr);

	for (i = 0; i < screen_size_y(s); i++) {
		line = grid_view_string_cells(s->grid, 0, i, screen_size_x(s));
		if (fnmatch(newsearchstr, line, 0) == 0) {
			msg = line;
			if (lineno != NULL)
				*lineno = i;
			break;
		}
		free(line);
	}

	free(newsearchstr);
	return (msg);
}

/* Find the pane directly above another. */
struct window_pane *
window_pane_find_up(struct window_pane *wp)
{
	struct window_pane     *wp2;
	u_int			left, top;

	if (wp == NULL || !window_pane_visible(wp))
		return (NULL);

	top = wp->yoff;
	if (top == 0)
		top = wp->window->sy + 1;
	left = wp->xoff;

	TAILQ_FOREACH(wp2, &wp->window->panes, entry) {
		if (!window_pane_visible(wp2))
			continue;
		if (wp2->yoff + wp2->sy + 1 != top)
			continue;
		if (left >= wp2->xoff && left <= wp2->xoff + wp2->sx)
			return (wp2);
	}
	return (NULL);
}

/* Find the pane directly below another. */
struct window_pane *
window_pane_find_down(struct window_pane *wp)
{
	struct window_pane     *wp2;
	u_int			left, bottom;

	if (wp == NULL || !window_pane_visible(wp))
		return (NULL);

	bottom = wp->yoff + wp->sy + 1;
	if (bottom >= wp->window->sy)
		bottom = 0;
	left = wp->xoff;

	TAILQ_FOREACH(wp2, &wp->window->panes, entry) {
		if (!window_pane_visible(wp2))
			continue;
		if (wp2->yoff != bottom)
			continue;
		if (left >= wp2->xoff && left <= wp2->xoff + wp2->sx)
			return (wp2);
	}
	return (NULL);
}

/*
 * Find the pane directly to the left of another, adjacent to the left side and
 * containing the top edge.
 */
struct window_pane *
window_pane_find_left(struct window_pane *wp)
{
	struct window_pane     *wp2;
	u_int			left, top;

	if (wp == NULL || !window_pane_visible(wp))
		return (NULL);

	left = wp->xoff;
	if (left == 0)
		left = wp->window->sx + 1;
	top = wp->yoff;

	TAILQ_FOREACH(wp2, &wp->window->panes, entry) {
		if (!window_pane_visible(wp2))
			continue;
		if (wp2->xoff + wp2->sx + 1 != left)
			continue;
		if (top >= wp2->yoff && top <= wp2->yoff + wp2->sy)
			return (wp2);
	}
	return (NULL);
}

/*
 * Find the pane directly to the right of another, that is adjacent to the
 * right edge and including the top edge.
 */
struct window_pane *
window_pane_find_right(struct window_pane *wp)
{
	struct window_pane     *wp2;
	u_int			right, top;

	if (wp == NULL || !window_pane_visible(wp))
		return (NULL);

	right = wp->xoff + wp->sx + 1;
	if (right >= wp->window->sx)
		right = 0;
	top = wp->yoff;

	TAILQ_FOREACH(wp2, &wp->window->panes, entry) {
		if (!window_pane_visible(wp2))
			continue;
		if (wp2->xoff != right)
			continue;
		if (top >= wp2->yoff && top <= wp2->yoff + wp2->sy)
			return (wp2);
	}
	return (NULL);
}

/* Clear alert flags for a winlink */
void
winlink_clear_flags(struct winlink *wl)
{
	struct winlink	*wm;
	struct session	*s;
	struct window	*w;
	u_int		 i;

	for (i = 0; i < ARRAY_LENGTH(&windows); i++) {
		if ((w = ARRAY_ITEM(&windows, i)) == NULL)
			continue;

		RB_FOREACH(s, sessions, &sessions) {
			if ((wm = session_has(s, w)) == NULL)
				continue;

			if (wm->window != wl->window)
				continue;
			if ((wm->flags & WINLINK_ALERTFLAGS) == 0)
				continue;

			wm->flags &= ~WINLINK_ALERTFLAGS;
			server_status_session(s);
		}
	}
}

/* Set the grid_cell with fg/bg/attr information when window is in a mode. */
void
window_mode_attrs(struct grid_cell *gc, struct options *oo)
{
	memcpy(gc, &grid_default_cell, sizeof *gc);
	colour_set_fg(gc, options_get_number(oo, "mode-fg"));
	colour_set_bg(gc, options_get_number(oo, "mode-bg"));
	gc->attr |= options_get_number(oo, "mode-attr");
}