/* $OpenBSD: resize.c,v 1.54 2026/02/10 10:02:11 nicm Exp $ */

/*
 * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
 *
 * 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 <string.h>

#include "tmux.h"

void
resize_window(struct window *w, u_int sx, u_int sy, int xpixel, int ypixel)
{
        int     zoomed;

        /* Check size limits. */
        if (sx < WINDOW_MINIMUM)
                sx = WINDOW_MINIMUM;
        if (sx > WINDOW_MAXIMUM)
                sx = WINDOW_MAXIMUM;
        if (sy < WINDOW_MINIMUM)
                sy = WINDOW_MINIMUM;
        if (sy > WINDOW_MAXIMUM)
                sy = WINDOW_MAXIMUM;

        /* If the window is zoomed, unzoom. */
        zoomed = w->flags & WINDOW_ZOOMED;
        if (zoomed)
                window_unzoom(w, 1);

        /* Resize the layout first. */
        layout_resize(w, sx, sy);

        /* Resize the window, it can be no smaller than the layout. */
        if (sx < w->layout_root->sx)
                sx = w->layout_root->sx;
        if (sy < w->layout_root->sy)
                sy = w->layout_root->sy;
        window_resize(w, sx, sy, xpixel, ypixel);
        log_debug("%s: @%u resized to %ux%u; layout %ux%u", __func__, w->id,
            sx, sy, w->layout_root->sx, w->layout_root->sy);

        /* Restore the window zoom state. */
        if (zoomed)
                window_zoom(w->active);

        tty_update_window_offset(w);
        server_redraw_window(w);
        notify_window("window-layout-changed", w);
        notify_window("window-resized", w);
        w->flags &= ~WINDOW_RESIZE;
}

static int
ignore_client_size(struct client *c)
{
        struct client   *loop;

        if (c->session == NULL)
                return (1);
        if (c->flags & CLIENT_NOSIZEFLAGS)
                return (1);
        if (c->flags & CLIENT_IGNORESIZE) {
                /*
                 * Ignore flagged clients if there are any attached clients
                 * that aren't flagged.
                 */
                TAILQ_FOREACH (loop, &clients, entry) {
                        if (loop->session == NULL)
                                continue;
                        if (loop->flags & CLIENT_NOSIZEFLAGS)
                                continue;
                        if (~loop->flags & CLIENT_IGNORESIZE)
                                return (1);
                }
        }
        if ((c->flags & CLIENT_CONTROL) &&
            (~c->flags & CLIENT_SIZECHANGED) &&
            (~c->flags & CLIENT_WINDOWSIZECHANGED))
                return (1);
        return (0);
}

static u_int
clients_with_window(struct window *w)
{
        struct client   *loop;
        u_int            n = 0;

        TAILQ_FOREACH(loop, &clients, entry) {
                if (ignore_client_size(loop) || !session_has(loop->session, w))
                        continue;
                if (++n > 1)
                        break;
        }
        return (n);
}

static int
clients_calculate_size(int type, int current, struct client *c,
    struct session *s, struct window *w, int (*skip_client)(struct client *,
    int, int, struct session *, struct window *), u_int *sx, u_int *sy,
    u_int *xpixel, u_int *ypixel)
{
        struct client           *loop;
        struct client_window    *cw;
        u_int                    cx, cy, n = 0;

        /*
         * Start comparing with 0 for largest and UINT_MAX for smallest or
         * latest.
         */
        if (type == WINDOW_SIZE_LARGEST) {
                *sx = 0;
                *sy = 0;
        } else if (w != NULL && type == WINDOW_SIZE_MANUAL) {
                *sx = w->manual_sx;
                *sy = w->manual_sy;
                log_debug("%s: manual size %ux%u", __func__, *sx, *sy);
        } else {
                *sx = UINT_MAX;
                *sy = UINT_MAX;
        }
        *xpixel = *ypixel = 0;

        /*
         * For latest, count the number of clients with this window. We only
         * care if there is more than one.
         */
        if (type == WINDOW_SIZE_LATEST && w != NULL)
                n = clients_with_window(w);

        /* Skip setting the size if manual */
        if (type == WINDOW_SIZE_MANUAL)
                goto skip;

        /* Loop over the clients and work out the size. */
        TAILQ_FOREACH(loop, &clients, entry) {
                if (loop != c && ignore_client_size(loop)) {
                        log_debug("%s: ignoring %s (1)", __func__, loop->name);
                        continue;
                }
                if (loop != c && skip_client(loop, type, current, s, w)) {
                        log_debug("%s: skipping %s (1)", __func__, loop->name);
                        continue;
                }

                /*
                 * If there are multiple clients attached, only accept the
                 * latest client; otherwise let the only client be chosen as
                 * for smallest.
                 */
                if (type == WINDOW_SIZE_LATEST && n > 1 && loop != w->latest) {
                        log_debug("%s: %s is not latest", __func__, loop->name);
                        continue;
                }

                /*
                 * If the client has a per-window size, use this instead if it is
                 * smaller.
                 */
                if (w != NULL)
                        cw = server_client_get_client_window(loop, w->id);
                else
                        cw = NULL;

                /* Work out this client's size. */
                if (cw != NULL && cw->sx != 0 && cw->sy != 0) {
                        cx = cw->sx;
                        cy = cw->sy;
                } else {
                        cx = loop->tty.sx;
                        cy = loop->tty.sy - status_line_size(loop);
                }

                /*
                 * If it is larger or smaller than the best so far, update the
                 * new size.
                 */
                if (type == WINDOW_SIZE_LARGEST) {
                        if (cx > *sx)
                                *sx = cx;
                        if (cy > *sy)
                                *sy = cy;
                } else {
                        if (cx < *sx)
                                *sx = cx;
                        if (cy < *sy)
                                *sy = cy;
                }
                if (loop->tty.xpixel > *xpixel && loop->tty.ypixel > *ypixel) {
                        *xpixel = loop->tty.xpixel;
                        *ypixel = loop->tty.ypixel;
                }
                log_debug("%s: after %s (%ux%u), size is %ux%u", __func__,
                    loop->name, cx, cy, *sx, *sy);
        }
        if (*sx != UINT_MAX && *sy != UINT_MAX)
                log_debug("%s: calculated size %ux%u", __func__, *sx, *sy);
        else
                log_debug("%s: no calculated size", __func__);

skip:
        /*
         * Do not allow any size to be larger than the per-client window size
         * if one exists.
         */
        if (w != NULL) {
                TAILQ_FOREACH(loop, &clients, entry) {
                        if (loop != c && ignore_client_size(loop))
                                continue;
                        if (loop != c && skip_client(loop, type, current, s, w))
                                continue;

                        /* Look up per-window size if any. */
                        if (~loop->flags & CLIENT_WINDOWSIZECHANGED)
                                continue;
                        cw = server_client_get_client_window(loop, w->id);
                        if (cw == NULL)
                                continue;

                        /* Clamp the size. */
                        log_debug("%s: %s size for @%u is %ux%u", __func__,
                            loop->name, w->id, cw->sx, cw->sy);
                        if (cw->sx != 0 && *sx > cw->sx)
                                *sx = cw->sx;
                        if (cw->sy != 0 && *sy > cw->sy)
                                *sy = cw->sy;
                }
        }
        if (*sx != UINT_MAX && *sy != UINT_MAX)
                log_debug("%s: calculated size %ux%u", __func__, *sx, *sy);
        else
                log_debug("%s: no calculated size", __func__);

        /* Return whether a suitable size was found. */
        if (type == WINDOW_SIZE_MANUAL) {
                log_debug("%s: type is manual", __func__);
                return (w != NULL);
        }
        if (type == WINDOW_SIZE_LARGEST) {
                log_debug("%s: type is largest", __func__);
                return (*sx != 0 && *sy != 0);
        }
        if (type == WINDOW_SIZE_LATEST)
                log_debug("%s: type is latest", __func__);
        else
                log_debug("%s: type is smallest", __func__);
        return (*sx != UINT_MAX && *sy != UINT_MAX);
}

static int
default_window_size_skip_client(struct client *loop, __unused int type,
    __unused int current, struct session *s, struct window *w)
{
        if (w != NULL && !session_has(loop->session, w))
                return (1);
        if (w == NULL && loop->session != s)
                return (1);
        return (0);
}

void
default_window_size(struct client *c, struct session *s, struct window *w,
        u_int *sx, u_int *sy, u_int *xpixel, u_int *ypixel, int type)
{
        const char      *value;

        /* Get type if not provided. */
        if (type == -1)
                type = options_get_number(global_w_options, "window-size");

        /*
         * Latest clients can use the given client if suitable. If there is no
         * client and no window, use the default size as for manual type.
         */
        if (type == WINDOW_SIZE_LATEST && c != NULL && !ignore_client_size(c)) {
                *sx = c->tty.sx;
                *sy = c->tty.sy - status_line_size(c);
                *xpixel = c->tty.xpixel;
                *ypixel = c->tty.ypixel;
                log_debug("%s: using %ux%u from %s", __func__, *sx, *sy,
                    c->name);
                goto done;
        }

        /*
         * Ignore the given client if it is a control client - the creating
         * client should only affect the size if it is not a control client.
         */
        if (c != NULL && (c->flags & CLIENT_CONTROL))
                c = NULL;

        /*
         * Look for a client to base the size on. If none exists (or the type
         * is manual), use the default-size option.
         */
        if (!clients_calculate_size(type, 0, c, s, w,
            default_window_size_skip_client, sx, sy, xpixel, ypixel)) {
                value = options_get_string(s->options, "default-size");
                if (sscanf(value, "%ux%u", sx, sy) != 2) {
                        *sx = 80;
                        *sy = 24;
                }
                log_debug("%s: using %ux%u from default-size", __func__, *sx,
                    *sy);
        }

done:
        /* Make sure the limits are enforced. */
        if (*sx < WINDOW_MINIMUM)
                *sx = WINDOW_MINIMUM;
        if (*sx > WINDOW_MAXIMUM)
                *sx = WINDOW_MAXIMUM;
        if (*sy < WINDOW_MINIMUM)
                *sy = WINDOW_MINIMUM;
        if (*sy > WINDOW_MAXIMUM)
                *sy = WINDOW_MAXIMUM;
        log_debug("%s: resulting size is %ux%u", __func__, *sx, *sy);
}

static int
recalculate_size_skip_client(struct client *loop, __unused int type,
    int current, __unused struct session *s, struct window *w)
{
        /*
         * If the current flag is set, then skip any client where this window
         * is not the current window - this is used for aggressive-resize.
         * Otherwise skip any session that doesn't contain the window.
         */
        if (loop->session->curw == NULL)
                return (1);
        if (current)
                return (loop->session->curw->window != w);
        return (session_has(loop->session, w) == 0);
}

void
recalculate_size(struct window *w, int now)
{
        u_int   sx, sy, xpixel = 0, ypixel = 0;
        int     type, current, changed;

        /*
         * Do not attempt to resize windows which have no pane, they must be on
         * the way to destruction.
         */
        if (w->active == NULL)
                return;
        log_debug("%s: @%u is %ux%u", __func__, w->id, w->sx, w->sy);

        /*
         * Type is manual, smallest, largest, latest. Current is the
         * aggressive-resize option (do not resize based on clients where the
         * window is not the current window).
         */
        type = options_get_number(w->options, "window-size");
        current = options_get_number(w->options, "aggressive-resize");

        /* Look for a suitable client and get the new size. */
        changed = clients_calculate_size(type, current, NULL, NULL, w,
            recalculate_size_skip_client, &sx, &sy, &xpixel, &ypixel);

        /*
         * Make sure the size has actually changed. If the window has already
         * got a resize scheduled, then use the new size; otherwise the old.
         */
        if (w->flags & WINDOW_RESIZE) {
                if (!now && changed && w->new_sx == sx && w->new_sy == sy)
                        changed = 0;
        } else {
                if (!now && changed && w->sx == sx && w->sy == sy)
                        changed = 0;
        }

        /*
         * If the size hasn't changed, update the window offset but not the
         * size.
         */
        if (!changed) {
                log_debug("%s: @%u no size change", __func__, w->id);
                tty_update_window_offset(w);
                return;
        }

        /*
         * If the now flag is set or if the window is sized manually, change
         * the size immediately. Otherwise set the flag and it will be done
         * later.
         */
        log_debug("%s: @%u new size %ux%u", __func__, w->id, sx, sy);
        if (now || type == WINDOW_SIZE_MANUAL)
                resize_window(w, sx, sy, xpixel, ypixel);
        else {
                w->new_sx = sx;
                w->new_sy = sy;
                w->new_xpixel = xpixel;
                w->new_ypixel = ypixel;

                w->flags |= WINDOW_RESIZE;
                tty_update_window_offset(w);
        }
}

void
recalculate_sizes(void)
{
        recalculate_sizes_now(0);
}

void
recalculate_sizes_now(int now)
{
        struct session  *s;
        struct client   *c;
        struct window   *w;

        /*
         * Clear attached count and update saved status line information for
         * each session.
         */
        RB_FOREACH(s, sessions, &sessions) {
                s->attached = 0;
                status_update_cache(s);
        }

        /*
         * Increment attached count and check the status line size for each
         * client.
         */
        TAILQ_FOREACH(c, &clients, entry) {
                s = c->session;
                if (s != NULL && !(c->flags & CLIENT_UNATTACHEDFLAGS))
                        s->attached++;
                if (ignore_client_size(c))
                        continue;
                if (c->tty.sy <= s->statuslines || (c->flags & CLIENT_CONTROL))
                        c->flags |= CLIENT_STATUSOFF;
                else
                        c->flags &= ~CLIENT_STATUSOFF;
        }

        /* Walk each window and adjust the size. */
        RB_FOREACH(w, windows, &windows)
                recalculate_size(w, now);
}