/*
 * Copyright (c) 2016 Cisco Systems, Inc. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */

package org.opendaylight.yangtools.yang.model.export.test;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotEquals;
import static org.junit.Assert.assertNotNull;

import com.google.common.base.Preconditions;
import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.StringWriter;
import java.net.URISyntaxException;
import javax.xml.stream.XMLStreamException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.TransformerFactoryConfigurationError;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.custommonkey.xmlunit.Diff;
import org.custommonkey.xmlunit.ElementNameAndAttributeQualifier;
import org.custommonkey.xmlunit.XMLAssert;
import org.custommonkey.xmlunit.XMLUnit;
import org.junit.Test;
import org.opendaylight.yangtools.util.xml.UntrustedXML;
import org.opendaylight.yangtools.yang.model.api.Module;
import org.opendaylight.yangtools.yang.model.api.SchemaContext;
import org.opendaylight.yangtools.yang.model.export.YinExportUtils;
import org.opendaylight.yangtools.yang.parser.spi.meta.ReactorException;
import org.opendaylight.yangtools.yang.test.util.YangParserTestUtils;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.xml.sax.SAXException;

public class SchemaContextEmitterTest {

    @Test
    public void testSchemaContextEmitter() throws ReactorException, IOException, URISyntaxException,
            XMLStreamException, SAXException {
        final SchemaContext schemaContext = YangParserTestUtils.parseYangSources("/schema-context-emitter-test");
        assertNotNull(schemaContext);
        assertEquals(1, schemaContext.getModules().size());

        final OutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        final BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(byteArrayOutputStream);

        for (Module module : schemaContext.getModules()) {
            YinExportUtils.writeModuleToOutputStream(schemaContext, module, bufferedOutputStream);
        }

        final String output = byteArrayOutputStream.toString();
        assertNotNull(output);
        assertNotEquals(0, output.length());

        final Document doc = loadDocument("/schema-context-emitter-test/foo.yin");
        final String expected = toString(doc.getDocumentElement());

        XMLUnit.setIgnoreWhitespace(true);
        XMLUnit.setNormalize(true);

        final Diff diff = new Diff(expected, output);
        diff.overrideElementQualifier(new ElementNameAndAttributeQualifier());
        XMLAssert.assertXMLEqual(diff, true);
    }

    private static Document loadDocument(final String xmlPath) throws IOException, SAXException {
        final InputStream resourceAsStream = SchemaContextEmitterTest.class.getResourceAsStream(xmlPath);
        final Document currentConfigElement = readXmlToDocument(resourceAsStream);
        Preconditions.checkNotNull(currentConfigElement);
        return currentConfigElement;
    }

    private static Document readXmlToDocument(final InputStream xmlContent) throws IOException, SAXException {
        final Document doc = UntrustedXML.newDocumentBuilder().parse(xmlContent);
        doc.getDocumentElement().normalize();
        return doc;
    }

    private static String toString(final Node xml) {
        try {
            final Transformer transformer = TransformerFactory.newInstance().newTransformer();
            transformer.setOutputProperty(OutputKeys.INDENT, "yes");
            transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");

            final StreamResult result = new StreamResult(new StringWriter());
            final DOMSource source = new DOMSource(xml);
            transformer.transform(source, result);

            return result.getWriter().toString();
        } catch (IllegalArgumentException | TransformerFactoryConfigurationError | TransformerException e) {
            throw new RuntimeException("Unable to serialize xml element " + xml, e);
        }
    }
}