/////////////////////////////////////////////////////////////////////
///
///	This solution contains the classes Instruction, InstructionOne,
///	AddIns, and HaltIns.  
///
/////////////////////////////////////////////////////////////////////


package duckMachine.architecture;
                         
/**
 * The class that represents memory instructions. A memory instruction is 
 * a machine word.
 * @see Word
 * @author Amr Sabry
 * @version jdk-1.1
 */

public abstract class Instruction extends Word {

  public Instruction (int op) { 
	super(op); 
  }

}

/////////////////////////////////////////////////////////////////////
///
///	InstructionOne
///
/////////////////////////////////////////////////////////////////////
                     
/**
 * The class that represents memory instructions. A memory instruction is 
 * a machine word.
 * @see Word
 * @author Amr Sabry
 * @version jdk-1.1
 */

public abstract class InstructionOne extends Instruction {
  private Address address;
  private int opcode;

  public InstructionOne (int op, Address a) { 
	super(op); 
	this.address = a;
 	this.opcode = op;
  }

  public Address getAddress () { return address; }

  public int toInt() {
        int a = address.toInt();
        int b = opcode;
     
        b = b << 28;
        int ans = a | b;
        return (ans);

  }

}


/////////////////////////////////////////////////////////////////////
///
///	ADD Instruction -- note:  All instructions that take an 
///	Address (all but HALT) look very similar to this AddIns, so
///	they are not included in this solution.
///
/////////////////////////////////////////////////////////////////////
                      
/**
 * The encapsulation of an ADD instruction.
 * @author Amr Sabry
 * @version jdk-1.1
 */

public class AddIns extends InstructionOne {
  public final static int OPCODE = 3;

  public AddIns (Address a) { 
    super(OPCODE,a);
  }

  public String toString () {
    return "ADD " + super.toString();
  }
}

/////////////////////////////////////////////////////////////////////
///
///	HALT Instruction -- this is the only instruction that does
///	not take an Address
///
/////////////////////////////////////////////////////////////////////
                        
/**
 * The encapsulation of a HALT instruction.
 * @author Amr Sabry
 * @version jdk-1.1
 */

public class HaltIns extends Instruction {
  public final static int OPCODE = 15;

  public HaltIns () {
    super(OPCODE);
  }

  public String toString () {
    return "HALT";
  }
}