/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * 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
 */

/// <reference types="jasmine-ajax" />

import {HTTP_INTERCEPTORS, HttpBackend, HttpClient, HttpClientModule, HttpEvent, HttpEventType, HttpHandler, HttpInterceptor, HttpRequest, HttpResponse} from '@angular/common/http';
import {Injectable} from '@angular/core';
import {TestBed, waitForAsync} from '@angular/core/testing';
import {HttpClientBackendService, HttpClientInMemoryWebApiModule} from 'angular-in-memory-web-api';
import {Observable, zip} from 'rxjs';
import {concatMap, map, tap} from 'rxjs/operators';

import {Hero} from './fixtures/hero';
import {HeroInMemDataOverrideService} from './fixtures/hero-in-mem-data-override-service';
import {HeroInMemDataService} from './fixtures/hero-in-mem-data-service';
import {HeroService} from './fixtures/hero-service';
import {HttpClientHeroService} from './fixtures/http-client-hero-service';

describe('HttpClient Backend Service', () => {
  const delay = 1;  // some minimal simulated latency delay

  describe('raw Angular HttpClient', () => {
    let http: HttpClient;

    beforeEach(() => {
      TestBed.configureTestingModule({
        imports: [
          HttpClientModule, HttpClientInMemoryWebApiModule.forRoot(HeroInMemDataService, {delay})
        ]
      });

      http = TestBed.get(HttpClient);
    });

    it('can get heroes', waitForAsync(() => {
         http.get<Hero[]>('api/heroes')
             .subscribe(
                 heroes => expect(heroes.length).toBeGreaterThan(0, 'should have heroes'),
                 failRequest);
       }));

    it('GET should be a "cold" observable', waitForAsync(() => {
         const httpBackend = TestBed.get(HttpBackend);
         const spy = spyOn(httpBackend, 'collectionHandler').and.callThrough();
         const get$ = http.get<Hero[]>('api/heroes');

         // spy on `collectionHandler` should not be called before subscribe
         expect(spy).not.toHaveBeenCalled();

         get$.subscribe(heroes => {
           expect(spy).toHaveBeenCalled();
           expect(heroes.length).toBeGreaterThan(0, 'should have heroes');
         }, failRequest);
       }));

    it('GET should wait until after delay to respond', waitForAsync(() => {
         // to make test fail, set `delay=0` above
         let gotResponse = false;

         http.get<Hero[]>('api/heroes').subscribe(heroes => {
           gotResponse = true;
           expect(heroes.length).toBeGreaterThan(0, 'should have heroes');
         }, failRequest);

         expect(gotResponse).toBe(false, 'should delay before response');
       }));

    it('Should only initialize the db once', waitForAsync(() => {
         const httpBackend = TestBed.get(HttpBackend);
         const spy = spyOn(httpBackend, 'resetDb').and.callThrough();

         // Simultaneous backend.handler calls
         // Only the first should initialize by calling `resetDb`
         // All should wait until the db is "ready"
         // then they share the same db instance.
         http.get<Hero[]>('api/heroes').subscribe();
         http.get<Hero[]>('api/heroes').subscribe();
         http.get<Hero[]>('api/heroes').subscribe();
         http.get<Hero[]>('api/heroes').subscribe();

         expect(spy.calls.count()).toBe(1);
       }));

    it('can get heroes (w/ a different base path)', waitForAsync(() => {
         http.get<Hero[]>('some-base-path/heroes').subscribe(heroes => {
           expect(heroes.length).toBeGreaterThan(0, 'should have heroes');
         }, failRequest);
       }));

    it('should 404 when GET unknown collection (after delay)', waitForAsync(() => {
         let gotError = false;
         const url = 'api/unknown-collection';
         http.get<Hero[]>(url).subscribe(
             () => fail(`should not have found data for '${url}'`), err => {
               gotError = true;
               expect(err.status).toBe(404, 'should have 404 status');
             });

         expect(gotError).toBe(false, 'should not get error until after delay');
       }));

    it('should return the hero w/id=1 for GET app/heroes/1', waitForAsync(() => {
         http.get<Hero>('api/heroes/1')
             .subscribe(
                 hero => expect(hero).toBeDefined('should find hero with id=1'), failRequest);
       }));

    // test where id is string that looks like a number
    it('should return the stringer w/id="10" for GET app/stringers/10', waitForAsync(() => {
         http.get<Hero>('api/stringers/10')
             .subscribe(
                 hero => expect(hero).toBeDefined('should find string with id="10"'), failRequest);
       }));

    it('should return 1-item array for GET app/heroes/?id=1', waitForAsync(() => {
         http.get<Hero[]>('api/heroes/?id=1')
             .subscribe(
                 heroes => expect(heroes.length).toBe(1, 'should find one hero w/id=1'),
                 failRequest);
       }));

    it('should return 1-item array for GET app/heroes?id=1', waitForAsync(() => {
         http.get<Hero[]>('api/heroes?id=1')
             .subscribe(
                 heroes => expect(heroes.length).toBe(1, 'should find one hero w/id=1'),
                 failRequest);
       }));

    it('should return undefined for GET app/heroes?id=not-found-id', waitForAsync(() => {
         http.get<Hero[]>('api/heroes?id=123456')
             .subscribe(heroes => expect(heroes.length).toBe(0), failRequest);
       }));

    it('should return 404 for GET app/heroes/not-found-id', waitForAsync(() => {
         const url = 'api/heroes/123456';
         http.get<Hero[]>(url).subscribe(
             () => fail(`should not have found data for '${url}'`),
             err => expect(err.status).toBe(404, 'should have 404 status'));
       }));

    it('can generate the id when add a hero with no id', waitForAsync(() => {
         const hero = new Hero(undefined, 'SuperDooper');
         http.post<Hero>('api/heroes', hero).subscribe(replyHero => {
           expect(replyHero.id).toBeDefined('added hero should have an id');
           expect(replyHero).not.toBe(hero, 'reply hero should not be the request hero');
         }, failRequest);
       }));

    it('can get nobodies (empty collection)', waitForAsync(() => {
         http.get<Hero[]>('api/nobodies').subscribe(nobodies => {
           expect(nobodies.length).toBe(0, 'should have no nobodies');
         }, failRequest);
       }));

    it('can add a nobody with an id to empty nobodies collection', waitForAsync(() => {
         const id = 'g-u-i-d';

         http.post('api/nobodies', {id, name: 'Noman'})
             .pipe(concatMap(() => http.get<{id: string; name: string;}[]>('api/nobodies')))
             .subscribe(nobodies => {
               expect(nobodies.length).toBe(1, 'should a nobody');
               expect(nobodies[0].name).toBe('Noman', 'should be "Noman"');
               expect(nobodies[0].id).toBe(id, 'should preserve the submitted, ' + id);
             }, failRequest);
       }));

    it('should fail when add a nobody without an id to empty nobodies collection',
       waitForAsync(() => {
         http.post('api/nobodies', {name: 'Noman'})
             .subscribe(
                 () => fail(`should not have been able to add 'Norman' to 'nobodies'`), err => {
                   expect(err.status).toBe(422, 'should have 422 status');
                   expect(err.body.error).toContain('id type is non-numeric');
                 });
       }));

    describe('can reset the database', () => {
      it('to empty (object db)', waitForAsync(() => resetDatabaseTest('object')));

      it('to empty (observable db)', waitForAsync(() => resetDatabaseTest('observable')));

      it('to empty (promise db)', waitForAsync(() => resetDatabaseTest('promise')));

      function resetDatabaseTest(returnType: string) {
        // Observable of the number of heroes and nobodies
        const sizes$ =
            zip(http.get<Hero[]>('api/heroes'), http.get<Hero[]>('api/nobodies'),
                http.get<Hero[]>('api/stringers'))
                .pipe(map(
                    ([h, n, s]) => ({heroes: h.length, nobodies: n.length, stringers: s.length})));

        // Add a nobody so that we have one
        http.post('api/nobodies', {id: 42, name: 'Noman'})
            .pipe(
                // Reset database with "clear" option
                concatMap(() => http.post('commands/resetDb', {clear: true, returnType})),
                // get the number of heroes and nobodies
                concatMap(() => sizes$))
            .subscribe(sizes => {
              expect(sizes.heroes).toBe(0, 'reset should have cleared the heroes');
              expect(sizes.nobodies).toBe(0, 'reset should have cleared the nobodies');
              expect(sizes.stringers).toBe(0, 'reset should have cleared the stringers');
            }, failRequest);
      }
    });
  });

  describe('raw Angular HttpClient w/ override service', () => {
    let http: HttpClient;

    beforeEach(() => {
      TestBed.configureTestingModule({
        imports: [
          HttpClientModule,
          HttpClientInMemoryWebApiModule.forRoot(HeroInMemDataOverrideService, {delay})
        ]
      });

      http = TestBed.get(HttpClient);
    });

    it('can get heroes', waitForAsync(() => {
         http.get<Hero[]>('api/heroes')
             .subscribe(
                 heroes => expect(heroes.length).toBeGreaterThan(0, 'should have heroes'),
                 failRequest);
       }));

    it('can translate `foo/heroes` to `heroes` via `parsedRequestUrl` override',
       waitForAsync(() => {
         http.get<Hero[]>('api/foo/heroes')
             .subscribe(
                 heroes => expect(heroes.length).toBeGreaterThan(0, 'should have heroes'),
                 failRequest);
       }));

    it('can get villains', waitForAsync(() => {
         http.get<Hero[]>('api/villains')
             .subscribe(
                 villains => expect(villains.length).toBeGreaterThan(0, 'should have villains'),
                 failRequest);
       }));

    it('should 404 when POST to villains', waitForAsync(() => {
         const url = 'api/villains';
         http.post<Hero[]>(url, {id: 42, name: 'Dr. Evil'})
             .subscribe(
                 () => fail(`should not have POSTed data for '${url}'`),
                 err => expect(err.status).toBe(404, 'should have 404 status'));
       }));

    it('should 404 when GET unknown collection', waitForAsync(() => {
         const url = 'api/unknown-collection';
         http.get<Hero[]>(url).subscribe(
             () => fail(`should not have found data for '${url}'`),
             err => expect(err.status).toBe(404, 'should have 404 status'));
       }));

    it('should use genId override to add new hero, "Maxinius"', waitForAsync(() => {
         http.post('api/heroes', {name: 'Maxinius'})
             .pipe(concatMap(() => http.get<Hero[]>('api/heroes?name=Maxi')))
             .subscribe(heroes => {
               expect(heroes.length).toBe(1, 'should have found "Maxinius"');
               expect(heroes[0].name).toBe('Maxinius');
               expect(heroes[0].id).toBeGreaterThan(1000);
             }, failRequest);
       }));

    it('should use genId override guid generator for a new nobody without an id',
       waitForAsync(() => {
         http.post('api/nobodies', {name: 'Noman'})
             .pipe(concatMap(() => http.get<{id: string; name: string}[]>('api/nobodies')))
             .subscribe(nobodies => {
               expect(nobodies.length).toBe(1, 'should a nobody');
               expect(nobodies[0].name).toBe('Noman', 'should be "Noman"');
               expect(typeof nobodies[0].id).toBe('string', 'should create a string (guid) id');
             }, failRequest);
       }));

    describe('can reset the database', () => {
      it('to empty (object db)', waitForAsync(() => resetDatabaseTest('object')));

      it('to empty (observable db)', waitForAsync(() => resetDatabaseTest('observable')));

      it('to empty (promise db)', waitForAsync(() => resetDatabaseTest('promise')));

      function resetDatabaseTest(returnType: string) {
        // Observable of the number of heroes, nobodies and villains
        const sizes$ = zip(http.get<Hero[]>('api/heroes'), http.get<Hero[]>('api/nobodies'),
                           http.get<Hero[]>('api/stringers'), http.get<Hero[]>('api/villains'))
                           .pipe(map(([h, n, s, v]) => ({
                                       heroes: h.length,
                                       nobodies: n.length,
                                       stringers: s.length,
                                       villains: v.length
                                     })));

        // Add a nobody so that we have one
        http.post('api/nobodies', {id: 42, name: 'Noman'})
            .pipe(
                // Reset database with "clear" option
                concatMap(() => http.post('commands/resetDb', {clear: true, returnType})),
                // count all the collections
                concatMap(() => sizes$))
            .subscribe(sizes => {
              expect(sizes.heroes).toBe(0, 'reset should have cleared the heroes');
              expect(sizes.nobodies).toBe(0, 'reset should have cleared the nobodies');
              expect(sizes.stringers).toBe(0, 'reset should have cleared the stringers');
              expect(sizes.villains).toBeGreaterThan(0, 'reset should NOT clear villains');
            }, failRequest);
      }
    });
  });

  describe('HttpClient HeroService', () => {
    beforeEach(() => {
      TestBed.configureTestingModule({
        imports: [
          HttpClientModule, HttpClientInMemoryWebApiModule.forRoot(HeroInMemDataService, {delay})
        ],
        providers: [{provide: HeroService, useClass: HttpClientHeroService}]
      });
    });

    describe('HeroService core', () => {
      let heroService: HeroService;

      beforeEach(() => {
        heroService = TestBed.get(HeroService);
      });

      it('can get heroes', waitForAsync(() => {
           heroService.getHeroes().subscribe(heroes => {
             expect(heroes.length).toBeGreaterThan(0, 'should have heroes');
           }, failRequest);
         }));

      it('can get hero w/ id=1', waitForAsync(() => {
           heroService.getHero(1).subscribe(hero => {
             expect(hero.name).toBe('Windstorm');
           }, () => fail('getHero failed'));
         }));

      it('should 404 when hero id not found', waitForAsync(() => {
           const id = 123456;
           heroService.getHero(id).subscribe(
               () => fail(`should not have found hero for id='${id}'`), err => {
                 expect(err.status).toBe(404, 'should have 404 status');
               });
         }));

      it('can add a hero', waitForAsync(() => {
           heroService.addHero('FunkyBob')
               .pipe(
                   tap(hero => expect(hero.name).toBe('FunkyBob')),
                   // Get the new hero by its generated id
                   concatMap(hero => heroService.getHero(hero.id)))
               .subscribe(hero => {
                 expect(hero.name).toBe('FunkyBob');
               }, () => failRequest('re-fetch of new hero failed'));
         }),
         10000);

      it('can delete a hero', waitForAsync(() => {
           const id = 1;
           heroService.deleteHero(id).subscribe((_: {}) => expect(_).toBeDefined(), failRequest);
         }));

      it('should allow delete of non-existent hero', waitForAsync(() => {
           const id = 123456;
           heroService.deleteHero(id).subscribe((_: {}) => expect(_).toBeDefined(), failRequest);
         }));

      it('can search for heroes by name containing "a"', waitForAsync(() => {
           heroService.searchHeroes('a').subscribe((heroes: Hero[]) => {
             expect(heroes.length).toBe(3, 'should find 3 heroes with letter "a"');
           }, failRequest);
         }));

      it('can update existing hero', waitForAsync(() => {
           const id = 1;
           heroService.getHero(id)
               .pipe(
                   concatMap(hero => {
                     hero.name = 'Thunderstorm';
                     return heroService.updateHero(hero);
                   }),
                   concatMap(() => heroService.getHero(id)))
               .subscribe(
                   hero => expect(hero.name).toBe('Thunderstorm'),
                   () => fail('re-fetch of updated hero failed'));
         }),
         10000);

      it('should create new hero when try to update non-existent hero', waitForAsync(() => {
           const falseHero = new Hero(12321, 'DryMan');
           heroService.updateHero(falseHero).subscribe(
               hero => expect(hero.name).toBe(falseHero.name), failRequest);
         }));
    });
  });

  describe('HttpClient interceptor', () => {
    let http: HttpClient;
    let interceptors: HttpInterceptor[];
    let httpBackend: HttpClientBackendService;

    /**
     * Test interceptor adds a request header and a response header
     */
    @Injectable()
    class TestHeaderInterceptor implements HttpInterceptor {
      intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        const reqClone = req.clone({setHeaders: {'x-test-req': 'req-test-header'}});

        return next.handle(reqClone).pipe(map(event => {
          if (event instanceof HttpResponse) {
            event = event.clone({headers: event.headers.set('x-test-res', 'res-test-header')});
          }
          return event;
        }));
      }
    }

    beforeEach(() => {
      TestBed.configureTestingModule({
        imports: [
          HttpClientModule, HttpClientInMemoryWebApiModule.forRoot(HeroInMemDataService, {delay})
        ],
        providers: [
          // Add test interceptor just for this test suite
          {provide: HTTP_INTERCEPTORS, useClass: TestHeaderInterceptor, multi: true}
        ]
      });

      http = TestBed.get(HttpClient);
      httpBackend = TestBed.get(HttpBackend);
      interceptors = TestBed.get(HTTP_INTERCEPTORS);
    });

    // sanity test
    it('TestingModule should provide the test interceptor', () => {
      const ti = interceptors.find(i => i instanceof TestHeaderInterceptor);
      expect(ti).toBeDefined();
    });

    it('should have GET request header from test interceptor', waitForAsync(() => {
         const handle = spyOn(httpBackend, 'handle').and.callThrough();

         http.get<Hero[]>('api/heroes').subscribe(heroes => {
           // HttpRequest is first arg of the first call to in-mem backend `handle`
           const req: HttpRequest<Hero[]> = handle.calls.argsFor(0)[0];
           const reqHeader = req.headers.get('x-test-req');
           expect(reqHeader).toBe('req-test-header');

           expect(heroes.length).toBeGreaterThan(0, 'should have heroes');
         }, failRequest);
       }));

    it('should have GET response header from test interceptor', waitForAsync(() => {
         let gotResponse = false;
         const req = new HttpRequest<any>('GET', 'api/heroes');
         http.request<Hero[]>(req).subscribe(event => {
           if (event.type === HttpEventType.Response) {
             gotResponse = true;

             const resHeader = event.headers.get('x-test-res');
             expect(resHeader).toBe('res-test-header');

             const heroes = event.body as Hero[];
             expect(heroes.length).toBeGreaterThan(0, 'should have heroes');
           }
         }, failRequest, () => expect(gotResponse).toBe(true, 'should have seen Response event'));
       }));
  });

  describe('HttpClient passThru', () => {
    let http: HttpClient;
    let httpBackend: HttpClientBackendService;
    let createPassThruBackend: jasmine.Spy;

    beforeEach(() => {
      TestBed.configureTestingModule({
        imports: [
          HttpClientModule,
          HttpClientInMemoryWebApiModule.forRoot(
              HeroInMemDataService, {delay, passThruUnknownUrl: true})
        ]
      });

      http = TestBed.get(HttpClient);
      httpBackend = TestBed.get(HttpBackend);
      createPassThruBackend = spyOn(<any>httpBackend, 'createPassThruBackend').and.callThrough();
    });

    beforeEach(() => {
      jasmine.Ajax.install();
    });

    afterEach(() => {
      jasmine.Ajax.uninstall();
    });

    it('can get heroes (no passthru)', waitForAsync(() => {
         http.get<Hero[]>('api/heroes').subscribe(heroes => {
           expect(createPassThruBackend).not.toHaveBeenCalled();
           expect(heroes.length).toBeGreaterThan(0, 'should have heroes');
         }, failRequest);
       }));

    // `passthru` is NOT a collection in the data store
    // so requests for it should pass thru to the "real" server

    it('can GET passthru', waitForAsync(() => {
         jasmine.Ajax.stubRequest('api/passthru').andReturn({
           'status': 200,
           'contentType': 'application/json',
           'response': JSON.stringify([{id: 42, name: 'Dude'}])
         });

         http.get<any[]>('api/passthru').subscribe(passthru => {
           expect(passthru.length).toBeGreaterThan(0, 'should have passthru data');
         }, failRequest);
       }));

    it('can ADD to passthru', waitForAsync(() => {
         jasmine.Ajax.stubRequest('api/passthru').andReturn({
           'status': 200,
           'contentType': 'application/json',
           'response': JSON.stringify({id: 42, name: 'Dude'})
         });

         http.post<any>('api/passthru', {name: 'Dude'}).subscribe(passthru => {
           expect(passthru).toBeDefined('should have passthru data');
           expect(passthru.id).toBe(42, 'passthru object should have id 42');
         }, failRequest);
       }));
  });

  describe('Http dataEncapsulation = true', () => {
    let http: HttpClient;

    beforeEach(() => {
      TestBed.configureTestingModule({
        imports: [
          HttpClientModule,
          HttpClientInMemoryWebApiModule.forRoot(
              HeroInMemDataService, {delay, dataEncapsulation: true})
        ]
      });

      http = TestBed.get(HttpClient);
    });

    it('can get heroes (encapsulated)', waitForAsync(() => {
         http.get<{data: any}>('api/heroes')
             .pipe(map(data => data.data as Hero[]))
             .subscribe(
                 heroes => expect(heroes.length).toBeGreaterThan(0, 'should have data.heroes'),
                 failRequest);
       }));
  });
});


/**
 * Fail a Jasmine test such that it displays the error object,
 * typically passed in the error path of an Observable.subscribe()
 */
function failRequest(err: any) {
  fail(JSON.stringify(err));
}