#include <wayland-util.h>
#include <wlr/types/wlr_touch.h>
#include <linux/input-event-codes.h>
#include <stdlib.h>
#include "touch.h"
#include "idle.h"
#include "node.h"
#include "seat.h"
#include "cursor.h"
struct touch_point
{
    int32_t touch_id;
    uint32_t x_offset;
    uint32_t y_offset;
    struct wlr_surface *surface;
    struct wl_list link; /* seat.touch_points */
};

static void seat_touch_down(struct wl_listener *listener, void *data)
{
    struct diyac_seat *seat = wl_container_of(listener, seat, touch_down);
    struct wlr_touch_down_event *event = data;

    diya_idle_manager_notify_activity(seat->wlr_seat);

    /* Compute layout => surface offset and save for this touch point */
    struct touch_point *touch_point = calloc(1, sizeof(*touch_point));
    double x_offset = 0.0, y_offset = 0.0;

    // get surface from touch point
    struct wlr_touch *touch = event->touch;
    /* Convert coordinates: first [0, 1] => layout, then layout => surface */
    double lx, ly;
    wlr_cursor_absolute_to_layout_coords(seat->cursor, &touch->base, event->x, event->y, &lx, &ly);
    double sx, sy;
    struct wlr_scene_node *node = wlr_scene_node_at(&seat->server->scene->tree.node, lx, ly, &sx, &sy);
    x_offset = lx - sx;
    y_offset = ly - sy;
    /* Find the surface and return it if it accepts touch events */
    struct wlr_surface *surface = diyac_wlr_surface_from_node(node);

    if (surface && !wlr_surface_accepts_touch(seat->wlr_seat, surface))
    {
        surface = NULL;
    }

    touch_point->surface = surface;
    touch_point->touch_id = event->touch_id;
    touch_point->x_offset = x_offset;
    touch_point->y_offset = y_offset;

    wl_list_insert(&seat->touch_points, &touch_point->link);
    int touch_point_count = wl_list_length(&seat->touch_points);

    /* hide the cursor when starting touch input */
    // cursor_set_visible(seat, /* visible */ false);

    if (touch_point->surface)
    {
        diyac_seat_pointer_end_grab(seat, touch_point->surface);
        /* Clear focus to not interfere with touch input */
        wlr_seat_pointer_notify_clear_focus(seat->wlr_seat);

        if (touch_point_count == 1)
        {
            wlr_cursor_warp_absolute(seat->cursor, &event->touch->base, event->x, event->y);
        }
        wlr_seat_touch_notify_down(seat->wlr_seat, touch_point->surface, event->time_msec, event->touch_id, sx, sy);
    }
    else
    {
        if (touch_point_count == 1)
        {
            diyac_cursor_emulate_move_absolute(seat, &event->touch->base, event->x, event->y, event->time_msec);
        }
        diyac_cursor_emulate_button(seat, BTN_LEFT, WL_POINTER_BUTTON_STATE_PRESSED, event->time_msec);
    }
}

static void seat_touch_up(struct wl_listener *listener, void *data)
{
    struct diyac_seat *seat = wl_container_of(listener, seat, touch_up);
    struct wlr_touch_up_event *event = data;

    diya_idle_manager_notify_activity(seat->wlr_seat);

    /* Remove the touch point from the seat */
    struct touch_point *touch_point, *tmp;
    wl_list_for_each_safe(touch_point, tmp, &seat->touch_points, link)
    {
        if (touch_point->touch_id == event->touch_id)
        {
            if (touch_point->surface)
            {
                wlr_seat_touch_notify_up(seat->wlr_seat, event->time_msec,
                                         event->touch_id);
            }
            else
            {
                diyac_cursor_emulate_button(seat, BTN_LEFT, WL_POINTER_BUTTON_STATE_RELEASED, event->time_msec);
            }
            wl_list_remove(&touch_point->link);
            free(touch_point);
            break;
        }
    }
}

static void seat_touch_motion(struct wl_listener *listener, void *data)
{
    struct diyac_seat *seat = wl_container_of(listener, seat, touch_motion);
    struct wlr_touch_motion_event *event = data;

    diya_idle_manager_notify_activity(seat->wlr_seat);

    int touch_point_count = wl_list_length(&seat->touch_points);

    /* Find existing touch point to determine initial offsets to subtract */
    struct touch_point *touch_point;
    wl_list_for_each(touch_point, &seat->touch_points, link)
    {
        if (touch_point->touch_id == event->touch_id)
        {
            if (touch_point->surface)
            {
                /* Convert coordinates: first [0, 1] => layout */
                double lx, ly;
                wlr_cursor_absolute_to_layout_coords(seat->cursor,
                                                     &event->touch->base, event->x, event->y, &lx, &ly);

                /* Apply offsets to get surface coords before reporting event */
                double sx = lx - touch_point->x_offset;
                double sy = ly - touch_point->y_offset;

                if (touch_point_count == 1)
                {
                    wlr_cursor_warp_absolute(seat->cursor, &event->touch->base, event->x, event->y);
                }
                wlr_seat_touch_notify_motion(seat->wlr_seat, event->time_msec,
                                             event->touch_id, sx, sy);
            }
            else
            {
                if (touch_point_count == 1)
                {
                    diyac_cursor_emulate_move_absolute(seat, &event->touch->base, event->x, event->y, event->time_msec);
                }
            }
            return;
        }
    }
}

static void seat_touch_frame(struct wl_listener *listener, void *data)
{
    (void) data;
    struct diyac_seat *seat = wl_container_of(listener, seat, touch_frame);

    wlr_seat_touch_notify_frame(seat->wlr_seat);
}

void diyac_touch_init(struct diyac_seat *seat)
{
    seat->touch_down.notify = seat_touch_down;
    wl_signal_add(&seat->cursor->events.touch_down, &seat->touch_down);

    seat->touch_up.notify = seat_touch_up;
    wl_signal_add(&seat->cursor->events.touch_up, &seat->touch_up);

    seat->touch_motion.notify = seat_touch_motion;
    wl_signal_add(&seat->cursor->events.touch_motion, &seat->touch_motion);

    seat->touch_frame.notify = seat_touch_frame;
    wl_signal_add(&seat->cursor->events.touch_frame, &seat->touch_frame);
}
void diyac_touch_drop(struct diyac_seat *seat)
{
    wl_list_remove(&seat->touch_points);

    wl_list_remove(&seat->touch_down.link);
    wl_list_remove(&seat->touch_up.link);
    wl_list_remove(&seat->touch_motion.link);
    wl_list_remove(&seat->touch_frame.link);
}