/*
 * Copyright 2000-2015 JetBrains s.r.o.
 *
 * 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.intellij.execution.testframework.actions;

import com.intellij.diff.DiffContentFactory;
import com.intellij.diff.contents.DiffContent;
import com.intellij.diff.impl.DiffRequestProcessor;
import com.intellij.diff.requests.DiffRequest;
import com.intellij.diff.requests.ErrorDiffRequest;
import com.intellij.diff.requests.NoDiffRequest;
import com.intellij.diff.requests.SimpleDiffRequest;
import com.intellij.diff.util.DiffPlaces;
import com.intellij.diff.util.DiffUserDataKeys;
import com.intellij.diff.util.DiffUserDataKeysEx.ScrollToPolicy;
import com.intellij.execution.ExecutionBundle;
import com.intellij.execution.testframework.stacktrace.DiffHyperlink;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.util.Pair;
import com.intellij.openapi.vfs.LocalFileSystem;
import com.intellij.openapi.vfs.VirtualFile;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.util.List;

public class TestDiffRequestProcessor extends DiffRequestProcessor {
  @NotNull private final List<DiffHyperlink> myRequests;
  private int myIndex;

  public TestDiffRequestProcessor(@Nullable Project project, @NotNull List<DiffHyperlink> requests, int index) {
    super(project, DiffPlaces.TESTS_FAILED_ASSERTIONS);
    myRequests = requests;
    myIndex = index;

    putContextUserData(DiffUserDataKeys.DO_NOT_IGNORE_WHITESPACES, true);
  }

  //
  // Impl
  //

  @Override
  public void updateRequest(boolean force, @Nullable ScrollToPolicy scrollToChangePolicy) {
    applyRequest(loadRequest(), force, scrollToChangePolicy);
  }

  @NotNull
  private DiffRequest loadRequest() {
    if (myIndex < 0 || myIndex >= myRequests.size()) return NoDiffRequest.INSTANCE;
    DiffHyperlink hyperlink = myRequests.get(myIndex);
    try {
      String title = hyperlink.getDiffTitle();

      Pair<String, DiffContent> content1 = createContentWithTitle("diff.content.expected.title",
                                                                  hyperlink.getLeft(), hyperlink.getFilePath());
      Pair<String, DiffContent> content2 = createContentWithTitle("diff.content.actual.title",
                                                                  hyperlink.getRight(), hyperlink.getActualFilePath());

      return new SimpleDiffRequest(title, content1.second, content2.second, content1.first, content2.first);
    }
    catch (Exception e) {
      return new ErrorDiffRequest(e);
    }
  }

  private Pair<String, DiffContent> createContentWithTitle(String titleKey, String contentString, String contentFilePath) {
    String title;
    DiffContent content;
    VirtualFile vFile;
    if (contentFilePath != null && (vFile = LocalFileSystem.getInstance().findFileByPath(contentFilePath)) != null) {
      title = ExecutionBundle.message(titleKey) + " (" + vFile.getPresentableUrl() + ")";
      content = DiffContentFactory.getInstance().create(getProject(), vFile);
    }
    else {
      title = ExecutionBundle.message(titleKey);
      content = DiffContentFactory.getInstance().create(contentString);
    }
    return Pair.create(title, content);
  }

  //
  // Navigation
  //

  @Override
  protected boolean hasNextChange() {
    return true; // TODO: disable looping ?
  }

  @Override
  protected boolean hasPrevChange() {
    return true;
  }

  @Override
  protected void goToNextChange(boolean fromDifferences) {
    myIndex++;
    if (myIndex >= myRequests.size()) myIndex = 0;

    updateRequest(false, fromDifferences ? ScrollToPolicy.FIRST_CHANGE : null);
  }

  @Override
  protected void goToPrevChange(boolean fromDifferences) {
    myIndex--;
    if (myIndex < 0) myIndex = myRequests.size() - 1;

    updateRequest(false, fromDifferences ? ScrollToPolicy.LAST_CHANGE : null);
  }

  @Override
  protected boolean isNavigationEnabled() {
    return myRequests.size() > 1;
  }
}