/* $OpenBSD$ */

/*
 * Copyright (c) 2026 Michael Grant <mgrant@grant.org>
 *
 * 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 <stdlib.h>
#include <string.h>

#include "tmux.h"

/*
 * float-pane: lift a tiled pane out of the layout tree into a floating pane.
 * tile-pane: insert a floating pane back into the tiled layout.
 *
 * saved_layout_cell is reused to remember the pane's tiled slot while it is
 * floating, using the same mechanism as minimise-pane.  The cell's wp pointer
 * is cleared while the pane is floating so that layout helpers treat the slot
 * as empty.
 */

static enum cmd_retval	cmd_float_pane_exec(struct cmd *, struct cmdq_item *);
static enum cmd_retval	cmd_tile_pane_exec(struct cmd *, struct cmdq_item *);

static enum cmd_retval	do_float_pane(struct window *, struct window_pane *,
			    int, int, u_int, u_int);
static enum cmd_retval	do_tile_pane(struct window *, struct window_pane *,
			    struct cmdq_item *);

const struct cmd_entry cmd_float_pane_entry = {
	.name = "float-pane",
	.alias = NULL,

	.args = { "t:x:y:w:h:", 0, 0, NULL },
	.usage = "[-h height] [-w width] [-x x] [-y y] "
		 CMD_TARGET_PANE_USAGE,

	.target = { 't', CMD_FIND_PANE, 0 },

	.flags = CMD_AFTERHOOK,
	.exec = cmd_float_pane_exec
};

const struct cmd_entry cmd_tile_pane_entry = {
	.name = "tile-pane",
	.alias = NULL,

	.args = { "t:", 0, 0, NULL },
	.usage = CMD_TARGET_PANE_USAGE,

	.target = { 't', CMD_FIND_PANE, 0 },

	.flags = CMD_AFTERHOOK,
	.exec = cmd_tile_pane_exec
};

/*
 * Parse geometry arguments for float-pane.
 * Returns 0 on success, -1 on error (error message already set on item).
 * x/y/sx/sy are set to parsed values or cascade defaults.
 * last_x/last_y are the static cascade counters; pass the address of the
 * caller's statics.
 */
static int
parse_float_geometry(struct args *args, struct cmdq_item *item,
    struct window *w, int *out_x, int *out_y, u_int *out_sx, u_int *out_sy,
    int *last_x, int *last_y)
{
	char	*cause = NULL;
	int	 x, y;
	u_int	 sx, sy;

	/* Default size: half the window. */
	sx = w->sx / 2;
	sy = w->sy / 2;

	if (args_has(args, 'w')) {
		sx = args_strtonum_and_expand(args, 'w', 1, USHRT_MAX, item,
		    &cause);
		if (cause != NULL) {
			cmdq_error(item, "width %s", cause);
			free(cause);
			return (-1);
		}
	}
	if (args_has(args, 'h')) {
		sy = args_strtonum_and_expand(args, 'h', 1, USHRT_MAX, item,
		    &cause);
		if (cause != NULL) {
			cmdq_error(item, "height %s", cause);
			free(cause);
			return (-1);
		}
	}

	/* Default position: cascade from (5,5), step +5, wrap at window edge. */
	if (args_has(args, 'x')) {
		x = args_strtonum_and_expand(args, 'x', SHRT_MIN, SHRT_MAX,
		    item, &cause);
		if (cause != NULL) {
			cmdq_error(item, "x %s", cause);
			free(cause);
			return (-1);
		}
	} else {
		if (*last_x == 0) {
			x = 5;
		} else {
			x = (*last_x += 5);
			if (*last_x > (int)w->sx)
				x = *last_x = 5;
		}
	}
	if (args_has(args, 'y')) {
		y = args_strtonum_and_expand(args, 'y', SHRT_MIN, SHRT_MAX,
		    item, &cause);
		if (cause != NULL) {
			cmdq_error(item, "y %s", cause);
			free(cause);
			return (-1);
		}
	} else {
		if (*last_y == 0) {
			y = 5;
		} else {
			y = (*last_y += 5);
			if (*last_y > (int)w->sy)
				y = *last_y = 5;
		}
	}

	*last_x = x;
	*last_y = y;
	*out_x = x;
	*out_y = y;
	*out_sx = sx;
	*out_sy = sy;
	return (0);
}

static enum cmd_retval
cmd_float_pane_exec(struct cmd *self, struct cmdq_item *item)
{
	struct args		*args = cmd_get_args(self);
	struct cmd_find_state	*target = cmdq_get_target(item);
	struct window		*w = target->wl->window;
	struct window_pane	*wp = target->wp;
	static int		 last_x = 0, last_y = 0;
	int			 x, y;
	u_int			 sx, sy;

	if (wp->flags & PANE_FLOATING) {
		cmdq_error(item, "pane is already floating");
		return (CMD_RETURN_ERROR);
	}
	if (wp->flags & PANE_MINIMISED) {
		cmdq_error(item, "can't float a minimised pane");
		return (CMD_RETURN_ERROR);
	}
	if (w->flags & WINDOW_ZOOMED) {
		cmdq_error(item, "can't float a pane while window is zoomed");
		return (CMD_RETURN_ERROR);
	}

	/*
	 * If no geometry was given explicitly and we have a saved floating
	 * position from a previous tile-pane, restore it.
	 */
	if ((wp->flags & PANE_SAVED_FLOAT) &&
	    !args_has(args, 'x') && !args_has(args, 'y') &&
	    !args_has(args, 'w') && !args_has(args, 'h')) {
		x  = wp->saved_float_xoff;
		y  = wp->saved_float_yoff;
		sx = wp->saved_float_sx;
		sy = wp->saved_float_sy;
	} else {
		if (parse_float_geometry(args, item, w, &x, &y, &sx, &sy,
		    &last_x, &last_y) != 0)
			return (CMD_RETURN_ERROR);
	}

	return (do_float_pane(w, wp, x, y, sx, sy));
}

static enum cmd_retval
cmd_tile_pane_exec(struct cmd *self, struct cmdq_item *item)
{
	__attribute((unused)) struct args	*args = cmd_get_args(self);
	struct cmd_find_state			*target = cmdq_get_target(item);
	struct window				*w = target->wl->window;
	struct window_pane			*wp = target->wp;

	if (!(wp->flags & PANE_FLOATING)) {
		cmdq_error(item, "pane is not floating");
		return (CMD_RETURN_ERROR);
	}
	if (w->flags & WINDOW_ZOOMED) {
		cmdq_error(item, "can't tile a pane while window is zoomed");
		return (CMD_RETURN_ERROR);
	}

	return (do_tile_pane(w, wp, item));
}

static enum cmd_retval
do_float_pane(struct window *w, struct window_pane *wp, int x, int y,
    u_int sx, u_int sy)
{
	struct layout_cell	*lc;

	/*
	 * Remove the pane from the tiled layout tree so neighbours reclaim
	 * the space.  layout_close_pane calls layout_destroy_cell which frees
	 * the tiled layout_cell and sets wp->layout_cell = NULL via
	 * layout_free_cell.  It also calls layout_fix_offsets/fix_panes and
	 * notify_window, which is fine to do here before we set up the
	 * floating cell.
	 */
	layout_close_pane(wp);		/* wp->layout_cell is NULL afterwards */

	/* Create a detached floating cell with the requested geometry. */
	lc = layout_create_cell(NULL);
	lc->xoff = x;
	lc->yoff = y;
	lc->sx = sx;
	lc->sy = sy;
	layout_make_leaf(lc, wp);	/* sets wp->layout_cell = lc, lc->wp = wp */

	wp->flags |= PANE_FLOATING;
	TAILQ_REMOVE(&w->z_index, wp, zentry);
	TAILQ_INSERT_HEAD(&w->z_index, wp, zentry);

	if (w->layout_root != NULL)
		layout_fix_offsets(w);
	layout_fix_panes(w, NULL);
	notify_window("window-layout-changed", w);
	server_redraw_window(w);

	return (CMD_RETURN_NORMAL);
}

static enum cmd_retval
do_tile_pane(struct window *w, struct window_pane *wp, struct cmdq_item *item)
{
	struct window_pane	*target_wp;
	struct layout_cell	*float_lc, *lc;

	/*
	 * Save the floating geometry so we can restore it next time this pane
	 * is floated without an explicit position/size.
	 */
	float_lc = wp->layout_cell;
	wp->saved_float_xoff = float_lc->xoff;
	wp->saved_float_yoff = float_lc->yoff;
	wp->saved_float_sx   = float_lc->sx;
	wp->saved_float_sy   = float_lc->sy;
	wp->flags |= PANE_SAVED_FLOAT;

	/*
	 * Free the detached floating cell.  Clear its wp pointer first so
	 * layout_free_cell's WINDOWPANE case does not corrupt wp->layout_cell.
	 */
	float_lc->wp = NULL;
	layout_free_cell(float_lc);		/* wp->layout_cell already NULL */
	wp->layout_cell = NULL;

	/*
	 * Find the best tiled pane to split after: prefer the active pane
	 * (if tiled), then the most-recently-visited tiled pane, then any
	 * visible tiled pane.
	 */
	target_wp = NULL;
	if (w->active != NULL && !(w->active->flags & PANE_FLOATING))
		target_wp = w->active;
	if (target_wp == NULL) {
		TAILQ_FOREACH(target_wp, &w->last_panes, sentry) {
			if (!(target_wp->flags & PANE_FLOATING) &&
			    window_pane_visible(target_wp))
				break;
		}
	}
	if (target_wp == NULL) {
		TAILQ_FOREACH(target_wp, &w->panes, entry) {
			if (!(target_wp->flags & PANE_FLOATING) &&
			    window_pane_visible(target_wp))
				break;
		}
	}

	if (target_wp != NULL) {
		lc = layout_split_pane(target_wp, LAYOUT_TOPBOTTOM, -1, 0);
		if (lc == NULL)
			lc = layout_split_pane(target_wp, LAYOUT_LEFTRIGHT,
			    -1, 0);
		if (lc == NULL) {
			cmdq_error(item, "not enough space to tile pane");
			return (CMD_RETURN_ERROR);
		}
		layout_assign_pane(lc, wp, 0);
	} else {
		/*
		 * No tiled panes at all: make this pane the sole tiled pane
		 * (new layout root).
		 */
		lc = layout_create_cell(NULL);
		lc->sx = w->sx;
		lc->sy = w->sy;
		lc->xoff = 0;
		lc->yoff = 0;
		w->layout_root = lc;
		layout_make_leaf(lc, wp);
	}

	wp->flags &= ~PANE_FLOATING;
	TAILQ_REMOVE(&w->z_index, wp, zentry);
	TAILQ_INSERT_TAIL(&w->z_index, wp, zentry);

	window_set_active_pane(w, wp, 1);

	if (w->layout_root != NULL)
		layout_fix_offsets(w);
	layout_fix_panes(w, NULL);
	notify_window("window-layout-changed", w);
	server_redraw_window(w);

	return (CMD_RETURN_NORMAL);
}