/**********************************************************************************
 * $URL: https://source.sakaiproject.org/svn/rwiki/tags/sakai_2-3-1/rwiki-impl/impl/src/java/uk/ac/cam/caret/sakai/rwiki/component/macros/SakaiLinkMacro.java $
 * $Id: SakaiLinkMacro.java 15385 2006-09-28 14:55:14Z andrew@caret.cam.ac.uk $
 ***********************************************************************************
 *
 * Copyright (c) 2003, 2004, 2005, 2006 The Sakai Foundation.
 *
 * Licensed under the Educational Community 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://www.opensource.org/licenses/ecl1.php
 *
 * 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 uk.ac.cam.caret.sakai.rwiki.component.macros;

import java.io.IOException;
import java.io.Writer;

import org.radeox.api.engine.ImageRenderEngine;
import org.radeox.api.engine.RenderEngine;
import org.radeox.macro.BaseLocaleMacro;
import org.radeox.macro.parameter.MacroParameter;
import org.radeox.util.Encoder;

import uk.ac.cam.caret.sakai.rwiki.component.radeox.service.impl.SpecializedRenderContext;

/**
 * This is a reimplementation of the LinkMacro but made aware of the sakai://
 * and worksite:// url formats
 * 
 * @author andrew
 */
public class SakaiLinkMacro extends BaseLocaleMacro
{
	private static String[] paramDescription = {
			"1,text: Text of the link ",
			"2,url: URL of the link, if this is external and no target is specified, a new window will open ",
			"3,img: (optional) if 'none' then no small URL image will be used",
			"4,target: (optional) Target window, if 'none' is specified, the url will use the current window",
			"Remember if using positional parameters, you must include dummies for the optional parameters" };

	private static String description = "Generated a link";

	public String[] getParamDescription()
	{
		return paramDescription;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.radeox.macro.Macro#getDescription()
	 */
	public String getDescription()
	{
		return description;
	}

	public String getLocaleKey()
	{
		return "macro.link";
	}

	public void execute(Writer writer, MacroParameter params)
			throws IllegalArgumentException, IOException
	{

		SpecializedRenderContext context = (SpecializedRenderContext) params
				.getContext();
		RenderEngine engine = context.getRenderEngine();

		String text = params.get("text", 0);
		String url = params.get("url", 1);
		String img = params.get("img", 2);
		String target = params.get("target", 3);

		// check for single url argument (text == url)
		if (params.getLength() == 1)
		{
			url = text;
			text = Encoder.toEntity(text.charAt(0))
					+ Encoder.escape(text.substring(1));
		}

		if (url != null && text != null)
		{
			if (target == null)
			{
				// FIXME make the context have a method to do this check
				if (url.startsWith("sakai:") || url.startsWith("worksite:/") || url.indexOf(":/") < 0 || url.indexOf(":/") > 10)
				{
					target = "none";
				}
				else
				{
					target = "rwikiexternal";
				}

			}

			writer.write("<span class=\"nobr\">");
			if (!"none".equals(img) && engine instanceof ImageRenderEngine)
			{
				writer.write(((ImageRenderEngine) engine)
						.getExternalImageLink());
			}
			
			url = context.convertLink(url);

			writer.write("<a href=\"" + Encoder.escape(url) + "\"");
			if (!"none".equals(target))
			{
				writer.write(" target=\"" + Encoder.escape(target) + "\"");
			}
			writer.write(">");
			writer.write(text);
			writer.write("</a></span>");
		}
		else
		{
			throw new IllegalArgumentException(
					"link needs a name and a url as argument");
		}
		return;
	}
}
