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);
     }
   }
 
   
 }