import { TileLayer } from 'leaflet';
import { registerWithParent, buildOptions, parseAttributeValue } from '../core/utils.js';
import { withProps } from '../core/with-props.js';

import {
  createChildRegisterHandler,
  type ChildEntry,
  LeafletRegisterEvent,
} from '../core/register.js';
import type { PropDef } from '../types/props.js';

const PROPS = {
  url: { kind: 'str', attr: 'url', default: '' },
  attribution: { kind: 'str', attr: 'attribution', default: '' },
  minZoom: { kind: 'num', attr: 'min-zoom', default: 0 },
  maxZoom: { kind: 'num', attr: 'max-zoom', default: 18 },
  opacity: { kind: 'num', attr: 'opacity', default: 1.0 },
  zIndex: { kind: 'num', attr: 'z-index', default: 0 },
} satisfies Record<string, PropDef>;

const PROP_BY_ATTR = new Map<string, string>(
  Object.entries(PROPS).map(([name, spec]) => [spec.attr, name]),
);

export class LeafletTileLayer extends withProps(HTMLElement, PROPS) {
  #obj?: TileLayer;
  #children = new Map<HTMLElement, ChildEntry>();
  #childHandler?: (e: LeafletRegisterEvent) => void;

  connectedCallback() {
    const url = this.getAttribute('url') || '';
    this.#obj = new TileLayer(url, buildOptions(this, PROPS, ['url']));
    this.#childHandler = createChildRegisterHandler(this.#obj, this.#children);
    this.addEventListener('leaflet-register', this.#childHandler);
    registerWithParent(this, this.#obj);
  }

  disconnectedCallback() {
    if (this.#childHandler) this.removeEventListener('leaflet-register', this.#childHandler);
    this.#children.clear();
    this.#obj?.remove();
    this.#obj = undefined;
  }

  attributeChangedCallback(name: string, _old: string | null, val: string | null) {
    if (!this.#obj) return;
    if (name === 'url') {
      if (val) this.#obj.setUrl(val);
    } else {
      const propName = PROP_BY_ATTR.get(name);
      if (!propName) return;
      const setter =
        `set${propName.charAt(0).toUpperCase()}${propName.slice(1)}` as keyof TileLayer;
      if (typeof this.#obj[setter] === 'function') {
        (this.#obj[setter] as (v: unknown) => void)(parseAttributeValue(val));
      }
    }
  }
}

customElements.define('leaflet-tile-layer', LeafletTileLayer);