/*
 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
 */
/*
 * 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.qetest.trax.sax;

import java.io.StringReader;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.stream.Collectors;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.sax.SAXTransformerFactory;
import javax.xml.transform.sax.TransformerHandler;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
import jaxp.library.JAXPFileBaseTest;
import static jaxp.library.JAXPTestUtilities.getNextFile;
import org.apache.qetest.xsl.CheckingSAXErrorHandler;
import static org.testng.Assert.assertEquals;
import org.testng.annotations.Test;
import org.xml.sax.SAXParseException;

/**
 * Basic functionality test for the TransformerHandler class of TRAX.
 */
public class TransformerHandlerTest extends JAXPFileBaseTest {

    /**
     * Un-formed XML string(note mismatched tags).
     */
    private static final String XML_ERROR_STR
            = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>"
            + "<root1></root2>";

    /**
     * Well-formed XML string.
     */
    private static final String XML_GOOD_STR
            = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>"
            + "<root>Hello world</root>";

    /**
     * XSLT string.
     */
    private static final String XSL_STR
            = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>"
            + "<xsl:stylesheet version=\"1.0\" xmlns:xsl=\"http://www.w3.org/1999/XSL/Transform\">"
            + "<xsl:template match=\"/\">"
            + "<xsl:copy-of select=\".\"/>"
            + "</xsl:template>"
            + "</xsl:stylesheet>";
    
    /**
     * Golden validation string.
     */
    private static final String GOLDEN_STR
            = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><root>Hello world</root>";

    /**
     * Transformer.transform on a not well-formed XML throws TransformerException.
     * 
     * @throws TransformerException If an unrecoverable error occurs during the 
     *         course of the transformation. 
     */
    @Test(expectedExceptions = TransformerException.class)
    public void negativeCase1() throws TransformerException {
        // No public constructor available: you must always ask
        //  a SAXTransformerFactory to give you one
        SAXTransformerFactory saxFactory
                = (SAXTransformerFactory) TransformerFactory.newInstance();
        try (StringReader sr1 = new StringReader(XSL_STR);
                StringReader sr2 = new StringReader(XML_ERROR_STR)) {
            Transformer reusedTransformer = saxFactory.newTransformer(
                    new StreamSource(sr1));
            reusedTransformer.transform(new StreamSource(sr2),
                    new StreamResult(getNextFile(TransformerHandlerTest.class)));
        }
    }

    /**
     * Reader.read on a not well-formed XML throws TransformerException. 
     * 
     * @throws Exception If any errors occur.
     */
    @Test(expectedExceptions = SAXParseException.class)
    public void testCase2() throws Exception {
        SAXTransformerFactory saxFactory
                = (SAXTransformerFactory) TransformerFactory.newInstance();
        try(StringReader sr1 = new StringReader(XSL_STR);
                StringReader sr2 = new StringReader(XML_ERROR_STR);) {
            TransformerHandler thandler = saxFactory.newTransformerHandler(
                    new StreamSource(sr1));
            SAXParserFactory spf1 = SAXParserFactory.newInstance();
            spf1.setNamespaceAware(true);
            SAXParser parser1 = spf1.newSAXParser();
            org.xml.sax.XMLReader reader = parser1.getXMLReader();
            reader.setContentHandler(thandler);
            reader.setErrorHandler(new CheckingSAXErrorHandler());
            thandler.setResult(new StreamResult(getNextFile(TransformerHandlerTest.class)));
            reader.parse(new org.xml.sax.InputSource(sr2));
        }
    }

    /**
     * Re-transform several times with XMLReader and Transformer. No exception 
     * should be thrown.
     * 
     * @throws Exception If any errors occur. 
     */
    @Test
    public void testCase3() throws Exception {
        SAXTransformerFactory saxFactory
                = (SAXTransformerFactory) TransformerFactory.newInstance();
        String outputFile1 = getNextFile(this.getClass());
        String outputFile2 = getNextFile(this.getClass());
        try(StringReader sr1 = new StringReader(XSL_STR);
                StringReader sr2 = new StringReader(XML_GOOD_STR);
                StringReader sr3 = new StringReader(XSL_STR);
                StringReader sr4 = new StringReader(XML_GOOD_STR)) {
            TransformerHandler thandler = saxFactory.newTransformerHandler(
                    new StreamSource(sr1));
            SAXParserFactory spf = SAXParserFactory.newInstance();
            spf.setNamespaceAware(true);
            SAXParser parser = spf.newSAXParser();
            org.xml.sax.XMLReader reader = parser.getXMLReader();
            thandler.setResult(new StreamResult(outputFile1));
            reader.setContentHandler(thandler);
            reader.setErrorHandler(new CheckingSAXErrorHandler());
            reader.parse(new org.xml.sax.InputSource(sr2));

            Transformer reusedTransformer = TransformerFactory.newInstance()
                    .newTransformer(new StreamSource(sr3));
            reusedTransformer.transform(new StreamSource(sr4),
                    new StreamResult(outputFile2));
        }
        String outputStr1 = Files.readAllLines(Paths.get(outputFile1)).stream()
                .collect(Collectors.joining(System.getProperty("line.separator")));
        String outputStr2 = Files.readAllLines(Paths.get(outputFile1)).stream()
                .collect(Collectors.joining(System.getProperty("line.separator")));
        assertEquals(outputStr1, GOLDEN_STR);
        assertEquals(outputStr2, GOLDEN_STR);
    }
}