import {Observable, of as observableOf, throwError as observableThrowError} from 'rxjs';
import {distinctUntilChanged, filter, map, mergeMap, tap} from 'rxjs/operators';
import {Inject, Injectable} from '@angular/core';
import {HALEndpointService} from '../shared/hal-endpoint.service';
import {RequestService} from '../data/request.service';
import {GLOBAL_CONFIG} from '../../../config';
import {GlobalConfig} from '../../../config/global-config.interface';
import {isNotEmpty} from '../../shared/empty.util';
import {AuthGetRequest, AuthPostRequest, GetRequest, PostRequest, RestRequest} from '../data/request.models';
import {AuthStatusResponse, ErrorResponse} from '../cache/response.models';
import {HttpOptions} from '../dspace-rest-v2/dspace-rest-v2.service';
import {getResponseFromEntry} from '../shared/operators';
import {HttpClient} from '@angular/common/http';

@Injectable()
export class AuthRequestService {
  protected linkName = 'authn';
  protected browseEndpoint = '';

  constructor(@Inject(GLOBAL_CONFIG) protected EnvConfig: GlobalConfig,
              protected halService: HALEndpointService,
              protected requestService: RequestService,
              private http: HttpClient) {
  }

  protected fetchRequest(request: RestRequest): Observable<any> {
    return this.requestService.getByUUID(request.uuid).pipe(
      getResponseFromEntry(),
      mergeMap((response) => {
        if (response.isSuccessful && isNotEmpty(response)) {
          return observableOf((response as AuthStatusResponse).response);
        } else if (!response.isSuccessful) {
          return observableThrowError(new Error((response as ErrorResponse).errorMessage));
        }
      })
    );
  }

  protected getEndpointByMethod(endpoint: string, method: string): string {
    return isNotEmpty(method) ? `${endpoint}/${method}` : `${endpoint}`;
  }

  public postToEndpoint(method: string, body?: any, options?: HttpOptions): Observable<any> {
    return this.halService.getEndpoint(this.linkName).pipe(
      filter((href: string) => isNotEmpty(href)),
      tap((href: string) => console.log('This is href in postToEndpoint(): ' , href)),
      map((endpointURL) => this.getEndpointByMethod(endpointURL, method)),
      tap((href2) => {console.log('href2', href2)}),
      distinctUntilChanged(),
      map((endpointURL: string) => new AuthPostRequest(this.requestService.generateRequestId(), endpointURL, body, options)),
      tap((request: PostRequest) => this.requestService.configure(request, true)),
      mergeMap((request: PostRequest) => this.fetchRequest(request)),
      distinctUntilChanged());
  }

  public getRequest(method: string, options?: HttpOptions): Observable<any> {
    console.log('auth.request getRequest() was called');
    return this.halService.getEndpoint(this.linkName).pipe(
      filter((href: string) => isNotEmpty(href)),
      tap((href) => console.log('auth-request.service getRequest()', href)),
      map((endpointURL) => this.getEndpointByMethod(endpointURL, method)),
      tap((whatsThis) => console.log('whatsThis: ', whatsThis)),
      distinctUntilChanged(),
      map((endpointURL: string) => new AuthGetRequest(this.requestService.generateRequestId(), endpointURL, options)),
      tap((request: GetRequest) => this.requestService.configure(request, true)),
      mergeMap((request: GetRequest) => this.fetchRequest(request)),
      distinctUntilChanged());
  }

}