///////////////////////////////////////////////////////////////////////
///
///  Part 1 -- Processor.java
///
///////////////////////////////////////////////////////////////////////
package duckMachine.architecture;
                         
/**
 * The processor of the machine.
 * @author Amr Sabry
 * @version jdk-1.1
 */

public class Processor implements ProcessorI {
  private ALUI alu;
  private Word pc, acc;
  private Instruction ir;

  public Processor () {
    alu = new ALU();
    pc = new Address(0);
    acc = new Data(0);
    ir = new HaltIns();
  }

  public ALUI getALU () { return alu; }

  public Word fetchPC () { return pc; }
  public Word fetchACC () { return acc; }
  public Instruction fetchIR () { return ir; }

  public void storePC (Word newpc) { pc = newpc; }
  public void storeACC (Word newacc) { acc = newacc; }
  public void storeIR (Instruction newir) { ir = newir; }

}



///////////////////////////////////////////////////////////////////////
///
///  Execute methods for all instructions -- note this is not a program 
///  that will run
///
///////////////////////////////////////////////////////////////////////
   
  HALT
    throw new HaltE();

  ADD
      Word w1 = proc.fetchACC();
      Word w2 = mem.fetch(i.getAddress());
      Word result = alu.add(w1,w2);
      proc.storeACC(result);

  CLEAR
    Word w = new Data(0);
    mem.store(i.getAddress(), w);
 

  COMPARE
    Word w1 = mem.fetch(i.getAddress());
    Word w2 = proc.fetchACC();
    alu.compare(w1,w2);

  DECREMENT 
    Word w = mem.fetch(i.getAddress());
    Word result = alu.dec(w);
    mem.store(i.getAddress(), result);
  
  IN
    Word w = io.readData();
    mem.store(i.getAddress(), w);
  
  INCREMENT
    Word w = mem.fetch(i.getAddress());
    Word result = alu.inc(w);
    mem.store(i.getAddress(), result);
  
  JUMPEQ
    if (alu.fetchEQ()) {
      proc.storePC(i.getAddress());
    }

  
  JUMPGT
    if (alu.fetchGT()) {
      proc.storePC(i.getAddress());
    }
  
  JUMPLT
    if (alu.fetchLT()) {
      proc.storePC(i.getAddress());
    }
 
  JUMPNEQ
    if (! alu.fetchEQ()) {
      proc.storePC(i.getAddress());
    }
  
  JUMP
    proc.storePC(i.getAddress());

  
  LOAD
    Word w = mem.fetch(i.getAddress());
    proc.storeACC(w);

  
  OUT
    Word w = mem.fetch(i.getAddress());
    io.writeData(w);


  STORE
    Word w = proc.fetchACC();
    mem.store(i.getAddress(), w);
  
  SUBTRACT
    Word w1 = proc.fetchACC();
    Word w2 = mem.fetch(i.getAddress());
    Word result = alu.sub(w1,w2);
    proc.storeACC(result);