/*
 * Copyright 2000-2012 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 git4idea.ui.branch;

import com.intellij.dvcs.DvcsUtil;
import com.intellij.dvcs.ui.BranchActionGroupPopup;
import com.intellij.dvcs.ui.RootAction;
import com.intellij.notification.Notification;
import com.intellij.notification.NotificationListener;
import com.intellij.openapi.actionSystem.ActionGroup;
import com.intellij.openapi.actionSystem.AnAction;
import com.intellij.openapi.actionSystem.DefaultActionGroup;
import com.intellij.openapi.options.ShowSettingsUtil;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.ui.popup.ListPopup;
import com.intellij.openapi.util.Condition;
import com.intellij.openapi.vcs.VcsNotifier;
import com.intellij.ui.popup.list.ListPopupImpl;
import com.intellij.util.containers.ContainerUtil;
import git4idea.GitLocalBranch;
import git4idea.GitUtil;
import git4idea.GitVcs;
import git4idea.branch.GitBranchUtil;
import git4idea.config.GitVcsSettings;
import git4idea.repo.GitRepository;
import git4idea.repo.GitRepositoryManager;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import javax.swing.*;
import javax.swing.event.HyperlinkEvent;
import java.util.List;

/**
 * The popup which allows to quickly switch and control Git branches.
 * <p/>
 */
class GitBranchPopup {

  private final Project myProject;
  private final GitRepositoryManager myRepositoryManager;
  private final GitVcsSettings myVcsSettings;
  private final GitVcs myVcs;
  private final GitMultiRootBranchConfig myMultiRootBranchConfig;

  private final GitRepository myCurrentRepository;
  private final ListPopupImpl myPopup;

  ListPopup asListPopup() {
    return myPopup;
  }

  /**
   * @param currentRepository Current repository, which means the repository of the currently open or selected file.
   *                          In the case of synchronized branch operations current repository matter much less, but sometimes is used,
   *                          for example, it is preselected in the repositories combobox in the compare branches dialog.
   */
  static GitBranchPopup getInstance(@NotNull Project project, @NotNull GitRepository currentRepository) {
    return new GitBranchPopup(project, currentRepository);
  }

  private GitBranchPopup(@NotNull Project project, @NotNull GitRepository currentRepository) {
    myProject = project;
    myCurrentRepository = currentRepository;
    myRepositoryManager = GitUtil.getRepositoryManager(project);
    myVcs = GitVcs.getInstance(project);
    myVcsSettings = GitVcsSettings.getInstance(myProject);

    myMultiRootBranchConfig = new GitMultiRootBranchConfig(myRepositoryManager.getRepositories());

    String title = createPopupTitle(currentRepository);

    Condition<AnAction> preselectActionCondition = new Condition<AnAction>() {
      @Override
      public boolean value(AnAction action) {
        if (action instanceof GitBranchPopupActions.LocalBranchActions) {
          GitBranchPopupActions.LocalBranchActions branchAction = (GitBranchPopupActions.LocalBranchActions)action;
          String branchName = branchAction.getBranchName();

          String recentBranch;
          List<GitRepository> repositories = branchAction.getRepositories();
          if (repositories.size() == 1) {
            recentBranch = myVcsSettings.getRecentBranchesByRepository().get(repositories.iterator().next().getRoot().getPath());
          }
          else {
            recentBranch = myVcsSettings.getRecentCommonBranch();
          }

          if (recentBranch != null && recentBranch.equals(branchName)) {
            return true;
          }
        }
        return false;
      }
    };

    myPopup = new BranchActionGroupPopup(title, project, preselectActionCondition, createActions());

    initBranchSyncPolicyIfNotInitialized();
    setCurrentBranchInfo();
    warnThatBranchesDivergedIfNeeded();
  }

  private void initBranchSyncPolicyIfNotInitialized() {
    if (myRepositoryManager.moreThanOneRoot() && myVcsSettings.getSyncSetting() == GitBranchSyncSetting.NOT_DECIDED) {
      if (!myMultiRootBranchConfig.diverged()) {
        notifyAboutSyncedBranches();
        myVcsSettings.setSyncSetting(GitBranchSyncSetting.SYNC);
      }
      else {
        myVcsSettings.setSyncSetting(GitBranchSyncSetting.DONT);
      }
    }
  }

  @NotNull
  private String createPopupTitle(@NotNull GitRepository currentRepository) {
    String title = "Git Branches";
    if (myRepositoryManager.moreThanOneRoot() &&
        (myMultiRootBranchConfig.diverged() || myVcsSettings.getSyncSetting() == GitBranchSyncSetting.DONT)) {
      title += " in " + DvcsUtil.getShortRepositoryName(currentRepository);
    }
    return title;
  }

  private void setCurrentBranchInfo() {
    String currentBranchText = "Current branch";
    if (myRepositoryManager.moreThanOneRoot()) {
      if (myMultiRootBranchConfig.diverged()) {
        currentBranchText += " in " + DvcsUtil.getShortRepositoryName(myCurrentRepository) + ": " +
                             GitBranchUtil.getDisplayableBranchText(myCurrentRepository);
      }
      else {
        currentBranchText += ": " + myMultiRootBranchConfig.getCurrentBranch();
      }
    }
    else {
      currentBranchText += ": " + GitBranchUtil.getDisplayableBranchText(myCurrentRepository);
    }
    myPopup.setAdText(currentBranchText, SwingConstants.CENTER);
  }

  private void notifyAboutSyncedBranches() {
    String description = "You have several Git roots in the project and they all are checked out at the same branch. " +
                         "We've enabled synchronous branch control for the project. <br/>" +
                         "If you wish to control branches in different roots separately, " +
                         "you may <a href='settings'>disable</a> the setting.";
    NotificationListener listener = new NotificationListener() {
      @Override
      public void hyperlinkUpdate(@NotNull Notification notification, @NotNull HyperlinkEvent event) {
        if (event.getEventType() == HyperlinkEvent.EventType.ACTIVATED) {
          ShowSettingsUtil.getInstance().showSettingsDialog(myProject, myVcs.getConfigurable().getDisplayName());
          if (myVcsSettings.getSyncSetting() == GitBranchSyncSetting.DONT) {
            notification.expire();
          }
        }
      }
    };
    VcsNotifier.getInstance(myProject).notifyImportantInfo("Synchronous branch control enabled", description, listener);
  }

  private ActionGroup createActions() {
    DefaultActionGroup popupGroup = new DefaultActionGroup(null, false);
    GitRepositoryManager repositoryManager = myRepositoryManager;
    if (repositoryManager.moreThanOneRoot()) {
      if (userWantsSyncControl()) {
        fillWithCommonRepositoryActions(popupGroup, repositoryManager);
      }
      else {
        fillPopupWithCurrentRepositoryActions(popupGroup, createRepositoriesActions());
      }
    }
    else {
      fillPopupWithCurrentRepositoryActions(popupGroup, null);
    }
    popupGroup.addSeparator();
    return popupGroup;
  }

  private boolean userWantsSyncControl() {
    return (myVcsSettings.getSyncSetting() != GitBranchSyncSetting.DONT);
  }

  private void fillWithCommonRepositoryActions(DefaultActionGroup popupGroup, GitRepositoryManager repositoryManager) {
    List<GitRepository> allRepositories = repositoryManager.getRepositories();
    popupGroup.add(new GitBranchPopupActions.GitNewBranchAction(myProject, allRepositories));

    popupGroup.addAll(createRepositoriesActions());

    popupGroup.addSeparator("Common Local Branches");
    for (String branch : myMultiRootBranchConfig.getLocalBranches()) {
      List<GitRepository> repositories = filterRepositoriesNotOnThisBranch(branch, allRepositories);
      if (!repositories.isEmpty()) {
        popupGroup.add(new GitBranchPopupActions.LocalBranchActions(myProject, repositories, branch, myCurrentRepository));
      }
    }

    popupGroup.addSeparator("Common Remote Branches");
    for (String branch : myMultiRootBranchConfig.getRemoteBranches()) {
      popupGroup.add(new GitBranchPopupActions.RemoteBranchActions(myProject, allRepositories, branch, myCurrentRepository));
    }
  }

  @NotNull
  private static List<GitRepository> filterRepositoriesNotOnThisBranch(@NotNull final String branch,
                                                                       @NotNull List<GitRepository> allRepositories) {
    return ContainerUtil.filter(allRepositories, new Condition<GitRepository>() {
      @Override
      public boolean value(GitRepository repository) {
        GitLocalBranch currentBranch = repository.getCurrentBranch();
        return currentBranch == null || !branch.equals(currentBranch.getName());
      }
    });
  }

  private void warnThatBranchesDivergedIfNeeded() {
    if (myRepositoryManager.moreThanOneRoot() && myMultiRootBranchConfig.diverged() && userWantsSyncControl()) {
      myPopup.setWarning("Branches have diverged");
    }
  }

  private DefaultActionGroup createRepositoriesActions() {
    DefaultActionGroup popupGroup = new DefaultActionGroup(null, false);
    popupGroup.addSeparator("Repositories");
    for (GitRepository repository : myRepositoryManager.getRepositories()) {
      popupGroup.add(new RootAction<GitRepository>(repository, highlightCurrentRepo() ? myCurrentRepository : null,
                                                   new GitBranchPopupActions(repository.getProject(), repository).createActions(null),
                                                   GitBranchUtil.getDisplayableBranchText(repository)));
    }
    return popupGroup;
  }

  private boolean highlightCurrentRepo() {
    return !userWantsSyncControl() || myMultiRootBranchConfig.diverged();
  }

  private void fillPopupWithCurrentRepositoryActions(@NotNull DefaultActionGroup popupGroup, @Nullable DefaultActionGroup actions) {
    popupGroup.addAll(new GitBranchPopupActions(myCurrentRepository.getProject(), myCurrentRepository).createActions(actions));
  }
}