/*

   * 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 org.apache.sling.scripting.jsp.jasper.runtime;

 import java.security.AccessController;

 import java.security.PrivilegedAction;

 import javax.servlet.Servlet;

 import javax.servlet.ServletContext;

 import javax.servlet.ServletRequest;

 import javax.servlet.ServletResponse;

 import  javax.servlet.jsp.JspApplicationContext;

 import  javax.servlet.jsp.JspEngineInfo;

 import  javax.servlet.jsp.JspFactory;

 import  javax.servlet.jsp.PageContext;

 import org.apache.juli.logging.Log;

 import org.apache.juli.logging.LogFactory;

 import org.apache.sling.scripting.jsp.jasper.Constants;

 public class JspFactoryImpl extends JspFactory {

     // Logger

     private Log log = LogFactory.getLog(JspFactoryImpl.class);

     private static final String SPEC_VERSION = "2.1";

     public PageContext getPageContext(Servlet servlet, ServletRequest request,

             ServletResponse response, String errorPageURL, boolean needsSession,

             int bufferSize, boolean autoflush) {

         if( Constants.IS_SECURITY_ENABLED ) {

             PrivilegedGetPageContext dp = new PrivilegedGetPageContext(

                     this, servlet, request, response, errorPageURL,

                     needsSession, bufferSize, autoflush);

             return (PageContext)AccessController.doPrivileged(dp);

         } else {

             return internalGetPageContext(servlet, request, response,

                     errorPageURL, needsSession,

                     bufferSize, autoflush);

         }

     }

     public void releasePageContext(PageContext pc) {

         if( pc == null )

             return;

         if( Constants.IS_SECURITY_ENABLED ) {

             PrivilegedReleasePageContext dp = new PrivilegedReleasePageContext(

                     this,pc);

             AccessController.doPrivileged(dp);

         } else {

             internalReleasePageContext(pc);

         }

     }

     public JspEngineInfo getEngineInfo() {

         return new JspEngineInfo() {

             public String getSpecificationVersion() {

                 return SPEC_VERSION;

             }

         };

     }

     private PageContext internalGetPageContext(Servlet servlet, ServletRequest request,

             ServletResponse response, String errorPageURL, boolean needsSession,

             int bufferSize, boolean autoflush) {

         try {

             PageContext pc = new PageContextImpl();

             pc.initialize(servlet, request, response, errorPageURL,

                     needsSession, bufferSize, autoflush);

             return pc;

         } catch (Throwable ex) {

             /* FIXME: need to do something reasonable here!! */

             log.fatal("Exception initializing page context", ex);

             return null;

         }

     }

     private void internalReleasePageContext(PageContext pc) {

         pc.release();

    }

    private class PrivilegedGetPageContext implements PrivilegedAction {

        private JspFactoryImpl factory;

        private Servlet servlet;

        private ServletRequest request;

        private ServletResponse response;

        private String errorPageURL;

        private boolean needsSession;

        private int bufferSize;

        private boolean autoflush;

        PrivilegedGetPageContext(JspFactoryImpl factory, Servlet servlet,

                ServletRequest request, ServletResponse response, String errorPageURL,

                boolean needsSession, int bufferSize, boolean autoflush) {

            this.factory = factory;

            this.servlet = servlet;

            this.request = request;

            this.response = response;

            this.errorPageURL = errorPageURL;

            this.needsSession = needsSession;

            this.bufferSize = bufferSize;

            this.autoflush = autoflush;

        }

        public Object run() {

            return factory.internalGetPageContext(servlet, request, response,

                    errorPageURL, needsSession, bufferSize, autoflush);

        }

    }

    private class PrivilegedReleasePageContext implements PrivilegedAction {

        private JspFactoryImpl factory;

        private PageContext pageContext;

        PrivilegedReleasePageContext(JspFactoryImpl factory,

                PageContext pageContext) {

            this.factory = factory;

            this.pageContext = pageContext;

        }

        public Object run() {

            factory.internalReleasePageContext(pageContext);

            return null;

        }

    }

    public JspApplicationContext getJspApplicationContext(ServletContext context) {

        return JspApplicationContextImpl.getInstance(context);

    }

}