/**
 * Copyright © 2010-2011 Nokia
 *
 * 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 com.github.restdriver.matchers;

import java.io.IOException;

import org.custommonkey.xmlunit.Diff;
import org.custommonkey.xmlunit.XMLUnit;
import org.hamcrest.Description;
import org.hamcrest.TypeSafeMatcher;
import org.xml.sax.SAXException;

import com.github.restdriver.exception.RuntimeAssertionFailure;

/**
 * Hamcrest matcher for comparing two strings containing XML and determining whether they are
 * equivalent (ignoring whitespace, attribute and element ordering etc.).
 */
public class IsEquivalentXml extends TypeSafeMatcher<String> {
    
    private final String xml;
    
    /**
     * Creates a new instance of the matcher.
     * 
     * @param xml The XML to compare with.
     */
    public IsEquivalentXml(String xml) {
        this.xml = xml;
    }
    
    @Override
    public final void describeTo(Description description) {
        description.appendText("A string with XML equivalent to: " + xml);
    }
    
    @Override
    protected boolean matchesSafely(String item) {
        
        try {
            Diff diff = XMLUnit.compareXML(xml, item);
            return diff.identical();
        } catch (IOException e) {
            throw new RuntimeAssertionFailure("Failed to compare XML", e);
        } catch (SAXException e) {
            throw new RuntimeAssertionFailure("Failed to compare XML", e);
        }
    }
    
}