import java.io.FileReader;
import java.io.FileWriter;
import java.io.PrintWriter;
import java.io.FileNotFoundException;
import java.io.IOException;

public class Program // Test driver for CPU simulator. 
// Illustrates readers/writers conflicts
{
	static FileReader inp;
	static PrintWriter outp;
	
	// Give symbolic names to two variables.
	static final int control = 0;
	static final int buffer = 1;
	
	// Define label names for the writer.
	static final int topW = 10;
	static final int waitW = 20;
	static final int startW = 30;
	
	// Define label names for the reader.
	static final int topR = 10;
	static final int waitR = 20;
	static final int startR = 30;
	
	public static void main(String argv[])
	{	boolean tracing = true;
		Simulator M = new Simulator();
		try { inp = new FileReader("prog.in");}
		catch(FileNotFoundException e)
		{	System.out.println("No input file--halting.");
			System.exit(1);
		}
		try 
		{ 	outp = new PrintWriter(new FileWriter("prog.out"));
			
			CPUProcess writer = new CPUProcess(0, inp, outp, tracing);
			
		// Use constants or literals to name memory locations	
			writer.declare(control);	// Memory 0 is the controller
			writer.declare(buffer);	// Memory 1 is the buffer
			writer.label(topW);
			writer.input();
			writer.JMP(startW);
			writer.label(waitW);
			writer.toss();			// Instr 4
			writer.label(startW);
			writer.pushv(control);
			writer.JGZ(waitW);		// busywait until empty (== 0)
			writer.toss();
			writer.pop(buffer);		// load the buffer
			writer.pushi(1);
			writer.pop(control);	// set the controller = full
			writer.JMP(topW);		// repeat
			writer.halt();			// not executed
			M.insertProcess(writer);
			
			System.out.print("Writer " + writer);
			
			CPUProcess reader1 = new CPUProcess(1, inp, outp, tracing);
			
			reader1.declare(control);
			reader1.declare(buffer);
			reader1.label(topR);
			reader1.JMP(startR);
			reader1.label(waitR);
			reader1.toss(); 		// Instr 3
			reader1.label(startR);
			reader1.pushv(control);
			reader1.JEZ(waitR); 	// busywait until full (== 1)
			reader1.toss();
			reader1.pushv(buffer);	// empty the buffer
			reader1.output();
			reader1.toss();
			reader1.pushi(0);
			reader1.pop(control);	// set the controller = empty
			reader1.JMP(topR);		// repeat
			reader1.halt();			// not executed
			M.insertProcess(reader1);

			System.out.print("Reader1 " + reader1);
			
			CPUProcess reader2 = (CPUProcess)reader1.clone();
			reader2.setSerialNumber(2);
			M.insertProcess(reader2);
			
			System.out.print("Reader2 " + reader2);

			M.step(1000);
		
			System.out.println( M );
			outp.close();
		}
		catch(IOException e)
		{	System.out.println("No output file. Can't run.");
		}
	}

}
	// exercises  
	// Add a control level that will make the use of this interactive.  Instead of the code in main
	// that you see here, provide a menu of options like 
	//   step n
	//   dump
	//   quit
	// The environment accepts and exeuctes commands until the user chooses quit. 
	//			You may want to adapt the scanner and parser from spreadsheet to this.
	//			You will want to write a grammar for your command language.