/*
 * 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.prefetch;

import com.google.idea.blaze.base.settings.Blaze;
import com.intellij.ProjectTopics;
import com.intellij.openapi.components.ProjectComponent;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.roots.ModuleRootAdapter;
import com.intellij.openapi.roots.ModuleRootEvent;
import com.intellij.util.messages.MessageBusConnection;
import org.jetbrains.annotations.NotNull;

/**
 * Instructs prefetchers to prefetch all project files when they may have changed / be stale.
 */
public class PrefetchServiceProjectComponent implements ProjectComponent {
  private final Project project;

  public PrefetchServiceProjectComponent(Project project) {
    this.project = project;
    MessageBusConnection connection = project.getMessageBus().connect(project);
    connection.subscribe(ProjectTopics.PROJECT_ROOTS, new ModuleRootAdapter() {
      @Override
      public void rootsChanged(ModuleRootEvent event) {
        prefetch();
      }
    });
  }

  @Override
  public void projectOpened() {
    prefetch();
  }

  private void prefetch() {
    if (!Blaze.isBlazeProject(project)) {
      return;
    }
    PrefetchService.getInstance().prefetchProjectFiles(project);
  }

  @Override
  public void projectClosed() {
  }

  @Override
  public void initComponent() {
  }

  @Override
  public void disposeComponent() {
  }

  @NotNull
  @Override
  public String getComponentName() {
    return "PrefetchServiceProjectComponent";
  }
}