/**
 * The contents of this file are subject to the OpenMRS Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://license.openmrs.org
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
 * License for the specific language governing rights and limitations
 * under the License.
 *
 * Copyright (C) OpenMRS, LLC.  All Rights Reserved.
 */
package org.openmrs.web.taglib;

import java.io.IOException;
import java.util.Date;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspTagException;
import javax.servlet.jsp.tagext.BodyTagSupport;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.jfree.chart.JFreeChart;
import org.openmrs.web.servlet.AbstractGraphServlet;
import org.openmrs.web.servlet.DisplayChartServlet;

public class DisplayChartTag extends BodyTagSupport {
	
	/**
	 * Serialized ID
	 */
	private static final long serialVersionUID = 1027317526568196572L;
	
	/**
	 * Log
	 */
	private final Log log = LogFactory.getLog(DisplayChartTag.class);
	
	/**
	 * Tag properties
	 */
	private JFreeChart chart;
	
	private Integer height = 300; // Default value = 300.  Should be set in config properties.
	
	private Integer width = 500; // Default value = 500.  Should be set in config properties.
	
	/**
	 * Render graph.
	 * 
	 * @return return result code
	 */
	public int doStartTag() throws JspException {
		if (chart != null) {
			try {
				HttpSession session = pageContext.getSession();
				HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();
				
				Long time = new Date().getTime();
				Double random = Math.random() * 1000.0;
				String key = "chart-" + time + "-" + session.getId() + "-" + random;
				session.setAttribute(key, chart);
				
				pageContext.getOut().write(
				    "<img src=\"" + request.getContextPath() + "/" + DisplayChartServlet.SERVLET_NAME + "?"
				            + DisplayChartServlet.CHART_KEY + "=" + key + "&mimeType=" + AbstractGraphServlet.PNG_MIME_TYPE
				            + "&width=" + width + "&height=" + height + "\" />");
				
			}
			catch (IOException e) {
				log.error("Unable to generate chart servlet url", e);
			}
		}
		
		return EVAL_BODY_BUFFERED;
	}
	
	/**
	 * @see javax.servlet.jsp.tagext.Tag#doEndTag()
	 */
	public int doEndTag() throws JspException {
		try {
			if (bodyContent != null)
				bodyContent.writeOut(bodyContent.getEnclosingWriter());
		}
		catch (java.io.IOException e) {
			throw new JspTagException("IO Error: " + e.getMessage());
		}
		return EVAL_PAGE;
	}
	
	/**
	 * @return the chart
	 */
	public JFreeChart getChart() {
		return chart;
	}
	
	/**
	 * @param chart the chart to set
	 */
	public void setChart(JFreeChart chart) {
		this.chart = chart;
	}
	
	/**
	 * @return the desired height of the image
	 */
	public Integer getHeight() {
		return this.height;
	}
	
	/**
	 * @param height the desired height of the image
	 */
	public void setHeight(Integer height) {
		this.height = height;
	}
	
	/**
	 * @return the desired height of the image
	 */
	public Integer getWidth() {
		return this.width;
	}
	
	/**
	 * @param width the desired height of the image
	 */
	public void setWidth(Integer width) {
		this.width = width;
	}
}