/*

 * Copyright (c) 2003, 2017, 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 com.sun.org.apache.xpath.internal.jaxp;

import com.sun.org.apache.xpath.internal.*;

import com.sun.org.apache.xpath.internal.objects.XObject;

import javax.xml.namespace.NamespaceContext;

import javax.xml.namespace.QName;

import javax.xml.transform.TransformerException;

import javax.xml.xpath.XPathConstants;

import javax.xml.xpath.XPathEvaluationResult;

import javax.xml.xpath.XPathExpression;

import javax.xml.xpath.XPathExpressionException;

import javax.xml.xpath.XPathFunctionResolver;

import javax.xml.xpath.XPathVariableResolver;

import jdk.xml.internal.JdkXmlFeatures;

import org.w3c.dom.Document;

import org.xml.sax.InputSource;

/**

 * The XPathImpl class provides implementation for the methods defined  in

 * javax.xml.xpath.XPath interface. This provides simple access to the results

 * of an XPath expression.

 *

 * @author  Ramesh Mandava

 *

 * Updated 12/04/2014:

 * New methods: evaluateExpression

 * Refactored to share code with XPathExpressionImpl.

 */

public class XPathImpl extends XPathImplUtil implements javax.xml.xpath.XPath {

    // Private variables

    private XPathVariableResolver origVariableResolver;

    private XPathFunctionResolver origFunctionResolver;

    private NamespaceContext namespaceContext=null;

    XPathImpl(XPathVariableResolver vr, XPathFunctionResolver fr) {

        this(vr, fr, false, new JdkXmlFeatures(false));

    }

    XPathImpl(XPathVariableResolver vr, XPathFunctionResolver fr,

            boolean featureSecureProcessing, JdkXmlFeatures featureManager) {

        this.origVariableResolver = this.variableResolver = vr;

        this.origFunctionResolver = this.functionResolver = fr;

        this.featureSecureProcessing = featureSecureProcessing;

        this.featureManager = featureManager;

        overrideDefaultParser = featureManager.getFeature(

                JdkXmlFeatures.XmlFeature.JDK_OVERRIDE_PARSER);

    }

    //-Override-

    public void setXPathVariableResolver(XPathVariableResolver resolver) {

        requireNonNull(resolver, "XPathVariableResolver");

        this.variableResolver = resolver;

    }

    //-Override-

    public XPathVariableResolver getXPathVariableResolver() {

        return variableResolver;

    }

    //-Override-

    public void setXPathFunctionResolver(XPathFunctionResolver resolver) {

        requireNonNull(resolver, "XPathFunctionResolver");

        this.functionResolver = resolver;

    }

    //-Override-

    public XPathFunctionResolver getXPathFunctionResolver() {

        return functionResolver;

    }

    //-Override-

    public void setNamespaceContext(NamespaceContext nsContext) {

        requireNonNull(nsContext, "NamespaceContext");

        this.namespaceContext = nsContext;

        this.prefixResolver = new JAXPPrefixResolver (nsContext);

    }

    //-Override-

    public NamespaceContext getNamespaceContext() {

        return namespaceContext;

    }

    /**

     * Evaluate an {@code XPath} expression in the specified context.

     * @param expression The XPath expression.

     * @param contextItem The starting context.

     * @return an XObject as the result of evaluating the expression

     * @throws TransformerException if evaluating fails

     */

    private XObject eval(String expression, Object contextItem)

        throws TransformerException {

        requireNonNull(expression, "XPath expression");

        com.sun.org.apache.xpath.internal.XPath xpath = new com.sun.org.apache.xpath.internal.XPath(expression,

            null, prefixResolver, com.sun.org.apache.xpath.internal.XPath.SELECT);

        return eval(contextItem, xpath);

    }

    //-Override-

    public Object evaluate(String expression, Object item, QName returnType)

            throws XPathExpressionException {

        //this check is necessary before calling eval to maintain binary compatibility

        requireNonNull(expression, "XPath expression");

        isSupported(returnType);

        try {

            XObject resultObject = eval(expression, item);

            return getResultAsType(resultObject, returnType);

        } catch (java.lang.NullPointerException npe) {

            // If VariableResolver returns null Or if we get

            // NullPointerException at this stage for some other reason

            // then we have to reurn XPathException

            throw new XPathExpressionException (npe);

        } catch (TransformerException te) {

            Throwable nestedException = te.getException();

            if (nestedException instanceof javax.xml.xpath.XPathFunctionException) {

                throw (javax.xml.xpath.XPathFunctionException)nestedException;

            } else {

                // For any other exceptions we need to throw

                // XPathExpressionException (as per spec)

                throw new XPathExpressionException (te);

            }

        }

    }

    //-Override-

    public String evaluate(String expression, Object item)

        throws XPathExpressionException {

        return (String)this.evaluate(expression, item, XPathConstants.STRING);

    }

    //-Override-

    public XPathExpression compile(String expression)

        throws XPathExpressionException {

        requireNonNull(expression, "XPath expression");

        try {

            com.sun.org.apache.xpath.internal.XPath xpath = new XPath (expression, null,

                    prefixResolver, com.sun.org.apache.xpath.internal.XPath.SELECT);

            // Can have errorListener

            XPathExpressionImpl ximpl = new XPathExpressionImpl (xpath,

                    prefixResolver, functionResolver, variableResolver,

                    featureSecureProcessing, featureManager);

            return ximpl;

        } catch (TransformerException te) {

            throw new XPathExpressionException (te) ;

        }

    }

    //-Override-

    public Object evaluate(String expression, InputSource source,

            QName returnType) throws XPathExpressionException {

        isSupported(returnType);

        try {

            Document document = getDocument(source);

            XObject resultObject = eval(expression, document);

            return getResultAsType(resultObject, returnType);

        } catch (TransformerException te) {

            Throwable nestedException = te.getException();

            if (nestedException instanceof javax.xml.xpath.XPathFunctionException) {

                throw (javax.xml.xpath.XPathFunctionException)nestedException;

            } else {

                throw new XPathExpressionException (te);

            }

        }

    }

    //-Override-

    public String evaluate(String expression, InputSource source)

        throws XPathExpressionException {

        return (String)this.evaluate(expression, source, XPathConstants.STRING);

    }

    //-Override-

    public void reset() {

        this.variableResolver = this.origVariableResolver;

        this.functionResolver = this.origFunctionResolver;

        this.namespaceContext = null;

    }

    //-Override-

    public <T> T evaluateExpression(String expression, Object item, Class<T> type)

            throws XPathExpressionException {

        isSupportedClassType(type);

        try {

            XObject resultObject = eval(expression, item);

            if (type.isAssignableFrom(XPathEvaluationResult.class)) {

                return getXPathResult(resultObject, type);

            } else {

                return XPathResultImpl.getValue(resultObject, type);

            }

        } catch (TransformerException te) {

            throw new XPathExpressionException (te);

        }

    }

    //-Override-

    public XPathEvaluationResult<?> evaluateExpression(String expression, Object item)

            throws XPathExpressionException {

        return evaluateExpression(expression, item, XPathEvaluationResult.class);

    }

    //-Override-

    public <T> T evaluateExpression(String expression, InputSource source, Class<T> type)

            throws XPathExpressionException {

        Document document = getDocument(source);

        return evaluateExpression(expression, document, type);

    }

    //-Override-

    public XPathEvaluationResult<?> evaluateExpression(String expression, InputSource source)

            throws XPathExpressionException {

        return evaluateExpression(expression, source, XPathEvaluationResult.class);

    }

}