package com.mckessonaps.jspwiki.handler.newpage;

import java.io.UnsupportedEncodingException;
import java.util.Iterator;
import java.util.Map;

import com.ecyrd.jspwiki.TranslatorReader;
import com.ecyrd.jspwiki.WikiContext;
import com.ecyrd.jspwiki.WikiEngine;
import com.ecyrd.jspwiki.WikiException;
import com.ecyrd.jspwiki.WikiPage;
import com.ecyrd.jspwiki.forms.FormHandler;
import com.ecyrd.jspwiki.plugin.PluginException;
import com.ecyrd.jspwiki.plugin.PluginManager;
import com.ecyrd.jspwiki.plugin.WikiPlugin;


/**
 * Creates a new page using the information provided by a form. Requried
 * parameters are: _body and newPageName Optional parameters are:
 * newPageNamePrefix - if you want a prefix automatically applied; autoIncrement -
 * if you want suffix numbers generated to make a unique page name.
 * 
 * Patched two bugs:
 * 
 * - Umlate where not correctly translated
 * - You can use Plugins now, use ({Plugin}) in your template syntax.
 * 
 * Christoph Sauer, 14-Sep-2006
 * 
 */
public class NewPageHandler implements FormHandler, WikiPlugin
{


	private static final String PARAM_NEW_PAGE_NAME = "newPageName";
	private static final String PARAM_NEW_PAGE_NAME_PREFIX = "newPageNamePrefix";
	private static final String PARAM_AUTO_INCREMENT = "autoIncrement";



	public String execute(WikiContext context, Map params) throws PluginException
	{
		String template = (String) params.get(PluginManager.PARAM_BODY);
		if (( null == template ) || ( template.trim().equals("") ))
			return "No template text for the new page was provided in the body of FormOutput.";

		//String newPageName = (String) params.get(PARAM_NEW_PAGE_NAME);
		
		String newPageName = safeParameter(params, PARAM_NEW_PAGE_NAME, context);
		
		if (( null == newPageName ) || ( newPageName.trim().equals("") ))
			return "Parameter 'newPageName' must be provided";

		String prefix = (String) params.get(PARAM_NEW_PAGE_NAME_PREFIX);
		if (null != prefix)
		{
			newPageName = prefix.trim() + newPageName;
		}

		newPageName = TranslatorReader.cleanLink(newPageName);

		if (exists(context, newPageName))
		{
			boolean autoIncrement = ( null != params.get(PARAM_AUTO_INCREMENT) );
			if (!autoIncrement)
				return "<a href='" + context.getEngine().getViewURL(newPageName) + "'>" + newPageName
				+ "</a> already exists.";

			newPageName = autoIncrement(context, newPageName);
		}

		String newPageWikiText = expandTemplate(params, template, context);

		String message = saveNewPage(context, newPageWikiText, newPageName);

		return message;
	}



	private boolean exists(WikiContext context, String newPageName)
	{
		return context.getEngine().pageExists(newPageName);
	}



	private String autoIncrement(WikiContext context, String barePageName)
	{
		int suffix = 1;
		String pageName = barePageName + suffix;

		while (exists(context, pageName))
		{
			suffix++;
			pageName = barePageName + suffix;
		}

		return pageName;
	}

	private String expandTemplate(Map params, String template, WikiContext context)
	{
		
		for (Iterator iter = params.keySet().iterator(); iter.hasNext();)
		{
			String paramName = (String) iter.next();
			String paramLabel = "\\$\\(" + paramName + "\\)";
			String value = safeParameter(params, paramName, context);
		
			template = template.replaceAll(paramLabel, value);
			
			template = escapePluginSyntax(template);
		}
		return template;
	}

	
	private String safeParameter(Map params, String paramName, WikiContext context) {

		WikiEngine engine = context.getEngine();
		
		String encoding = "UTF-8";
		if (engine != null) {
			encoding = engine.getContentEncoding();
		}

		String value = (String) params.get(paramName);
		
		try {	
			// see Problem Description in coment to WikiEngine.saveGetParameter()
			value = new String(value.getBytes("ISO-8859-1"), encoding);
	       }
        catch( UnsupportedEncodingException e ) {
           System.out.println( "WARNING ScriptParameter: Unsupported encoding" + e );
           value = (String) params.get(paramName);
        }
		
        return value;
	}

	private String saveNewPage(WikiContext context, String template, String newPageName)
	{
		String message;
		WikiPage newPage = new WikiPage(newPageName);
		WikiContext newContext = (WikiContext) context.clone();
		newContext.setPage(newPage);


		try
		{
			context.getEngine().saveText(newContext, template);
			message = "<a href='" + context.getEngine().getViewURL(newPageName) + "'>" + newPageName
			+ "</a> created.";
		}
		catch (WikiException e)
		{
			message = "Failed to save page: " + newPageName;
		}

		return message;
	}

	
	// to enable Plugins within plugins this is quick workaround: use 
	// ({ }) instead of [{ }] in our dynamic output.
	private String escapePluginSyntax(String s) {
		
		if (s == null) {
			return null;
		}
		
		s = s.replaceAll("\\(\\{", "\\[\\{");
		s = s.replaceAll("\\}\\)", "\\}\\]");
		
		return s;	
	}
	
}