import { EBiometricsEnvironment, EBiometricsMessage, EBiometricsState, MessageCode } from '../models';
import { EBM_WEBSOCKET_API_ENDPOINT_DEVELOPMENT, EBM_WEBSOCKET_API_ENDPOINT_PRODUCTION } from '../constants';

export class WebsocketService {
  private _url: string;
  private _room: string | undefined;
  private _websocket: WebSocket | undefined;

  constructor() {
    this._url = EBM_WEBSOCKET_API_ENDPOINT_DEVELOPMENT;
  }

  private _configure(state: EBiometricsState): void {
    this._room = state.id;
    if (state.environment === EBiometricsEnvironment.production) {
      this._url = EBM_WEBSOCKET_API_ENDPOINT_PRODUCTION;
    }
  }

  private _processMessage(data: string, state: EBiometricsState): void {
    const message: EBiometricsMessage = JSON.parse(data);

    if (message.code === MessageCode.BIOMETRICS_RETRY) {
      state.onRetry();
    }

    if (message.code === MessageCode.BIOMETRICS_ERROR) {
      state.onError({ message: message.content });
    }

    if (message.code === MessageCode.BIOMETRICS_COMPLETED) {
      state.onSuccess({ id: message.content });
    }
  }

  connect(state: EBiometricsState): void {
    this._configure(state);
    this._websocket = new WebSocket(`${this._url}?room=${this._room}`);

    this._websocket.onerror = () => {
      this.connect(state);
    };

    this._websocket.onclose = () => {
      this.connect(state);
    }

    this._websocket.onmessage = (event: any) => {
      if (event && event.data) {
        this._processMessage(event.data, state);
      }
    };
  }
}