import { Connection, NotificationType } from "vscode-languageserver";

// XXX I think we want to combine this into an interface
// with the errors tooling as well

export interface LoadingHandler {
  handle<T>(message: string, value: Promise<T>): Promise<T>;
  handleSync<T>(message: string, value: () => T): T;
  showError(message: string): void;
}

export class LanguageServerLoadingHandler implements LoadingHandler {
  constructor(private connection: Connection) {}
  private latestLoadingToken = 0;
  async handle<T>(message: string, value: Promise<T>): Promise<T> {
    const token = this.latestLoadingToken;
    this.latestLoadingToken += 1;
    this.connection.sendNotification(
      new NotificationType<any>("apollographql/loading"),
      { message, token }
    );
    try {
      const ret = await value;
      this.connection.sendNotification(
        new NotificationType<any>("apollographql/loadingComplete"),
        token
      );
      return ret;
    } catch (e) {
      this.connection.sendNotification(
        new NotificationType<any>("apollographql/loadingComplete"),
        token
      );
      this.showError(`Error in "${message}": ${e}`);
      throw e;
    }
  }
  handleSync<T>(message: string, value: () => T): T {
    const token = this.latestLoadingToken;
    this.latestLoadingToken += 1;
    this.connection.sendNotification(
      new NotificationType<any>("apollographql/loading"),
      { message, token }
    );
    try {
      const ret = value();
      this.connection.sendNotification(
        new NotificationType<any>("apollographql/loadingComplete"),
        token
      );
      return ret;
    } catch (e) {
      this.connection.sendNotification(
        new NotificationType<any>("apollographql/loadingComplete"),
        token
      );
      this.showError(`Error in "${message}": ${e}`);
      throw e;
    }
  }
  showError(message: string) {
    this.connection.window.showErrorMessage(message);
  }
}