/***
 * Copyright (c) 2009 Caelum - www.caelum.com.br/opensource All rights reserved.
 *
 * 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 br.com.caelum.vraptor.serialization.xstream;

import java.io.IOException;
import java.io.PrintWriter;

import javax.annotation.PostConstruct;
import javax.enterprise.context.RequestScoped;
import javax.inject.Inject;
import javax.servlet.http.HttpServletResponse;

import br.com.caelum.vraptor.environment.Environment;
import br.com.caelum.vraptor.serialization.Serializer;
import br.com.caelum.vraptor.serialization.SerializerBuilder;
import br.com.caelum.vraptor.serialization.XMLSerialization;
import br.com.caelum.vraptor.view.ResultException;

import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
import com.thoughtworks.xstream.io.xml.CompactWriter;
import com.thoughtworks.xstream.io.xml.PrettyPrintWriter;

/**
 * XStream implementation for XmlSerialization
 *
 * @author Lucas Cavalcanti
 * @since 3.0.2
 */
@RequestScoped
public class XStreamXMLSerialization implements XMLSerialization {

	private final HttpServletResponse response;
	private final XStreamBuilder builder;
	private final Environment environment;
	private boolean indented;

	/** 
	 * @deprecated CDI eyes only
	 */
	protected XStreamXMLSerialization() {
		this(null, null, null);
	}

	@Inject
	public XStreamXMLSerialization(HttpServletResponse response, XStreamBuilder builder, Environment environment) {
		this.response = response;
		this.builder = builder;
		this.environment = environment;
	}

	@PostConstruct
	protected void init() {
		indented = environment.supports(ENVIRONMENT_INDENTED_KEY);
	}

	@Override
	public boolean accepts(String format) {
		return "xml".equals(format);
	}
	
	@Override
	public XMLSerialization indented() {
		indented = true;
		return this;
	}

	@Override
	public <T> Serializer from(T object) {
		response.setContentType("application/xml");
		return getSerializer().from(object);
	}

	protected SerializerBuilder getSerializer() {
		return new XStreamSerializer(builder.xmlInstance(), getWriter());
	}

	protected HierarchicalStreamWriter getWriter() {
		try {
			PrintWriter writer = response.getWriter();
			return indented ? new PrettyPrintWriter(writer) : new CompactWriter(writer);
		} catch (IOException e) {
			throw new ResultException("Unable to serialize data", e);
		}
	}

	@Override
	public <T> Serializer from(T object, String alias) {
		response.setContentType("application/xml");
		return getSerializer().from(object, alias);
	}
}