/*
    * Copyright 2010 James Pether Sörling
    *
    * 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.
   *
   *	$Id$
   *  $HeadURL$
  */
  package com.hack23.cia.service.external.common.impl;
  
  import java.io.BufferedReader;
  import java.io.ByteArrayInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.Reader;
  import java.net.URL;
  import java.net.URLConnection;
  import java.nio.charset.StandardCharsets;
  import java.util.Locale;
  
  import javax.xml.transform.Source;
  import javax.xml.transform.stream.StreamSource;
  
  import org.apache.http.client.fluent.Request;
  import org.jdom2.Document;
  import org.jdom2.Namespace;
  import org.jdom2.input.SAXBuilder;
  import org.jdom2.input.sax.XMLReaderSAX2Factory;
  import org.jdom2.transform.JDOMSource;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.oxm.Unmarshaller;
  import org.springframework.stereotype.Service;
  
  import com.hack23.cia.service.external.common.api.XmlAgent;
  
  /**
   * The Class XmlAgentImpl.
   */
  @Service
  final class XmlAgentImpl implements XmlAgent {
  
  	/** The Constant LOGGER. */
  	private static final Logger LOGGER = LoggerFactory
  			.getLogger(XmlAgentImpl.class);
  
  	/**
  	 * Instantiates a new xml agent impl.
  	 */
  	public XmlAgentImpl() {
  		super();
  	}
  
  	/**
  	 * Read with string buffer.
  	 *
  	 * @param fr
  	 *            the fr
  	 * @return the string
  	 * @throws IOException
  	 *             Signals that an I/O exception has occurred.
  	 */
  	private static String readWithStringBuffer(final Reader fr) throws IOException {
  
  		final BufferedReader br = new BufferedReader(fr);
  		String line;
  		final StringBuilder result = new StringBuilder();
  		while ((line = br.readLine()) != null) {
  			result.append(line);
  		}
  
  		return result.toString();
  	}
  
  	@Override
  	public String retriveContent(final String accessUrl) throws Exception {
  		final URL url = new URL(accessUrl.replace(" ",""));
  
  		final BufferedReader inputStream = new BufferedReader(new InputStreamReader(
  				url.openStream(),StandardCharsets.UTF_8));
  
  		return readWithStringBuffer(inputStream);
  	}
  
  	/**
  	 * Sets the name space on xml stream.
  	 *
  	 * @param in
 	 *            the in
 	 * @param nameSpace
 	 *            the name space
 	 * @return the source
 	 * @throws Exception
 	 *             the exception
 	 */
 	private static Source setNameSpaceOnXmlStream(final InputStream in, final String nameSpace)
 			throws Exception {
 		final SAXBuilder sb = new SAXBuilder(new XMLReaderSAX2Factory(false));
 		final Document doc = sb.build(in);
 		doc.getRootElement().setNamespace(Namespace.getNamespace(nameSpace));
 		return new JDOMSource(doc);
 	}
 
 
 	@Override
 	public Object unmarshallXml(final Unmarshaller unmarshaller, final String accessUrl) throws Exception {
 		return unmarshallXml(unmarshaller, accessUrl,null,null,null);
 	}
 
 	@Override
 	public Object unmarshallXml(final Unmarshaller unmarshaller, final String accessUrl,
 			final String nameSpace,final String replace, final String with) throws Exception {
 
 		LOGGER.info("Calls {}", accessUrl);
 
 		final boolean isWeb = accessUrl.toLowerCase(Locale.ENGLISH).startsWith("http://") || accessUrl.toLowerCase(Locale.ENGLISH).startsWith("https://");
 
 		String xmlContent;
 		if (isWeb) {
 			xmlContent = Request.Get(accessUrl.replace(" ","")).execute().returnContent().asString(StandardCharsets.UTF_8);
 		} else {
 			xmlContent = readInputStream(accessUrl.replace(" ",""));
 		}
 
 		if (replace != null) {
 			xmlContent = xmlContent.replace(replace, with);
 		}
 
 		final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(
 				xmlContent.getBytes(StandardCharsets.UTF_8));
 
 		Source source;
 		if (nameSpace != null) {
 			source = setNameSpaceOnXmlStream(byteArrayInputStream, nameSpace);
 		} else {
 			source = new StreamSource(byteArrayInputStream);
 		}
 
 		return unmarshaller.unmarshal(source);
 	}
 
 	/**
 	 * Read input stream.
 	 *
 	 * @param accessUrl
 	 *            the access url
 	 * @return the string
 	 * @throws Exception
 	 *             the exception
 	 */
 	private static String readInputStream(final String accessUrl) throws Exception{
 		final URL url = new URL(accessUrl.replace(" ",""));
 
 		final URLConnection connection = url.openConnection();
 
 		final InputStream stream = connection.getInputStream();
 
 
 		final BufferedReader inputStream = new BufferedReader(new InputStreamReader(
 				stream,StandardCharsets.UTF_8));
 
 		return readWithStringBuffer(inputStream);
 	}
 }