/* ================================================================

  * Cewolf : Chart enabling Web Objects Framework

  * ================================================================

  *

  * Project Info:  http://cewolf.sourceforge.net

  * Project Lead:  Guido Laures (guido@laures.de);

  *

  * (C) Copyright 2002, by Guido Laures

  *

  * This library is free software; you can redistribute it and/or modify it under the terms

  * of the GNU Lesser General Public License as published by the Free Software Foundation;

  * either version 2.1 of

  * the License, or (at your option) any later version.

  *

  * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;

  * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

  * See the GNU Lesser General Public License for more details.

  *

  * You should have received a copy of the GNU Lesser General Public License along with this

  * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,

  * Boston, MA 02111-1307, USA.

  */

 package de.laures.cewolf.taglib.tags;

 import java.io.IOException;

 import java.io.Writer;

 import javax.servlet.http.HttpServletRequest;

 import javax.servlet.http.HttpServletResponse;

 import javax.servlet.jsp.JspException;

 import javax.servlet.jsp.JspWriter;

 import javax.servlet.jsp.PageContext;

 import javax.servlet.jsp.tagext.BodyContent;

 import de.laures.cewolf.CewolfException;

 import de.laures.cewolf.ChartHolder;

 import de.laures.cewolf.ChartImage;

 import de.laures.cewolf.Configuration;

 import de.laures.cewolf.Storage;

 import de.laures.cewolf.WebConstants;

 import de.laures.cewolf.taglib.ChartImageDefinition;

 import de.laures.cewolf.taglib.TaglibConstants;

 import de.laures.cewolf.taglib.html.HTMLImgTag;

 import de.laures.cewolf.taglib.util.MIMEExtensionHelper;

 import de.laures.cewolf.taglib.util.PageUtils;

 /**

  * This is the tag implementation of the <img> tag. This tag inputs the

  * proper <img> tag into the HTML page delivered to the client. It

  * therefor determines the chart ID which will be used by the rendering servlet

  * to retrieve the chart.

  * 

  * @author glaures

  * @see de.laures.cewolf.ChartImage

  */

 public class ChartImgTag extends HTMLImgTag implements CewolfRootTag, Mapped, TaglibConstants, WebConstants

 {

   private static final String  DEFAULT_MIME_TYPE = MIME_PNG;

   private static final String  TAG_NAME_SVG      = "EMBED";

   private static final int     DEFAULT_TIMEOUT   = 300;

   private String               chartId           = null;

   private String               renderer;

   private String               mimeType          = DEFAULT_MIME_TYPE;

   private int                  timeout           = DEFAULT_TIMEOUT;

   protected String             sessionKey        = null;

   private ChartImageDefinition chartImageDefinition;

   public int doStartTag() throws JspException

   {

     final ChartHolder chartHolder = PageUtils.getChartHolder(chartId, pageContext);

     this.chartImageDefinition = new ChartImageDefinition(chartHolder, width, height, ChartImage.IMG_TYPE_CHART, mimeType,timeout);

     Storage storage = Configuration.getInstance(pageContext.getServletContext()).getStorage();

     try

     {

       this.sessionKey = storage.storeChartImage(chartImageDefinition, pageContext);

     }

     catch (CewolfException cwex)

     {

       throw new JspException(cwex.getMessage());

     }

     return EVAL_PAGE;

   }

   public int doAfterBody() throws JspException

   {

     try

     {

       // double checking for null as Resin had problems with that

       final BodyContent body = getBodyContent();

       if ( body != null )

       {

         final JspWriter writer = getPreviousOut();

         if ( writer != null )

         {

           body.writeOut(writer);

         }

       }

     }

     catch (IOException ioex)

     {

       log.error(ioex);	

       throw new JspException(ioex.getMessage());

     }

     return SKIP_BODY;

   }

   public int doEndTag() throws JspException

   {

     super.doStartTag();

     final StringBuffer buffer = new StringBuffer(" src=\"");

     buffer.append(getImgURL());

     buffer.append("\"");

     try

     {

       pageContext.getOut().write(buffer.toString());

     }

     catch (IOException ioex)

     {

       reset();

       log.error(ioex);

       throw new JspException(ioex.getMessage());

     }

     return super.doEndTag();

   }

   /**

    * Fix an absolute url given as attribute by adding the full application url path to it.

    * It is considered absolute url (not relative) when it starts with "/"

    * @param url The url to fix

    * @param request The http request

    * @return Fixed url contains the full path

    */

   public static String fixAbsolutURL(String url, HttpServletRequest request) {

     if ( url.startsWith("/") )

     {

       //final HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();

       final String context = request.getContextPath();

       url = context + url;

     }

     return url;

   }

   /**

    * Same as the other fixAbsolutURL, convinience only.

    * @param url The url to fix

    * @param pageContext The page context

    * @return Fixed url contains the full path

    */

   public static String fixAbsolutURL(String url, PageContext pageContext) {

   	return fixAbsolutURL(url, (HttpServletRequest) pageContext.getRequest());

   }

   /**

    * Build the image url

    * @param renderer the url of the renderer

    * @param pageContext Page context

    * @param sessionKey The session key for the image stored.

    * @param width The width 

    * @param height The height

    * @param mimeType the mime-type (for example png) of it

    * @return The full url 

    */

   public static String buildImgURL(

 		  String renderer, PageContext pageContext, String sessionKey, int width, int height, String mimeType,

 		  boolean forceSessionId, boolean removeAfterRender) {

 	renderer = fixAbsolutURL(renderer, pageContext);

 	final HttpServletResponse response = (HttpServletResponse) pageContext.getResponse();

 	StringBuffer url = new StringBuffer(response.encodeURL(renderer));

 	if ( url.toString().indexOf(SESSIONID_KEY) == -1 )

 	{

 		if (forceSessionId)

 		{

 			  final String sessionId = pageContext.getSession().getId();

 			  url.append(";" + SESSIONID_KEY + "=" + sessionId);			

 		}

 	}

 	url.append("?" + IMG_PARAM + "=" + sessionKey);

 	url.append(AMPERSAND + WIDTH_PARAM + "=" + width);

 	url.append(AMPERSAND + HEIGHT_PARAM + "=" + height);

 	if (removeAfterRender)

 	{

 		url.append(AMPERSAND + REMOVE_AFTER_RENDERING + "=true");		

 	}

 	url.append(AMPERSAND + "iehack=" + MIMEExtensionHelper.getExtensionForMimeType(mimeType));

 	return url.toString();  	

   }

   /**

    * To enable further server side scriptings on JSP output the session ID is

    * always encoded into the image URL even if cookies are enabled on the client

    * side.

    */

   protected String getImgURL()

   {

   	return buildImgURL(renderer, pageContext, sessionKey, width, height, mimeType, forceSessionId, removeAfterRender);

   }

   public Object getRenderingInfo() throws CewolfException

   {

     return chartImageDefinition.getRenderingInfo();

   }

   protected String getMimeType()

   {

     return mimeType;

   }

   protected void reset()

   {

     this.mimeType = DEFAULT_MIME_TYPE;

     // as of a weird JSP compiler in resin

     // a reused tag's attribute is only set if

     // it changes. So width an height may not

     // be unset to ensure correct values.

     int lHeight = this.height;

     int lWidth = this.width;

     int lTimeout = this.timeout;

     super.reset();

     this.height = lHeight;

     this.width = lWidth;

     this.timeout = lTimeout;

   }

   public void enableMapping()

   {

     setUsemap("#" + chartId);

   }

   public String getChartId()

   {

     return getChartid();

   }

   public void setChartid( String id )

   {

     this.chartId = id;

   }

   public String getChartid()

   {

     return chartId;

   }

   public void setRenderer( String renderer )

   {

     this.renderer = renderer;

   }

   protected String getRenderer()

   {

     return this.renderer;

   }

   public int getWidth()

   {

     return this.width;

   }

   public int getHeight()

   {

     return height;

   }

   /**

    * Sets the mimeType.

    * 

    * @param mimeType

    *          The mimeType to set

    */

   public void setMime( String mimeType )

   {

     this.mimeType = mimeType;

   }

   /**

    * @see de.laures.cewolf.taglib.html.AbstractHTMLBaseTag#getTagName()

    */

   protected String getTagName()

   {

     if ( MIME_SVG.equals(mimeType) )

     {

       return TAG_NAME_SVG;

     }

     return super.getTagName();

   }

   /**

    * @see de.laures.cewolf.taglib.html.AbstractHTMLBaseTag#writeAttributes(Writer)

    */

   public void writeAttributes( Writer wr )

   {

     super.writeAttributes(wr);

     if ( MIME_SVG.equals(mimeType) )

     {

       try

       {

         appendAttributeDeclaration(wr, "http://www.adobe.com/svg/viewer/install/", "PLUGINSPAGE");

       }

       catch (IOException ioex)

       {

         ioex.printStackTrace();

       }

     }

   }

   /**

    * @return Returns the timeout.

    */

   public int getTimeout()

   {

     return timeout;

   }

   /**

    * @param timeout The timeout to set.

    */

   public void setTimeout( int timeout )

   {

     this.timeout = timeout;

   }

 }