/**
 * @license
 * Copyright Google LLC All Rights Reserved.sonpCallbackContext
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */

import {HttpHandler} from '@angular/common/http/src/backend';
import {HttpClient} from '@angular/common/http/src/client';
import {HttpContext, HttpContextToken} from '@angular/common/http/src/context';
import {HTTP_INTERCEPTORS, HttpInterceptor} from '@angular/common/http/src/interceptor';
import {HttpRequest} from '@angular/common/http/src/request';
import {HttpEvent, HttpResponse} from '@angular/common/http/src/response';
import {HttpTestingController} from '@angular/common/http/testing/src/api';
import {HttpClientTestingModule} from '@angular/common/http/testing/src/module';
import {TestRequest} from '@angular/common/http/testing/src/request';
import {Injectable, Injector} from '@angular/core';
import {TestBed} from '@angular/core/testing';
import {Observable} from 'rxjs';
import {map} from 'rxjs/operators';

const IS_INTERCEPTOR_C_ENABLED = new HttpContextToken<boolean|undefined>(() => undefined);

class TestInterceptor implements HttpInterceptor {
  constructor(private value: string) {}

  intercept(req: HttpRequest<any>, delegate: HttpHandler): Observable<HttpEvent<any>> {
    const existing = req.headers.get('Intercepted');
    const next = !!existing ? existing + ',' + this.value : this.value;
    req = req.clone({setHeaders: {'Intercepted': next}});
    return delegate.handle(req).pipe(map(event => {
      if (event instanceof HttpResponse) {
        const existing = event.headers.get('Intercepted');
        const next = !!existing ? existing + ',' + this.value : this.value;
        return event.clone({headers: event.headers.set('Intercepted', next)});
      }
      return event;
    }));
  }
}

class InterceptorA extends TestInterceptor {
  constructor() {
    super('A');
  }
}

class InterceptorB extends TestInterceptor {
  constructor() {
    super('B');
  }
}

class InterceptorC extends TestInterceptor {
  constructor() {
    super('C');
  }

  override intercept(req: HttpRequest<any>, delegate: HttpHandler): Observable<HttpEvent<any>> {
    if (req.context.get(IS_INTERCEPTOR_C_ENABLED) === true) {
      return super.intercept(req, delegate);
    }
    return delegate.handle(req);
  }
}

@Injectable()
class ReentrantInterceptor implements HttpInterceptor {
  constructor(private client: HttpClient) {}

  intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    return next.handle(req);
  }
}

describe('HttpClientModule', () => {
  let injector: Injector;
  beforeEach(() => {
    injector = TestBed.configureTestingModule({
      imports: [HttpClientTestingModule],
      providers: [
        {provide: HTTP_INTERCEPTORS, useClass: InterceptorA, multi: true},
        {provide: HTTP_INTERCEPTORS, useClass: InterceptorB, multi: true},
        {provide: HTTP_INTERCEPTORS, useClass: InterceptorC, multi: true},
      ],
    });
  });
  it('initializes HttpClient properly', done => {
    injector.get(HttpClient).get('/test', {responseType: 'text'}).subscribe((value: string) => {
      expect(value).toBe('ok!');
      done();
    });
    injector.get(HttpTestingController).expectOne('/test').flush('ok!');
  });
  it('intercepts outbound responses in the order in which interceptors were bound', done => {
    injector.get(HttpClient)
        .get('/test', {observe: 'response', responseType: 'text'})
        .subscribe(() => done());
    const req = injector.get(HttpTestingController).expectOne('/test') as TestRequest;
    expect(req.request.headers.get('Intercepted')).toEqual('A,B');
    req.flush('ok!');
  });
  it('intercepts outbound responses in the order in which interceptors were bound and include specifically enabled interceptor',
     done => {
       injector.get(HttpClient)
           .get('/test', {
             observe: 'response',
             responseType: 'text',
             context: new HttpContext().set(IS_INTERCEPTOR_C_ENABLED, true)
           })
           .subscribe(value => done());
       const req = injector.get(HttpTestingController).expectOne('/test') as TestRequest;
       expect(req.request.headers.get('Intercepted')).toEqual('A,B,C');
       req.flush('ok!');
     });
  it('intercepts inbound responses in the right (reverse binding) order', done => {
    injector.get(HttpClient)
        .get('/test', {observe: 'response', responseType: 'text'})
        .subscribe((value: HttpResponse<string>) => {
          expect(value.headers.get('Intercepted')).toEqual('B,A');
          done();
        });
    injector.get(HttpTestingController).expectOne('/test').flush('ok!');
  });
  it('allows interceptors to inject HttpClient', done => {
    TestBed.resetTestingModule();
    injector = TestBed.configureTestingModule({
      imports: [HttpClientTestingModule],
      providers: [
        {provide: HTTP_INTERCEPTORS, useClass: ReentrantInterceptor, multi: true},
      ],
    });
    injector.get(HttpClient).get('/test').subscribe(() => {
      done();
    });
    injector.get(HttpTestingController).expectOne('/test').flush('ok!');
  });
});