package StateMachine import java util import StateMachine Node import

package StateMachine;

import java.util.*;
import StateMachine.Node;
import java.io.FileInputStream;

public class StateMachine {//extends Thread {
	String[] alphabet;
	State[] states;
	TreeMap<String, TreeMap<String, String> > transitions;
	boolean finished = false;
	LinkedList<Node> queue = new LinkedList<Node>();
	String startingState = new String();
	String endingState = new String();
	String[] badwords = {};
	public StateMachine(String[] alphabet, String startingState, String endingState,
			            TreeMap<String, TreeMap<String, String>> transitions ) {
		this.alphabet = alphabet;
		this.transitions = transitions;
		this.startingState = startingState;
		this.endingState = endingState;
	}
	
	public String make_step() {
		String answer = new String();
		while (this.queue.size()>0 && !this.finished) {
			Node current = this.queue.pop();
			String newstate = this.transitions.get(current.state)
                                              .get(current.current);
			if (newstate == null) continue;
			if (newstate.equals(this.endingState)) {
				boolean bad = false;
				for(String w : this.badwords) {
					if (w.equals(newstate)) {
						bad = true;
						break;
					}
				}
				if (!bad) {
					this.finished = true;
					answer = current.value;
					break;
				}
			}
			this.queue.addAll(current.expand(newstate));
		}
		return answer;
	}
	
	public void run() {
		String ans = new String();
		for(String sym : this.alphabet)
			this.queue.add(new Node(this.alphabet, (new String())+sym,
					                sym, this.startingState));
		while (!this.finished) {
			ans = this.make_step();
		}
		System.out.println("Answer is: "+ans);
	}
	/**
	 * @param args
	 */
	public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.print("Enter first state machine file name: ");
		String filename = in.nextLine();
		String text = new String();
		FileInputStream input;
		try {
			input = new FileInputStream(filename);
			while (input.available() > 0) {
				text += (char)input.read();
			}
			TreeMap<String, TreeMap<String, String> > transitions = new TreeMap<String, TreeMap<String, String>>();
			String start = new String();
			String end = new String();
			String[] alphabet = {};
			for(String line: text.split("\n"))
			{
				System.out.println(line);
				if (line.startsWith("ALPHABET: ")) {
					alphabet = line.replace("ALPHABET: ", "").split(", ");
					continue;
				}
				else if (line.startsWith("START: ")) {
					start = line.replace("START: ", "");
					continue;
				}
				else if (line.startsWith("END: ")) {
					end = line.replace("END: ", "");
					continue;
				}
				System.out.println(line);
				String from = line.split(" ")[0];
				String at = line.split(" ")[1];
				String to = line.split(" ")[2];
				TreeMap<String, String> newval = new TreeMap<String, String>();
				newval.put(at, to);
				transitions.put(from, newval);
			}
			System.out.println("Initializin state machine...");
			System.out.print("Alphabet: ");
			for(String sym: alphabet) System.out.print(sym+" ");
			System.out.print('\n');
			System.out.println("Starting state: " + start);
			System.out.println("Ending state: " + end);
			System.out.println("Transitions map: " + transitions.toString());
			StateMachine machine = new StateMachine(alphabet, start, end, transitions);
			System.out.println("Starting state machine...");
			machine.run();
			
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		
		
		
	}

}