/* This class is an extension (aka "child" or "subclass") of the KeyValPair 
** class.  Its instances have, in addition to the 'key' and 'value' components
** inherited from its parent, two new components, the purposes of which are
** to store the number of times that the 'key' and 'value' components,
** respectively, were accessed as a result of calls to the getKey() and
** getValue() methods.  Two new observer methods allow clients to access
** those counts.
**
** Authors: P.M.J. and R.W.M
** last modified: 12/06/2025
*/
public class KeyValPairWithCounts extends KeyValPair {

   // instance variables (fields/attributes)
   // --------------------------------------

   private int keyAccessCount = 0;   // # times this object's key was accessed
   private int valueAccessCount = 0; // # times this object's value was accessed
   
   
   // constructors
   // ------------

   /* Initializes this KeyValPairWithCounts object to have the given
   ** strings as its key and value components and to have zero as the
   ** value of each of its two access count components.
   */
   public KeyValPairWithCounts(String key, String value) {
      setTo(key,0,value,0);
   }

   /* Initializes this KeyValPairWithCounts object to be that
   ** described by the given string, which is expected to be in
   ** the format
   **
   ** key : value [ : keyAccessCount : valueAccessCount ]
   **
   ** where the square brackets indicate an optional part.
   ** If the two access count values are missing, they are taken
   ** to be zero.
   **
   */
   public KeyValPairWithCounts(String fromString) {
      setTo("",0,"",0);  //Set default values
      //Separate the string into its four (or two) parts
      int index = fromString.indexOf(DELIMITER);
      if (index != -1) {
         this.key = fromString.substring(0,index).trim();
         String rest = fromString.substring((index+DELIMITER.length())).trim();
         //Determine if access counts are present
         index = rest.indexOf(DELIMITER);
         if (index == -1) {
            this.value = rest;
         } else { // Access and value counts should be present
            this.value = rest.substring(0,index);
            rest = rest.substring((index+DELIMITER.length())).trim();
            //Isolate the two counts
            index = rest.indexOf(DELIMITER);
            if(index > 0) {
               String accessCount = rest.substring(0,index);
               String valueCount = rest.substring((index+DELIMITER.length()));
               this.keyAccessCount = Integer.parseInt(accessCount);
               this.valueAccessCount = Integer.parseInt(valueCount);
            }
         }
      }
   }

   

   // observers
   // ---------
   
   /* Returns the key component of this object 
   ** and increments its key access count.
   */
   @Override
   public String getKey() {
      keyAccessCount = keyAccessCount + 1;
      return super.getKey();
   }

   /* Returns the value component of this object 
   ** and increments its value access count.
   */
   @Override
   public String getValue() {
      valueAccessCount = valueAccessCount + 1;
      return super.getValue();
   }

   /* Returns the number of times that getKey() was invoked
   ** upon this KeyValPairWithCounts object.
   */
   public int getKeyAccessCount() { return this.keyAccessCount; }

   /* Returns the number of times that getValue() was invoked
   ** upon this KeyValPairWithCounts object.
   */
   public int getValueAccessCount() { return this.valueAccessCount; }

   /* Returns a string of the following form that represents the current
   ** state and value of this object:
   **   
   **   key : value : keyAccessCount : valueAccessCount       
   */
   @Override
   public String toString() {
      return //key + DELIMITER + value 
             super.toString() 
             + DELIMITER + keyAccessCount + DELIMITER + valueAccessCount; 
   }


  // mutators
  // --------
  
   /* Resets the key access count to zero.
   */
   public void resetKeyAccessCount() { this.keyAccessCount = 0; }
  
   /* Resets the value access count to zero.
   */
   public void resetValueAccessCount() { this.valueAccessCount = 0; }
  

   // private mutator
   // ---------------

   /* Sets the four components of this object to be the
   ** values of the parameters.
   */
   private void setTo(String key, int keyAccessCount,
                      String value, int valueAccessCount) {
      super.setTo(key, value);  // Use parent class's setTo() method
      this.keyAccessCount = keyAccessCount;
      this.valueAccessCount = valueAccessCount;
   }

}