/*
    * Copyright 2006-2010 the original author or authors.
    *
    * 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
    *
    * https://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.springframework.security.oauth2.common;
  
  import java.io.IOException;
  import java.util.Date;
  import java.util.Map;
  import java.util.Set;
  
  import org.springframework.util.Assert;
  
  import com.fasterxml.jackson.core.JsonGenerationException;
  import com.fasterxml.jackson.core.JsonGenerator;
  import com.fasterxml.jackson.databind.SerializerProvider;
  import com.fasterxml.jackson.databind.ser.std.StdSerializer;
  
  /**
   * Provides the ability to serialize an {@link org.springframework.security.oauth2.common.OAuth2AccessToken} with jackson2 by implementing {@link com.fasterxml.jackson.databind.JsonDeserializer}.
   *
   * The expected format of the access token is defined by <a href="https://tools.ietf.org/html/draft-ietf-oauth-v2-22#section-5.1">Successful Response</a>.
   *
   * @author Rob Winch
   * @author Brian Clozel
   * @see org.springframework.security.oauth2.common.OAuth2AccessTokenJackson2Deserializer
   */
  public final class OAuth2AccessTokenJackson2Serializer extends StdSerializer<OAuth2AccessToken> {
  
  	public OAuth2AccessTokenJackson2Serializer() {
  		super(OAuth2AccessToken.class);
  	}
  
  	@Override
  	public void serialize(OAuth2AccessToken token, JsonGenerator jgen, SerializerProvider provider) throws IOException,
  			JsonGenerationException {
  		jgen.writeStartObject();
  		jgen.writeStringField(OAuth2AccessToken.ACCESS_TOKEN, token.getValue());
  		jgen.writeStringField(OAuth2AccessToken.TOKEN_TYPE, token.getTokenType());
  		OAuth2RefreshToken refreshToken = token.getRefreshToken();
  		if (refreshToken != null) {
  			jgen.writeStringField(OAuth2AccessToken.REFRESH_TOKEN, refreshToken.getValue());
  		}
  		Date expiration = token.getExpiration();
  		if (expiration != null) {
  			long now = System.currentTimeMillis();
  			jgen.writeNumberField(OAuth2AccessToken.EXPIRES_IN, (expiration.getTime() - now) / 1000);
  		}
  		Set<String> scope = token.getScope();
  		if (scope != null && !scope.isEmpty()) {
  			StringBuffer scopes = new StringBuffer();
  			for (String s : scope) {
  				Assert.hasLength(s, "Scopes cannot be null or empty. Got " + scope + "");
  				scopes.append(s);
  				scopes.append(" ");
  			}
  			jgen.writeStringField(OAuth2AccessToken.SCOPE, scopes.substring(0, scopes.length() - 1));
  		}
  		Map<String, Object> additionalInformation = token.getAdditionalInformation();
  		for (String key : additionalInformation.keySet()) {
  			jgen.writeObjectField(key, additionalInformation.get(key));
  		}
  		jgen.writeEndObject();
  	}
  }