/*
 * Cage: A Wayland kiosk.
 *
 * Copyright (C) 2018-2019 Jente Hidskes
 *
 * See the LICENSE file accompanying this file.
 */

#define _POSIX_C_SOURCE 200809L

#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <wayland-server.h>
#include <wlr/types/wlr_box.h>
#include <wlr/types/wlr_output.h>
#include <wlr/types/wlr_surface.h>

#include "output.h"
#include "seat.h"
#include "server.h"
#include "view.h"

char *
view_get_title(struct cg_view *view)
{
	const char *title = view->get_title(view);
	return strndup(title, strlen(title));
}

void
view_activate(struct cg_view *view, bool activate)
{
	view->activate(view, activate);
}

static void
view_maximize(struct cg_view *view)
{
	struct cg_output *output = view->server->output;
	int output_width, output_height;

	wlr_output_effective_resolution(output->wlr_output, &output_width, &output_height);
	view->maximize(view, output_width, output_height);
}

static void
view_center(struct cg_view *view)
{
	struct wlr_output *output = view->server->output->wlr_output;

	int output_width, output_height;
	wlr_output_effective_resolution(output, &output_width, &output_height);

	int width, height;
	view->get_geometry(view, &width, &height);

	view->x = (output_width - width) / 2;
	view->y = (output_height - height) / 2;
}

void
view_for_each_surface(struct cg_view *view, wlr_surface_iterator_func_t iterator,
		      void *data)
{
	view->for_each_surface(view, iterator, data);
}

struct wlr_surface *
view_wlr_surface_at(struct cg_view *view, double sx, double sy, double *sub_x, double *sub_y)
{
	return view->wlr_surface_at(view, sx, sy, sub_x, sub_y);
}

bool
view_is_primary(struct cg_view *view)
{
	return view->is_primary(view);
}

bool
view_has_children(struct cg_server *server, struct cg_view *parent)
{
	struct cg_view *child;
	wl_list_for_each(child, &server->views, link) {
		if (parent != child && parent->is_parent(parent, child)) {
			return true;
		}
	}
	return false;
}

void
view_position(struct cg_view *view)
{
	if (view_is_primary(view)) {
		view_maximize(view);
	} else {
		view_center(view);
	}
}

void
view_unmap(struct cg_view *view)
{
	wl_list_remove(&view->link);
	view->wlr_surface = NULL;
}

void
view_map(struct cg_view *view, struct wlr_surface *surface)
{
	view->wlr_surface = surface;

	view_position(view);

	wl_list_insert(&view->server->views, &view->link);
	seat_set_focus(view->server->seat, view);
}

void
view_destroy(struct cg_view *view)
{
	struct cg_server *server = view->server;
	bool mapped = true;

#if CAGE_HAS_XWAYLAND
	/* Some applications that aren't yet Wayland-native or
	   otherwise "special" (e.g. Firefox Nightly and Google
	   Chrome/Chromium) spawn an XWayland surface upon startup
	   that is almost immediately closed again. This makes Cage
	   think there are no views left, which results in it
	   exiting. However, after this initial (unmapped) surface,
	   the "real" application surface is opened. This leads to
	   these applications' startup sequences being interrupted by
	   Cage exiting. Hence, to work around this issue, Cage checks
	   whether an XWayland surface has been mapped and exits only
	   if 1) the XWayland surface has been mapped and 2) this was
	   the last surface Cage manages. */
	if (view->type == CAGE_XWAYLAND_VIEW) {
		mapped = view->xwayland_surface->mapped;
	}
#endif

	if (view->wlr_surface != NULL) {
		view_unmap(view);
	}
	free(view);

	/* If there is a previous view in the list, focus that. */
	bool empty = wl_list_empty(&server->views);
	if (!empty) {
		struct cg_view *prev = wl_container_of(server->views.next, prev, link);
		seat_set_focus(server->seat, prev);
	} else if (mapped) {
		/* The list is empty and the last view has been
		   mapped, so we can safely exit. */
		wl_display_terminate(server->wl_display);
	}
}

struct cg_view *
cg_view_create(struct cg_server *server)
{
	struct cg_view *view = calloc(1, sizeof(struct cg_view));

	view->server = server;
	return view;
}

struct cg_view *
cg_view_from_wlr_surface(struct cg_server *server, struct wlr_surface *surface)
{
	struct cg_view *view;
	wl_list_for_each(view, &server->views, link) {
		if (view->wlr_surface == surface) {
			return view;
		}
	}
	return NULL;
}