import { Polygon, type PolylineOptions } from 'leaflet';
import { pathProps } from '../core/shared-props.ts';
import {
  WithProps,
  type LeafletAddEventListener,
  type LeafletElementConstructor,
  type LeafletRemoveEventListener,
} from '../core/with-props.ts';
import type { PathEvents } from '../core/event-types.ts';
import type { LeafletLineRemoveEvent, LeafletLineSyncEvent } from '../core/register.ts';
import { VertexTracker } from '../core/vertex-tracker.ts';

const PROPS = { ...pathProps } as const;
const Base: LeafletElementConstructor<Polygon, typeof PROPS> = WithProps(PROPS);

/** `<leaflet-polygon>` — a Leaflet `Polygon`. Vertices come from `<leaflet-line>` children, not an attribute. */
export default class LeafletPolygonElement extends Base {
  declare readonly leafletObject?: Polygon;
  declare addEventListener: LeafletAddEventListener<PathEvents>;
  declare removeEventListener: LeafletRemoveEventListener<PathEvents>;

  #vertices = new VertexTracker();

  createLeafletObject(options: PolylineOptions): Polygon {
    return new Polygon(this.#vertices.coords(), options);
  }

  // Vertices come from <leaflet-line> children rather than an attribute --
  // each one announces its own position via leaflet-line-sync/-remove, we
  // never read a child's state directly.
  connectedCallback(): void {
    super.connectedCallback();
    this.addEventListener('leaflet-line-sync', this.#onLineSync);
    this.addEventListener('leaflet-line-remove', this.#onLineRemove);
  }

  disconnectedCallback(): void {
    this.removeEventListener('leaflet-line-sync', this.#onLineSync);
    this.removeEventListener('leaflet-line-remove', this.#onLineRemove);
    super.disconnectedCallback();
  }

  #onLineSync = (e: LeafletLineSyncEvent) => {
    this.#vertices.sync(e.detail.element, e.detail.latlng);
    this.leafletObject?.setLatLngs(this.#vertices.coords());
  };

  #onLineRemove = (e: LeafletLineRemoveEvent) => {
    this.#vertices.remove(e.detail.element);
    this.leafletObject?.setLatLngs(this.#vertices.coords());
  };
}