package turingMachine.io;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.LineNumberReader;
import java.io.Reader;

import turingMachine.*;
import turingMachine.tape.Direction;
import turingMachine.tape.MultiTapeReadWriteData;
import finiteStateMachine.state.State;

public class TuringMachineReader {



	public static TuringMachine<Character> read(InputStream input) {





		return null;
	}

	public static TuringMachine<Character> read(Reader input) throws IOException {

		int part = 0;
		int tapeCount = 0;
		String transition[];

		MultiTapeReadWriteData<Character> in = null;
		MultiTapeReadWriteData<Character> out = null;
		TuringTransitionOutput<Character> output = null;
		Direction[] directions = null;
		Direction direction = null;

		LineNumberReader reader = new LineNumberReader(input);
		TuringMachine<Character> turi = null;

		for(;;) {

			String line = reader.readLine();

			if(line.matches("^#") || line.matches("")) {
				//nichts, wird ignoriert

			} else if(part == 0) {
				if(!line.matches("[0-9]+") || line.matches("0")) {
					throw new IllegalArgumentException("<Anzahl der Bänder> gefordert!");
				}
				for(int i=0; i<line.length(); i++) {
					tapeCount += Integer.parseInt(line.charAt(i)+"") * (line.length()-i);
				}
				turi = new TuringMachine<Character>(tapeCount);
				in = new MultiTapeReadWriteData<Character>(tapeCount);
				out = new MultiTapeReadWriteData<Character>(tapeCount);
				part++;

			} else if(part == 1) {
				for(int i=1; i<=line.length(); i++) {
					if(!line.matches(i + ":[_0-9]+")) {
						throw new IllegalArgumentException("<Position des Lesekopfes (startend bei 1)>:<Bandinhalt ab Position 1> gefordert!");
					}
					for(int j=2; j<line.length()-2; j++) {
						if(line.charAt(j) == '_') {
							turi.getTapes().getTapes().get(i).write(null);
						} else {
							turi.getTapes().getTapes().get(i).write(line.charAt(j));
						}
					}
				}
				part++;

			} else if(part == 2) {
				if(!line.matches("((.+),)*.+")) {
					throw new IllegalArgumentException("Durch Komma getrennte Namen der Zustände gefordert!");
				}
				String[] states = line.split(",");
				for(int i=0; i<states.length; i++) {
					turi.addState(states[i]);
				}
				part++;

			} else if(part == 3) {
				turi.setCurrentState(line);
				part++;

			} else if(part == 4) {
				if(!line.matches("((.+),)*.+")) {
					throw new IllegalArgumentException("Durch Komma getrennte Namen der akzeptierten Zustände gefordert!");
				}
				String[] accStates = line.split(",");
				for(int i=0; i<accStates.length; i++) {
					turi.getState(accStates[i]).setAccepted(true);
				}
				part++;

			} else if(part == 5) {
				if(!line.matches(".+,[_0-9] -> .+,[_0-9],[RLN]")) {
					throw new IllegalArgumentException("Name des Anfangszustands>,<Inhalt der einzelnen Bänder> -> <Name des Zielzustands>,<Werte, die auf die einzelnen Bänder zu schreiben sind>,<Richtungen für die einzelnen Köpfe: R für Rechts; L für Links, N für keine Bewegung> gefordert!");
				}
				transition = line.split(",| -> ");
				for(int i=1; i<transition.length-1; i++) {
					if(i<=(transition.length-1)/2) {
						in.set(i-1, transition[i].charAt(0));
					} else {
						out.set(i-1, transition[i].charAt(0));
					}
				}
				if(transition[transition.length-1].matches("R")) {
					direction = Direction.RIGHT;
				} else if(transition[transition.length-1].matches("L")) {
					direction = Direction.LEFT;
				} else {
					direction = Direction.NON;
				}
				for(int i=0; i<tapeCount; i++) {
					directions[i] = direction;
				}
				output = new TuringTransitionOutput<Character>(out, directions);

				turi.addTransition(transition[0], in, transition[transition.length-2], output);
			}

		}
	}
}