/* $OpenBSD$ */

/*
 * Copyright (c) 2017 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 <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "tmux.h"

enum mode_tree_search_dir {
	MODE_TREE_SEARCH_FORWARD,
	MODE_TREE_SEARCH_BACKWARD
};

enum mode_tree_preview {
	MODE_TREE_PREVIEW_OFF,
	MODE_TREE_PREVIEW_NORMAL,
	MODE_TREE_PREVIEW_BIG
};

struct mode_tree_item;
TAILQ_HEAD(mode_tree_list, mode_tree_item);

struct mode_tree_data {
	int			  dead;
	u_int			  references;
	int			  zoomed;

	struct window_pane	 *wp;
	void			 *modedata;
	const struct menu_item	 *menu;

	const char		**sort_list;
	u_int			  sort_size;
	struct mode_tree_sort_criteria sort_crit;

	mode_tree_build_cb        buildcb;
	mode_tree_draw_cb         drawcb;
	mode_tree_search_cb       searchcb;
	mode_tree_menu_cb         menucb;
	mode_tree_height_cb       heightcb;
	mode_tree_key_cb	  keycb;

	struct mode_tree_list	  children;
	struct mode_tree_list	  saved;

	struct mode_tree_line	 *line_list;
	u_int			  line_size;

	u_int			  depth;

	u_int			  width;
	u_int			  height;

	u_int			  offset;
	u_int			  current;

	struct screen		  screen;

	int			  preview;
	char			 *search;
	char			 *filter;
	int			  no_matches;
	enum mode_tree_search_dir search_dir;
};

struct mode_tree_item {
	struct mode_tree_item		*parent;
	void				*itemdata;
	u_int				 line;

	key_code			 key;
	const char			*keystr;
	size_t				 keylen;

	uint64_t			 tag;
	const char			*name;
	const char			*text;

	int				 expanded;
	int				 tagged;

	int				 draw_as_parent;
	int				 no_tag;

	struct mode_tree_list		 children;
	TAILQ_ENTRY(mode_tree_item)	 entry;
};

struct mode_tree_line {
	struct mode_tree_item		*item;
	u_int				 depth;
	int				 last;
	int				 flat;
};

struct mode_tree_menu {
	struct mode_tree_data		*data;
	struct client			*c;
	u_int				 line;
};

static void mode_tree_free_items(struct mode_tree_list *);

static const struct menu_item mode_tree_menu_items[] = {
	{ "Scroll Left", '<', NULL },
	{ "Scroll Right", '>', NULL },
	{ "", KEYC_NONE, NULL },
	{ "Cancel", 'q', NULL },

	{ NULL, KEYC_NONE, NULL }
};

static struct mode_tree_item *
mode_tree_find_item(struct mode_tree_list *mtl, uint64_t tag)
{
	struct mode_tree_item	*mti, *child;

	TAILQ_FOREACH(mti, mtl, entry) {
		if (mti->tag == tag)
			return (mti);
		child = mode_tree_find_item(&mti->children, tag);
		if (child != NULL)
			return (child);
	}
	return (NULL);
}

static void
mode_tree_free_item(struct mode_tree_item *mti)
{
	mode_tree_free_items(&mti->children);

	free((void *)mti->name);
	free((void *)mti->text);
	free((void *)mti->keystr);

	free(mti);
}

static void
mode_tree_free_items(struct mode_tree_list *mtl)
{
	struct mode_tree_item	*mti, *mti1;

	TAILQ_FOREACH_SAFE(mti, mtl, entry, mti1) {
		TAILQ_REMOVE(mtl, mti, entry);
		mode_tree_free_item(mti);
	}
}

static void
mode_tree_check_selected(struct mode_tree_data *mtd)
{
	/*
	 * If the current line would now be off screen reset the offset to the
	 * last visible line.
	 */
	if (mtd->current > mtd->height - 1)
		mtd->offset = mtd->current - mtd->height + 1;
}

static void
mode_tree_clear_lines(struct mode_tree_data *mtd)
{
	free(mtd->line_list);
	mtd->line_list = NULL;
	mtd->line_size = 0;
}

static void
mode_tree_build_lines(struct mode_tree_data *mtd,
    struct mode_tree_list *mtl, u_int depth)
{
	struct mode_tree_item	*mti;
	struct mode_tree_line	*line;
	u_int			 i;
	int			 flat = 1;

	mtd->depth = depth;
	TAILQ_FOREACH(mti, mtl, entry) {
		mtd->line_list = xreallocarray(mtd->line_list,
		    mtd->line_size + 1, sizeof *mtd->line_list);

		line = &mtd->line_list[mtd->line_size++];
		line->item = mti;
		line->depth = depth;
		line->last = (mti == TAILQ_LAST(mtl, mode_tree_list));

		mti->line = (mtd->line_size - 1);
		if (!TAILQ_EMPTY(&mti->children))
			flat = 0;
		if (mti->expanded)
			mode_tree_build_lines(mtd, &mti->children, depth + 1);

		if (mtd->keycb != NULL) {
			mti->key = mtd->keycb(mtd->modedata, mti->itemdata,
			    mti->line);
			if (mti->key == KEYC_UNKNOWN)
				mti->key = KEYC_NONE;
		} else if (mti->line < 10)
			mti->key = '0' + mti->line;
		else if (mti->line < 36)
			mti->key = KEYC_META|('a' + mti->line - 10);
		else
			mti->key = KEYC_NONE;
		if (mti->key != KEYC_NONE) {
			mti->keystr = xstrdup(key_string_lookup_key(mti->key,
			    0));
			mti->keylen = strlen(mti->keystr);
		} else {
			mti->keystr = NULL;
			mti->keylen = 0;
		}
	}
	TAILQ_FOREACH(mti, mtl, entry) {
		for (i = 0; i < mtd->line_size; i++) {
			line = &mtd->line_list[i];
			if (line->item == mti)
				line->flat = flat;
		}
	}
}

static void
mode_tree_clear_tagged(struct mode_tree_list *mtl)
{
	struct mode_tree_item	*mti;

	TAILQ_FOREACH(mti, mtl, entry) {
		mti->tagged = 0;
		mode_tree_clear_tagged(&mti->children);
	}
}

void
mode_tree_up(struct mode_tree_data *mtd, int wrap)
{
	if (mtd->current == 0) {
		if (wrap) {
			mtd->current = mtd->line_size - 1;
			if (mtd->line_size >= mtd->height)
				mtd->offset = mtd->line_size - mtd->height;
		}
	} else {
		mtd->current--;
		if (mtd->current < mtd->offset)
			mtd->offset--;
	}
}

int
mode_tree_down(struct mode_tree_data *mtd, int wrap)
{
	if (mtd->current == mtd->line_size - 1) {
		if (wrap) {
			mtd->current = 0;
			mtd->offset = 0;
		} else
			return (0);
	} else {
		mtd->current++;
		if (mtd->current > mtd->offset + mtd->height - 1)
			mtd->offset++;
	}
	return (1);
}

void *
mode_tree_get_current(struct mode_tree_data *mtd)
{
	return (mtd->line_list[mtd->current].item->itemdata);
}

const char *
mode_tree_get_current_name(struct mode_tree_data *mtd)
{
	return (mtd->line_list[mtd->current].item->name);
}

void
mode_tree_expand_current(struct mode_tree_data *mtd)
{
	if (!mtd->line_list[mtd->current].item->expanded) {
		mtd->line_list[mtd->current].item->expanded = 1;
		mode_tree_build(mtd);
	}
}

void
mode_tree_collapse_current(struct mode_tree_data *mtd)
{
	if (mtd->line_list[mtd->current].item->expanded) {
		mtd->line_list[mtd->current].item->expanded = 0;
		mode_tree_build(mtd);
	}
}

static int
mode_tree_get_tag(struct mode_tree_data *mtd, uint64_t tag, u_int *found)
{
	u_int	i;

	for (i = 0; i < mtd->line_size; i++) {
		if (mtd->line_list[i].item->tag == tag)
			break;
	}
	if (i != mtd->line_size) {
		*found = i;
		return (1);
	}
	return (0);
}

void
mode_tree_expand(struct mode_tree_data *mtd, uint64_t tag)
{
	u_int	found;

	if (!mode_tree_get_tag(mtd, tag, &found))
	    return;
	if (!mtd->line_list[found].item->expanded) {
		mtd->line_list[found].item->expanded = 1;
		mode_tree_build(mtd);
	}
}

int
mode_tree_set_current(struct mode_tree_data *mtd, uint64_t tag)
{
	u_int	found;

	if (mode_tree_get_tag(mtd, tag, &found)) {
		mtd->current = found;
		if (mtd->current > mtd->height - 1)
			mtd->offset = mtd->current - mtd->height + 1;
		else
			mtd->offset = 0;
		return (1);
	}
	if (mtd->current >= mtd->line_size) {
		mtd->current = mtd->line_size - 1;
		if (mtd->current > mtd->height - 1)
			mtd->offset = mtd->current - mtd->height + 1;
		else
			mtd->offset = 0;
	}
	return (0);
}

u_int
mode_tree_count_tagged(struct mode_tree_data *mtd)
{
	struct mode_tree_item	*mti;
	u_int			 i, tagged;

	tagged = 0;
	for (i = 0; i < mtd->line_size; i++) {
		mti = mtd->line_list[i].item;
		if (mti->tagged)
			tagged++;
	}
	return (tagged);
}

void
mode_tree_each_tagged(struct mode_tree_data *mtd, mode_tree_each_cb cb,
    struct client *c, key_code key, int current)
{
	struct mode_tree_item	*mti;
	u_int			 i;
	int			 fired;

	fired = 0;
	for (i = 0; i < mtd->line_size; i++) {
		mti = mtd->line_list[i].item;
		if (mti->tagged) {
			fired = 1;
			cb(mtd->modedata, mti->itemdata, c, key);
		}
	}
	if (!fired && current) {
		mti = mtd->line_list[mtd->current].item;
		cb(mtd->modedata, mti->itemdata, c, key);
	}
}

struct mode_tree_data *
mode_tree_start(struct window_pane *wp, struct args *args,
    mode_tree_build_cb buildcb, mode_tree_draw_cb drawcb,
    mode_tree_search_cb searchcb, mode_tree_menu_cb menucb,
    mode_tree_height_cb heightcb, mode_tree_key_cb keycb, void *modedata,
    const struct menu_item *menu, const char **sort_list, u_int sort_size,
    struct screen **s)
{
	struct mode_tree_data	*mtd;
	const char		*sort;
	u_int			 i;

	mtd = xcalloc(1, sizeof *mtd);
	mtd->references = 1;

	mtd->wp = wp;
	mtd->modedata = modedata;
	mtd->menu = menu;

	mtd->sort_list = sort_list;
	mtd->sort_size = sort_size;

	if (args_has(args, 'N') > 1)
		mtd->preview = MODE_TREE_PREVIEW_BIG;
	else if (args_has(args, 'N'))
		mtd->preview = MODE_TREE_PREVIEW_OFF;
	else
		mtd->preview = MODE_TREE_PREVIEW_NORMAL;

	sort = args_get(args, 'O');
	if (sort != NULL) {
		for (i = 0; i < sort_size; i++) {
			if (strcasecmp(sort, sort_list[i]) == 0)
				mtd->sort_crit.field = i;
		}
	}
	mtd->sort_crit.reversed = args_has(args, 'r');

	if (args_has(args, 'f'))
		mtd->filter = xstrdup(args_get(args, 'f'));
	else
		mtd->filter = NULL;

	mtd->buildcb = buildcb;
	mtd->drawcb = drawcb;
	mtd->searchcb = searchcb;
	mtd->menucb = menucb;
	mtd->heightcb = heightcb;
	mtd->keycb = keycb;

	TAILQ_INIT(&mtd->children);

	*s = &mtd->screen;
	screen_init(*s, screen_size_x(&wp->base), screen_size_y(&wp->base), 0);
	(*s)->mode &= ~MODE_CURSOR;

	return (mtd);
}

void
mode_tree_zoom(struct mode_tree_data *mtd, struct args *args)
{
	struct window_pane	*wp = mtd->wp;

	if (args_has(args, 'Z')) {
		mtd->zoomed = (wp->window->flags & WINDOW_ZOOMED);
		if (!mtd->zoomed && window_zoom(wp) == 0)
			server_redraw_window(wp->window);
	} else
		mtd->zoomed = -1;
}

static void
mode_tree_set_height(struct mode_tree_data *mtd)
{
	struct screen	*s = &mtd->screen;
	u_int		 height;

	if (mtd->heightcb != NULL) {
		height = mtd->heightcb(mtd, screen_size_y(s));
		if (height < screen_size_y(s))
		    mtd->height = screen_size_y(s) - height;
	} else {
		if (mtd->preview == MODE_TREE_PREVIEW_NORMAL) {
			mtd->height = (screen_size_y(s) / 3) * 2;
			if (mtd->height > mtd->line_size)
				mtd->height = screen_size_y(s) / 2;
			if (mtd->height < 10)
				mtd->height = screen_size_y(s);
		} else if (mtd->preview == MODE_TREE_PREVIEW_BIG) {
			mtd->height = screen_size_y(s) / 4;
			if (mtd->height > mtd->line_size)
				mtd->height = mtd->line_size;
			if (mtd->height < 2)
				mtd->height = 2;
		} else
			mtd->height = screen_size_y(s);
	}
	if (screen_size_y(s) - mtd->height < 2)
		mtd->height = screen_size_y(s);
}

void
mode_tree_build(struct mode_tree_data *mtd)
{
	struct screen	*s = &mtd->screen;
	uint64_t	 tag;

	if (mtd->line_list != NULL)
		tag = mtd->line_list[mtd->current].item->tag;
	else
		tag = UINT64_MAX;

	TAILQ_CONCAT(&mtd->saved, &mtd->children, entry);
	TAILQ_INIT(&mtd->children);

	mtd->buildcb(mtd->modedata, &mtd->sort_crit, &tag, mtd->filter);
	mtd->no_matches = TAILQ_EMPTY(&mtd->children);
	if (mtd->no_matches)
		mtd->buildcb(mtd->modedata, &mtd->sort_crit, &tag, NULL);

	mode_tree_free_items(&mtd->saved);
	TAILQ_INIT(&mtd->saved);

	mode_tree_clear_lines(mtd);
	mode_tree_build_lines(mtd, &mtd->children, 0);

	if (mtd->line_list != NULL && tag == UINT64_MAX)
		tag = mtd->line_list[mtd->current].item->tag;
	mode_tree_set_current(mtd, tag);

	mtd->width = screen_size_x(s);
	if (mtd->preview != MODE_TREE_PREVIEW_OFF)
		mode_tree_set_height(mtd);
	else
		mtd->height = screen_size_y(s);
	mode_tree_check_selected(mtd);
}

static void
mode_tree_remove_ref(struct mode_tree_data *mtd)
{
	if (--mtd->references == 0)
		free(mtd);
}

void
mode_tree_free(struct mode_tree_data *mtd)
{
	struct window_pane	*wp = mtd->wp;

	if (mtd->zoomed == 0)
		server_unzoom_window(wp->window);

	mode_tree_free_items(&mtd->children);
	mode_tree_clear_lines(mtd);
	screen_free(&mtd->screen);

	free(mtd->search);
	free(mtd->filter);

	mtd->dead = 1;
	mode_tree_remove_ref(mtd);
}

void
mode_tree_resize(struct mode_tree_data *mtd, u_int sx, u_int sy)
{
	struct screen	*s = &mtd->screen;

	screen_resize(s, sx, sy, 0);

	mode_tree_build(mtd);
	mode_tree_draw(mtd);

	mtd->wp->flags |= PANE_REDRAW;
}

struct mode_tree_item *
mode_tree_add(struct mode_tree_data *mtd, struct mode_tree_item *parent,
    void *itemdata, uint64_t tag, const char *name, const char *text,
    int expanded)
{
	struct mode_tree_item	*mti, *saved;

	log_debug("%s: %llu, %s %s", __func__, (unsigned long long)tag,
	    name, (text == NULL ? "" : text));

	mti = xcalloc(1, sizeof *mti);
	mti->parent = parent;
	mti->itemdata = itemdata;

	mti->tag = tag;
	mti->name = xstrdup(name);
	if (text != NULL)
		mti->text = xstrdup(text);

	saved = mode_tree_find_item(&mtd->saved, tag);
	if (saved != NULL) {
		if (parent == NULL || parent->expanded)
			mti->tagged = saved->tagged;
		mti->expanded = saved->expanded;
	} else if (expanded == -1)
		mti->expanded = 1;
	else
		mti->expanded = expanded;

	TAILQ_INIT(&mti->children);

	if (parent != NULL)
		TAILQ_INSERT_TAIL(&parent->children, mti, entry);
	else
		TAILQ_INSERT_TAIL(&mtd->children, mti, entry);

	return (mti);
}

void
mode_tree_draw_as_parent(struct mode_tree_item *mti)
{
	mti->draw_as_parent = 1;
}

void
mode_tree_no_tag(struct mode_tree_item *mti)
{
	mti->no_tag = 1;
}

void
mode_tree_remove(struct mode_tree_data *mtd, struct mode_tree_item *mti)
{
	struct mode_tree_item	*parent = mti->parent;

	if (parent != NULL)
		TAILQ_REMOVE(&parent->children, mti, entry);
	else
		TAILQ_REMOVE(&mtd->children, mti, entry);
	mode_tree_free_item(mti);
}

void
mode_tree_draw(struct mode_tree_data *mtd)
{
	struct window_pane	*wp = mtd->wp;
	struct screen		*s = &mtd->screen;
	struct mode_tree_line	*line;
	struct mode_tree_item	*mti;
	struct options		*oo = wp->window->options;
	struct screen_write_ctx	 ctx;
	struct grid_cell	 gc0, gc;
	u_int			 w, h, i, j, sy, box_x, box_y, width;
	char			*text, *start, *key;
	const char		*tag, *symbol;
	size_t			 size, n;
	int			 keylen, pad;

	if (mtd->line_size == 0)
		return;

	memcpy(&gc0, &grid_default_cell, sizeof gc0);
	memcpy(&gc, &grid_default_cell, sizeof gc);
	style_apply(&gc, oo, "mode-style", NULL);

	w = mtd->width;
	h = mtd->height;

	screen_write_start(&ctx, s);
	screen_write_clearscreen(&ctx, 8);

	keylen = 0;
	for (i = 0; i < mtd->line_size; i++) {
		mti = mtd->line_list[i].item;
		if (mti->key == KEYC_NONE)
			continue;
		if ((int)mti->keylen + 3 > keylen)
			keylen = mti->keylen + 3;
	}

	for (i = 0; i < mtd->line_size; i++) {
		if (i < mtd->offset)
			continue;
		if (i > mtd->offset + h - 1)
			break;
		line = &mtd->line_list[i];
		mti = line->item;

		screen_write_cursormove(&ctx, 0, i - mtd->offset, 0);

		pad = keylen - 2 - mti->keylen;
		if (mti->key != KEYC_NONE)
			xasprintf(&key, "(%s)%*s", mti->keystr, pad, "");
		else
			key = xstrdup("");

		if (line->flat)
			symbol = "";
		else if (TAILQ_EMPTY(&mti->children))
			symbol = "  ";
		else if (mti->expanded)
			symbol = "- ";
		else
			symbol = "+ ";

		if (line->depth == 0)
			start = xstrdup(symbol);
		else {
			size = (4 * line->depth) + 32;

			start = xcalloc(1, size);
			for (j = 1; j < line->depth; j++) {
				if (mti->parent != NULL &&
				    mtd->line_list[mti->parent->line].last)
					strlcat(start, "    ", size);
				else
					strlcat(start, "\001x\001   ", size);
			}
			if (line->last)
				strlcat(start, "\001mq\001> ", size);
			else
				strlcat(start, "\001tq\001> ", size);
			strlcat(start, symbol, size);
		}

		if (mti->tagged)
			tag = "*";
		else
			tag = "";
		xasprintf(&text, "%-*s%s%s%s%s", keylen, key, start, mti->name,
		    tag, (mti->text != NULL) ? ": " : "" );
		width = utf8_cstrwidth(text);
		if (width > w)
			width = w;
		free(start);

		if (mti->tagged) {
			gc.attr ^= GRID_ATTR_BRIGHT;
			gc0.attr ^= GRID_ATTR_BRIGHT;
		}

		if (i != mtd->current) {
			screen_write_clearendofline(&ctx, 8);
			screen_write_nputs(&ctx, w, &gc0, "%s", text);
			if (mti->text != NULL) {
				format_draw(&ctx, &gc0, w - width, mti->text,
				    NULL, 0);
			}
		} else {
			screen_write_clearendofline(&ctx, gc.bg);
			screen_write_nputs(&ctx, w, &gc, "%s", text);
			if (mti->text != NULL) {
				format_draw(&ctx, &gc, w - width, mti->text,
				    NULL, 0);
			}
		}
		free(text);
		free(key);

		if (mti->tagged) {
			gc.attr ^= GRID_ATTR_BRIGHT;
			gc0.attr ^= GRID_ATTR_BRIGHT;
		}
	}

	if (mtd->preview == MODE_TREE_PREVIEW_OFF)
		goto done;

	sy = screen_size_y(s);
	if (sy <= 4 || h < 2 || sy - h <= 4 || w <= 4)
		goto done;

	line = &mtd->line_list[mtd->current];
	mti = line->item;
	if (mti->draw_as_parent)
		mti = mti->parent;

	screen_write_cursormove(&ctx, 0, h, 0);
	screen_write_box(&ctx, w, sy - h, BOX_LINES_DEFAULT, NULL, NULL);

	if (mtd->sort_list != NULL) {
		xasprintf(&text, " %s (sort: %s%s)", mti->name,
		    mtd->sort_list[mtd->sort_crit.field],
		    mtd->sort_crit.reversed ? ", reversed" : "");
	} else
		xasprintf(&text, " %s", mti->name);
	if (w - 2 >= strlen(text)) {
		screen_write_cursormove(&ctx, 1, h, 0);
		screen_write_puts(&ctx, &gc0, "%s", text);

		if (mtd->no_matches)
			n = (sizeof "no matches") - 1;
		else
			n = (sizeof "active") - 1;
		if (mtd->filter != NULL && w - 2 >= strlen(text) + 10 + n + 2) {
			screen_write_puts(&ctx, &gc0, " (filter: ");
			if (mtd->no_matches)
				screen_write_puts(&ctx, &gc, "no matches");
			else
				screen_write_puts(&ctx, &gc0, "active");
			screen_write_puts(&ctx, &gc0, ") ");
		} else
			screen_write_puts(&ctx, &gc0, " ");
	}
	free(text);

	box_x = w - 4;
	box_y = sy - h - 2;

	if (box_x != 0 && box_y != 0) {
		screen_write_cursormove(&ctx, 2, h + 1, 0);
		mtd->drawcb(mtd->modedata, mti->itemdata, &ctx, box_x, box_y);
	}

done:
	screen_write_cursormove(&ctx, 0, mtd->current - mtd->offset, 0);
	screen_write_stop(&ctx);
}

static struct mode_tree_item *
mode_tree_search_backward(struct mode_tree_data *mtd)
{
    struct mode_tree_item	*mti, *last, *prev;

    if (mtd->search == NULL)
	    return (NULL);

    mti = last = mtd->line_list[mtd->current].item;
    for (;;) {
        if ((prev = TAILQ_PREV(mti, mode_tree_list, entry)) != NULL) {
		/* Point to the last child in the previous subtree. */
		while (!TAILQ_EMPTY(&prev->children))
			prev = TAILQ_LAST(&prev->children, mode_tree_list);
		mti = prev;
        } else {
		/* If prev is NULL, jump to the parent. */
		mti = mti->parent;
        }

	if (mti == NULL) {
		/* Point to the last child in the last root subtree. */
		prev = TAILQ_LAST(&mtd->children, mode_tree_list);
		while (!TAILQ_EMPTY(&prev->children))
			prev = TAILQ_LAST(&prev->children, mode_tree_list);
		mti = prev;
	}
	if (mti == last)
		break;

	if (mtd->searchcb == NULL) {
		if (strstr(mti->name, mtd->search) != NULL)
			return (mti);
		continue;
	}
	if (mtd->searchcb(mtd->modedata, mti->itemdata, mtd->search))
		return (mti);
    }
    return (NULL);
}


static struct mode_tree_item *
mode_tree_search_forward(struct mode_tree_data *mtd)
{
	struct mode_tree_item	*mti, *last, *next;

	if (mtd->search == NULL)
		return (NULL);

	mti = last = mtd->line_list[mtd->current].item;
	for (;;) {
		if (!TAILQ_EMPTY(&mti->children))
			mti = TAILQ_FIRST(&mti->children);
		else if ((next = TAILQ_NEXT(mti, entry)) != NULL)
			mti = next;
		else {
			for (;;) {
				mti = mti->parent;
				if (mti == NULL)
					break;
				if ((next = TAILQ_NEXT(mti, entry)) != NULL) {
					mti = next;
					break;
				}
			}
		}
		if (mti == NULL)
			mti = TAILQ_FIRST(&mtd->children);
		if (mti == last)
			break;

		if (mtd->searchcb == NULL) {
			if (strstr(mti->name, mtd->search) != NULL)
				return (mti);
			continue;
		}
		if (mtd->searchcb(mtd->modedata, mti->itemdata, mtd->search))
			return (mti);
	}
	return (NULL);
}

static void
mode_tree_search_set(struct mode_tree_data *mtd)
{
	struct mode_tree_item	*mti, *loop;
	uint64_t		 tag;

	if (mtd->search_dir == MODE_TREE_SEARCH_FORWARD)
		mti = mode_tree_search_forward(mtd);
	else
		mti = mode_tree_search_backward(mtd);
	if (mti == NULL)
		return;
	tag = mti->tag;

	loop = mti->parent;
	while (loop != NULL) {
		loop->expanded = 1;
		loop = loop->parent;
	}

	mode_tree_build(mtd);
	mode_tree_set_current(mtd, tag);
	mode_tree_draw(mtd);
	mtd->wp->flags |= PANE_REDRAW;
}

static int
mode_tree_search_callback(__unused struct client *c, void *data, const char *s,
    __unused int done)
{
	struct mode_tree_data	*mtd = data;

	if (mtd->dead)
		return (0);

	free(mtd->search);
	if (s == NULL || *s == '\0') {
		mtd->search = NULL;
		return (0);
	}
	mtd->search = xstrdup(s);
	mode_tree_search_set(mtd);

	return (0);
}

static void
mode_tree_search_free(void *data)
{
	mode_tree_remove_ref(data);
}

static int
mode_tree_filter_callback(__unused struct client *c, void *data, const char *s,
    __unused int done)
{
	struct mode_tree_data	*mtd = data;

	if (mtd->dead)
		return (0);

	if (mtd->filter != NULL)
		free(mtd->filter);
	if (s == NULL || *s == '\0')
		mtd->filter = NULL;
	else
		mtd->filter = xstrdup(s);

	mode_tree_build(mtd);
	mode_tree_draw(mtd);
	mtd->wp->flags |= PANE_REDRAW;

	return (0);
}

static void
mode_tree_filter_free(void *data)
{
	mode_tree_remove_ref(data);
}

static void
mode_tree_menu_callback(__unused struct menu *menu, __unused u_int idx,
    key_code key, void *data)
{
	struct mode_tree_menu	*mtm = data;
	struct mode_tree_data	*mtd = mtm->data;

	if (mtd->dead || key == KEYC_NONE)
		goto out;

	if (mtm->line >= mtd->line_size)
		goto out;
	mtd->current = mtm->line;
	mtd->menucb(mtd->modedata, mtm->c, key);

out:
	mode_tree_remove_ref(mtd);
	free(mtm);
}

static void
mode_tree_display_menu(struct mode_tree_data *mtd, struct client *c, u_int x,
    u_int y, int outside)
{
	struct mode_tree_item	*mti;
	struct menu		*menu;
	const struct menu_item	*items;
	struct mode_tree_menu	*mtm;
	char			*title;
	u_int			 line;

	if (mtd->offset + y > mtd->line_size - 1)
		line = mtd->current;
	else
		line = mtd->offset + y;
	mti = mtd->line_list[line].item;

	if (!outside) {
		items = mtd->menu;
		xasprintf(&title, "#[align=centre]%s", mti->name);
	} else {
		items = mode_tree_menu_items;
		title = xstrdup("");
	}
	menu = menu_create(title);
	menu_add_items(menu, items, NULL, c, NULL);
	free(title);

	mtm = xmalloc(sizeof *mtm);
	mtm->data = mtd;
	mtm->c = c;
	mtm->line = line;
	mtd->references++;

	if (x >= (menu->width + 4) / 2)
		x -= (menu->width + 4) / 2;
	else
		x = 0;
	if (menu_display(menu, 0, 0, NULL, x, y, c, BOX_LINES_DEFAULT, NULL,
	    NULL, NULL, NULL, mode_tree_menu_callback, mtm) != 0) {
		mode_tree_remove_ref(mtd);
		free(mtm);
		menu_free(menu);
	}
}

int
mode_tree_key(struct mode_tree_data *mtd, struct client *c, key_code *key,
    struct mouse_event *m, u_int *xp, u_int *yp)
{
	struct mode_tree_line	*line;
	struct mode_tree_item	*current, *parent, *mti;
	u_int			 i, x, y;
	int			 choice;

	if (KEYC_IS_MOUSE(*key) && m != NULL) {
		if (cmd_mouse_at(mtd->wp, m, &x, &y, 0) != 0) {
			*key = KEYC_NONE;
			return (0);
		}
		if (xp != NULL)
			*xp = x;
		if (yp != NULL)
			*yp = y;
		if (x > mtd->width || y > mtd->height) {
			if (*key == KEYC_MOUSEDOWN3_PANE)
				mode_tree_display_menu(mtd, c, x, y, 1);
			if (mtd->preview == MODE_TREE_PREVIEW_OFF)
				*key = KEYC_NONE;
			return (0);
		}
		if (mtd->offset + y < mtd->line_size) {
			if (*key == KEYC_MOUSEDOWN1_PANE ||
			    *key == KEYC_MOUSEDOWN3_PANE ||
			    *key == KEYC_DOUBLECLICK1_PANE)
				mtd->current = mtd->offset + y;
			if (*key == KEYC_DOUBLECLICK1_PANE)
				*key = '\r';
			else {
				if (*key == KEYC_MOUSEDOWN3_PANE)
					mode_tree_display_menu(mtd, c, x, y, 0);
				*key = KEYC_NONE;
			}
		} else {
			if (*key == KEYC_MOUSEDOWN3_PANE)
				mode_tree_display_menu(mtd, c, x, y, 0);
			*key = KEYC_NONE;
		}
		return (0);
	}

	line = &mtd->line_list[mtd->current];
	current = line->item;

	choice = -1;
	for (i = 0; i < mtd->line_size; i++) {
		if (*key == mtd->line_list[i].item->key) {
			choice = i;
			break;
		}
	}
	if (choice != -1) {
		if ((u_int)choice > mtd->line_size - 1) {
			*key = KEYC_NONE;
			return (0);
		}
		mtd->current = choice;
		*key = '\r';
		return (0);
	}

	switch (*key) {
	case 'q':
	case '\033': /* Escape */
	case 'g'|KEYC_CTRL:
		return (1);
	case KEYC_UP:
	case 'k':
	case KEYC_WHEELUP_PANE:
	case 'p'|KEYC_CTRL:
		mode_tree_up(mtd, 1);
		break;
	case KEYC_DOWN:
	case 'j':
	case KEYC_WHEELDOWN_PANE:
	case 'n'|KEYC_CTRL:
		mode_tree_down(mtd, 1);
		break;
	case KEYC_PPAGE:
	case 'b'|KEYC_CTRL:
		for (i = 0; i < mtd->height; i++) {
			if (mtd->current == 0)
				break;
			mode_tree_up(mtd, 1);
		}
		break;
	case KEYC_NPAGE:
	case 'f'|KEYC_CTRL:
		for (i = 0; i < mtd->height; i++) {
			if (mtd->current == mtd->line_size - 1)
				break;
			mode_tree_down(mtd, 1);
		}
		break;
	case 'g':
	case KEYC_HOME:
		mtd->current = 0;
		mtd->offset = 0;
		break;
	case 'G':
	case KEYC_END:
		mtd->current = mtd->line_size - 1;
		if (mtd->current > mtd->height - 1)
			mtd->offset = mtd->current - mtd->height + 1;
		else
			mtd->offset = 0;
		break;
	case 't':
		/*
		 * Do not allow parents and children to both be tagged: untag
		 * all parents and children of current.
		 */
		if (current->no_tag)
			break;
		if (!current->tagged) {
			parent = current->parent;
			while (parent != NULL) {
				parent->tagged = 0;
				parent = parent->parent;
			}
			mode_tree_clear_tagged(&current->children);
			current->tagged = 1;
		} else
			current->tagged = 0;
		if (m != NULL)
			mode_tree_down(mtd, 0);
		break;
	case 'T':
		for (i = 0; i < mtd->line_size; i++)
			mtd->line_list[i].item->tagged = 0;
		break;
	case 't'|KEYC_CTRL:
		for (i = 0; i < mtd->line_size; i++) {
			if ((mtd->line_list[i].item->parent == NULL &&
			    !mtd->line_list[i].item->no_tag) ||
			    (mtd->line_list[i].item->parent != NULL &&
			    mtd->line_list[i].item->parent->no_tag))
				mtd->line_list[i].item->tagged = 1;
			else
				mtd->line_list[i].item->tagged = 0;
		}
		break;
	case 'O':
		mtd->sort_crit.field++;
		if (mtd->sort_crit.field >= mtd->sort_size)
			mtd->sort_crit.field = 0;
		mode_tree_build(mtd);
		break;
	case 'r':
		mtd->sort_crit.reversed = !mtd->sort_crit.reversed;
		mode_tree_build(mtd);
		break;
	case KEYC_LEFT:
	case 'h':
	case '-':
		if (line->flat || !current->expanded)
			current = current->parent;
		if (current == NULL)
			mode_tree_up(mtd, 0);
		else {
			current->expanded = 0;
			mtd->current = current->line;
			mode_tree_build(mtd);
		}
		break;
	case KEYC_RIGHT:
	case 'l':
	case '+':
		if (line->flat || current->expanded)
			mode_tree_down(mtd, 0);
		else if (!line->flat) {
			current->expanded = 1;
			mode_tree_build(mtd);
		}
		break;
	case '-'|KEYC_META:
		TAILQ_FOREACH(mti, &mtd->children, entry)
			mti->expanded = 0;
		mode_tree_build(mtd);
		break;
	case '+'|KEYC_META:
		TAILQ_FOREACH(mti, &mtd->children, entry)
			mti->expanded = 1;
		mode_tree_build(mtd);
		break;
	case '?':
	case '/':
	case 's'|KEYC_CTRL:
		mtd->references++;
		status_prompt_set(c, NULL, "(search) ", "",
		    mode_tree_search_callback, mode_tree_search_free, mtd,
		    PROMPT_NOFORMAT, PROMPT_TYPE_SEARCH);
		break;
	case 'n':
		mtd->search_dir = MODE_TREE_SEARCH_FORWARD;
		mode_tree_search_set(mtd);
		break;
	case 'N':
		mtd->search_dir = MODE_TREE_SEARCH_BACKWARD;
		mode_tree_search_set(mtd);
		break;
	case 'f':
		mtd->references++;
		status_prompt_set(c, NULL, "(filter) ", mtd->filter,
		    mode_tree_filter_callback, mode_tree_filter_free, mtd,
		    PROMPT_NOFORMAT, PROMPT_TYPE_SEARCH);
		break;
	case 'v':
		switch (mtd->preview) {
		case MODE_TREE_PREVIEW_OFF:
			mtd->preview = MODE_TREE_PREVIEW_BIG;
			break;
		case MODE_TREE_PREVIEW_NORMAL:
			mtd->preview = MODE_TREE_PREVIEW_OFF;
			break;
		case MODE_TREE_PREVIEW_BIG:
			mtd->preview = MODE_TREE_PREVIEW_NORMAL;
			break;
		}
		mode_tree_build(mtd);
		if (mtd->preview != MODE_TREE_PREVIEW_OFF)
			mode_tree_check_selected(mtd);
		break;
	}
	return (0);
}

void
mode_tree_run_command(struct client *c, struct cmd_find_state *fs,
    const char *template, const char *name)
{
	struct cmdq_state	*state;
	char			*command, *error;
	enum cmd_parse_status	 status;

	command = cmd_template_replace(template, name, 1);
	if (command != NULL && *command != '\0') {
		state = cmdq_new_state(fs, NULL, 0);
		status = cmd_parse_and_append(command, NULL, c, state, &error);
		if (status == CMD_PARSE_ERROR) {
			if (c != NULL) {
				*error = toupper((u_char)*error);
				status_message_set(c, -1, 1, 0, "%s", error);
			}
			free(error);
		}
		cmdq_free_state(state);
	}
	free(command);
}