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

 * 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;

  }

}