import 'dart:convert';
import 'dart:js_interop';

@JS('window.__zendegi__')
external _ZendegiBridge? get _bridge;

extension type _ZendegiBridge._(JSObject _) implements JSObject {
  external JSString getState();
  external void onEvent(JSString json);
  external set updateState(JSFunction callback);
}

Map<String, dynamic>? readInitialState() {
  final bridge = _bridge;
  if (bridge == null) return null;
  final json = bridge.getState().toDart;
  return jsonDecode(json) as Map<String, dynamic>;
}

void onStateUpdated(void Function(Map<String, dynamic> state) callback) {
  final bridge = _bridge;
  if (bridge == null) return;
  bridge.updateState = ((JSString json) {
    final decoded = jsonDecode(json.toDart) as Map<String, dynamic>;
    callback(decoded);
  }).toJS;
}

void emitEvent(String type, [Map<String, dynamic>? payload]) {
  final bridge = _bridge;
  if (bridge == null) return;
  final event = <String, dynamic>{'type': type};
  if (payload != null) {
    event['payload'] = payload;
  }
  bridge.onEvent(jsonEncode(event).toJS);
}