/* $OpenBSD: server-fn.c,v 1.149 2026/07/27 14:25:46 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 <sys/queue.h>
#include <sys/wait.h>
#include <sys/uio.h>

#include <imsg.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "tmux.h"

static void     server_destroy_session_group(struct session *);
static void     server_fire_pane_exit(const char *, struct window_pane *);

static void
server_fire_pane_exit(const char *name, struct window_pane *wp)
{
        struct event_payload    *ep;
        struct cmd_find_state    fs;
        int                      status = wp->status;
        const char              *signame;

        if (WIFSIGNALED(status))
                signame = sig2name(WTERMSIG(status));

        ep = event_payload_create();
        cmd_find_from_pane(&fs, wp, 0);
        event_payload_set_target(ep, &fs);
        event_payload_set_pane(ep, "pane", wp);
        event_payload_set_window(ep, "window", wp->window);
        if (WIFEXITED(status))
                event_payload_set_int(ep, "exit_status", WEXITSTATUS(status));
        else if (WIFSIGNALED(status))
                event_payload_set_string(ep, "exit_signal", "%s", signame);
        event_payload_set_int(ep, "exit_success", status == 0);
        events_fire(name, ep);
}

void
server_redraw_client(struct client *c)
{
        c->flags |= CLIENT_ALLREDRAWFLAGS;
}

void
server_status_client(struct client *c)
{
        c->flags |= CLIENT_REDRAWSTATUS;
}

void
server_redraw_session(struct session *s)
{
        struct client   *c;

        TAILQ_FOREACH(c, &clients, entry) {
                if (c->session == s)
                        server_redraw_client(c);
        }
}

void
server_redraw_session_group(struct session *s)
{
        struct session_group    *sg;

        if ((sg = session_group_contains(s)) == NULL)
                server_redraw_session(s);
        else {
                TAILQ_FOREACH(s, &sg->sessions, gentry)
                        server_redraw_session(s);
        }
}

void
server_status_session(struct session *s)
{
        struct client   *c;

        TAILQ_FOREACH(c, &clients, entry) {
                if (c->session == s)
                        server_status_client(c);
        }
}

void
server_status_session_group(struct session *s)
{
        struct session_group    *sg;

        if ((sg = session_group_contains(s)) == NULL)
                server_status_session(s);
        else {
                TAILQ_FOREACH(s, &sg->sessions, gentry)
                        server_status_session(s);
        }
}

void
server_redraw_window(struct window *w)
{
        struct client   *c;

        TAILQ_FOREACH(c, &clients, entry) {
                if (c->session != NULL &&
                    c->session->curw != NULL &&
                    c->session->curw->window == w)
                        server_redraw_client(c);
        }
}

void
server_redraw_window_menu(struct window *w)
{
        struct client   *c;

        TAILQ_FOREACH(c, &clients, entry) {
                if (c->session != NULL &&
                    c->session->curw != NULL &&
                    c->session->curw->window == w)
                        c->flags |= CLIENT_REDRAWMENU;
        }
}

void
server_redraw_window_borders(struct window *w)
{
        struct client   *c;

        TAILQ_FOREACH(c, &clients, entry) {
                if (c->session != NULL &&
                    c->session->curw != NULL &&
                    c->session->curw->window == w)
                        c->flags |= CLIENT_REDRAWBORDERS;
        }
}

void
server_status_window(struct window *w)
{
        struct session  *s;

        /*
         * This is slightly different. We want to redraw the status line of any
         * clients containing this window rather than anywhere it is the
         * current window.
         */

        RB_FOREACH(s, sessions, &sessions) {
                if (session_has(s, w))
                        server_status_session(s);
        }
}

void
server_lock(void)
{
        struct client   *c;

        TAILQ_FOREACH(c, &clients, entry) {
                if (c->session != NULL)
                        server_lock_client(c);
        }
}

void
server_lock_session(struct session *s)
{
        struct client   *c;

        TAILQ_FOREACH(c, &clients, entry) {
                if (c->session == s)
                        server_lock_client(c);
        }
}

void
server_lock_client(struct client *c)
{
        const char      *cmd;

        if (c->flags & CLIENT_CONTROL)
                return;

        if (c->flags & CLIENT_SUSPENDED)
                return;

        cmd = options_get_string(c->session->options, "lock-command");
        if (*cmd == '\0' || strlen(cmd) + 1 > MAX_IMSGSIZE - IMSG_HEADER_SIZE)
                return;

        tty_stop_tty(&c->tty);
        tty_raw(&c->tty, tty_term_string(c->tty.term, TTYC_SMCUP));
        tty_raw(&c->tty, tty_term_string(c->tty.term, TTYC_CLEAR));
        tty_raw(&c->tty, tty_term_string(c->tty.term, TTYC_E3));

        c->flags |= CLIENT_SUSPENDED;
        proc_send(c->peer, MSG_LOCK, -1, cmd, strlen(cmd) + 1);
}

void
server_kill_pane(struct window_pane *wp)
{
        struct window   *w = wp->window;

        if (window_count_panes(w, 1) == 1) {
                server_kill_window(w, 1);
                recalculate_sizes();
        } else {
                server_unzoom_window(w);
                server_client_remove_pane(wp);
                layout_close_pane(wp);
                window_remove_pane(w, wp);
                server_redraw_window(w);
        }
}

void
server_kill_window(struct window *w, int renumber)
{
        struct session  *s, *s1;
        struct winlink  *wl;

        window_add_ref(w, __func__);
        RB_FOREACH_SAFE(s, sessions, &sessions, s1) {
                if (!session_has(s, w))
                        continue;

                server_unzoom_window(w);
                while ((wl = winlink_find_by_window(&s->windows, w)) != NULL) {
                        if (session_detach(s, wl)) {
                                server_destroy_session_group(s);
                                break;
                        }
                        server_redraw_session_group(s);
                }

                if (renumber)
                        server_renumber_session(s);
        }
        recalculate_sizes();
        window_remove_ref(w, __func__);
}

void
server_renumber_session(struct session *s)
{
        struct session_group    *sg;

        if (options_get_number(s->options, "renumber-windows")) {
                if ((sg = session_group_contains(s)) != NULL) {
                        TAILQ_FOREACH(s, &sg->sessions, gentry)
                            session_renumber_windows(s);
                } else
                        session_renumber_windows(s);
        }
}

void
server_renumber_all(void)
{
        struct session  *s;

        RB_FOREACH(s, sessions, &sessions)
                server_renumber_session(s);
}

int
server_link_window(struct session *src, struct winlink *srcwl,
    struct session *dst, int dstidx, int killflag, int selectflag,
    char **cause)
{
        struct winlink          *dstwl;
        struct session_group    *srcsg, *dstsg;

        srcsg = session_group_contains(src);
        dstsg = session_group_contains(dst);
        if (src != dst && srcsg != NULL && dstsg != NULL && srcsg == dstsg) {
                xasprintf(cause, "sessions are grouped");
                return (-1);
        }

        dstwl = NULL;
        if (dstidx != -1)
                dstwl = winlink_find_by_index(&dst->windows, dstidx);
        if (dstwl != NULL) {
                if (dstwl->window == srcwl->window) {
                        xasprintf(cause, "same index: %d", dstidx);
                        return (-1);
                }
                if (killflag) {
                        /*
                         * Can't use session_detach as it will destroy session
                         * if this makes it empty.
                         */
                        events_fire_winlink("window-unlinked", dstwl);
                        dstwl->flags &= ~WINLINK_ALERTFLAGS;
                        winlink_stack_remove(&dst->lastw, dstwl);
                        winlink_remove(&dst->windows, dstwl);

                        /* Force select/redraw if current. */
                        if (dstwl == dst->curw) {
                                selectflag = 1;
                                dst->curw = NULL;
                        }
                }
        }

        if (dstidx == -1)
                dstidx = -1 - options_get_number(dst->options, "base-index");
        dstwl = session_attach(dst, srcwl->window, dstidx, cause);
        if (dstwl == NULL)
                return (-1);

        if (marked_pane.wl == srcwl)
                marked_pane.wl = dstwl;
        if (selectflag)
                session_select(dst, dstwl->idx);
        server_redraw_session_group(dst);

        return (0);
}

void
server_unlink_window(struct session *s, struct winlink *wl)
{
        if (session_detach(s, wl))
                server_destroy_session_group(s);
        else
                server_redraw_session_group(s);
}

void
server_destroy_pane(struct window_pane *wp, int notify)
{
        struct window           *w = wp->window;
        struct screen_write_ctx  ctx;
        struct grid_cell         gc;
        int                      remain_on_exit;
        const char              *s;
        char                    *expanded;
        u_int                    sx = screen_size_x(&wp->base);
        u_int                    sy = screen_size_y(&wp->base);

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

        remain_on_exit = options_get_number(wp->options, "remain-on-exit");
        if (remain_on_exit != 0 && (~wp->flags & PANE_STATUSREADY))
                return;
        switch (remain_on_exit) {
        case 0:
                break;
        case 2:
                if (WIFEXITED(wp->status) && WEXITSTATUS(wp->status) == 0)
                        break;
                /* FALLTHROUGH */
        case 1:
        case 3:
                if (wp->flags & PANE_STATUSDRAWN)
                        return;
                wp->flags |= PANE_STATUSDRAWN;

                gettimeofday(&wp->dead_time, NULL);
                if (notify)
                        server_fire_pane_exit("pane-died", wp);

                s = options_get_string(wp->options, "remain-on-exit-format");
                if (*s != '\0') {
                        screen_write_start_pane(&ctx, wp, &wp->base);
                        screen_write_scrollregion(&ctx, 0, sy - 1);
                        screen_write_cursormove(&ctx, 0, sy - 1, 0);
                        screen_write_linefeed(&ctx, 1, 8);
                        memcpy(&gc, &grid_default_cell, sizeof gc);

                        expanded = format_single(NULL, s, NULL, NULL, NULL, wp);
                        format_draw(&ctx, &gc, sx, expanded, NULL, 0);
                        free(expanded);

                        screen_write_stop(&ctx);
                }
                wp->base.mode &= ~MODE_CURSOR;

                wp->flags |= PANE_REDRAW;
                return;
        }

        if (notify)
                server_fire_pane_exit("pane-exited", wp);

        server_unzoom_window(w);
        server_client_remove_pane(wp);
        layout_close_pane(wp);
        window_remove_pane(w, wp);

        if (TAILQ_EMPTY(&w->panes))
                server_kill_window(w, 1);
        else
                server_redraw_window(w);
}

static void
server_destroy_session_group(struct session *s)
{
        struct session_group    *sg;
        struct session          *s1;

        if ((sg = session_group_contains(s)) == NULL) {
                server_destroy_session(s);
                session_destroy(s, 1, __func__);
        } else {
                TAILQ_FOREACH_SAFE(s, &sg->sessions, gentry, s1) {
                        server_destroy_session(s);
                        session_destroy(s, 1, __func__);
                }
        }
}

static struct session *
server_find_session(struct session *s,
    int (*f)(struct session *, struct session *))
{
        struct session *s_loop, *s_out = NULL;

        RB_FOREACH(s_loop, sessions, &sessions) {
                if (s_loop != s && f(s_loop, s_out))
                        s_out = s_loop;
        }
        return (s_out);
}

static int
server_newer_session(struct session *s_loop, struct session *s_out)
{
        if (s_out == NULL)
                return (1);
        return (timercmp(&s_loop->activity_time, &s_out->activity_time, >));
}

static int
server_newer_detached_session(struct session *s_loop, struct session *s_out)
{
        if (s_loop->attached)
                return (0);
        return (server_newer_session(s_loop, s_out));
}

void
server_destroy_session(struct session *s)
{
        struct client   *c;
        struct session  *s_new = NULL, *cs_new = NULL, *use_s;
        struct sort_criteria     sort_crit = { .order = SORT_NAME };
        int              detach_on_destroy;

        detach_on_destroy = options_get_number(s->options, "detach-on-destroy");
        if (detach_on_destroy == 0)
                s_new = server_find_session(s, server_newer_session);
        else if (detach_on_destroy == 2)
                s_new = server_find_session(s, server_newer_detached_session);
        else if (detach_on_destroy == 3)
                s_new = session_previous_session(s, &sort_crit);
        else if (detach_on_destroy == 4)
                s_new = session_next_session(s, &sort_crit);
        if (s_new == s)
                s_new = NULL;

        /*
         * If no suitable new session was found above, then look for any
         * session as an alternative in case a client needs it.
         */
        if (s_new == NULL &&
            (detach_on_destroy == 1 || detach_on_destroy == 2))
                cs_new = server_find_session(s, server_newer_session);

        TAILQ_FOREACH(c, &clients, entry) {
                if (c->session != s)
                        continue;
                use_s = s_new;
                if (use_s == NULL && (c->flags & CLIENT_NO_DETACH_ON_DESTROY))
                        use_s = cs_new;

                c->session = NULL;
                c->last_session = NULL;
                server_client_set_session(c, use_s);
                if (use_s == NULL)
                        c->flags |= CLIENT_EXIT;
        }
        recalculate_sizes();
}

void
server_check_unattached(void)
{
        struct session          *s;
        struct session_group    *sg;

        /*
         * If any sessions are no longer attached and have destroy-unattached
         * set, collect them.
         */
        RB_FOREACH(s, sessions, &sessions) {
                if (s->attached != 0)
                        continue;
                switch (options_get_number(s->options, "destroy-unattached")) {
                case 0: /* off */
                        continue;
                case 1: /* on */
                        break;
                case 2: /* keep-last */
                        sg = session_group_contains(s);
                        if (sg == NULL || session_group_count(sg) <= 1)
                                continue;
                        break;
                case 3: /* keep-group */
                        sg = session_group_contains(s);
                        if (sg != NULL && session_group_count(sg) == 1)
                                continue;
                        break;
                }
                session_destroy(s, 1, __func__);
        }
}

void
server_unzoom_window(struct window *w)
{
        if (window_unzoom(w, 1) == 0)
                server_redraw_window(w);
}