/*
    * Copyright 2002-2013 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
    *
    *      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.springframework.test.util;
  
  import java.io.StringReader;
  import java.util.Map;
  import javax.xml.parsers.DocumentBuilder;
  import javax.xml.parsers.DocumentBuilderFactory;
  import javax.xml.transform.Source;
  import javax.xml.transform.dom.DOMSource;
  
  import org.custommonkey.xmlunit.Diff;
  import org.custommonkey.xmlunit.XMLUnit;
  import org.hamcrest.Matcher;
  import org.w3c.dom.Document;
  import org.w3c.dom.Node;
  import org.xml.sax.InputSource;
  
  import static org.springframework.test.util.MatcherAssertionErrors.*;
  
  /**
   * A helper class for assertions on XML content.
   *
   * @author Rossen Stoyanchev
   * @since 3.2
   */
  public class XmlExpectationsHelper {
  
  	/**
  	 * Parse the content as {@link Node} and apply a {@link Matcher}.
  	 */
  	public void assertNode(String content, Matcher<? super Node> matcher) throws Exception {
  		Document document = parseXmlString(content);
  		assertThat("Body content", document, matcher);
  	}
  
  	private Document parseXmlString(String xml) throws Exception  {
  		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
  		factory.setNamespaceAware(true);
  		DocumentBuilder documentBuilder = factory.newDocumentBuilder();
  		InputSource inputSource = new InputSource(new StringReader(xml));
  		return documentBuilder.parse(inputSource);
  	}
  
  	/**
  	 * Parse the content as {@link DOMSource} and apply a {@link Matcher}.
  	 * @see <a href="http://code.google.com/p/xml-matchers/">xml-matchers</a>
  	 */
  	public void assertSource(String content, Matcher<? super Source> matcher) throws Exception {
  		Document document = parseXmlString(content);
  		assertThat("Body content", new DOMSource(document), matcher);
  	}
  
  	/**
  	 * Parse the expected and actual content strings as XML and assert that the
  	 * two are "similar" -- i.e. they contain the same elements and attributes
  	 * regardless of order.
  	 * <p>Use of this method assumes the
  	 * <a href="http://xmlunit.sourceforge.net/">XMLUnit<a/> library is available.
  	 * @param expected the expected XML content
  	 * @param actual the actual XML content
  	 * @see org.springframework.test.web.servlet.result.MockMvcResultMatchers#xpath(String, Object...)
  	 * @see org.springframework.test.web.servlet.result.MockMvcResultMatchers#xpath(String, Map, Object...)
  	 */
  	public void assertXmlEqual(String expected, String actual) throws Exception {
  		XMLUnit.setIgnoreWhitespace(true);
  		XMLUnit.setIgnoreComments(true);
  		XMLUnit.setIgnoreAttributeOrder(true);
  
  		Document control = XMLUnit.buildControlDocument(expected);
  		Document test = XMLUnit.buildTestDocument(actual);
  		Diff diff = new Diff(control, test);
  		if (!diff.similar()) {
  			AssertionErrors.fail("Body content " + diff.toString());
  		}
  	}
  
  }