/*
 * Copyright Red Hat, Inc. and/or its affiliates
 * and other contributors as indicated by the @author tags and
 * the COPYRIGHT.txt file distributed with this work.
 *
 * 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 org.teiid.resource.adapter.google.v4;

import static org.teiid.resource.adapter.google.v4.ClientConstants.*;

import java.io.IOException;

import org.teiid.resource.adapter.google.auth.AuthHeaderFactory;
import org.teiid.translator.google.api.SpreadsheetAuthException;

import com.google.api.client.googleapis.auth.oauth2.GoogleCredential;

public class OAuth2HeaderFactory implements AuthHeaderFactory {
	private GoogleCredential credential = null;
	private String refreshToken;
	private String clientId;
	private String clientSecret;
	
	public OAuth2HeaderFactory(String refreshToken, String clientId, String clientSecret){
	    this.refreshToken = refreshToken;
	    this.clientId = clientId;
	    this.clientSecret = clientSecret;
	}
	
	public void refreshToken() {
		try {
		    if (credential == null) {
		        credential = new GoogleCredential.Builder()
	                .setClientSecrets(clientId, clientSecret)
	                .setTransport(HTTP_TRANSPORT)
	                .setJsonFactory(JSON_FACTORY)
	                .build();
	            credential.setRefreshToken(refreshToken);
		    }
		    credential.refreshToken();
        } catch (IOException e) {
            throw new SpreadsheetAuthException(
                    "Error reading TokenRequest response", e);
        }
	}
	
	public String getAuthHeader() {
		return "Bearer "+  credential.getAccessToken(); //$NON-NLS-1$
	}
	
	public GoogleCredential getCredential() {
        return credential;
    }

}
