// Copyright 2018 The Feed Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.google.android.libraries.feed.infraintegration;

import static org.mockito.MockitoAnnotations.initMocks;

import com.google.android.libraries.feed.api.common.MutationContext;
import com.google.android.libraries.feed.api.common.testing.ContentIdGenerators;
import com.google.android.libraries.feed.api.sessionmanager.SessionManager;
import com.google.android.libraries.feed.common.testing.InfraIntegrationScope;
import com.google.android.libraries.feed.common.testing.ModelProviderValidator;
import com.google.android.libraries.feed.common.testing.PagingState;
import com.google.android.libraries.feed.common.testing.ResponseBuilder;
import com.google.android.libraries.feed.host.logging.RequestReason;
import com.google.android.libraries.feed.internalapi.modelprovider.ModelChild;
import com.google.android.libraries.feed.internalapi.modelprovider.ModelProvider;
import com.google.android.libraries.feed.internalapi.modelprovider.ModelProviderFactory;
import com.google.android.libraries.feed.testing.requestmanager.FakeFeedRequestManager;
import com.google.search.now.feed.client.StreamDataProto.UiContext;
import com.google.search.now.wire.feed.ContentIdProto.ContentId;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.robolectric.RobolectricTestRunner;

/** Test which verifies that multiple session page correctly when limited paging is on. */
@RunWith(RobolectricTestRunner.class)
public class LimitedPagingTest {
  // Create a simple stream with a root and three features
  private static final ContentId[] PAGE_1 =
      new ContentId[] {
        ResponseBuilder.createFeatureContentId(1),
        ResponseBuilder.createFeatureContentId(2),
        ResponseBuilder.createFeatureContentId(3)
      };
  private static final ContentId[] PAGE_2 =
      new ContentId[] {
        ResponseBuilder.createFeatureContentId(4),
        ResponseBuilder.createFeatureContentId(5),
        ResponseBuilder.createFeatureContentId(6)
      };

  private FakeFeedRequestManager fakeFeedRequestManager;
  private SessionManager sessionManager;
  private ModelProviderFactory modelProviderFactory;
  private ModelProviderValidator modelValidator;

  private final ContentIdGenerators contentIdGenerators = new ContentIdGenerators();

  @Before
  public void setUp() {
    initMocks(this);
    InfraIntegrationScope scope = new InfraIntegrationScope.Builder().build();
    fakeFeedRequestManager = scope.getFakeFeedRequestManager();
    sessionManager = scope.getSessionManager();
    modelProviderFactory = scope.getModelProviderFactory();
    modelValidator = new ModelProviderValidator(scope.getProtocolAdapter());
  }

  @Test
  public void testPagingDetachedSession() {
    PagingState s1State = new PagingState(PAGE_1, PAGE_2, 1, contentIdGenerators);
    fakeFeedRequestManager.queueResponse(s1State.initialResponse);
    fakeFeedRequestManager.triggerRefresh(
        RequestReason.OPEN_WITHOUT_CONTENT,
        sessionManager.getUpdateConsumer(MutationContext.EMPTY_CONTEXT));

    // Create the sessionOne from page1 and a token
    ModelProvider sessionOne = modelProviderFactory.createNew(null, UiContext.getDefaultInstance());
    ModelChild tokenChild = modelValidator.assertCursorContentsWithToken(sessionOne, PAGE_1);

    // Create the sessionTwo matching sessionOne
    ModelProvider sessionTwo = modelProviderFactory.createNew(null, UiContext.getDefaultInstance());
    modelValidator.assertCursorContentsWithToken(sessionTwo, PAGE_1);

    // Now Page session one and verify both session are as expected, only session one will contain
    // the paged content
    fakeFeedRequestManager.queueResponse(s1State.pageResponse);
    sessionOne.handleToken(tokenChild.getModelToken());

    // Create the sessionOne from page1 and a token
    modelValidator.assertCursorContents(
        sessionOne, PAGE_1[0], PAGE_1[1], PAGE_1[2], PAGE_2[0], PAGE_2[1], PAGE_2[2]);
    modelValidator.assertCursorContentsWithToken(sessionTwo, PAGE_1);

    // Now create a new session from $HEAD to verify that the page response was added to $HEAD
    ModelProvider sessionThree =
        modelProviderFactory.createNew(null, UiContext.getDefaultInstance());
    modelValidator.assertCursorContents(
        sessionThree, PAGE_1[0], PAGE_1[1], PAGE_1[2], PAGE_2[0], PAGE_2[1], PAGE_2[2]);

    // Page session two, this should not change anything else
    fakeFeedRequestManager.queueResponse(s1State.pageResponse);
    sessionTwo.handleToken(tokenChild.getModelToken());
    modelValidator.assertCursorContents(
        sessionOne, PAGE_1[0], PAGE_1[1], PAGE_1[2], PAGE_2[0], PAGE_2[1], PAGE_2[2]);
    modelValidator.assertCursorContents(
        sessionTwo, PAGE_1[0], PAGE_1[1], PAGE_1[2], PAGE_2[0], PAGE_2[1], PAGE_2[2]);
    modelValidator.assertCursorContents(
        sessionThree, PAGE_1[0], PAGE_1[1], PAGE_1[2], PAGE_2[0], PAGE_2[1], PAGE_2[2]);

    // Verify that paging session two did not update $HEAD
    ModelProvider sessionFour =
        modelProviderFactory.createNew(null, UiContext.getDefaultInstance());
    modelValidator.assertCursorContents(
        sessionFour, PAGE_1[0], PAGE_1[1], PAGE_1[2], PAGE_2[0], PAGE_2[1], PAGE_2[2]);
  }
}