import java.awt.*;

/***********************************************************************
 *	File:     ExtendedALUControl.java
 *    Aurthor:  Dr. Dalton R. Hunkins
 *              Computer Science Department
 *              St. Bonaventure University
 *    Date:     17 January 2006
 *
 *    Purpose:
 *       The file is a stub that allows the reader/programmer to extend
 *       the ALU Control Unit within the Data Path Simulator, PathSim, 
 *       to handle additional MIPS operators. The extension is 
 *       accomplished through adding java code to the method execute. 
 *       See the lab instruction comment given below.
 *
 *   Class Modified by:
 ***********************************************************************/   

class ExtendedALUControl extends ALUControl {
	private DataLine aluOp, func, aluControl;
	private DataPath parent;
	
/***********************************************************************
   The Data Lines are
	aluOp       - the line coming from the Control unit
	func        - the line holding the function field of the 
                    instruction (Instruction[5-0])
	aluControl  - the output line going to the ALU
*****************************************************************************/
	
	public ExtendedALUControl(double x, double y, double w, double h,
                                Color c, 
	                          String label1, String label2,
                                String name,
					  DataLine aluOp, DataLine func,
                                DataLine aluControl, DataPath parent) {
	                  	
	    super(x, y, w, h, c, label1, label2, name, aluOp,
                func, aluControl);
	    this.func       = func;
	    this.aluOp      = aluOp;
	    this.aluControl = aluControl;  
	    this.parent     = parent;
    }
    
  
    public void execute() {
    	int function  = (int) hexStringToUnsigned(func.getValue());
    	int operation = (int) hexStringToUnsigned(aluOp.getValue());
/*********************************************************************
    function
        is the function field of the MIPS instruction and
        represented here as a decimal (base 10) number versus a 
        hexadecimal number.
    operation
        is the value placed on the data line ALUOp by the (extended)
        control unit
**********************************************************************/    
    

/*********************************************************************
               INSTRUCTIONS FOR LABS B and C
   Currently, the method is implemented by the call super.execute()
   as seen with the code written below. However, the parent super
   does nothing with the extensions. Therefore, you must write your 
   code here for those extensions. In particular, super handles 
   the operation values 0 and 1 and the combination of operation 2 
   and function numbers 32, 34, 36, 37 and 42. Now for Lab B, your
   code must handle any of the following function numbers for 
   operation 2 by placing on the output line (this.aluControl) the
   given (string) value
         0x27 = 39 -> nor		aluControl = 3
         0x26 = 38 -> xor		aluControl = 4
         0x4  =  4 -> sllv		aluControl = 5
         0x7  =  7 -> srav		aluControl = 8
         0x6  =  6 -> srlv		aluControl = 9
    And for lab C, your code must handle any of the following
    operatons by placing on the output line (this.aluControl)
    the appropriate value (you should be able to determine these
    aluControl values from the MIPS operators already implemented
    in PathSim).
	   addi -> 3				
	   andi -> 4
         ori  -> 5
    Last for lab C, your code must handle any of the following
    operations by placing on the output line (this.aluControl)
    the given (string) value
         xori -> 6			aluControl = 4 (why 4?)
         bne  -> 7			aluControl = A

    To accomplish your task for lab B and/or lab C, you will 
    need to use the method setValue belonging to the DataLine 
    class and the inherited utility method signedToHexString.
    The two methods are described as follows:

    public void setValue(String value) 
	precondition: 
	   value is any String
	postcondition:
	   value is put on the data line and appears with
	   a mouse click on the line

    protected String signedToHexString(int number, 
                                       int numberOfDigits) {
	precondition:
	   number is any 32 bit integer
       numberOfDigits is any positive integer
	postcondition:
	   a String of numberOfDigits (e.g. 8 digit) is returned. The
       string is a sequence of hex digits that is equivalent to
       the 32 bit integer

    For development/debugging purposes, you may also wish to use the
    the following method:

    parent.displayMessage(String message)
       precondition:
          message is any string
       postcondition:
          the message is displayed in an alert box

**********************************************************************/
       super.execute();
    }
}