package org.melati.template;

 import java.io.IOException;

 import java.util.Enumeration;

 import java.util.List;

 import org.melati.Melati;

 import org.melati.poem.Persistent;

 import org.melati.poem.PoemLocale;

 import org.melati.template.AbstractMarkupLanguage;

 import org.melati.template.AttributeMarkupLanguage;

 import org.melati.template.MarkupLanguage;

 import org.melati.template.TemplateIOException;

 import org.melati.template.TempletLoader;

 import org.melati.util.MelatiWriter;

 /**

  * A representation of JSON such that Java objects can be serialised 

  * to it.

  *  

  * @author timp

  * @since 09 Nov 2012

  *

  */

 public class JSONMarkupLanguage extends AbstractMarkupLanguage implements MarkupLanguage {

   public JSONMarkupLanguage(Melati melati, TempletLoader templetLoader, PoemLocale locale) {

     super("json", melati, templetLoader, locale);

   }

   @Override

   public AttributeMarkupLanguage getAttr() {

     throw new RuntimeException("Not expected to be called in JSON");

   }

   @Override

   public String escaped(String s) {

     return escape(s);

   }

   public static String escape(String s) { 

     return s

         .replace("\"", "\\\"")

         .replace("\\", "\\\\")

         .replace("/", "\\/");    

   }

   @Override

   public String escaped(Persistent o) {

     throw new RuntimeException("Not implemented yet");

   }

   @Override

   public String encoded(String s) {

     throw new RuntimeException("Not expected to be called in JSON");

   }

   @Override

   public String decoded(String s) {

     throw new RuntimeException("Not expected to be called in JSON");

   }

   /**

    * Where all content Strings are actually escaped and written out.

    * @see org.melati.template.AbstractMarkupLanguage#render(java.lang.String, org.melati.util.MelatiWriter)

    */

   @Override

   public void render(String s, MelatiWriter writer) {

     try {

       writer.write(escaped(s));

     } catch (IOException e) {

       throw new TemplateIOException("Problem writing " + s, e);

     }      

   }

   @Override

   protected void renderMarkup(String s, MelatiWriter writer) {

     throw new RuntimeException("Not expected to be called in JSON");

   }

   /**

    * Render an Object in a MarkupLanguage specific way, rendering to

    * a supplied Writer.

    *

    * NOTE The context always contains objects with the names melati, object and  ml  

    *

    * @param o - the Object to be rendered

    * @param writer - the MelatiWriter to render this Object to

    */

   protected void render(Object o, MelatiWriter writer) {

     if (o == null)

       writer.output("null");

     else if (o instanceof String) { 

         writer.output("\"" + o + "\"");

     } else if (o instanceof Boolean) { 

       if (((Boolean)o).booleanValue())

         writer.output("true");

       else

         writer.output("false");

     } else if (o instanceof List) { 

         List<?> l = (List<?>)o;

         writer.output("[");

         boolean seenOne = false;

         for (int i = 0; i < l.size(); i++) { 

           if (seenOne)

             writer.output(",");            

           render(l.get(i), writer);

           seenOne = true;

         }

         writer.output("]\n");

     } else if (o instanceof Enumeration) { 

       Enumeration<?> e = (Enumeration<?>) o;

       writer.output("[");

       boolean seenOne = false;

       while (e.hasMoreElements()) { 

         if (seenOne)

           writer.output(",");            

         render(e.nextElement(), writer);

         seenOne = true;        

       }

       writer.output("]\n");

     } else {

         Template templet =

           templetLoader.templet(melati.getTemplateEngine(), this, o.getClass());

         TemplateContext vars =

             melati.getTemplateEngine().getTemplateContext();

         vars.put("object", o);

         vars.put("melati", melati);

         vars.put("ml", melati.getMarkupLanguage());

         expandTemplet(templet, vars, writer);

     }

   }

 }