/**

 * Copyright (C) 2005-2009 Alfresco Software Limited.

 *

 * This file is part of the Spring Surf Extension project.

 *

 * 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.

 */



package org.springframework.extensions.surf.util;



import java.io.IOException;

import java.util.ArrayList;

import java.util.Enumeration;

import java.util.HashMap;

import java.util.Iterator;

import java.util.Map;



import javax.el.ELContext;



import javax.servlet.Servlet;

import javax.servlet.ServletConfig;

import javax.servlet.ServletContext;

import javax.servlet.ServletException;

import javax.servlet.ServletRequest;

import javax.servlet.ServletResponse;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

import javax.servlet.jsp.JspWriter;

import javax.servlet.jsp.PageContext;

import javax.servlet.jsp.el.ExpressionEvaluator;

import javax.servlet.jsp.el.VariableResolver;



import org.springframework.extensions.surf.site.RequestUtil;



/**

 * Fake Jsp PageContext implementation which wraps predescribed HTTP objects.

 * 

 * @author muzquiano

 */

public class FakeJspPageContext

    extends PageContext

{

    

    /** The exception. */

    protected Exception exception;

    

    /** The values. */

    protected Map<String, Object> values;

    

    /** The context. */

    protected ServletContext context;

    

    /** The request. */

    protected HttpServletRequest request;

    

    /** The response. */

    protected HttpServletResponse response;

    

    /** The out. */

    protected JspWriter out;

    

    /**

     * Instantiates a new fake jsp page context

     * 

     * @param context The ServletContext to wrap

     * @param request The HttpServletRequest instance to wrap

     * @param response The HttpServletResponse instance to wrap

     * @param out The JspWriter to wrap

     */

    public FakeJspPageContext(ServletContext context, HttpServletRequest request, HttpServletResponse response, JspWriter out)

    {

        this.context = context;

        this.request = request;

        this.response = response;

        this.out = out;

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.PageContext#getRequest()

     */

    public ServletRequest getRequest()

    {

        return this.request;

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.PageContext#getResponse()

     */

    public ServletResponse getResponse()

    {

        return this.response;

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.PageContext#getServletContext()

     */

    public ServletContext getServletContext()

    {

        return this.context;

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.PageContext#getServletConfig()

     */

    public ServletConfig getServletConfig()

    {

        return null;

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.JspContext#getOut()

     */

    public JspWriter getOut()

    {

        return this.out;

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.PageContext#getSession()

     */

    public HttpSession getSession()

    {

        return this.request.getSession();

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.JspContext#findAttribute(java.lang.String)

     */

    public Object findAttribute(String name)

    {

        Object ret = getAttribute(name, PAGE_SCOPE);

        if (ret != null)

            return ret;

        ret = getAttribute(name, REQUEST_SCOPE);

        if (ret != null)

            return ret;

        ret = getAttribute(name, SESSION_SCOPE);

        if (ret != null)

            return ret;

        ret = getAttribute(name, APPLICATION_SCOPE);

        if (ret != null)

            return ret;

        return null;

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.JspContext#getAttribute(java.lang.String)

     */

    public Object getAttribute(String name)

    {

        return findAttribute(name);

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.JspContext#getAttribute(java.lang.String, int)

     */

    public Object getAttribute(String name, int scope)

    {

        switch (scope)

        {

            case APPLICATION_SCOPE:

                return getServletContext().getAttribute(name);

            case REQUEST_SCOPE:

                Object ret = getRequest().getAttribute(name);

                if (ret == null)

                    ret = getRequest().getParameter(name);

                return ret;

            case SESSION_SCOPE:

                if (getSession() != null)

                    return getSession().getAttribute(name);

                else

                    return null;

            case PAGE_SCOPE:

                return getValue(name);

        }

        return null;

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.JspContext#setAttribute(java.lang.String, java.lang.Object)

     */

    public void setAttribute(String name, Object obj)

    {

        setValue(name, obj);

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.JspContext#setAttribute(java.lang.String, java.lang.Object, int)

     */

    public void setAttribute(String name, Object obj, int scope)

    {

        switch (scope)

        {

            case APPLICATION_SCOPE:

                getServletContext().setAttribute(name, obj);

                break;

            case REQUEST_SCOPE:

                getRequest().setAttribute(name, obj);

                break;

            case SESSION_SCOPE:

                if (getSession() != null)

                    getSession().setAttribute(name, obj);

                break;

            case PAGE_SCOPE:

                setValue(name, obj);

                break;

        }

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.JspContext#removeAttribute(java.lang.String)

     */

    public void removeAttribute(String name)

    {

        removeValue(name);

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.JspContext#removeAttribute(java.lang.String, int)

     */

    public void removeAttribute(String name, int scope)

    {

        switch (scope)

        {

            case APPLICATION_SCOPE:

                getServletContext().removeAttribute(name);

                break;

            case REQUEST_SCOPE:

                getRequest().removeAttribute(name);

                break;

            case SESSION_SCOPE:

                if (getSession() != null)

                    getSession().removeAttribute(name);

                break;

            case PAGE_SCOPE:

                removeValue(name);

                break;

        }

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.JspContext#getAttributeNamesInScope(int)

     */

    public Enumeration getAttributeNamesInScope(int scope)

    {

        switch (scope)

        {

            case APPLICATION_SCOPE:

                return getServletContext().getAttributeNames();

            case REQUEST_SCOPE:

                return getRequest().getAttributeNames();

            case SESSION_SCOPE:

                return getSession().getAttributeNames();

            case PAGE_SCOPE:

                return getValueNames();

        }

        return null;

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.JspContext#getAttributesScope(java.lang.String)

     */

    public int getAttributesScope(String name)

    {

        if (getValue(name) != null)

            return PAGE_SCOPE;



        // allow request attributes to override request parameters

        if (getRequest().getAttribute(name) != null)

            return REQUEST_SCOPE;

        if (getRequest().getParameter(name) != null)

            return REQUEST_SCOPE;

        if (getSession().getAttribute(name) != null)

            return SESSION_SCOPE;

        if (getServletContext().getAttribute(name) != null)

            return APPLICATION_SCOPE;



        return 0;

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.PageContext#forward(java.lang.String)

     */

    public void forward(String url) throws ServletException, IOException

    {

        RequestUtil.forward(getServletContext(), getRequest(), getResponse(), url);        

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.PageContext#include(java.lang.String)

     */

    public void include(String url) throws ServletException, IOException

    {

        include(url, true);

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.PageContext#include(java.lang.String, boolean)

     */

    public void include(String url, boolean b) throws ServletException,

            IOException

    {

        RequestUtil.include(getServletContext(), getRequest(), getResponse(), url);

        

        // make sure everything is flushed before doing an include -- important for included JSP files

        flushOut();

    }



    /**

     * Flush out.

     * 

     * @throws IOException

     *             Signals that an I/O exception has occurred.

     */

    public void flushOut() throws java.io.IOException

    {

        out.flush();

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.PageContext#release()

     */

    public void release()

    {

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.JspContext#getExpressionEvaluator()

     */

    public ExpressionEvaluator getExpressionEvaluator()

    {

        return null;



    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.JspContext#getVariableResolver()

     */

    public VariableResolver getVariableResolver()

    {

        return null;



    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.PageContext#handlePageException(java.lang.Throwable)

     */

    public void handlePageException(Throwable t)

    {

        // TODO?

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.PageContext#handlePageException(java.lang.Exception)

     */

    public void handlePageException(Exception e)

    {

        exception = e;

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.PageContext#getException()

     */

    public Exception getException()

    {

        return exception;

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.PageContext#getPage()

     */

    public Object getPage()

    {

        return null;

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.PageContext#getELContext()

     */

    @Override

    public ELContext getELContext()

    {

        return null;

    }



    /* (non-Javadoc)

     * @see javax.servlet.jsp.PageContext#initialize(javax.servlet.Servlet, javax.servlet.ServletRequest, javax.servlet.ServletResponse, java.lang.String, boolean, int, boolean)

     */

    public void initialize(Servlet srv, ServletRequest req,

            ServletResponse res, String s1, boolean b1, int i1, boolean b2)

    {

    }

    

    

    // local page context helper methods

    

    /**

     * Gets the value.

     * 

     * @param key

     *            the key

     * 

     * @return the value

     */

    protected Object getValue(String key)

    {

        if (values == null)

            values = new HashMap<String, Object>();

        return values.get(key);

    }

    

    /**

     * Sets the value.

     * 

     * @param key

     *            the key

     * @param value

     *            the value

     */

    protected void setValue(String key, Object value)

    {

        if (values == null)

            values = new HashMap<String, Object>();

        values.put(key, value);

    }

    

    /**

     * Removes the value.

     * 

     * @param key

     *            the key

     */

    protected void removeValue(String key)

    {

        if (values == null)

            values = new HashMap<String, Object>();

        values.remove(key);

    }

    

    /**

     * Gets the value names.

     * 

     * @return the value names

     */

    protected Enumeration getValueNames()

    {

        ArrayList<Object> array = new ArrayList<Object>();



        Iterator it = values.keySet().iterator();

        while (it.hasNext())

        {

            array.add(it.next());

        }



        return java.util.Collections.enumeration(array);

    }





}