/**
 * @license
 * Copyright Google Inc. 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
 */

import {CacheDatabase} from '../src/db-cache';
import {Driver} from '../src/driver';
import {Manifest} from '../src/manifest';
import {MockRequest} from '../testing/fetch';
import {MockFileSystemBuilder, MockServerStateBuilder, tmpHashTableForFs} from '../testing/mock';
import {SwTestHarness, SwTestHarnessBuilder} from '../testing/scope';

(function() {
// Skip environments that don't support the minimum APIs needed to run the SW tests.
if (!SwTestHarness.envIsSupported()) {
  return;
}

const dist = new MockFileSystemBuilder()
                 .addFile('/foo.txt', 'this is foo')
                 .addFile('/bar.txt', 'this is bar')
                 .addFile('/api/test', 'version 1')
                 .addFile('/api/a', 'version A')
                 .addFile('/api/b', 'version B')
                 .addFile('/api/c', 'version C')
                 .addFile('/api/d', 'version D')
                 .addFile('/api/e', 'version E')
                 .addFile('/fresh/data', 'this is fresh data')
                 .addFile('/refresh/data', 'this is some data')
                 .build();


const distUpdate = new MockFileSystemBuilder()
                       .addFile('/foo.txt', 'this is foo v2')
                       .addFile('/bar.txt', 'this is bar')
                       .addFile('/api/test', 'version 2')
                       .addFile('/fresh/data', 'this is fresher data')
                       .addFile('/refresh/data', 'this is refreshed data')
                       .build();

const manifest: Manifest = {
  configVersion: 1,
  timestamp: 1234567890123,
  index: '/index.html',
  assetGroups: [
    {
      name: 'assets',
      installMode: 'prefetch',
      updateMode: 'prefetch',
      urls: [
        '/foo.txt',
        '/bar.txt',
      ],
      patterns: [],
    },
  ],
  dataGroups: [
    {
      name: 'testPerf',
      maxSize: 3,
      strategy: 'performance',
      patterns: ['^/api/.*$'],
      timeoutMs: 1000,
      maxAge: 5000,
      version: 1,
    },
    {
      name: 'testRefresh',
      maxSize: 3,
      strategy: 'performance',
      patterns: ['^/refresh/.*$'],
      timeoutMs: 1000,
      refreshAheadMs: 1000,
      maxAge: 5000,
      version: 1,
    },
    {
      name: 'testFresh',
      maxSize: 3,
      strategy: 'freshness',
      patterns: ['^/fresh/.*$'],
      timeoutMs: 1000,
      maxAge: 5000,
      version: 1,
    },
  ],
  navigationUrls: [],
  hashTable: tmpHashTableForFs(dist),
};

const seqIncreasedManifest: Manifest = {
  ...manifest,
  dataGroups: [
    {
      ...manifest.dataGroups![0],
      version: 2,
    },
    manifest.dataGroups![1],
    manifest.dataGroups![2],
  ],
};


const server = new MockServerStateBuilder().withStaticFiles(dist).withManifest(manifest).build();

const serverUpdate =
    new MockServerStateBuilder().withStaticFiles(distUpdate).withManifest(manifest).build();

const serverSeqUpdate = new MockServerStateBuilder()
                            .withStaticFiles(distUpdate)
                            .withManifest(seqIncreasedManifest)
                            .build();


describe('data cache', () => {
  let scope: SwTestHarness;
  let driver: Driver;
  beforeEach(async () => {
    scope = new SwTestHarnessBuilder().withServerState(server).build();
    driver = new Driver(scope, scope, new CacheDatabase(scope, scope));

    // Initialize.
    expect(await makeRequest(scope, '/foo.txt')).toEqual('this is foo');
    await driver.initialized;
    server.clearRequests();
    serverUpdate.clearRequests();
    serverSeqUpdate.clearRequests();
  });
  afterEach(() => {
    server.reset();
    serverUpdate.reset();
    serverSeqUpdate.reset();
  });

  describe('in performance mode', () => {
    it('names the caches correctly', async () => {
      expect(await makeRequest(scope, '/api/test')).toEqual('version 1');
      const keys = await scope.caches.keys();
      expect(keys.every(key => key.startsWith('ngsw:/:'))).toEqual(true);
    });

    it('caches a basic request', async () => {
      expect(await makeRequest(scope, '/api/test')).toEqual('version 1');
      server.assertSawRequestFor('/api/test');
      scope.advance(1000);
      expect(await makeRequest(scope, '/api/test')).toEqual('version 1');
      server.assertNoOtherRequests();
    });

    it('does not cache opaque responses', async () => {
      expect(await makeNoCorsRequest(scope, '/api/test')).toBe('');
      server.assertSawRequestFor('/api/test');

      expect(await makeNoCorsRequest(scope, '/api/test')).toBe('');
      server.assertSawRequestFor('/api/test');
    });

    it('refreshes after awhile', async () => {
      expect(await makeRequest(scope, '/api/test')).toEqual('version 1');
      server.clearRequests();
      scope.advance(10000);
      scope.updateServerState(serverUpdate);
      expect(await makeRequest(scope, '/api/test')).toEqual('version 2');
    });

    it('expires the least recently used entry', async () => {
      expect(await makeRequest(scope, '/api/a')).toEqual('version A');
      expect(await makeRequest(scope, '/api/b')).toEqual('version B');
      expect(await makeRequest(scope, '/api/c')).toEqual('version C');
      expect(await makeRequest(scope, '/api/d')).toEqual('version D');
      expect(await makeRequest(scope, '/api/e')).toEqual('version E');
      server.clearRequests();
      expect(await makeRequest(scope, '/api/c')).toEqual('version C');
      expect(await makeRequest(scope, '/api/d')).toEqual('version D');
      expect(await makeRequest(scope, '/api/e')).toEqual('version E');
      server.assertNoOtherRequests();
      expect(await makeRequest(scope, '/api/a')).toEqual('version A');
      expect(await makeRequest(scope, '/api/b')).toEqual('version B');
      server.assertSawRequestFor('/api/a');
      server.assertSawRequestFor('/api/b');
      server.assertNoOtherRequests();
    });

    it('does not carry over cache with new version', async () => {
      expect(await makeRequest(scope, '/api/test')).toEqual('version 1');
      scope.updateServerState(serverSeqUpdate);
      expect(await driver.checkForUpdate()).toEqual(true);
      await driver.updateClient(await scope.clients.get('default'));
      expect(await makeRequest(scope, '/api/test')).toEqual('version 2');
    });
  });

  describe('in freshness mode', () => {
    it('goes to the server first', async () => {
      expect(await makeRequest(scope, '/fresh/data')).toEqual('this is fresh data');
      server.assertSawRequestFor('/fresh/data');
      server.clearRequests();
      expect(await makeRequest(scope, '/fresh/data')).toEqual('this is fresh data');
      server.assertSawRequestFor('/fresh/data');
      server.assertNoOtherRequests();
      scope.updateServerState(serverUpdate);
      expect(await makeRequest(scope, '/fresh/data')).toEqual('this is fresher data');
      serverUpdate.assertSawRequestFor('/fresh/data');
      serverUpdate.assertNoOtherRequests();
    });

    it('caches opaque responses', async () => {
      expect(await makeNoCorsRequest(scope, '/fresh/data')).toBe('');
      server.assertSawRequestFor('/fresh/data');

      server.online = false;

      expect(await makeRequest(scope, '/fresh/data')).toBe('');
      server.assertNoOtherRequests();
    });

    it('falls back on the cache when server times out', async () => {
      expect(await makeRequest(scope, '/fresh/data')).toEqual('this is fresh data');
      server.assertSawRequestFor('/fresh/data');
      server.clearRequests();
      scope.updateServerState(serverUpdate);
      serverUpdate.pause();
      const [res, done] = makePendingRequest(scope, '/fresh/data');

      await serverUpdate.nextRequest;

      // Since the network request doesn't return within the timeout of 1,000ms,
      // this should return cached data.
      scope.advance(2000);

      expect(await res).toEqual('this is fresh data');

      // Unpausing allows the worker to continue with caching.
      serverUpdate.unpause();
      await done;

      serverUpdate.pause();
      const [res2, done2] = makePendingRequest(scope, '/fresh/data');
      await serverUpdate.nextRequest;
      scope.advance(2000);
      expect(await res2).toEqual('this is fresher data');
    });

    it('refreshes ahead', async () => {
      server.assertNoOtherRequests();
      serverUpdate.assertNoOtherRequests();
      expect(await makeRequest(scope, '/refresh/data')).toEqual('this is some data');
      server.assertSawRequestFor('/refresh/data');
      server.clearRequests();
      expect(await makeRequest(scope, '/refresh/data')).toEqual('this is some data');
      server.assertNoOtherRequests();
      scope.updateServerState(serverUpdate);
      scope.advance(1500);
      expect(await makeRequest(scope, '/refresh/data')).toEqual('this is some data');
      serverUpdate.assertSawRequestFor('/refresh/data');
      expect(await makeRequest(scope, '/refresh/data')).toEqual('this is refreshed data');
      serverUpdate.assertNoOtherRequests();
    });

    it('caches opaque responses on refresh', async () => {
      // Make the initial request and populate the cache.
      expect(await makeRequest(scope, '/fresh/data')).toBe('this is fresh data');
      server.assertSawRequestFor('/fresh/data');
      server.clearRequests();

      // Update the server state and pause the server, so the next request times out.
      scope.updateServerState(serverUpdate);
      serverUpdate.pause();
      const [res, done] =
          makePendingRequest(scope, new MockRequest('/fresh/data', {mode: 'no-cors'}));

      // The network request times out after 1,000ms and the cached response is returned.
      await serverUpdate.nextRequest;
      scope.advance(2000);
      expect(await res).toBe('this is fresh data');

      // Unpause the server to allow the network request to complete and be cached.
      serverUpdate.unpause();
      await done;

      // Pause the server to force the cached (opaque) response to be returned.
      serverUpdate.pause();
      const [res2] = makePendingRequest(scope, '/fresh/data');
      await serverUpdate.nextRequest;
      scope.advance(2000);

      expect(await res2).toBe('');
    });
  });
});
})();

function makeRequest(scope: SwTestHarness, url: string, clientId?: string): Promise<string|null> {
  const [resTextPromise, done] = makePendingRequest(scope, url, clientId);
  return done.then(() => resTextPromise);
}

function makeNoCorsRequest(
    scope: SwTestHarness, url: string, clientId?: string): Promise<string|null> {
  const req = new MockRequest(url, {mode: 'no-cors'});
  const [resTextPromise, done] = makePendingRequest(scope, req, clientId);
  return done.then(() => resTextPromise);
}

function makePendingRequest(scope: SwTestHarness, urlOrReq: string|MockRequest, clientId?: string):
    [Promise<string|null>, Promise<void>] {
  const req = (typeof urlOrReq === 'string') ? new MockRequest(urlOrReq) : urlOrReq;
  const [resPromise, done] = scope.handleFetch(req, clientId || 'default');
  return [
    resPromise.then<string|null>(res => res ? res.text() : null),
    done,
  ];
}