import { Room, MatrixEvent } from 'matrix-js-sdk';
import { useMemo } from 'react';
import { Widget } from 'matrix-widget-api';
import { StateEvent } from '../../../../types/matrix/room';
import { StateKeyToEvents, useRoomState } from '../../../hooks/useRoomState';
import { isWidgetUrlSafe } from './widgetUtils';

/**
 * Builds the `Widget` list from raw `im.vector.modular.widgets` state events.
 *
 * NOTE: we do NOT use `WidgetParser.parseWidgetsFromRoomState` here. In
 * matrix-widget-api 1.17.0 its `isValidUrl` compares `URL.protocol` (which is
 * always colon-suffixed, e.g. "https:") against the bare strings "http"/
 * "https", so it rejects every URL and the parser always returns []. We build
 * the `Widget`s ourselves with a correct scheme check plus the existing
 * `isWidgetUrlSafe` origin check.
 */
export const widgetsFromStateEvents = (
  widgetEvents: StateKeyToEvents | undefined,
  appOrigin: string,
): Widget[] => {
  if (!widgetEvents) return [];
  const widgets: Widget[] = [];
  Array.from(widgetEvents.values()).forEach((event: MatrixEvent) => {
    const content = event.getContent();
    // Removed widgets are represented as an empty content state event.
    if (!content || Object.keys(content).length === 0) return;

    const id = event.getStateKey();
    const { type, url, name, data, waitForIframeLoad } = content;
    const creatorUserId = content.creatorUserId || event.getSender();
    if (!id || !type || !url || !creatorUserId) return;

    let scheme: string;
    try {
      scheme = new URL(url).protocol;
    } catch {
      return;
    }
    if (scheme !== 'https:') return;
    if (!isWidgetUrlSafe(url, appOrigin)) return;

    widgets.push(
      new Widget({
        id,
        creatorUserId,
        type,
        url,
        name,
        data,
        waitForIframeLoad,
      }),
    );
  });
  return widgets;
};

/**
 * All valid `im.vector.modular.widgets` room widgets, reactive on room state.
 */
export const useRoomWidgets = (room: Room): Widget[] => {
  const state = useRoomState(room);
  return useMemo(
    () => widgetsFromStateEvents(state.get(StateEvent.Widget), window.location.origin),
    [state],
  );
};