#define _XOPEN_SOURCE 700
#ifdef __linux__
#include <linux/input-event-codes.h>
#elif __FreeBSD__
#include <dev/evdev/input-event-codes.h>
#endif
#include <wlr/types/wlr_cursor.h>
#include <wlr/types/wlr_xcursor_manager.h>
#include "list.h"
#include "log.h"
#include "sway/input/cursor.h"
#include "sway/layers.h"
#include "sway/output.h"
#include "sway/tree/view.h"
#include "wlr-layer-shell-unstable-v1-protocol.h"

static void cursor_update_position(struct sway_cursor *cursor) {
	double x = cursor->cursor->x;
	double y = cursor->cursor->y;

	cursor->x = x;
	cursor->y = y;
}

static struct wlr_surface *layer_surface_at(struct sway_output *output,
		struct wl_list *layer, double ox, double oy, double *sx, double *sy) {
	struct sway_layer_surface *sway_layer;
	wl_list_for_each_reverse(sway_layer, layer, link) {
		struct wlr_surface *wlr_surface =
			sway_layer->layer_surface->surface;
		double _sx = ox - sway_layer->geo.x;
		double _sy = oy - sway_layer->geo.y;
		// TODO: Test popups/subsurfaces
		if (wlr_surface_point_accepts_input(wlr_surface, _sx, _sy)) {
			*sx = _sx;
			*sy = _sy;
			return wlr_surface;
		}
	}
	return NULL;
}

/**
 * Returns the container at the cursor's position. If there is a surface at that
 * location, it is stored in **surface (it may not be a view).
 */
static struct sway_container *container_at_cursor(struct sway_cursor *cursor,
		struct wlr_surface **surface, double *sx, double *sy) {
	// check for unmanaged views first
	struct wl_list *unmanaged = &root_container.sway_root->xwayland_unmanaged;
	struct sway_xwayland_unmanaged *unmanaged_surface;
	wl_list_for_each_reverse(unmanaged_surface, unmanaged, link) {
		struct wlr_xwayland_surface *xsurface =
			unmanaged_surface->wlr_xwayland_surface;

		double _sx = cursor->x - unmanaged_surface->lx;
		double _sy = cursor->y - unmanaged_surface->ly;
		if (wlr_surface_point_accepts_input(xsurface->surface, _sx, _sy)) {
			*surface = xsurface->surface;
			*sx = _sx;
			*sy = _sy;
			return NULL;
		}
	}

	// find the output the cursor is on
	struct wlr_output_layout *output_layout =
		root_container.sway_root->output_layout;
	struct wlr_output *wlr_output =
		wlr_output_layout_output_at(output_layout, cursor->x, cursor->y);
	if (wlr_output == NULL) {
		return NULL;
	}
	struct sway_output *output = wlr_output->data;
	double ox = cursor->x, oy = cursor->y;
	wlr_output_layout_output_coords(output_layout, wlr_output, &ox, &oy);

	// find the focused workspace on the output for this seat
	struct sway_container *ws =
		seat_get_focus_inactive(cursor->seat, output->swayc);
	if (ws && ws->type != C_WORKSPACE) {
		ws = container_parent(ws, C_WORKSPACE);
	}
	if (!ws) {
		return output->swayc;
	}

	if ((*surface = layer_surface_at(output,
				&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY],
				ox, oy, sx, sy))) {
		return ws;
	}
	if ((*surface = layer_surface_at(output,
				&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_TOP],
				ox, oy, sx, sy))) {
		return ws;
	}

	struct sway_container *c;
	if ((c = container_at(ws, cursor->x, cursor->y, surface, sx, sy))) {
		return c;
	}

	if ((*surface = layer_surface_at(output,
				&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM],
				ox, oy, sx, sy))) {
		return ws;
	}
	if ((*surface = layer_surface_at(output,
				&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND],
				ox, oy, sx, sy))) {
		return ws;
	}

	c = seat_get_focus_inactive(cursor->seat, output->swayc);
	if (c) {
		return c;
	}
	if (!c && output->swayc->children->length) {
		c = output->swayc->children->items[0];
		return c;
	}

	return output->swayc;
}

static void cursor_send_pointer_motion(struct sway_cursor *cursor,
		uint32_t time) {
	struct wlr_seat *seat = cursor->seat->wlr_seat;
	struct wlr_surface *surface = NULL;
	double sx, sy;
	struct sway_container *c = container_at_cursor(cursor, &surface, &sx, &sy);
	if (c && config->focus_follows_mouse) {
		seat_set_focus_warp(cursor->seat, c, false);
	}

	// reset cursor if switching between clients
	struct wl_client *client = NULL;
	if (surface != NULL) {
		client = wl_resource_get_client(surface->resource);
	}
	if (client != cursor->image_client) {
		wlr_xcursor_manager_set_cursor_image(cursor->xcursor_manager,
			"left_ptr", cursor->cursor);
		cursor->image_client = client;
	}

	// send pointer enter/leave
	if (surface != NULL) {
		if (seat_is_input_allowed(cursor->seat, surface)) {
			wlr_seat_pointer_notify_enter(seat, surface, sx, sy);
			wlr_seat_pointer_notify_motion(seat, time, sx, sy);
		}
	} else {
		wlr_seat_pointer_clear_focus(seat);
	}
}

static void handle_cursor_motion(struct wl_listener *listener, void *data) {
	struct sway_cursor *cursor = wl_container_of(listener, cursor, motion);
	struct wlr_event_pointer_motion *event = data;
	wlr_cursor_move(cursor->cursor, event->device,
		event->delta_x, event->delta_y);
	cursor_update_position(cursor);
	cursor_send_pointer_motion(cursor, event->time_msec);
}

static void handle_cursor_motion_absolute(
		struct wl_listener *listener, void *data) {
	struct sway_cursor *cursor =
		wl_container_of(listener, cursor, motion_absolute);
	struct wlr_event_pointer_motion_absolute *event = data;
	wlr_cursor_warp_absolute(cursor->cursor, event->device, event->x, event->y);
	cursor_update_position(cursor);
	cursor_send_pointer_motion(cursor, event->time_msec);
}

static void dispatch_cursor_button(struct sway_cursor *cursor,
		uint32_t time_msec, uint32_t button, enum wlr_button_state state) {
	struct wlr_surface *surface = NULL;
	double sx, sy;
	struct sway_container *cont =
		container_at_cursor(cursor, &surface, &sx, &sy);
	if (surface && wlr_surface_is_layer_surface(surface)) {
		struct wlr_layer_surface *layer =
			wlr_layer_surface_from_wlr_surface(surface);
		if (layer->current.keyboard_interactive) {
			seat_set_focus_layer(cursor->seat, layer);
			return;
		}
	}
	// Avoid moving keyboard focus from a surface that accepts it to one
	// that does not unless the change would move us to a new workspace.
	//
	// This prevents, for example, losing focus when clicking on swaybar.
	if (surface && cont && cont->type != C_VIEW) {
		struct sway_container *new_ws = cont;
		if (new_ws && new_ws->type != C_WORKSPACE) {
			new_ws = container_parent(new_ws, C_WORKSPACE);
		}
		struct sway_container *old_ws = seat_get_focus(cursor->seat);
		if (old_ws && old_ws->type != C_WORKSPACE) {
			old_ws = container_parent(old_ws, C_WORKSPACE);
		}
		if (new_ws != old_ws) {
			seat_set_focus(cursor->seat, cont);
		}
	} else {
		seat_set_focus(cursor->seat, cont);
	}

	wlr_seat_pointer_notify_button(cursor->seat->wlr_seat,
			time_msec, button, state);
}

static void handle_cursor_button(struct wl_listener *listener, void *data) {
	struct sway_cursor *cursor = wl_container_of(listener, cursor, button);
	struct wlr_event_pointer_button *event = data;
	dispatch_cursor_button(cursor,
			event->time_msec, event->button, event->state);
}

static void handle_cursor_axis(struct wl_listener *listener, void *data) {
	struct sway_cursor *cursor = wl_container_of(listener, cursor, axis);
	struct wlr_event_pointer_axis *event = data;
	wlr_seat_pointer_notify_axis(cursor->seat->wlr_seat, event->time_msec,
		event->orientation, event->delta);
}

static void handle_touch_down(struct wl_listener *listener, void *data) {
	struct sway_cursor *cursor = wl_container_of(listener, cursor, touch_down);
	struct wlr_event_touch_down *event = data;
	wlr_log(L_DEBUG, "TODO: handle touch down event: %p", event);
}

static void handle_touch_up(struct wl_listener *listener, void *data) {
	struct sway_cursor *cursor = wl_container_of(listener, cursor, touch_up);
	struct wlr_event_touch_up *event = data;
	wlr_log(L_DEBUG, "TODO: handle touch up event: %p", event);
}

static void handle_touch_motion(struct wl_listener *listener, void *data) {
	struct sway_cursor *cursor =
		wl_container_of(listener, cursor, touch_motion);
	struct wlr_event_touch_motion *event = data;
	wlr_log(L_DEBUG, "TODO: handle touch motion event: %p", event);
}

static void handle_tool_axis(struct wl_listener *listener, void *data) {
	struct sway_cursor *cursor = wl_container_of(listener, cursor, tool_axis);
	struct wlr_event_tablet_tool_axis *event = data;

	if ((event->updated_axes & WLR_TABLET_TOOL_AXIS_X) &&
			(event->updated_axes & WLR_TABLET_TOOL_AXIS_Y)) {
		wlr_cursor_warp_absolute(cursor->cursor, event->device,
			event->x, event->y);
		cursor_update_position(cursor);
		cursor_send_pointer_motion(cursor, event->time_msec);
	} else if ((event->updated_axes & WLR_TABLET_TOOL_AXIS_X)) {
		wlr_cursor_warp_absolute(cursor->cursor, event->device, event->x, -1);
		cursor_update_position(cursor);
		cursor_send_pointer_motion(cursor, event->time_msec);
	} else if ((event->updated_axes & WLR_TABLET_TOOL_AXIS_Y)) {
		wlr_cursor_warp_absolute(cursor->cursor, event->device, -1, event->y);
		cursor_update_position(cursor);
		cursor_send_pointer_motion(cursor, event->time_msec);
	}
}

static void handle_tool_tip(struct wl_listener *listener, void *data) {
	struct sway_cursor *cursor = wl_container_of(listener, cursor, tool_tip);
	struct wlr_event_tablet_tool_tip *event = data;
	dispatch_cursor_button(cursor, event->time_msec,
			BTN_LEFT, event->state == WLR_TABLET_TOOL_TIP_DOWN ?
				WLR_BUTTON_PRESSED : WLR_BUTTON_RELEASED);
}

static void handle_tool_button(struct wl_listener *listener, void *data) {
	struct sway_cursor *cursor = wl_container_of(listener, cursor, tool_button);
	struct wlr_event_tablet_tool_button *event = data;
	// TODO: the user may want to configure which tool buttons are mapped to
	// which simulated pointer buttons
	switch (event->state) {
	case WLR_BUTTON_PRESSED:
		if (cursor->tool_buttons == 0) {
			dispatch_cursor_button(cursor,
					event->time_msec, BTN_RIGHT, event->state);
		}
		cursor->tool_buttons++;
		break;
	case WLR_BUTTON_RELEASED:
		if (cursor->tool_buttons == 1) {
			dispatch_cursor_button(cursor,
					event->time_msec, BTN_RIGHT, event->state);
		}
		cursor->tool_buttons--;
		break;
	}
}

static void handle_request_set_cursor(struct wl_listener *listener,
		void *data) {
	struct sway_cursor *cursor =
		wl_container_of(listener, cursor, request_set_cursor);
	struct wlr_seat_pointer_request_set_cursor_event *event = data;

	struct wl_client *focused_client = NULL;
	struct wlr_surface *focused_surface =
		cursor->seat->wlr_seat->pointer_state.focused_surface;
	if (focused_surface != NULL) {
		focused_client = wl_resource_get_client(focused_surface->resource);
	}

	// TODO: check cursor mode
	if (focused_client == NULL ||
			event->seat_client->client != focused_client) {
		wlr_log(L_DEBUG, "denying request to set cursor from unfocused client");
		return;
	}

	wlr_cursor_set_surface(cursor->cursor, event->surface, event->hotspot_x,
		event->hotspot_y);
	cursor->image_client = focused_client;
}

void sway_cursor_destroy(struct sway_cursor *cursor) {
	if (!cursor) {
		return;
	}

	wlr_xcursor_manager_destroy(cursor->xcursor_manager);
	wlr_cursor_destroy(cursor->cursor);
	free(cursor);
}

struct sway_cursor *sway_cursor_create(struct sway_seat *seat) {
	struct sway_cursor *cursor = calloc(1, sizeof(struct sway_cursor));
	if (!sway_assert(cursor, "could not allocate sway cursor")) {
		return NULL;
	}

	struct wlr_cursor *wlr_cursor = wlr_cursor_create();
	if (!sway_assert(wlr_cursor, "could not allocate wlr cursor")) {
		free(cursor);
		return NULL;
	}

	cursor->seat = seat;
	wlr_cursor_attach_output_layout(wlr_cursor,
		root_container.sway_root->output_layout);

	// input events
	wl_signal_add(&wlr_cursor->events.motion, &cursor->motion);
	cursor->motion.notify = handle_cursor_motion;

	wl_signal_add(&wlr_cursor->events.motion_absolute,
		&cursor->motion_absolute);
	cursor->motion_absolute.notify = handle_cursor_motion_absolute;

	wl_signal_add(&wlr_cursor->events.button, &cursor->button);
	cursor->button.notify = handle_cursor_button;

	wl_signal_add(&wlr_cursor->events.axis, &cursor->axis);
	cursor->axis.notify = handle_cursor_axis;

	wl_signal_add(&wlr_cursor->events.touch_down, &cursor->touch_down);
	cursor->touch_down.notify = handle_touch_down;

	wl_signal_add(&wlr_cursor->events.touch_up, &cursor->touch_up);
	cursor->touch_up.notify = handle_touch_up;

	wl_signal_add(&wlr_cursor->events.touch_motion,
		&cursor->touch_motion);
	cursor->touch_motion.notify = handle_touch_motion;

	// TODO: tablet protocol support
	// Note: We should emulate pointer events for clients that don't support the
	// tablet protocol when the time comes
	wl_signal_add(&wlr_cursor->events.tablet_tool_axis,
		&cursor->tool_axis);
	cursor->tool_axis.notify = handle_tool_axis;

	wl_signal_add(&wlr_cursor->events.tablet_tool_tip, &cursor->tool_tip);
	cursor->tool_tip.notify = handle_tool_tip;

	wl_signal_add(&wlr_cursor->events.tablet_tool_button, &cursor->tool_button);
	cursor->tool_button.notify = handle_tool_button;

	wl_signal_add(&seat->wlr_seat->events.request_set_cursor,
			&cursor->request_set_cursor);
	cursor->request_set_cursor.notify = handle_request_set_cursor;

	cursor->cursor = wlr_cursor;

	return cursor;
}