#include <assert.h>
#include <stdlib.h>
#include <stdbool.h>
#include <wayland-server.h>
#include <wlr/types/wlr_box.h>
#include <wlr/types/wlr_surface.h>
#include <wlr/types/wlr_xdg_shell_v6.h>
#include <wlr/util/log.h>
#include "rootston/desktop.h"
#include "rootston/server.h"
#include "rootston/input.h"

static void get_size(const struct roots_view *view, struct wlr_box *box) {
	assert(view->type == ROOTS_XDG_SHELL_V6_VIEW);
	struct wlr_xdg_surface_v6 *surface = view->xdg_surface_v6;

	if (surface->geometry->width > 0 && surface->geometry->height > 0) {
		box->width = surface->geometry->width;
		box->height = surface->geometry->height;
	} else {
		box->width = view->wlr_surface->current->width;
		box->height = view->wlr_surface->current->height;
	}
}

static void activate(struct roots_view *view, bool active) {
	assert(view->type == ROOTS_XDG_SHELL_V6_VIEW);
	struct wlr_xdg_surface_v6 *surface = view->xdg_surface_v6;
	if (surface->role == WLR_XDG_SURFACE_V6_ROLE_TOPLEVEL) {
		wlr_xdg_toplevel_v6_set_activated(surface, active);
	}
}

static void apply_size_constraints(struct wlr_xdg_surface_v6 *surface,
		uint32_t width, uint32_t height, uint32_t *dest_width,
		uint32_t *dest_height) {
	*dest_width = width;
	*dest_height = height;

	struct wlr_xdg_toplevel_v6_state *state = &surface->toplevel_state->current;
	if (width < state->min_width) {
		*dest_width = state->min_width;
	} else if (state->max_width > 0 &&
			width > state->max_width) {
		*dest_width = state->max_width;
	}
	if (height < state->min_height) {
		*dest_height = state->min_height;
	} else if (state->max_height > 0 &&
			height > state->max_height) {
		*dest_height = state->max_height;
	}
}

static void resize(struct roots_view *view, uint32_t width, uint32_t height) {
	assert(view->type == ROOTS_XDG_SHELL_V6_VIEW);
	struct wlr_xdg_surface_v6 *surface = view->xdg_surface_v6;
	if (surface->role != WLR_XDG_SURFACE_V6_ROLE_TOPLEVEL) {
		return;
	}

	uint32_t constrained_width, constrained_height;
	apply_size_constraints(surface, width, height, &constrained_width,
		&constrained_height);

	wlr_xdg_toplevel_v6_set_size(surface, constrained_width,
		constrained_height);
}

static void move_resize(struct roots_view *view, double x, double y,
		uint32_t width, uint32_t height) {
	assert(view->type == ROOTS_XDG_SHELL_V6_VIEW);
	struct roots_xdg_surface_v6 *roots_surface = view->roots_xdg_surface_v6;
	struct wlr_xdg_surface_v6 *surface = view->xdg_surface_v6;
	if (surface->role != WLR_XDG_SURFACE_V6_ROLE_TOPLEVEL) {
		return;
	}

	bool update_x = x != view->x;
	bool update_y = y != view->y;

	uint32_t constrained_width, constrained_height;
	apply_size_constraints(surface, width, height, &constrained_width,
		&constrained_height);

	if (update_x) {
		x = x + width - constrained_width;
	}
	if (update_y) {
		y = y + height - constrained_height;
	}

	view->pending_move_resize.update_x = update_x;
	view->pending_move_resize.update_y = update_y;
	view->pending_move_resize.x = x;
	view->pending_move_resize.y = y;
	view->pending_move_resize.width = constrained_width;
	view->pending_move_resize.height = constrained_height;

	uint32_t serial = wlr_xdg_toplevel_v6_set_size(surface, constrained_width,
		constrained_height);
	if (serial > 0) {
		roots_surface->pending_move_resize_configure_serial = serial;
	} else {
		view->x = x;
		view->y = y;
	}
}

static void maximize(struct roots_view *view, bool maximized) {
	assert(view->type == ROOTS_XDG_SHELL_V6_VIEW);
	struct wlr_xdg_surface_v6 *surface = view->xdg_surface_v6;
	if (surface->role != WLR_XDG_SURFACE_V6_ROLE_TOPLEVEL) {
		return;
	}

	wlr_xdg_toplevel_v6_set_maximized(surface, maximized);
}

static void set_fullscreen(struct roots_view *view, bool fullscreen) {
	assert(view->type == ROOTS_XDG_SHELL_V6_VIEW);
	struct wlr_xdg_surface_v6 *surface = view->xdg_surface_v6;
	if (surface->role != WLR_XDG_SURFACE_V6_ROLE_TOPLEVEL) {
		return;
	}

	wlr_xdg_toplevel_v6_set_fullscreen(surface, fullscreen);
}

static void close(struct roots_view *view) {
	assert(view->type == ROOTS_XDG_SHELL_V6_VIEW);
	struct wlr_xdg_surface_v6 *surface = view->xdg_surface_v6;
	if (surface->role == WLR_XDG_SURFACE_V6_ROLE_TOPLEVEL) {
		wlr_xdg_toplevel_v6_send_close(surface);
	}
}

static void handle_request_move(struct wl_listener *listener, void *data) {
	struct roots_xdg_surface_v6 *roots_xdg_surface =
		wl_container_of(listener, roots_xdg_surface, request_move);
	struct roots_view *view = roots_xdg_surface->view;
	struct roots_input *input = view->desktop->server->input;
	struct wlr_xdg_toplevel_v6_move_event *e = data;
	struct roots_seat *seat = input_seat_from_wlr_seat(input, e->seat->seat);
	// TODO verify event serial
	if (!seat || seat->cursor->mode != ROOTS_CURSOR_PASSTHROUGH) {
		return;
	}
	roots_seat_begin_move(seat, view);
}

static void handle_request_resize(struct wl_listener *listener, void *data) {
	struct roots_xdg_surface_v6 *roots_xdg_surface =
		wl_container_of(listener, roots_xdg_surface, request_resize);
	struct roots_view *view = roots_xdg_surface->view;
	struct roots_input *input = view->desktop->server->input;
	struct wlr_xdg_toplevel_v6_resize_event *e = data;
	// TODO verify event serial
	struct roots_seat *seat = input_seat_from_wlr_seat(input, e->seat->seat);
	assert(seat);
	if (!seat || seat->cursor->mode != ROOTS_CURSOR_PASSTHROUGH) {
		return;
	}
	roots_seat_begin_resize(seat, view, e->edges);
}

static void handle_request_maximize(struct wl_listener *listener, void *data) {
	struct roots_xdg_surface_v6 *roots_xdg_surface =
		wl_container_of(listener, roots_xdg_surface, request_maximize);
	struct roots_view *view = roots_xdg_surface->view;
	struct wlr_xdg_surface_v6 *surface = view->xdg_surface_v6;

	if (surface->role != WLR_XDG_SURFACE_V6_ROLE_TOPLEVEL) {
		return;
	}

	view_maximize(view, surface->toplevel_state->next.maximized);
}

static void handle_request_fullscreen(struct wl_listener *listener,
		void *data) {
	struct roots_xdg_surface_v6 *roots_xdg_surface =
		wl_container_of(listener, roots_xdg_surface, request_fullscreen);
	struct roots_view *view = roots_xdg_surface->view;
	struct wlr_xdg_surface_v6 *surface = view->xdg_surface_v6;
	struct wlr_xdg_toplevel_v6_set_fullscreen_event *e = data;

	if (surface->role != WLR_XDG_SURFACE_V6_ROLE_TOPLEVEL) {
		return;
	}

	view_set_fullscreen(view, e->fullscreen, e->output);
}

static void handle_commit(struct wl_listener *listener, void *data) {
	struct roots_xdg_surface_v6 *roots_surface =
		wl_container_of(listener, roots_surface, commit);
	struct roots_view *view = roots_surface->view;
	struct wlr_xdg_surface_v6 *surface = view->xdg_surface_v6;

	uint32_t pending_serial =
		roots_surface->pending_move_resize_configure_serial;
	if (pending_serial > 0 && pending_serial >= surface->configure_serial) {
		struct wlr_box size;
		get_size(view, &size);

		if (view->pending_move_resize.update_x) {
			view->x = view->pending_move_resize.x +
				view->pending_move_resize.width - size.width;
		}
		if (view->pending_move_resize.update_y) {
			view->y = view->pending_move_resize.y +
				view->pending_move_resize.height - size.height;
		}

		if (pending_serial == surface->configure_serial) {
			roots_surface->pending_move_resize_configure_serial = 0;
		}
	}
}

static void handle_destroy(struct wl_listener *listener, void *data) {
	struct roots_xdg_surface_v6 *roots_xdg_surface =
		wl_container_of(listener, roots_xdg_surface, destroy);
	wl_list_remove(&roots_xdg_surface->commit.link);
	wl_list_remove(&roots_xdg_surface->destroy.link);
	wl_list_remove(&roots_xdg_surface->request_move.link);
	wl_list_remove(&roots_xdg_surface->request_resize.link);
	wl_list_remove(&roots_xdg_surface->view->link);
	view_destroy(roots_xdg_surface->view);
	free(roots_xdg_surface);
}

void handle_xdg_shell_v6_surface(struct wl_listener *listener, void *data) {
	struct wlr_xdg_surface_v6 *surface = data;
	assert(surface->role != WLR_XDG_SURFACE_V6_ROLE_NONE);

	if (surface->role == WLR_XDG_SURFACE_V6_ROLE_POPUP) {
		wlr_log(L_DEBUG, "new xdg popup");
		return;
	}

	struct roots_desktop *desktop =
		wl_container_of(listener, desktop, xdg_shell_v6_surface);

	wlr_log(L_DEBUG, "new xdg toplevel: title=%s, app_id=%s",
		surface->title, surface->app_id);
	wlr_xdg_surface_v6_ping(surface);

	struct roots_xdg_surface_v6 *roots_surface =
		calloc(1, sizeof(struct roots_xdg_surface_v6));
	if (!roots_surface) {
		return;
	}
	roots_surface->commit.notify = handle_commit;
	wl_signal_add(&surface->surface->events.commit, &roots_surface->commit);
	roots_surface->destroy.notify = handle_destroy;
	wl_signal_add(&surface->events.destroy, &roots_surface->destroy);
	roots_surface->request_move.notify = handle_request_move;
	wl_signal_add(&surface->events.request_move, &roots_surface->request_move);
	roots_surface->request_resize.notify = handle_request_resize;
	wl_signal_add(&surface->events.request_resize,
		&roots_surface->request_resize);
	roots_surface->request_maximize.notify = handle_request_maximize;
	wl_signal_add(&surface->events.request_maximize,
		&roots_surface->request_maximize);
	roots_surface->request_fullscreen.notify = handle_request_fullscreen;
	wl_signal_add(&surface->events.request_fullscreen,
		&roots_surface->request_fullscreen);

	struct roots_view *view = calloc(1, sizeof(struct roots_view));
	if (!view) {
		free(roots_surface);
		return;
	}
	view->type = ROOTS_XDG_SHELL_V6_VIEW;
	view->xdg_surface_v6 = surface;
	view->roots_xdg_surface_v6 = roots_surface;
	view->wlr_surface = surface->surface;
	view->get_size = get_size;
	view->activate = activate;
	view->resize = resize;
	view->move_resize = move_resize;
	view->maximize = maximize;
	view->set_fullscreen = set_fullscreen;
	view->close = close;
	roots_surface->view = view;
	view_init(view, desktop);
	wl_list_insert(&desktop->views, &view->link);

	view_setup(view);
}