// Robert Bradshaw 11/98

import java.awt.*;

public class TuringMachine {
  
  TuringTape tape;
  private int state;
  private TuringRule[] rules;
  
  public TuringMachine(String tapeS, String rulesS) {
    this(tapeS, 0, rulesS);
  }
  public TuringMachine(String tapeS, int index, String rulesS) {
    tape=new TuringTape(tapeS, index);
    rules=TuringRule.parseRules(rulesS);
  }
  
  public int step() {
    int i;
    for(i=0; i<rules.length; i++) {
      if (rules[i].apply(this)) break;
    }
    //System.out.println(this);
    if (i==rules.length) return -1;
    else return i;
  }
  
  public int getState() { return state; }
  public void setState(int s) { state=s; }
  public TuringTape getTape() { return tape; } 
  public void setTape(TuringTape t) { tape=t; }
  public TuringRule getRule(int i) { return rules[i]; }
  public void setRules(TuringRule[] rules) {this.rules=rules; }
  public TuringRule[] getRules() { return rules; }
  
  public void draw(Graphics g, Rectangle r) {
    g.setColor(Color.white);
    g.fillRect(r.x, r.y+10, r.width, 20);
    g.setColor(Color.black);
    g.drawRect(r.x, r.y+10, r.width, 20);
    g.drawRect(r.x+r.width/2-10, r.y+9, 20, 22);
    g.drawRect(r.x+r.width/2-11, r.y+8, 22, 24);
    g.drawString(""+state, r.x+r.width/2-3, r.y+45);
    int sideLen=r.width/30;
    char[] tapeData=tape.getData(-sideLen,sideLen);
    for(int i=-sideLen; i<sideLen; i++) {
      g.drawChars(tapeData, i+sideLen, 1, r.x+r.width/2+15*i-3, r.y+24);
    }
  }
  
  public String toString() {
    return toString(79);   // edited 4/2006
  }
  
  // added 4/2006
  String spaces; 
  
  public String toString(int size) {
    int tapeSize = (size - 10)/2;
    if (spaces==null || spaces.length() < tapeSize) {
      char[] cs = new char[tapeSize];
      java.util.Arrays.fill(cs, ' ');
      spaces = new String(cs);
    }
    return tape.toString(tapeSize)+"  State: "+state+"\n"+spaces.substring(0, tapeSize)+"^";
  }
  
}