/*
 * Copyright 2016 The Bazel Authors. All rights reserved.
 *
 * 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.idea.blaze.base.vcs;

import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.ListeningExecutorService;
import com.google.idea.blaze.base.model.primitives.WorkspaceRoot;
import com.google.idea.blaze.base.projectview.ProjectViewSet;
import com.google.idea.blaze.base.scope.BlazeContext;
import com.google.idea.blaze.base.sync.workspace.BlazeRoots;
import com.google.idea.blaze.base.sync.workspace.WorkingSet;
import com.google.idea.blaze.base.sync.workspace.WorkspacePathResolver;
import com.intellij.openapi.extensions.ExtensionPointName;
import com.intellij.openapi.project.Project;

import javax.annotation.Nullable;

/**
 * Provides a diff against the version control system.
 */
public interface BlazeVcsHandler {
  ExtensionPointName<BlazeVcsHandler> EP_NAME = ExtensionPointName.create("com.google.idea.blaze.VcsHandler");

  /**
   * Optionally returns a client name if the supplied workspace root corresponds to this VCS type.
   */
  @Nullable
  String getClientName(WorkspaceRoot workspaceRoot);

  /**
   * Returns whether this vcs handler can manage this project
   */
  boolean handlesProject(Project project, WorkspaceRoot workspaceRoot);

  /**
   * Returns the working set of modified files compared to some "upstream".
   */
  ListenableFuture<WorkingSet> getWorkingSet(Project project,
                                             WorkspaceRoot workspaceRoot,
                                             ListeningExecutorService executor);

  /**
   * Optionally creates a sync handler to perform vcs-specific computation during sync.
   */
  @Nullable
  BlazeVcsSyncHandler createSyncHandler(Project project, WorkspaceRoot workspaceRoot);

  interface BlazeVcsSyncHandler {
    enum ValidationResult {
      OK,
      Error,
      RestartSync, /** The sync process needs restarting **/
    }

    /**
     * Updates the vcs state of the project.
     *
     * @return True for OK, false to abort the sync process.
     */
    boolean update(BlazeContext context, BlazeRoots blazeRoots, ListeningExecutorService executor);

    /**
     * Returns a custom workspace path resolver for this vcs.
     */
    @Nullable
    WorkspacePathResolver getWorkspacePathResolver();

    /**
     * Validates the project view. Can cause sync to fail or restart.
     */
    ValidationResult validateProjectView(BlazeContext context, ProjectViewSet projectViewSet);
  }
}