package org.lcsim.geometry.util;
   
   /**
    *
    * @author tonyj
    */
   public class IDDecoder
   {
       private IDDescriptor desc;
      private long id;
      
      /** Creates a new instance of IIDecoder */
      public IDDecoder(IDDescriptor desc)
      {
          this.desc = desc;
      }
      
      public void setID(long id)
      {
          this.id = id;
      }
      
      public long getID()
      {
      	return this.id;
      }
          
      public int getFieldIndex(String name)
      {
          return desc.indexOf(name);
      }
      
      public int getValue(String name)
      {
          return getValue(desc.indexOf(name));
      }
      
      public int getValue(int index)
      {
          int start = desc.fieldStart(index);
          int length = desc.fieldLength(index);
          int mask = (1<<length) - 1;
          
          int result = (int) ((id >> start) & mask);
          if (desc.isSigned(index))
          {
              int signBit = 1<<(length-1);
              if ((result & signBit) != 0) result -= (1<<length);
          }
          return result;
      }
      
      public int[] getValues(int[] buffer)
      {
          if (buffer.length != desc.fieldCount()) throw new IllegalArgumentException("Invalid buffer length");
          for (int i=0; i<buffer.length; i++)
          {
              buffer[i] = getValue(i);
          }
          return buffer;
      }
      
      public int getFieldCount()
      {
          return desc.fieldCount();
      }
      
      public String getFieldName(int index)
      {
          return desc.fieldName(index);
      }
      
      public String toString()
      {
          StringBuffer sb = new StringBuffer();
          for (int i=0; i<desc.fieldCount();)
          {
              sb.append(desc.fieldName(i));
              sb.append(':');
              sb.append(getValue(i));
              if (++i >= desc.fieldCount()) break;
              sb.append(',');
          }
          return sb.toString();
      }
  }