/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.any23.extractor.html;

import org.apache.any23.AbstractAny23TestBase;
import org.junit.Assert;
import org.junit.Test;
import org.w3c.dom.DOMImplementation;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.List;

/**
 * Reference test class for the {@link DomUtils} class.
 *
 * @author Davide Palmisano (dpalmisano@gmail.com)
 */
public class DomUtilsTest extends AbstractAny23TestBase {

    private final static XPath xPathEngine = XPathFactory.newInstance().newXPath();

    @Test
    public void testGetXPathForNode() throws Exception {
        check("/microformats/hcard/01-tantek-basic.html", "//DIV[@class='vcard']", "/HTML[1]/BODY[1]/DIV[1]");
        check("/microformats/hcard/02-multiple-class-names-on-vcard.html", "//SPAN[@class='fn n']",
                "/HTML[1]/BODY[1]/DIV[1]/SPAN[1]");
        check("/microformats/hcard/02-multiple-class-names-on-vcard.html", "//SPAN/SPAN[@class='fn n']",
                "/HTML[1]/BODY[1]/P[1]/SPAN[1]/SPAN[1]");
        check("/microformats/hcard/02-multiple-class-names-on-vcard.html", "//SPAN/SPAN/*[@class='given-name']",
                "/HTML[1]/BODY[1]/P[1]/SPAN[1]/SPAN[1]/SPAN[1]");
        check("/microformats/hcard/02-multiple-class-names-on-vcard.html", "//SPAN/SPAN/*[@class='family-name']",
                "/HTML[1]/BODY[1]/P[1]/SPAN[1]/SPAN[1]/SPAN[2]");
    }

    @Test
    public void testFindAllByClassName() throws Exception {
        Node dom = new HTMLFixture(copyResourceToTempFile("/microformats/hcard/02-multiple-class-names-on-vcard.html"))
                .getDOM();
        Assert.assertNotNull(dom);
        List<Node> nodes = DomUtils.findAllByClassName(dom, "vcard");
        NodeList nodeList = null;
        try {
            nodeList = (NodeList) xPathEngine.evaluate("//*[contains(@class, 'vcard')]", dom, XPathConstants.NODESET);
        } catch (XPathExpressionException e) {
            Assert.fail(e.getMessage());
        }
        Assert.assertNotNull(nodeList);
        Assert.assertEquals("vcard elements number does not match", nodes.size(), nodeList.getLength());
        for (int i = 0; i < nodeList.getLength(); i++) {
            Assert.assertTrue(nodes.contains(nodeList.item(i)));
        }
    }

    @Test
    public void testFindAllByTag() throws Exception {
        Node dom = new HTMLFixture(copyResourceToTempFile("/microformats/hcard/02-multiple-class-names-on-vcard.html"))
                .getDOM();
        Assert.assertNotNull(dom);
        List<Node> nodes = DomUtils.findAllByTag(dom, "SPAN");
        NodeList nodeList = null;
        try {
            nodeList = (NodeList) xPathEngine.evaluate("./descendant-or-self::SPAN", dom, XPathConstants.NODESET);
        } catch (XPathExpressionException e) {
            Assert.fail(e.getMessage());
        }

        Assert.assertEquals("number of elements does not match", nodes.size(), nodeList.getLength());

        for (int i = 0; i < nodeList.getLength(); i++) {
            Assert.assertTrue(nodes.contains(nodeList.item(i)));
        }
    }

    @Test
    public void testFindAllByTagAndClassName() throws Exception {
        Node dom = new HTMLFixture(copyResourceToTempFile("/microformats/hcard/02-multiple-class-names-on-vcard.html"))
                .getDOM();
        Assert.assertNotNull(dom);
        List<Node> nodes = DomUtils.findAllByTagAndClassName(dom, "SPAN", "family-name");
        NodeList nodeList = null;
        try {
            nodeList = (NodeList) xPathEngine.evaluate("./descendant-or-self::SPAN[contains(@class,'family-name')]",
                    dom, XPathConstants.NODESET);
        } catch (XPathExpressionException e) {
            Assert.fail(e.getMessage());
        }

        Assert.assertEquals("number of elements does not match", nodes.size(), nodeList.getLength());

        for (int i = 0; i < nodeList.getLength(); i++) {
            Assert.assertTrue(nodes.contains(nodeList.item(i)));
        }

    }

    @Test
    public void testHasClassName() throws Exception {
        Node dom = new HTMLFixture(copyResourceToTempFile("/microformats/hcard/02-multiple-class-names-on-vcard.html"))
                .getDOM();
        Assert.assertNotNull(dom);
        List<Node> nodes = DomUtils.findAllByClassName(dom, "vcard");
        for (Node node : nodes) {
            Assert.assertTrue(DomUtils.hasClassName(node, "vcard"));
        }
    }

    @Test
    public void testReadAttribute() throws Exception {
        Node dom = new HTMLFixture(copyResourceToTempFile("/microformats/hcard/02-multiple-class-names-on-vcard.html"))
                .getDOM();
        Assert.assertNotNull(dom);
        List<Node> nodes = DomUtils.findAllByClassName(dom, "vcard");
        for (Node node : nodes) {
            // every node in nodes should have a class attribute containing vcard.
            Assert.assertTrue(DomUtils.readAttribute(node, "class").contains("vcard"));
        }

    }

    @Test
    public void testSerializeToXML() throws ParserConfigurationException, TransformerException, IOException {
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = factory.newDocumentBuilder();
        DOMImplementation impl = builder.getDOMImplementation();
        Document doc = impl.createDocument(null, null, null);
        Node n1 = doc.createElement("DIV");
        Node n2 = doc.createElement("SPAN");
        Node n3 = doc.createElement("P");
        n1.setTextContent("Content 1");
        n2.setTextContent("Content 2");
        n3.setTextContent("Content 3");
        n1.appendChild(n2);
        n2.appendChild(n3);
        doc.appendChild(n1);

        Assert.assertEquals("<DIV>Content 1<SPAN>Content 2<P>Content 3</P></SPAN></DIV>",
                DomUtils.serializeToXML(doc, false));
    }

    private void check(String file, String xpath, String reverseXPath) throws FileNotFoundException, IOException {
        Node dom = new HTMLFixture(copyResourceToTempFile(file)).getDOM();
        Assert.assertNotNull(dom);
        Node node;
        try {
            node = (Node) xPathEngine.evaluate(xpath, dom, XPathConstants.NODE);
            Assert.assertNotNull(node);
            Assert.assertEquals(Node.ELEMENT_NODE, node.getNodeType());
            String newPath = DomUtils.getXPathForNode(node);
            Assert.assertEquals(reverseXPath, newPath);
            Node newNode = (Node) xPathEngine.evaluate(newPath, dom, XPathConstants.NODE);
            Assert.assertEquals(node, newNode);

        } catch (XPathExpressionException ex) {
            Assert.fail(ex.getMessage());
        }
    }

}
