/*
 * 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.
 */
#if !defined(XALAN_EXTENSIONNSHANDLER_HEADER_GUARD)
#define XALAN_EXTENSIONNSHANDLER_HEADER_GUARD


// Base include file.   Must be first.
#include "XSLTDefinitions.hpp"


// Base class
#include "ExtensionFunctionHandler.hpp"


#include <xalanc/Include/XalanSet.hpp>


#include <xalanc/XalanDOM/XalanDOMString.hpp>


#include <xalanc/PlatformSupport/DOMStringHelper.hpp>


namespace XALAN_CPP_NAMESPACE {


class Stylesheet;
class StylesheetExecutionContext;
class XalanElement;
class XalanNode;
class XalanQName;


class XALAN_XSLT_EXPORT ExtensionNSHandler : public ExtensionFunctionHandler
{    
public: 

    /**
     * Construct a new extension namespace handler for a given extension NS.
     * This doesn't do anything - just hang on to the namespace URI.
     * 
     * @param namespaceUri extension namespace URI being implemented
     */
    ExtensionNSHandler(
            const XalanDOMString&   namespaceUri,
            MemoryManager&          theManager);

    static ExtensionNSHandler*
    create(
            const XalanDOMString&   namespaceUri,
            MemoryManager&          theManager);

    /**
     * Construct a new extension namespace handler given all the information
     * needed. 
     * 
     * @param namespaceUri extension namespace URI being implemented
     * @param elemNames    string containing list of elements of extension NS
     * @param funcNames    string containing list of functions of extension NS
     * @param lang         language of code implementing the extension
     * @param srcURL       value of src attribute (if any) - treated as a URL
     *                     or a classname depending on the value of lang. If
     *                     srcURL is not null, then scriptSrc is ignored.
     * @param scriptSrc    the actual script code (if any)
     */
    ExtensionNSHandler(
            MemoryManager&          theManager,
            const XalanDOMString&   namespaceUri,
            const XalanDOMString&   elemNames,
            const XalanDOMString&   funcNames,
            const XalanDOMString&   lang,
            const XalanDOMString&   srcURL,
            const XalanDOMString&   src);

    /**
     * Set function local parts of extension NS. Super does the work; I
     * just record that a component desc has been loaded.
     *
     * @param functions whitespace separated list of function names defined
     *                  by this extension namespace
    */
    virtual void
    setFunctions(const XalanDOMString&  funcNames); 

    /**
     * Set the script data for this extension NS. Deferred to super for
     * actual work - only record that a component desc has been loaded.
     *
     * @param lang      language of the script
     * @param srcURL    value of src attribute (if any) - treated as a URL
     *                  or a classname depending on the value of lang. If
     *                  srcURL is not null, then scriptSrc is ignored.
     * @param scriptSrc the actual script code (if any)
     */
    virtual void
    setScript(
            const XalanDOMString&   lang,
            const XalanDOMString&   srcURL,
            const XalanDOMString&   scriptSrc); 

    /**
     * Set element local parts of extension NS.
     *
     * @param elemNames whitespace separated list of element names defined
     *                  by this extension namespace
     */
    void
    setElements(const XalanDOMString&   elemNames); 

    /**
     * Tests whether a certain element name is known within this namespace.
     *
     * @param element name of the element being tested
     * @return true if known, false if not
     */
    bool
    isElementAvailable (const XalanDOMString&   element) const;

    /**
     * Process a call to this extension namespace via an element. As a side
     * effect, the results are sent to the XSLTProcessor's result tree.
     *
     * @param localPart      element name's local part
     * @param element        extension element being processed
     * @param stylesheetTree compiled stylesheet tree
     * @param mode           current mode
     * @param sourceTree     root of the source tree (but don't assume it's a
     *                       document)
     * @param sourceNode     current context node
     * @exception XSLProcessorException thrown if something goes wrong 
     *                                  while running the extension handler
     * @exception MalformedURLException if loading trouble
     * @exception FileNotFoundException if loading trouble
     * @exception IOException           if loading trouble
     * @exception SAXException          if parsing trouble
     */
    void
    processElement (
            StylesheetExecutionContext&     executionContext,
            const XalanDOMString&           localPart,
            const XalanElement*             element,
            Stylesheet&                     stylesheetTree, 
            const XalanNode*                sourceTree,
            const XalanNode*                sourceNode,
            const XalanQName&               mode);

protected:

    /**
     * Start the component up by executing any script that needs to run
     * at startup time. This needs to happen before any functions can be
     * called on the component.
     * 
     */
    virtual void
    startupComponent();

private:

    typedef XalanSet<XalanDOMString>    ExtensionSetType;

    // Extension elements of this namespace
    ExtensionSetType    m_elements;

    // True when info from the component description has been loaded. This gets
    // set as soon as any of the info has been specified. If this is false,
    // when processElement or processFunction is called it will use the
    // namespace URI as a URL and try to load that location as the component
    // description
    bool m_componentDescLoaded;

    /**
     * Load the component spec for this extension namespace taking the URI
     * of this namespace as the URL to read from.
     */
    void
    loadComponentDescription();

    /**
     * extract the text nodes and CDATA content children of the given
     * elem and return as a string. Any other types of node children
     * are ignored
     *
     * @param elem element whose text and cdata children are to be 
     *              concatenated together.
     *
     * @return string resulting from concatanating the text/cdata child
     *               nodes' values.
     */
    static XalanDOMString&
    getScriptString(const XalanElement&     elem, XalanDOMString& theResult);
};


}


#endif  // XALAN_EXTENSIONNSHANDLER_HEADER_GUARD