/*
 * Copyright 2022 Google Inc.
 *
 * 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.
 */

// [START auth_cloud_implicit_adc]

import com.google.api.gax.paging.Page;
import com.google.cloud.storage.Bucket;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;
import java.io.IOException;

public class AuthenticateImplicitWithAdc {

  public static void main(String[] args) throws IOException {
    // TODO(Developer):
    //  1. Before running this sample,
    //  set up Application Default Credentials as described in
    //  https://cloud.google.com/docs/authentication/external/set-up-adc
    //  2. Replace the project variable below.
    //  3. Make sure you have the necessary permission to list storage buckets
    //  "storage.buckets.list"
    String projectId = "your-google-cloud-project-id";
    authenticateImplicitWithAdc(projectId);
  }

  // When interacting with Google Cloud Client libraries, the library can auto-detect the
  // credentials to use.
  public static void authenticateImplicitWithAdc(String project) throws IOException {

    // *NOTE*: Replace the client created below with the client required for your application.
    // Note that the credentials are not specified when constructing the client.
    // Hence, the client library will look for credentials using ADC.
    //
    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests.
    Storage storage = StorageOptions.newBuilder().setProjectId(project).build().getService();

    System.out.println("Buckets:");
    Page<Bucket> buckets = storage.list();
    for (Bucket bucket : buckets.iterateAll()) {
      System.out.println(bucket.toString());
    }
    System.out.println("Listed all storage buckets.");
  }
}
// [END auth_cloud_implicit_adc]