/*
 * 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 <xalanc/Include/PlatformDefinitions.hpp>



#include <cmath>
#include <ctime>
#if defined(XALAN_CLASSIC_IOSTREAMS)
#include <iostream.h>
#else
#include <iostream>
#endif



#include <xercesc/util/PlatformUtils.hpp>



#include <xalanc/XalanTransformer/XalanTransformer.hpp>



#include <xalanc/XPath/Function.hpp>
#include <xalanc/XPath/XObjectFactory.hpp>



XALAN_USING_XALAN(Function)
XALAN_USING_XALAN(XPathExecutionContext)
XALAN_USING_XALAN(XalanDOMString)
XALAN_USING_XALAN(XalanNode)
XALAN_USING_XALAN(StaticStringToDOMString)
XALAN_USING_XALAN(XObjectPtr)
XALAN_USING_XALAN(MemoryManagerType)
XALAN_USING_XALAN(XalanCopyConstruct)

// This class defines a function that will return the square root
// of its argument.
class FunctionSquareRoot : public Function
{
public:

	/**
	 * Execute an XPath function object.  The function must return a valid
	 * object.  Extension functions should override this version of execute(),
	 * rather than one of the other calls designed for a specific number of
	 * arguments.
	 *
	 * @param executionContext executing context
	 * @param context          current context node
	 * @param args             vector of pointers to XObject arguments
	 * @param locator		   Locator for the XPath expression that contains the function call
	 * @return                 pointer to the result XObject
	 */
	virtual XObjectPtr
	execute(
			XPathExecutionContext&			executionContext,
			XalanNode*						context,
			const XObjectArgVectorType&		args,
			const LocatorType*				locator) const
	{
		if (args.size() != 1)
		{
            XPathExecutionContext::GetAndReleaseCachedString	theGuard(executionContext);

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

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

#if defined(XALAN_STRICT_ANSI_HEADERS)
		using std::sqrt;
#endif

		return executionContext.getXObjectFactory().createNumber(sqrt(args[0]->num()));
	}

#if !defined(XALAN_NO_USING_DECLARATION)
	using Function::execute;
#endif

	/**
	 * Create a copy of the function object.
	 *
	 * @return pointer to the new object
	 */
#if defined(XALAN_NO_COVARIANT_RETURN_TYPE)
	virtual Function*
#else
	virtual FunctionSquareRoot*
#endif
	clone(MemoryManagerType&    theManager) const
	{
	    return XalanCopyConstruct(theManager, *this);
	}

protected:

	/**
	 * Get the error message to report when
	 * the function is called with the wrong
	 * number of arguments.
	 *
	 * @return function error message
	 */
	const XalanDOMString&
	getError(XalanDOMString&    theResult) const
	{
        theResult.assign("The square-root() function accepts one argument!");

		return theResult;
	}

private:

	// Not implemented...
	FunctionSquareRoot&
	operator=(const FunctionSquareRoot&);

	bool
	operator==(const FunctionSquareRoot&) const;
};



// This class defines a function that will return the cube
// of its argument.
class FunctionCube : public Function
{
public:

	/**
	 * Execute an XPath function object.  The function must return a valid
	 * object.  Extension functions should override this version of execute(),
	 * rather than one of the other calls designed for a specific number of
	 * arguments.
	 *
	 * @param executionContext executing context
	 * @param context          current context node
	 * @param args             vector of pointers to XObject arguments
	 * @param locator		   Locator for the XPath expression that contains the function call
	 * @return                 pointer to the result XObject
	 */
	virtual XObjectPtr
	execute(
			XPathExecutionContext&			executionContext,
			XalanNode*						context,
			const XObjectArgVectorType&		args,
			const LocatorType*				locator) const
	{
		if (args.size() != 1)
		{
            XPathExecutionContext::GetAndReleaseCachedString	theGuard(executionContext);

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

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

#if defined(XALAN_STRICT_ANSI_HEADERS)
		using std::pow;
#endif

		return executionContext.getXObjectFactory().createNumber(pow(args[0]->num(), 3));
	}

#if !defined(XALAN_NO_USING_DECLARATION)
	using Function::execute;
#endif

	/**
	 * Create a copy of the function object.
	 *
	 * @return pointer to the new object
	 */
#if defined(XALAN_NO_COVARIANT_RETURN_TYPE)
	virtual Function*
#else
	virtual FunctionCube*
#endif
	clone(MemoryManagerType&    theManager) const
	{
	    return XalanCopyConstruct(theManager, *this);
	}

protected:

	/**
	 * Get the error message to report when
	 * the function is called with the wrong
	 * number of arguments.
	 *
	 * @return function error message
	 */
	const XalanDOMString&
	getError(XalanDOMString&    theResult) const
	{
        theResult.assign("The cube() function accepts one argument!");

		return theResult;
	}

private:

	// Not implemented...
	FunctionCube&
	operator=(const FunctionCube&);

	bool
	operator==(const FunctionCube&) const;
};



// This class defines a function that runs the C function
// asctime() using the current system time.
class FunctionAsctime : public Function
{
public:

	/**
	 * Execute an XPath function object.  The function must return a valid
	 * object.  Extension functions should override this version of execute(),
	 * rather than one of the other calls designed for a specific number of
	 * arguments.
	 *
	 * @param executionContext executing context
	 * @param context          current context node
	 * @param args             vector of pointers to XObject arguments
	 * @param locator		   Locator for the XPath expression that contains the function call
	 * @return                 pointer to the result XObject
	 */
	virtual XObjectPtr
	execute(
			XPathExecutionContext&			executionContext,
			XalanNode*						context,
			const XObjectArgVectorType&		args,
			const LocatorType*				locator) const
	{
		if (args.empty() == false)
		{
            XPathExecutionContext::GetAndReleaseCachedString	theGuard(executionContext);

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

#if defined(XALAN_STRICT_ANSI_HEADERS)
		using std::time;
		using std::time_t;
		using std::localtime;
		using std::asctime;
		using std::strlen;
#endif

		time_t	theTime;

		time(&theTime);

		char* const	theTimeString = asctime(localtime(&theTime));
		assert(theTimeString != 0);

		// The resulting string has a newline character at the end,
		// so get rid of it.
		theTimeString[strlen(theTimeString) - 1] = '\0';

		return executionContext.getXObjectFactory().createString(XalanDOMString(theTimeString));
	}

#if !defined(XALAN_NO_USING_DECLARATION)
	using Function::execute;
#endif

	/**
	 * Create a copy of the function object.
	 *
	 * @return pointer to the new object
	 */
#if defined(XALAN_NO_COVARIANT_RETURN_TYPE)
	virtual Function*
#else
	virtual FunctionAsctime*
#endif
	clone(MemoryManagerType&    theManager) const
	{
	    return XalanCopyConstruct(theManager, *this);
	}

protected:

	/**
	 * Get the error message to report when
	 * the function is called with the wrong
	 * number of arguments.
	 *
	 * @return function error message
	 */
	const XalanDOMString&
	getError(XalanDOMString& theResult) const
	{
        theResult.assign("The asctime() function accepts one argument!");

		return theResult;
	}

private:

	// Not implemented...
	FunctionAsctime&
	operator=(const FunctionAsctime&);

	bool
	operator==(const FunctionAsctime&) const;
};



int
main(
			int		argc,
			char*	/* argv */[])
{
	XALAN_USING_STD(cerr)
	XALAN_USING_STD(endl)

	int	theResult = 0;

	if (argc != 1)
	{
		cerr << "Usage: ExternalFunction"
			 << endl
			 << endl;
	}
	else
	{
		XALAN_USING_XERCES(XMLPlatformUtils)
		XALAN_USING_XERCES(XMLException)

		XALAN_USING_XALAN(XalanTransformer)

		// Call the static initializer for Xerces.
		try
		{
			 XMLPlatformUtils::Initialize();
		}
		catch (const XMLException& toCatch)
		{
			 cerr << "Error during Xerces initialization.  Error code was "
                  << toCatch.getCode()
                  << "."
                  << endl;

			 theResult = -1;
		}

		if (theResult == 0)
		{
			// Initialize Xalan.
			XalanTransformer::initialize();

			{
				// Create a XalanTransformer.
				XalanTransformer	theXalanTransformer;

				// The namespace for our functions...
				const XalanDOMString	theNamespace("http://ExternalFunction.xalan-c++.xml.apache.org");

				// Install the functions in the local space.  They will only
				// be installed in this instance, so no other instances
				// will know about them...
				theXalanTransformer.installExternalFunction(
					theNamespace,
					XalanDOMString("asctime"),
					FunctionAsctime());

				theXalanTransformer.installExternalFunction(
					theNamespace,
					XalanDOMString("square-root"),
					FunctionSquareRoot());

				theXalanTransformer.installExternalFunction(
					theNamespace,
					XalanDOMString("cube"),
					FunctionCube());

				// Do the transform.
				theResult = theXalanTransformer.transform("foo.xml", "foo.xsl", "foo.out");
    
				if(theResult != 0)
				{
					cerr << "ExternalFunction Error: \n" << theXalanTransformer.getLastError()
						 << endl
						 << endl;
				}
			}

			// Terminate Xalan...
			XalanTransformer::terminate();
		}

		// Terminate Xerces...
		XMLPlatformUtils::Terminate();

		// Clean up the ICU, if it's integrated...
		XalanTransformer::ICUCleanUp();
	}

	return theResult;
}
