import { useCallback, useEffect, useRef, useState } from 'react';
import { SyncState } from 'matrix-js-sdk';
import { CALL_ERROR_CHANGED, CallControl } from '../plugins/call/CallControl';
import { CallErrorState } from '../plugins/call/callError';
import { useMatrixClient } from './useMatrixClient';
import { useSyncState } from './useSyncState';

/** [Gitea #318] The fork's current call error (null while the call is fine). */
export function useCallError(control: CallControl): CallErrorState {
  const [err, setErr] = useState(control.callError);
  useEffect(() => {
    const on = () => setErr(control.callError);
    on();
    control.on(CALL_ERROR_CHANGED, on);
    return () => {
      control.off(CALL_ERROR_CHANGED, on);
    };
  }, [control]);
  return err;
}

/**
 * [Gitea #318] After a homeserver stall the call drops with "Connection
 * lost". Once sync is back, reconnect automatically (once per drop).
 */
export function useReconnectWhenSynced(control: CallControl): void {
  const mx = useMatrixClient();
  const err = useCallError(control);
  const tried = useRef<CallErrorState>(null);
  useSyncState(
    mx,
    useCallback(
      (state: SyncState | null) => {
        if (state !== SyncState.Syncing || !err?.recoverable || tried.current === err) return;
        tried.current = err;
        control.reconnect();
      },
      [err, control],
    ),
  );
}