/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed 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.
 */
#include "FunctionEvaluate.hpp"



#include <xalanc/PlatformSupport/PrefixResolver.hpp>
#include <xalanc/PlatformSupport/XalanMessageLoader.hpp>



#include <xalanc/DOMSupport/DOMServices.hpp>



#include <xalanc/XalanDOM/XalanElement.hpp>



#include <xalanc/XPath/ElementPrefixResolverProxy.hpp>
#include <xalanc/XPath/XObjectFactory.hpp>
#include <xalanc/XPath/XPath.hpp>
#include <xalanc/XPath/XPathConstructionContextDefault.hpp>
#include <xalanc/XPath/XPathProcessorImpl.hpp>



XALAN_CPP_NAMESPACE_BEGIN



FunctionEvaluate::FunctionEvaluate()
{
}



FunctionEvaluate::~FunctionEvaluate()
{
}



inline XObjectPtr
doExecute(
            XPathExecutionContext&          executionContext,
            XalanNode*                      context,
            const XalanDOMString&           expression,
            const PrefixResolver&           resolver,
            const Function::LocatorType*    locator)
{
    // $$$ ToDo: Consider moving all of this into a member function of
    // XPathExecutionContext.
    XPathProcessorImpl                  theProcessor(executionContext.getMemoryManager());

    XPathConstructionContextDefault     theConstructionContext(executionContext.getMemoryManager());

    XPath                               theXPath(executionContext.getMemoryManager(), locator);

    theProcessor.initXPath(
            theXPath,
            theConstructionContext,
            expression,
            resolver,
            locator);

    return theXPath.execute(context, resolver, executionContext);
}



inline XObjectPtr
doExecute(
            XPathExecutionContext&          executionContext,
            XalanNode*                      context,
            const XalanDOMString&           expression,
            const XalanNode*                resolver,
            const Function::LocatorType*    locator)
{
    assert(resolver == 0 || resolver->getNodeType() == XalanNode::ELEMENT_NODE);

#if defined(XALAN_OLD_STYLE_CASTS)
    ElementPrefixResolverProxy  theProxy((const XalanElement*)resolver, 
                                            executionContext.getMemoryManager());
#else
    ElementPrefixResolverProxy  theProxy(static_cast<const XalanElement*>(resolver), 
                                            executionContext.getMemoryManager());
#endif

    return doExecute(executionContext, context, expression, theProxy, locator);
}



XObjectPtr
FunctionEvaluate::execute(
            XPathExecutionContext&          executionContext,
            XalanNode*                      context,
            const XObjectArgVectorType&     args,
            const LocatorType*              locator) const
{
    if (args.size() != 1)
    {
        XPathExecutionContext::GetAndReleaseCachedString theString(executionContext);

        executionContext.error(getError(theString.get()), context, locator);
    }

    assert(args[0].null() == false);

    const XalanDOMString&   theExpression = args[0]->str();

    const PrefixResolver* const theResolver =
        executionContext.getPrefixResolver();

    if (theResolver != 0)
    {
        return doExecute(executionContext, context, theExpression, *theResolver, locator);
    }
    else
    {
        const XalanNode*    resolverNode = context;

        if (resolverNode->getNodeType() != XalanNode::ELEMENT_NODE)
        {
            resolverNode = DOMServices::getParentOfNode(*resolverNode);

            if (context->getNodeType() != XalanNode::ELEMENT_NODE)
            {
                const XPathExecutionContext::GetCachedString    theString(executionContext);

                executionContext.warn(
                    XalanMessageLoader::getMessage(
                        theString.get(),
                        XalanMessages::NoPrefixResolverAvailable),
                    context,
                    locator);

                resolverNode = 0;
            }
        }

        return doExecute(executionContext, context, theExpression, resolverNode, locator);
    }
}



#if defined(XALAN_NO_COVARIANT_RETURN_TYPE)
Function*
#else
FunctionEvaluate*
#endif
FunctionEvaluate::clone(MemoryManagerType&  theManager) const
{
    return XalanCopyConstruct(theManager, *this);
}



const XalanDOMString&
FunctionEvaluate::getError(XalanDOMString&  theResult) const
{
    return XalanMessageLoader::getMessage(
                theResult,
                XalanMessages::FunctionAcceptsOneArgument_1Param,
                "evaluate");
}



XALAN_CPP_NAMESPACE_END