/*
 *  IronJacamar, a Java EE Connector Architecture implementation
 *  Copyright 2016, Red Hat Inc, and individual contributors
 *  as indicated by the @author tags. See the copyright.txt file in the
 *  distribution for a full listing of individual contributors.
 *
 *  This is free software; you can redistribute it and/or modify it
 *  under the terms of the Eclipse Public License 1.0 as
 *  published by the Free Software Foundation.
 *
 *  This software 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 Eclipse
 *  Public License for more details.
 *
 *  You should have received a copy of the Eclipse Public License
 *  along with this software; if not, write to the Free
 *  Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 *  02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.ironjacamar.codegenerator;

import java.io.IOException;
import java.io.Writer;
import java.net.URL;
import java.util.Map;

/**
 * A SimpleTemplate.
 *
 * @author Jeff Zhang
 * @version $Revision: $
 */
public class SimpleTemplate implements Template
{
   /**
    * template file
    */

   private URL input;

   /**
    * template string
    */
   String templateText = null;

   /**
    * SimpleTemplate
    *
    * @param input template string
    */
   public SimpleTemplate(String input)
   {
      this.templateText = input;
   }

   /**
    * SimpleTemplate
    *
    * @param input template string
    */
   public SimpleTemplate(URL input)
   {
      this.input = input;
   }

   /**
    * Processes the template
    *
    * @param varMap variable map
    * @param out    the writer to output the text to.
    */
   @Override
   public void process(Map<String, String> varMap, Writer out)
   {
      try
      {
         if (templateText == null)
         {
            templateText = Utils.readFileIntoString(input);
         }
         String replacedString = replace(varMap);
         out.write(replacedString);
         out.flush();
      }
      catch (IOException e)
      {
         e.printStackTrace();
      }
   }

   /**
    * Replace string in the template text
    *
    * @param varMap variable map
    * @return replaced string
    */
   public String replace(Map<String, String> varMap)
   {
      StringBuilder newString = new StringBuilder();

      int p = 0;
      int p0 = 0;
      while (true)
      {
         p = templateText.indexOf("${", p);
         if (p == -1)
         {
            newString.append(templateText.substring(p0, templateText.length()));
            break;
         }
         else
         {
            newString.append(templateText.substring(p0, p));
         }
         p0 = p;
         p = templateText.indexOf("}", p);
         if (p != -1)
         {
            String varName = templateText.substring(p0 + 2, p).trim();
            if (varMap.containsKey(varName))
            {
               newString.append(varMap.get(varName));
               p0 = p + 1;
            }
         }
      }
      return newString.toString();
   }

}