/* $OpenBSD: cmd-find.c,v 1.87 2026/07/17 12:42:51 nicm Exp $ */

/*
 * Copyright (c) 2015 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 <fnmatch.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <paths.h>
#include <unistd.h>

#include "tmux.h"

static int      cmd_find_session_better(struct session *, struct session *,
                    int);
static struct session *cmd_find_best_session(struct session **, u_int, int);
static int      cmd_find_best_session_with_window(struct cmd_find_state *);
static int      cmd_find_best_winlink_with_window(struct cmd_find_state *);

static const char *cmd_find_map_table(const char *[][2], const char *);

static void     cmd_find_log_state(const char *, struct cmd_find_state *);
static int      cmd_find_get_session(struct cmd_find_state *, const char *);
static int      cmd_find_get_window(struct cmd_find_state *, const char *, int);
static int      cmd_find_get_window_with_session(struct cmd_find_state *,
                    const char *);
static int      cmd_find_get_pane(struct cmd_find_state *, const char *, int);
static int      cmd_find_get_pane_with_session(struct cmd_find_state *,
                    const char *);
static int      cmd_find_get_pane_with_window(struct cmd_find_state *,
                    const char *);

static const char *cmd_find_session_table[][2] = {
        { NULL, NULL }
};
static const char *cmd_find_window_table[][2] = {
        { "{start}", "^" },
        { "{last}", "!" },
        { "{end}", "$" },
        { "{next}", "+" },
        { "{previous}", "-" },
        { NULL, NULL }
};
static const char *cmd_find_pane_table[][2] = {
        { "{last}", "!" },
        { "{next}", "+" },
        { "{previous}", "-" },
        { "{top}", "top" },
        { "{bottom}", "bottom" },
        { "{left}", "left" },
        { "{right}", "right" },
        { "{top-left}", "top-left" },
        { "{top-right}", "top-right" },
        { "{bottom-left}", "bottom-left" },
        { "{bottom-right}", "bottom-right" },
        { "{up-of}", "{up-of}" },
        { "{down-of}", "{down-of}" },
        { "{left-of}", "{left-of}" },
        { "{right-of}", "{right-of}" },
        { NULL, NULL }
};

/* Find pane containing client if any. */
static struct window_pane *
cmd_find_inside_pane(struct client *c)
{
        struct window_pane      *wp;
        struct environ_entry    *envent;

        if (c == NULL)
                return (NULL);

        RB_FOREACH(wp, window_pane_tree, &all_window_panes) {
                if (wp->fd != -1 && strcmp(wp->tty, c->ttyname) == 0)
                        break;
        }
        if (wp == NULL) {
                envent = environ_find(c->environ, "TMUX_PANE");
                if (envent != NULL)
                        wp = window_pane_find_by_id_str(envent->value);
        }
        if (wp != NULL)
                log_debug("%s: got pane %%%u (%s)", __func__, wp->id, wp->tty);
        return (wp);
}

/* Is this client better? */
static int
cmd_find_client_better(struct client *c, struct client *than)
{
        if (than == NULL)
                return (1);
        return (timercmp(&c->activity_time, &than->activity_time, >));
}

/* Find best client for session. */
struct client *
cmd_find_best_client(struct session *s)
{
        struct client   *c_loop, *c;

        if (s->attached == 0)
                s = NULL;

        c = NULL;
        TAILQ_FOREACH(c_loop, &clients, entry) {
                if (c_loop->session == NULL)
                        continue;
                if (s != NULL && c_loop->session != s)
                        continue;
                if (cmd_find_client_better(c_loop, c))
                        c = c_loop;
        }
        return (c);
}

/* Is this session better? */
static int
cmd_find_session_better(struct session *s, struct session *than, int flags)
{
        int     attached;

        if (than == NULL)
                return (1);
        if (flags & CMD_FIND_PREFER_UNATTACHED) {
                attached = (than->attached != 0);
                if (attached && s->attached == 0)
                        return (1);
                else if (!attached && s->attached != 0)
                        return (0);
        }
        return (timercmp(&s->activity_time, &than->activity_time, >));
}

/* Can this session be usefully targeted? */
static int
cmd_find_session_valid(struct session *s)
{
        if (!session_alive(s) ||
            s->curw == NULL ||
            s->curw->window == NULL ||
            s->curw->window->active == NULL)
                return (0);
        return (1);
}

/* Find best session from a list, or all if list is NULL. */
static struct session *
cmd_find_best_session(struct session **slist, u_int ssize, int flags)
{
        struct session   *s_loop, *s;
        u_int             i;

        log_debug("%s: %u sessions to try", __func__, ssize);

        s = NULL;
        if (slist != NULL) {
                for (i = 0; i < ssize; i++) {
                        if (!cmd_find_session_valid(slist[i]))
                                continue;
                        if (cmd_find_session_better(slist[i], s, flags))
                                s = slist[i];
                }
        } else {
                RB_FOREACH(s_loop, sessions, &sessions) {
                        if (!cmd_find_session_valid(s_loop))
                                continue;
                        if (cmd_find_session_better(s_loop, s, flags))
                                s = s_loop;
                }
        }
        return (s);
}

/* Find best session and winlink for window. */
static int
cmd_find_best_session_with_window(struct cmd_find_state *fs)
{
        struct session  **slist = NULL;
        u_int             ssize;
        struct session   *s;

        log_debug("%s: window is @%u", __func__, fs->w->id);

        ssize = 0;
        RB_FOREACH(s, sessions, &sessions) {
                if (!session_has(s, fs->w))
                        continue;
                slist = xreallocarray(slist, ssize + 1, sizeof *slist);
                slist[ssize++] = s;
        }
        if (ssize == 0)
                goto fail;
        fs->s = cmd_find_best_session(slist, ssize, fs->flags);
        if (fs->s == NULL)
                goto fail;
        free(slist);
        return (cmd_find_best_winlink_with_window(fs));

fail:
        free(slist);
        return (-1);
}

/*
 * Find the best winlink for a window (the current if it contains the window,
 * otherwise the first).
 */
static int
cmd_find_best_winlink_with_window(struct cmd_find_state *fs)
{
        struct winlink   *wl, *wl_loop;

        log_debug("%s: window is @%u", __func__, fs->w->id);

        wl = NULL;
        if (fs->s->curw != NULL && fs->s->curw->window == fs->w)
                wl = fs->s->curw;
        else {
                RB_FOREACH(wl_loop, winlinks, &fs->s->windows) {
                        if (wl_loop->window == fs->w) {
                                wl = wl_loop;
                                break;
                        }
                }
        }
        if (wl == NULL)
                return (-1);
        fs->wl = wl;
        fs->idx = fs->wl->idx;
        return (0);
}

/* Maps string in table. */
static const char *
cmd_find_map_table(const char *table[][2], const char *s)
{
        u_int   i;

        for (i = 0; table[i][0] != NULL; i++) {
                if (strcmp(s, table[i][0]) == 0)
                        return (table[i][1]);
        }
        return (s);
}

/* Find session from string. Fills in s. */
static int
cmd_find_get_session(struct cmd_find_state *fs, const char *session)
{
        struct session  *s, *s_loop;
        struct client   *c;

        log_debug("%s: %s", __func__, session);

        /* Check for session ids starting with $. */
        if (*session == '$') {
                fs->s = session_find_by_id_str(session);
                if (fs->s == NULL)
                        return (-1);
                return (0);
        }

        /* Look for exactly this session. */
        fs->s = session_find(session);
        if (fs->s != NULL)
                return (0);

        /* Look for as a client. */
        c = cmd_find_client(NULL, session, 1);
        if (c != NULL && c->session != NULL) {
                fs->s = c->session;
                return (0);
        }

        /* Stop now if exact only. */
        if (fs->flags & CMD_FIND_EXACT_SESSION)
                return (-1);

        /* Otherwise look for prefix. */
        s = NULL;
        RB_FOREACH(s_loop, sessions, &sessions) {
                if (strncmp(session, s_loop->name, strlen(session)) == 0) {
                        if (s != NULL)
                                return (-1);
                        s = s_loop;
                }
        }
        if (s != NULL) {
                fs->s = s;
                return (0);
        }

        /* Then as a pattern. */
        s = NULL;
        RB_FOREACH(s_loop, sessions, &sessions) {
                if (fnmatch(session, s_loop->name, 0) == 0) {
                        if (s != NULL)
                                return (-1);
                        s = s_loop;
                }
        }
        if (s != NULL) {
                fs->s = s;
                return (0);
        }

        return (-1);
}

/* Find window from string. Fills in s, wl, w. */
static int
cmd_find_get_window(struct cmd_find_state *fs, const char *window, int only)
{
        log_debug("%s: %s", __func__, window);

        /* Check for window ids starting with @. */
        if (*window == '@') {
                fs->w = window_find_by_id_str(window);
                if (fs->w == NULL)
                        return (-1);
                return (cmd_find_best_session_with_window(fs));
        }

        /* Not a window id, so use the current session. */
        fs->s = fs->current->s;

        /* We now only need to find the winlink in this session. */
        if (cmd_find_get_window_with_session(fs, window) == 0)
                return (0);

        /* Otherwise try as a session itself. */
        if (!only && cmd_find_get_session(fs, window) == 0) {
                fs->wl = fs->s->curw;
                fs->w = fs->wl->window;
                if (~fs->flags & CMD_FIND_WINDOW_INDEX)
                        fs->idx = fs->wl->idx;
                return (0);
        }

        return (-1);
}

/*
 * Find window from string, assuming it is in given session. Needs s, fills in
 * wl and w.
 */
static int
cmd_find_get_window_with_session(struct cmd_find_state *fs, const char *window)
{
        struct winlink  *wl;
        const char      *errstr;
        int              idx, n, exact;
        struct session  *s;

        log_debug("%s: %s", __func__, window);
        exact = (fs->flags & CMD_FIND_EXACT_WINDOW);

        /*
         * Start with the current window as the default. So if only an index is
         * found, the window will be the current.
         */
        fs->wl = fs->s->curw;
        fs->w = fs->wl->window;

        /* Check for window ids starting with @. */
        if (*window == '@') {
                fs->w = window_find_by_id_str(window);
                if (fs->w == NULL || !session_has(fs->s, fs->w))
                        return (-1);
                return (cmd_find_best_winlink_with_window(fs));
        }

        /* Try as an offset. */
        if (!exact && (window[0] == '+' || window[0] == '-')) {
                if (window[1] != '\0')
                        n = strtonum(window + 1, 1, INT_MAX, NULL);
                else
                        n = 1;
                s = fs->s;
                if (fs->flags & CMD_FIND_WINDOW_INDEX) {
                        if (window[0] == '+') {
                                if (INT_MAX - s->curw->idx < n)
                                        return (-1);
                                fs->idx = s->curw->idx + n;
                        } else {
                                if (n > s->curw->idx)
                                        return (-1);
                                fs->idx = s->curw->idx - n;
                        }
                        return (0);
                }
                if (window[0] == '+')
                        fs->wl = winlink_next_by_number(s->curw, s, n);
                else
                        fs->wl = winlink_previous_by_number(s->curw, s, n);
                if (fs->wl != NULL) {
                        fs->idx = fs->wl->idx;
                        fs->w = fs->wl->window;
                        return (0);
                }
        }

        /* Try special characters. */
        if (!exact) {
                if (strcmp(window, "!") == 0) {
                        fs->wl = TAILQ_FIRST(&fs->s->lastw);
                        if (fs->wl == NULL)
                                return (-1);
                        fs->idx = fs->wl->idx;
                        fs->w = fs->wl->window;
                        return (0);
                } else if (strcmp(window, "^") == 0) {
                        fs->wl = RB_MIN(winlinks, &fs->s->windows);
                        if (fs->wl == NULL)
                                return (-1);
                        fs->idx = fs->wl->idx;
                        fs->w = fs->wl->window;
                        return (0);
                } else if (strcmp(window, "$") == 0) {
                        fs->wl = RB_MAX(winlinks, &fs->s->windows);
                        if (fs->wl == NULL)
                                return (-1);
                        fs->idx = fs->wl->idx;
                        fs->w = fs->wl->window;
                        return (0);
                }
        }

        /* First see if this is a valid window index in this session. */
        if (window[0] != '+' && window[0] != '-') {
                idx = strtonum(window, 0, INT_MAX, &errstr);
                if (errstr == NULL) {
                        fs->wl = winlink_find_by_index(&fs->s->windows, idx);
                        if (fs->wl != NULL) {
                                fs->idx = fs->wl->idx;
                                fs->w = fs->wl->window;
                                return (0);
                        }
                        if (fs->flags & CMD_FIND_WINDOW_INDEX) {
                                fs->idx = idx;
                                return (0);
                        }
                }
        }

        /* Look for exact matches, error if more than one. */
        fs->wl = NULL;
        RB_FOREACH(wl, winlinks, &fs->s->windows) {
                if (strcmp(window, wl->window->name) == 0) {
                        if (fs->wl != NULL)
                                return (-1);
                        fs->wl = wl;
                }
        }
        if (fs->wl != NULL) {
                fs->idx = fs->wl->idx;
                fs->w = fs->wl->window;
                return (0);
        }

        /* Stop now if exact only. */
        if (exact)
                return (-1);

        /* Try as the start of a window name, error if multiple. */
        fs->wl = NULL;
        RB_FOREACH(wl, winlinks, &fs->s->windows) {
                if (strncmp(window, wl->window->name, strlen(window)) == 0) {
                        if (fs->wl != NULL)
                                return (-1);
                        fs->wl = wl;
                }
        }
        if (fs->wl != NULL) {
                fs->idx = fs->wl->idx;
                fs->w = fs->wl->window;
                return (0);
        }

        /* Now look for pattern matches, again error if multiple. */
        fs->wl = NULL;
        RB_FOREACH(wl, winlinks, &fs->s->windows) {
                if (fnmatch(window, wl->window->name, 0) == 0) {
                        if (fs->wl != NULL)
                                return (-1);
                        fs->wl = wl;
                }
        }
        if (fs->wl != NULL) {
                fs->idx = fs->wl->idx;
                fs->w = fs->wl->window;
                return (0);
        }

        return (-1);
}

/* Find pane from string. Fills in s, wl, w, wp. */
static int
cmd_find_get_pane(struct cmd_find_state *fs, const char *pane, int only)
{
        log_debug("%s: %s", __func__, pane);

        /* Check for pane ids starting with %. */
        if (*pane == '%') {
                fs->wp = window_pane_find_by_id_str(pane);
                if (fs->wp == NULL)
                        return (-1);
                fs->w = fs->wp->window;
                return (cmd_find_best_session_with_window(fs));
        }

        /* Not a pane id, so try the current session and window. */
        fs->s = fs->current->s;
        fs->wl = fs->current->wl;
        fs->idx = fs->current->idx;
        fs->w = fs->current->w;

        /* We now only need to find the pane in this window. */
        if (cmd_find_get_pane_with_window(fs, pane) == 0)
                return (0);

        /* Otherwise try as a window itself (this will also try as session). */
        if (!only && cmd_find_get_window(fs, pane, 0) == 0) {
                fs->wp = fs->w->active;
                return (0);
        }

        return (-1);
}

/*
 * Find pane from string, assuming it is in given session. Needs s, fills in wl
 * and w and wp.
 */
static int
cmd_find_get_pane_with_session(struct cmd_find_state *fs, const char *pane)
{
        log_debug("%s: %s", __func__, pane);

        /* Check for pane ids starting with %. */
        if (*pane == '%') {
                fs->wp = window_pane_find_by_id_str(pane);
                if (fs->wp == NULL)
                        return (-1);
                fs->w = fs->wp->window;
                return (cmd_find_best_winlink_with_window(fs));
        }

        /* Otherwise use the current window. */
        fs->wl = fs->s->curw;
        fs->idx = fs->wl->idx;
        fs->w = fs->wl->window;

        /* Now we just need to look up the pane. */
        return (cmd_find_get_pane_with_window(fs, pane));
}

/*
 * Find pane from string, assuming it is in the given window. Needs w, fills in
 * wp.
 */
static int
cmd_find_get_pane_with_window(struct cmd_find_state *fs, const char *pane)
{
        const char              *errstr;
        int                      idx;
        struct window_pane      *wp;
        u_int                    n;

        log_debug("%s: %s", __func__, pane);

        /* Check for pane ids starting with %. */
        if (*pane == '%') {
                fs->wp = window_pane_find_by_id_str(pane);
                if (fs->wp == NULL)
                        return (-1);
                if (fs->wp->window != fs->w)
                        return (-1);
                return (0);
        }

        /* Try special characters. */
        if (strcmp(pane, "!") == 0) {
                fs->wp = TAILQ_FIRST(&fs->w->last_panes);
                if (fs->wp == NULL)
                        return (-1);
                return (0);
        } else if (strcmp(pane, "{up-of}") == 0) {
                fs->wp = window_pane_find_up(fs->w->active);
                if (fs->wp == NULL)
                        return (-1);
                return (0);
        } else if (strcmp(pane, "{down-of}") == 0) {
                fs->wp = window_pane_find_down(fs->w->active);
                if (fs->wp == NULL)
                        return (-1);
                return (0);
        } else if (strcmp(pane, "{left-of}") == 0) {
                fs->wp = window_pane_find_left(fs->w->active);
                if (fs->wp == NULL)
                        return (-1);
                return (0);
        } else if (strcmp(pane, "{right-of}") == 0) {
                fs->wp = window_pane_find_right(fs->w->active);
                if (fs->wp == NULL)
                        return (-1);
                return (0);
        }

        /* Try as an offset. */
        if (pane[0] == '+' || pane[0] == '-') {
                if (pane[1] != '\0')
                        n = strtonum(pane + 1, 1, INT_MAX, NULL);
                else
                        n = 1;
                wp = fs->w->active;
                if (pane[0] == '+')
                        fs->wp = window_pane_next_by_number(fs->w, wp, n);
                else
                        fs->wp = window_pane_previous_by_number(fs->w, wp, n);
                if (fs->wp != NULL)
                        return (0);
        }

        /* Get pane by index. */
        idx = strtonum(pane, 0, INT_MAX, &errstr);
        if (errstr == NULL) {
                fs->wp = window_pane_at_index(fs->w, idx);
                if (fs->wp != NULL)
                        return (0);
        }

        /* Try as a description. */
        fs->wp = window_find_string(fs->w, pane);
        if (fs->wp != NULL)
                return (0);

        return (-1);
}

/* Clear state. */
void
cmd_find_clear_state(struct cmd_find_state *fs, int flags)
{
        memset(fs, 0, sizeof *fs);

        fs->flags = flags;

        fs->idx = -1;
}

/* Check if state is empty. */
int
cmd_find_empty_state(struct cmd_find_state *fs)
{
        if (fs->s == NULL && fs->wl == NULL && fs->w == NULL && fs->wp == NULL)
                return (1);
        return (0);
}

/* Check if a state if valid. */
int
cmd_find_valid_state(struct cmd_find_state *fs)
{
        struct winlink  *wl;

        if (fs->s == NULL || fs->wl == NULL || fs->w == NULL || fs->wp == NULL)
                return (0);

        if (!session_alive(fs->s))
                return (0);

        RB_FOREACH(wl, winlinks, &fs->s->windows) {
                if (wl->window == fs->w && wl == fs->wl)
                        break;
        }
        if (wl == NULL)
                return (0);

        if (fs->w != fs->wl->window)
                return (0);

        return (window_has_pane(fs->w, fs->wp));
}

/* Copy a state. */
void
cmd_find_copy_state(struct cmd_find_state *dst, struct cmd_find_state *src)
{
        dst->s = src->s;
        dst->wl = src->wl;
        dst->idx = src->idx;
        dst->w = src->w;
        dst->wp = src->wp;
}

/* Log the result. */
static void
cmd_find_log_state(const char *prefix, struct cmd_find_state *fs)
{
        if (fs->s != NULL)
                log_debug("%s: s=$%u %s", prefix, fs->s->id, fs->s->name);
        else
                log_debug("%s: s=none", prefix);
        if (fs->wl != NULL) {
                log_debug("%s: wl=%u %d w=@%u %s", prefix, fs->wl->idx,
                    fs->wl->window == fs->w, fs->w->id, fs->w->name);
        } else
                log_debug("%s: wl=none", prefix);
        if (fs->wp != NULL)
                log_debug("%s: wp=%%%u", prefix, fs->wp->id);
        else
                log_debug("%s: wp=none", prefix);
        if (fs->idx != -1)
                log_debug("%s: idx=%d", prefix, fs->idx);
        else
                log_debug("%s: idx=none", prefix);
}

/* Find state from a session. */
void
cmd_find_from_session(struct cmd_find_state *fs, struct session *s, int flags)
{
        cmd_find_clear_state(fs, flags);

        fs->s = s;
        fs->wl = fs->s->curw;
        fs->w = fs->wl->window;
        fs->wp = fs->w->active;

        cmd_find_log_state(__func__, fs);
}

/* Find state from a winlink. */
void
cmd_find_from_winlink(struct cmd_find_state *fs, struct winlink *wl, int flags)
{
        cmd_find_clear_state(fs, flags);

        fs->s = wl->session;
        fs->wl = wl;
        fs->w = wl->window;
        fs->wp = wl->window->active;

        cmd_find_log_state(__func__, fs);
}

/* Find state from a session and window. */
int
cmd_find_from_session_window(struct cmd_find_state *fs, struct session *s,
    struct window *w, int flags)
{
        cmd_find_clear_state(fs, flags);

        fs->s = s;
        fs->w = w;
        if (cmd_find_best_winlink_with_window(fs) != 0) {
                cmd_find_clear_state(fs, flags);
                return (-1);
        }
        fs->wp = fs->w->active;

        cmd_find_log_state(__func__, fs);
        return (0);
}

/* Find state from a window. */
int
cmd_find_from_window(struct cmd_find_state *fs, struct window *w, int flags)
{
        cmd_find_clear_state(fs, flags);

        fs->w = w;
        if (cmd_find_best_session_with_window(fs) != 0) {
                cmd_find_clear_state(fs, flags);
                return (-1);
        }
        if (cmd_find_best_winlink_with_window(fs) != 0) {
                cmd_find_clear_state(fs, flags);
                return (-1);
        }
        fs->wp = fs->w->active;

        cmd_find_log_state(__func__, fs);
        return (0);
}

/* Find state from a winlink and pane. */
void
cmd_find_from_winlink_pane(struct cmd_find_state *fs, struct winlink *wl,
    struct window_pane *wp, int flags)
{
        cmd_find_clear_state(fs, flags);

        fs->s = wl->session;
        fs->wl = wl;
        fs->idx = fs->wl->idx;
        fs->w = fs->wl->window;
        fs->wp = wp;

        cmd_find_log_state(__func__, fs);
}

/* Find state from a pane. */
int
cmd_find_from_pane(struct cmd_find_state *fs, struct window_pane *wp, int flags)
{
        if (cmd_find_from_window(fs, wp->window, flags) != 0)
                return (-1);
        fs->wp = wp;

        cmd_find_log_state(__func__, fs);
        return (0);
}

/* Find state from nothing. */
int
cmd_find_from_nothing(struct cmd_find_state *fs, int flags)
{
        cmd_find_clear_state(fs, flags);

        fs->s = cmd_find_best_session(NULL, 0, flags);
        if (fs->s == NULL) {
                cmd_find_clear_state(fs, flags);
                return (-1);
        }
        fs->wl = fs->s->curw;
        fs->idx = fs->wl->idx;
        fs->w = fs->wl->window;
        fs->wp = fs->w->active;

        cmd_find_log_state(__func__, fs);
        return (0);
}

/* Find state from mouse. */
int
cmd_find_from_mouse(struct cmd_find_state *fs, struct mouse_event *m, int flags)
{
        cmd_find_clear_state(fs, flags);

        if (!m->valid)
                return (-1);

        fs->wp = cmd_mouse_pane(m, &fs->s, &fs->wl);
        if (fs->wp == NULL) {
                cmd_find_clear_state(fs, flags);
                return (-1);
        }
        fs->w = fs->wl->window;

        cmd_find_log_state(__func__, fs);
        return (0);
}

/* Find state from client. */
int
cmd_find_from_client(struct cmd_find_state *fs, struct client *c, int flags)
{
        struct window_pane      *wp;

        /* If no client, treat as from nothing. */
        if (c == NULL)
                return (cmd_find_from_nothing(fs, flags));

        /* If this is an attached client, all done. */
        if (c->session != NULL) {
                cmd_find_clear_state(fs, flags);

                fs->wp = c->session->curw->window->active;
                if (fs->wp == NULL) {
                        cmd_find_from_session(fs, c->session, flags);
                        return (0);
                }
                fs->s = c->session;
                fs->wl = fs->s->curw;
                fs->w = fs->wl->window;

                cmd_find_log_state(__func__, fs);
                return (0);
        }
        cmd_find_clear_state(fs, flags);

        /*
         * If this is an unattached client running in a pane, we can use that
         * to limit the list of sessions to those containing that pane.
         */
        wp = cmd_find_inside_pane(c);
        if (wp == NULL)
                goto unknown_pane;

        /*
         * Don't have a session, or it doesn't have this pane. Try all
         * sessions.
         */
        fs->w = wp->window;
        if (cmd_find_best_session_with_window(fs) != 0) {
                /*
                 * The window may have been destroyed but the pane
                 * still on all_window_panes due to something else
                 * holding a reference.
                 */
                goto unknown_pane;
        }
        fs->wl = fs->s->curw;
        fs->w = fs->wl->window;
        fs->wp = fs->w->active; /* use active pane */

        cmd_find_log_state(__func__, fs);
        return (0);

unknown_pane:
        /* We can't find the pane so need to guess. */
        return (cmd_find_from_nothing(fs, flags));
}

/*
 * Split target into pieces and resolve for the given type. Fills in the given
 * state. Returns 0 on success or -1 on error.
 */
int
cmd_find_target(struct cmd_find_state *fs, struct cmdq_item *item,
    const char *target, enum cmd_find_type type, int flags)
{
        struct mouse_event      *m;
        struct client           *c;
        struct cmd_find_state    current;
        char                    *colon, *period, *copy = NULL, tmp[256];
        const char              *session, *window, *pane, *s;
        int                      window_only = 0, pane_only = 0;

        /* Can fail flag implies quiet. */
        if (flags & CMD_FIND_CANFAIL)
                flags |= CMD_FIND_QUIET;

        /* Log the arguments. */
        if (type == CMD_FIND_PANE)
                s = "pane";
        else if (type == CMD_FIND_WINDOW)
                s = "window";
        else if (type == CMD_FIND_SESSION)
                s = "session";
        else
                s = "unknown";
        *tmp = '\0';
        if (flags & CMD_FIND_PREFER_UNATTACHED)
                strlcat(tmp, "PREFER_UNATTACHED,", sizeof tmp);
        if (flags & CMD_FIND_QUIET)
                strlcat(tmp, "QUIET,", sizeof tmp);
        if (flags & CMD_FIND_WINDOW_INDEX)
                strlcat(tmp, "WINDOW_INDEX,", sizeof tmp);
        if (flags & CMD_FIND_DEFAULT_MARKED)
                strlcat(tmp, "DEFAULT_MARKED,", sizeof tmp);
        if (flags & CMD_FIND_EXACT_SESSION)
                strlcat(tmp, "EXACT_SESSION,", sizeof tmp);
        if (flags & CMD_FIND_EXACT_WINDOW)
                strlcat(tmp, "EXACT_WINDOW,", sizeof tmp);
        if (flags & CMD_FIND_CANFAIL)
                strlcat(tmp, "CANFAIL,", sizeof tmp);
        if (*tmp != '\0')
                tmp[strlen(tmp) - 1] = '\0';
        else
                strlcat(tmp, "NONE", sizeof tmp);
        log_debug("%s: target %s, type %s, item %p, flags %s", __func__,
            target == NULL ? "none" : target, s, item, tmp);

        /* Clear new state. */
        cmd_find_clear_state(fs, flags);

        /* Find current state. */
        if (server_check_marked() && (flags & CMD_FIND_DEFAULT_MARKED)) {
                fs->current = &marked_pane;
                log_debug("%s: current is marked pane", __func__);
        } else if (cmd_find_valid_state(cmdq_get_current(item))) {
                fs->current = cmdq_get_current(item);
                log_debug("%s: current is from queue", __func__);
        } else if (cmd_find_from_client(&current, cmdq_get_client(item),
            flags) == 0) {
                fs->current = &current;
                log_debug("%s: current is from client", __func__);
        } else {
                if (~flags & CMD_FIND_QUIET)
                        cmdq_error(item, "no current target");
                goto error;
        }
        if (!cmd_find_valid_state(fs->current))
                fatalx("invalid current find state");

        /* An empty or NULL target is the current. */
        if (target == NULL || *target == '\0')
                goto current;

        if (strcmp(target, "@") == 0 ||
            strcmp(target, "{active}") == 0 ||
            strcmp(target, "{current}") == 0) {
                c = cmdq_get_client(item);
                if (c == NULL || c->session == NULL) {
                        cmdq_error(item, "no current client");
                        goto error;
                }
                fs->wl = c->session->curw;
                fs->wp = c->session->curw->window->active;
                fs->w = c->session->curw->window;
                goto found;
        }

        /* Mouse target is a plain = or {mouse}. */
        if (strcmp(target, "=") == 0 || strcmp(target, "{mouse}") == 0) {
                m = &cmdq_get_event(item)->m;
                switch (type) {
                case CMD_FIND_PANE:
                        fs->wp = cmd_mouse_pane(m, &fs->s, &fs->wl);
                        if (fs->wp != NULL) {
                                fs->w = fs->wl->window;
                                break;
                        }
                        /* FALLTHROUGH */
                case CMD_FIND_WINDOW:
                case CMD_FIND_SESSION:
                        fs->wl = cmd_mouse_window(m, &fs->s);
                        if (fs->wl == NULL && fs->s != NULL)
                                fs->wl = fs->s->curw;
                        if (fs->wl != NULL) {
                                fs->w = fs->wl->window;
                                fs->wp = fs->w->active;
                        }
                        break;
                }
                if (fs->wp == NULL) {
                        if (~flags & CMD_FIND_QUIET)
                                cmdq_error(item, "no mouse target");
                        goto error;
                }
                goto found;
        }

        /* Marked target is a plain ~ or {marked}. */
        if (strcmp(target, "~") == 0 || strcmp(target, "{marked}") == 0) {
                if (!server_check_marked()) {
                        if (~flags & CMD_FIND_QUIET)
                                cmdq_error(item, "no marked target");
                        goto error;
                }
                cmd_find_copy_state(fs, &marked_pane);
                goto found;
        }

        /* Find separators if they exist. */
        copy = xstrdup(target);
        colon = strchr(copy, ':');
        if (colon != NULL)
                *colon++ = '\0';
        if (colon == NULL)
                period = strchr(copy, '.');
        else
                period = strchr(colon, '.');
        if (period != NULL)
                *period++ = '\0';

        /* Set session, window and pane parts. */
        session = window = pane = NULL;
        if (colon != NULL && period != NULL) {
                session = copy;
                window = colon;
                window_only = 1;
                pane = period;
                pane_only = 1;
        } else if (colon != NULL && period == NULL) {
                session = copy;
                window = colon;
                window_only = 1;
        } else if (colon == NULL && period != NULL) {
                window = copy;
                pane = period;
                pane_only = 1;
        } else {
                if (*copy == '$')
                        session = copy;
                else if (*copy == '@')
                        window = copy;
                else if (*copy == '%')
                        pane = copy;
                else {
                        switch (type) {
                        case CMD_FIND_SESSION:
                                session = copy;
                                break;
                        case CMD_FIND_WINDOW:
                                window = copy;
                                break;
                        case CMD_FIND_PANE:
                                pane = copy;
                                break;
                        }
                }
        }

        /* Set exact match flags. */
        if (session != NULL && *session == '=') {
                session++;
                fs->flags |= CMD_FIND_EXACT_SESSION;
        }
        if (window != NULL && *window == '=') {
                window++;
                fs->flags |= CMD_FIND_EXACT_WINDOW;
        }

        /* Empty is the same as NULL. */
        if (session != NULL && *session == '\0')
                session = NULL;
        if (window != NULL && *window == '\0')
                window = NULL;
        if (pane != NULL && *pane == '\0')
                pane = NULL;

        /* Map though conversion table. */
        if (session != NULL)
                session = cmd_find_map_table(cmd_find_session_table, session);
        if (window != NULL)
                window = cmd_find_map_table(cmd_find_window_table, window);
        if (pane != NULL)
                pane = cmd_find_map_table(cmd_find_pane_table, pane);

        if (session != NULL || window != NULL || pane != NULL) {
                log_debug("%s: target %s is %s%s%s%s%s%s",
                    __func__, target,
                    session == NULL ? "" : "session ",
                    session == NULL ? "" : session,
                    window == NULL ? "" : "window ",
                    window == NULL ? "" : window,
                    pane == NULL ? "" : "pane ",
                    pane == NULL ? "" : pane);
        }

        /* No pane is allowed if want an index. */
        if (pane != NULL && (flags & CMD_FIND_WINDOW_INDEX)) {
                if (~flags & CMD_FIND_QUIET)
                        cmdq_error(item, "can't specify pane here");
                goto error;
        }

        /* If the session isn't NULL, look it up. */
        if (session != NULL) {
                /* This will fill in session. */
                if (cmd_find_get_session(fs, session) != 0)
                        goto no_session;

                /* If window and pane are NULL, use that session's current. */
                if (window == NULL && pane == NULL) {
                        fs->wl = fs->s->curw;
                        fs->idx = -1;
                        fs->w = fs->wl->window;
                        fs->wp = fs->w->active;
                        goto found;
                }

                /* If window is present but pane not, find window in session. */
                if (window != NULL && pane == NULL) {
                        /* This will fill in winlink and window. */
                        if (cmd_find_get_window_with_session(fs, window) != 0)
                                goto no_window;
                        if (fs->wl != NULL) /* can be NULL if index only */
                                fs->wp = fs->wl->window->active;
                        goto found;
                }

                /* If pane is present but window not, find pane. */
                if (window == NULL && pane != NULL) {
                        /* This will fill in winlink and window and pane. */
                        if (cmd_find_get_pane_with_session(fs, pane) != 0)
                                goto no_pane;
                        goto found;
                }

                /*
                 * If window and pane are present, find both in session. This
                 * will fill in winlink and window.
                 */
                if (cmd_find_get_window_with_session(fs, window) != 0)
                        goto no_window;
                /* This will fill in pane. */
                if (cmd_find_get_pane_with_window(fs, pane) != 0)
                        goto no_pane;
                goto found;
        }

        /* No session. If window and pane, try them. */
        if (window != NULL && pane != NULL) {
                /* This will fill in session, winlink and window. */
                if (cmd_find_get_window(fs, window, window_only) != 0)
                        goto no_window;
                /* This will fill in pane. */
                if (cmd_find_get_pane_with_window(fs, pane) != 0)
                        goto no_pane;
                goto found;
        }

        /* If just window is present, try it. */
        if (window != NULL && pane == NULL) {
                /* This will fill in session, winlink and window. */
                if (cmd_find_get_window(fs, window, window_only) != 0)
                        goto no_window;
                if (fs->wl != NULL) /* can be NULL if index only */
                        fs->wp = fs->wl->window->active;
                goto found;
        }

        /* If just pane is present, try it. */
        if (window == NULL && pane != NULL) {
                /* This will fill in session, winlink, window and pane. */
                if (cmd_find_get_pane(fs, pane, pane_only) != 0)
                        goto no_pane;
                goto found;
        }

current:
        /* Use the current session. */
        cmd_find_copy_state(fs, fs->current);
        if (flags & CMD_FIND_WINDOW_INDEX)
                fs->idx = -1;
        goto found;

error:
        fs->current = NULL;
        log_debug("%s: error", __func__);

        free(copy);
        if (flags & CMD_FIND_CANFAIL)
                return (0);
        return (-1);

found:
        fs->current = NULL;
        cmd_find_log_state(__func__, fs);

        free(copy);
        return (0);

no_session:
        if (~flags & CMD_FIND_QUIET)
                cmdq_error(item, "can't find session: %s", session);
        goto error;

no_window:
        if (~flags & CMD_FIND_QUIET)
                cmdq_error(item, "can't find window: %s", window);
        goto error;

no_pane:
        if (~flags & CMD_FIND_QUIET)
                cmdq_error(item, "can't find pane: %s", pane);
        goto error;
}

/* Find the current client. */
static struct client *
cmd_find_current_client(struct cmdq_item *item, int quiet)
{
        struct client           *c = NULL, *found;
        struct session          *s;
        struct window_pane      *wp;
        struct cmd_find_state    fs;

        if (item != NULL)
                c = cmdq_get_client(item);
        if (c != NULL && c->session != NULL)
                return (c);

        found = NULL;
        if (c != NULL && (wp = cmd_find_inside_pane(c)) != NULL) {
                cmd_find_clear_state(&fs, CMD_FIND_QUIET);
                fs.w = wp->window;
                if (cmd_find_best_session_with_window(&fs) == 0)
                        found = cmd_find_best_client(fs.s);
        } else {
                s = cmd_find_best_session(NULL, 0, CMD_FIND_QUIET);
                if (s != NULL)
                        found = cmd_find_best_client(s);
        }
        if (found == NULL && item != NULL && !quiet)
                cmdq_error(item, "no current client");
        log_debug("%s: no target, return %p", __func__, found);
        return (found);
}

/* Find the target client or report an error and return NULL. */
struct client *
cmd_find_client(struct cmdq_item *item, const char *target, int quiet)
{
        struct client   *c;
        char            *copy;
        size_t           size;

        /* A NULL argument means the current client. */
        if (target == NULL)
                return (cmd_find_current_client(item, quiet));
        copy = xstrdup(target);

        /* Trim a single trailing colon if any. */
        size = strlen(copy);
        if (size != 0 && copy[size - 1] == ':')
                copy[size - 1] = '\0';

        /* Check name and path of each client. */
        TAILQ_FOREACH(c, &clients, entry) {
                if (c->session == NULL)
                        continue;
                if (strcmp(copy, c->name) == 0)
                        break;

                if (*c->ttyname == '\0')
                        continue;
                if (strcmp(copy, c->ttyname) == 0)
                        break;
                if (strncmp(c->ttyname, _PATH_DEV, (sizeof _PATH_DEV) - 1) != 0)
                        continue;
                if (strcmp(copy, c->ttyname + (sizeof _PATH_DEV) - 1) == 0)
                        break;
        }

        /* If no client found, report an error. */
        if (c == NULL && !quiet)
                cmdq_error(item, "can't find client: %s", copy);

        free(copy);
        log_debug("%s: target %s, return %p", __func__, target, c);
        return (c);
}