/*
 * Copyright 2012-2023 The Feign 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
 *
 * 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 feign.jaxb;

import feign.RequestTemplate;
import feign.codec.EncodeException;
import feign.codec.Encoder;
import jakarta.xml.bind.JAXBException;
import jakarta.xml.bind.Marshaller;
import java.io.StringWriter;
import java.lang.reflect.Type;

/**
 * Encodes requests using JAXB with Jakarta Api. <br>
 * <p>
 * Basic example with with Feign.Builder:
 * </p>
 * 
 * <pre>
 * JAXBContextFactory jaxbFactory = new JAXBContextFactory.Builder()
 *     .withMarshallerJAXBEncoding("UTF-8")
 *     .withMarshallerSchemaLocation("http://apihost http://apihost/schema.xsd")
 *     .build();
 *
 * api = Feign.builder()
 *     .encoder(new JAXBEncoder(jaxbFactory))
 *     .target(MyApi.class, "http://api");
 * </pre>
 * <p>
 * The JAXBContextFactory should be reused across requests as it caches the created JAXB contexts.
 * </p>
 */
public class JAXBEncoder implements Encoder {

  private final JAXBContextFactory jaxbContextFactory;

  public JAXBEncoder(JAXBContextFactory jaxbContextFactory) {
    this.jaxbContextFactory = jaxbContextFactory;
  }

  @Override
  public void encode(Object object, Type bodyType, RequestTemplate template) {
    if (!(bodyType instanceof Class)) {
      throw new UnsupportedOperationException(
          "JAXB only supports encoding raw types. Found " + bodyType);
    }
    try {
      Marshaller marshaller = jaxbContextFactory.createMarshaller((Class<?>) bodyType);
      StringWriter stringWriter = new StringWriter();
      marshaller.marshal(object, stringWriter);
      template.body(stringWriter.toString());
    } catch (JAXBException e) {
      throw new EncodeException(e.toString(), e);
    }
  }
}
