backend.service.ts

import { Injectable, Inject } from '@angular/core';
import {HttpClient, HttpParams} from '@angular/common/http';
import { Observable, of } from 'rxjs';
import {catchError, map, switchMap} from 'rxjs/operators';
import {LoginData, BookletStatus, PersonTokenAndTestId, KeyValuePair, SysConfig} from './app.interfaces';
import {ErrorHandler, ServerError} from 'iqb-components';

// ============================================================================
@Injectable({
  providedIn: 'root'
})
export class BackendService {

  constructor(
    @Inject('SERVER_URL') private readonly serverUrl: string,
    private http: HttpClient
  ) {}


  login(name: string, password: string): Observable<LoginData | ServerError> {

    return this.http
        .put<LoginData>(this.serverUrl + 'session/login', {name, password})
        .pipe(
          catchError(ErrorHandler.handle),
          switchMap(myLoginData => {
            if (myLoginData instanceof ServerError) {
              if ((myLoginData as ServerError).code === 401) {
                return this.http
                  .put<LoginData>(this.serverUrl + 'session/admin', {name, password})
                  .pipe(catchError(ErrorHandler.handle));
              } else {
                return of(myLoginData);
              }
            } else {
              return of(myLoginData);
            }
          })
        );
  }


  getSession(loginToken: string, personToken: string): Observable<LoginData | ServerError> {

    const authToken = JSON.stringify({l: loginToken, p: personToken});
    return this.http
      .get<LoginData>(this.serverUrl + 'session', {headers: {'AuthToken': authToken}})
      .pipe(catchError(ErrorHandler.handle));
  }


  getAdminSession(adminToken: string): Observable<LoginData | ServerError> {

    const authToken = JSON.stringify({at: adminToken});
    return this.http
      .get<LoginData>(this.serverUrl + 'session', {headers: {'AuthToken': authToken}})
      .pipe(catchError(ErrorHandler.handle));
  }


  getSysConfig(): Observable<KeyValuePair> {

    return this.http
      .get<SysConfig>(this.serverUrl + `system/config`)
      .pipe(catchError(() => of(null)))
      .pipe(map((sysConfig: SysConfig): KeyValuePair => {
        console.log(sysConfig.version); // TODO check for system version mismatch https://github.com/iqb-berlin/testcenter-iqb-ng/issues/53
        return sysConfig.customTexts;
      }));
  }


  getBookletState(bookletName: string, code = ''): Observable<BookletStatus | ServerError> {

    // TODO after https://github.com/iqb-berlin/testcenter-iqb-ng/issues/52 is resolved,
    //  this must be removed, we would have a personToken here
    const params = new HttpParams().set('code', code);

    return this.http
      .get<BookletStatus>(this.serverUrl + `booklet/${bookletName}/state`, {params})
      .pipe(catchError(ErrorHandler.handle));
  }


  startBooklet(code: string, bookletName: string, bookletLabel: string): Observable<PersonTokenAndTestId | ServerError> {

    return this.http
      .put<PersonTokenAndTestId>(this.serverUrl + `test`, {code, bookletName, bookletLabel})
      .pipe(catchError(ErrorHandler.handle));
  }


  addBookletLogClose(testId: number): Observable<boolean | ServerError> {

    return this.http
      .put<boolean>(this.serverUrl + `test/${testId}/log`, {timestamp: Date.now(), entry: 'BOOKLETLOCKEDbyTESTEE'})
      .pipe(catchError(ErrorHandler.handle));
  }


  lockBooklet(testId: number): Observable<boolean | ServerError> {

    return this.http
      .patch<boolean>(this.serverUrl + `test/${testId}/lock`, {})
      .pipe(catchError(ErrorHandler.handle));
  }
}