/*
 * Copyright (c) 2014 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.data.impl.codec.xml;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;
import com.google.common.base.Optional;
import com.google.common.collect.Maps;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.AbstractMap;
import java.util.Arrays;
import java.util.Map;
import javax.xml.stream.XMLOutputFactory;
import javax.xml.stream.XMLStreamWriter;
import org.custommonkey.xmlunit.Diff;
import org.custommonkey.xmlunit.XMLUnit;
import org.junit.BeforeClass;
import org.junit.Ignore;
import org.junit.Test;
import org.opendaylight.yangtools.yang.common.QName;
import org.opendaylight.yangtools.yang.common.QNameModule;
import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
import org.opendaylight.yangtools.yang.model.api.LeafSchemaNode;
import org.opendaylight.yangtools.yang.model.api.Module;
import org.opendaylight.yangtools.yang.model.api.SchemaContext;
import org.opendaylight.yangtools.yang.model.api.TypeDefinition;
import org.opendaylight.yangtools.yang.model.api.type.LeafrefTypeDefinition;
import org.opendaylight.yangtools.yang.model.util.InstanceIdentifierType;
import org.opendaylight.yangtools.yang.model.util.SchemaContextUtil;
import org.opendaylight.yangtools.yang.model.util.StringType;
import org.opendaylight.yangtools.yang.parser.impl.YangParserImpl;
import org.w3c.dom.Document;

public class XmlStreamUtilsTest {

    public static final XMLOutputFactory XML_OUTPUT_FACTORY = XMLOutputFactory.newFactory();

    private static SchemaContext schemaContext;
    private static Module leafRefModule;

    @BeforeClass
    public static void initialize() throws URISyntaxException {
        final YangParserImpl yangParser = new YangParserImpl();
        final File file = new File(XmlStreamUtils.class.getResource("/leafref-test.yang").toURI());
        schemaContext = yangParser.parseFiles(Arrays.asList(file));
        assertNotNull(schemaContext);
        assertEquals(1,schemaContext.getModules().size());
        leafRefModule = schemaContext.getModules().iterator().next();
        assertNotNull(leafRefModule);
    }


    @Test
    public void testWriteAttribute() throws Exception {
        final ByteArrayOutputStream out = new ByteArrayOutputStream();
        final XMLStreamWriter writer =  XML_OUTPUT_FACTORY.createXMLStreamWriter(out);
        writer.writeStartElement("element");

        QName name = getAttrQName("namespace", "2012-12-12", "attr", Optional.of("prefix"));
        final Map.Entry<QName, String> attributeEntry = new AbstractMap.SimpleEntry<>(name, "value");

        name = getAttrQName("namespace2", "2012-12-12", "attr", Optional.<String>absent());
        final Map.Entry<QName, String> attributeEntryNoPrefix = new AbstractMap.SimpleEntry<>(name, "value");

        final RandomPrefix randomPrefix = new RandomPrefix();
        XmlStreamUtils.writeAttribute(writer, attributeEntry, randomPrefix);
        XmlStreamUtils.writeAttribute(writer, attributeEntryNoPrefix, randomPrefix);

        writer.writeEndElement();
        writer.close();
        out.close();

        final String xmlAsString = new String(out.toByteArray());

        final Map<String, String> mappedPrefixes = mapPrefixed(randomPrefix.getPrefixes());
        assertEquals(2, mappedPrefixes.size());
        final String randomPrefixValue = mappedPrefixes.get("namespace2");

        final String expectedXmlAsString = "<element xmlns:a=\"namespace\" a:attr=\"value\" xmlns:" + randomPrefixValue + "=\"namespace2\" " + randomPrefixValue + ":attr=\"value\"></element>";

        XMLUnit.setIgnoreAttributeOrder(true);
        final Document control = XMLUnit.buildControlDocument(expectedXmlAsString);
        final Document test = XMLUnit.buildTestDocument(xmlAsString);
        final Diff diff = XMLUnit.compareXML(control, test);

        final boolean identical = diff.identical();
        assertTrue("Xml differs: " + diff.toString(), identical);
    }

    /**
     * One leafref reference to other leafref via relative references
     */
    @Test
    public void testLeafRefRelativeChaining() {
        getTargetNodeForLeafRef("leafname3",StringType.class);
    }

    @Test
    public void testLeafRefRelative() {
        getTargetNodeForLeafRef("pointToStringLeaf",StringType.class);
    }

    @Test
    public void testLeafRefAbsoluteWithSameTarget() {
        getTargetNodeForLeafRef("absname",InstanceIdentifierType.class);
    }

    /**
     * Tests relative path with double point inside path (e. g. "../../lf:interface/../lf:cont2/lf:stringleaf")
     */
    @Ignore //ignored because this isn't implemented
    @Test
    public void testLeafRefWithDoublePointInPath() {
        getTargetNodeForLeafRef("lf-with-double-point-inside",StringType.class);
    }

    @Test
    public void testLeafRefRelativeAndAbsoluteWithSameTarget() {
        final TypeDefinition<?> targetNodeForAbsname = getTargetNodeForLeafRef("absname",InstanceIdentifierType.class);
        final TypeDefinition<?> targetNodeForRelname = getTargetNodeForLeafRef("relname",InstanceIdentifierType.class);
        assertEquals(targetNodeForAbsname, targetNodeForRelname);
    }

    private TypeDefinition<?> getTargetNodeForLeafRef(final String nodeName, final Class<?> clas) {
        final LeafSchemaNode schemaNode = findSchemaNodeWithLeafrefType(leafRefModule, nodeName);
        assertNotNull(schemaNode);
        final LeafrefTypeDefinition leafrefTypedef = findLeafrefType(schemaNode);
        assertNotNull(leafrefTypedef);
        final TypeDefinition<?> targetBaseType = SchemaContextUtil.getBaseTypeForLeafRef(leafrefTypedef, schemaContext, schemaNode);
        assertEquals("Wrong class found.", clas, targetBaseType.getClass());
        return targetBaseType;
    }

    private static Map<String, String> mapPrefixed(final Iterable<Map.Entry<URI, String>> prefixes) {
        final Map<String, String> mappedPrefixes = Maps.newHashMap();
        for (final Map.Entry<URI, String> prefix : prefixes) {
            mappedPrefixes.put(prefix.getKey().toString(), prefix.getValue());
        }
        return mappedPrefixes;
    }

    private static QName getAttrQName(final String namespace, final String revision, final String localName, final Optional<String> prefix) {
        if (prefix.isPresent()) {
            final QName moduleQName = QName.create(namespace, revision, "module");
            final QNameModule module = QNameModule.create(moduleQName.getNamespace(), moduleQName.getRevision());
            return QName.create(module, localName);
        } else {
            return QName.create(namespace, revision, localName);
        }
    }

    private LeafSchemaNode findSchemaNodeWithLeafrefType(final DataNodeContainer module, final String nodeName) {
        for (final DataSchemaNode childNode : module.getChildNodes()) {
            if (childNode instanceof DataNodeContainer) {
                LeafSchemaNode leafrefFromRecursion = findSchemaNodeWithLeafrefType((DataNodeContainer)childNode, nodeName);
                if (leafrefFromRecursion != null) {
                    return leafrefFromRecursion;
                }
            } else if (childNode.getQName().getLocalName().equals(nodeName) && childNode instanceof LeafSchemaNode) {
                final TypeDefinition<?> leafSchemaNodeType = ((LeafSchemaNode)childNode).getType();
                if (leafSchemaNodeType instanceof LeafrefTypeDefinition) {
                    return (LeafSchemaNode)childNode;
                }
            }
        }
        return null;
    }

    private static LeafrefTypeDefinition findLeafrefType(final LeafSchemaNode schemaNode) {
        final TypeDefinition<?> type = schemaNode.getType();
        if (type instanceof LeafrefTypeDefinition) {
            return (LeafrefTypeDefinition)type;
        }
        return null;
    }
}