OAuth2CredentialFactoryImpl.java

/**
 * Licensed to The Apereo Foundation under one or more contributor license
 * agreements. See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 *
 * The Apereo Foundation licenses this file to you under the Educational
 * Community 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://opensource.org/licenses/ecl2.txt
 *
 * 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 org.opencastproject.publication.youtube.auth;

import com.google.api.client.auth.oauth2.Credential;
import com.google.api.client.auth.oauth2.StoredCredential;
import com.google.api.client.extensions.java6.auth.oauth2.AuthorizationCodeInstalledApp;
import com.google.api.client.extensions.jetty.auth.oauth2.LocalServerReceiver;
import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow;
import com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets;
import com.google.api.client.googleapis.auth.oauth2.GoogleCredential;
import com.google.api.client.http.javanet.NetHttpTransport;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.client.util.store.DataStore;
import com.google.api.client.util.store.FileDataStoreFactory;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.text.MessageFormat;

/**
 * @see com.google.api.client.googleapis.auth.oauth2.GoogleCredential
 */
public final class OAuth2CredentialFactoryImpl implements OAuth2CredentialFactory {

  private final Logger logger = LoggerFactory.getLogger(this.getClass());

  public OAuth2CredentialFactoryImpl() {
  }

  @Override
  public GoogleCredential getGoogleCredential(final ClientCredentials credentials) throws IOException {
    // Use the default which is file-based; name and location are configurable
    final DataStore<StoredCredential> datastore = getDataStore(credentials.getCredentialDatastore(),
        credentials.getDataStoreDirectory());
    return getGoogleCredential(datastore, credentials);
  }

  @Override
  public DataStore<StoredCredential> getDataStore(final String id, final String dataStoreDirectory) throws IOException {
    return new FileDataStoreFactory(new File(dataStoreDirectory)).getDataStore(id);
  }

  @Override
  public GoogleCredential getGoogleCredential(final DataStore<StoredCredential> datastore, final ClientCredentials authContext)
          throws IOException {
    final GoogleCredential gCred;
    final LocalServerReceiver localReceiver = new LocalServerReceiver();
    final String accessToken;
    final String refreshToken;

    try {
      // Reads the client id and client secret from a file name passed in authContext
      final GoogleClientSecrets gClientSecrets = GoogleClientSecrets.load(new JacksonFactory(),
              new FileReader(authContext.getClientSecrets()));

      // Obtain tokens from credential in data store, or obtains a new one from
      // Google if one doesn't exist
      final StoredCredential sCred = datastore.get(authContext.getClientId());
      if (sCred != null) {
        accessToken = sCred.getAccessToken();
        refreshToken = sCred.getRefreshToken();
        logger.debug(MessageFormat.format("Found credential for client {0} in data store {1}", authContext.getClientId(), datastore.getId()));
      } else {
        // This flow supports installed applications
        final GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(new NetHttpTransport(), new JacksonFactory(),
                gClientSecrets, authContext.getScopes()).setCredentialDataStore(datastore).setApprovalPrompt("auto")
                .setAccessType("offline").build();
        final Credential cred = new AuthorizationCodeInstalledApp(flow, localReceiver).authorize(authContext.getClientId());
        accessToken = cred.getAccessToken();
        refreshToken = cred.getRefreshToken();
        logger.debug(MessageFormat.format("Created new credential for client {0} in data store {1}", authContext.getClientId(), datastore.getId()));
      }
      gCred = new GoogleCredential.Builder()
          .setClientSecrets(gClientSecrets).setJsonFactory(new JacksonFactory())
          .setTransport(new NetHttpTransport()).build();
      gCred.setAccessToken(accessToken);
      gCred.setRefreshToken(refreshToken);
      logger.debug(MessageFormat.format("Found credential {0} using {1}", gCred.getRefreshToken(), authContext.toString()));
    } finally {
      localReceiver.stop();
    }
    return gCred;
  }
}