package de.vanitasvitae.enigmandroid.enigma;

import android.util.Log;

import java.math.BigInteger;

import de.vanitasvitae.enigmandroid.MainActivity;
import de.vanitasvitae.enigmandroid.enigma.parts.EntryWheel;
import de.vanitasvitae.enigmandroid.enigma.parts.Plugboard;
import de.vanitasvitae.enigmandroid.enigma.parts.Reflector;
import de.vanitasvitae.enigmandroid.enigma.parts.Rotor;

/**
 * Concrete implementation of an enigma machine of name D
 * This machine has a rewirable UKW, non changeable rotors.
 * Copyright (C) 2015  Paul Schaub

 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License along
 with this program; if not, write to the Free Software Foundation, Inc.,
 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 * @author vanitasvitae
 */
public class Enigma_D extends Enigma {

	private EntryWheel entryWheel;
	private Rotor rotor1;
	private Rotor rotor2;
	private Rotor rotor3;
	private Reflector reflector;

	public Enigma_D()
	{
		super();
		machineType = "D";
		Log.d(MainActivity.APP_ID, "Created Enigma D");
	}

	@Override
	protected void establishAvailableParts()
	{
		addAvailableEntryWheel(new EntryWheel.EntryWheel_QWERTZ());

		addAvailableRotor(new Rotor.Rotor_K_D_I(0, 0));
		addAvailableRotor(new Rotor.Rotor_K_D_II(0, 0));
		addAvailableRotor(new Rotor.Rotor_K_D_III(0, 0));

		addAvailableReflector(new Reflector.ReflectorEnigma_D_G31());
	}

	@Override
	public void initialize()
	{
		this.entryWheel = availableEntryWheels.get(0);
		this.rotor1 = availableRotors.get(0);
		this.rotor2 = availableRotors.get(1);
		this.rotor3 = availableRotors.get(2);
		this.reflector = availableReflectors.get(0);
	}

	@Override
	public void nextState()
	{
		rotor1.rotate();
		if (rotor1.isAtTurnoverPosition() || this.doAnomaly)
		{
			rotor2.rotate();
			this.doAnomaly = rotor2.doubleTurnAnomaly();
			if (rotor2.isAtTurnoverPosition())
			{
				rotor3.rotate();
			}
		}
	}

	@Override
	protected void generateState() {
		int rot1 = rand.nextInt(26);
		int rot2 = rand.nextInt(26);
		int rot3 = rand.nextInt(26);
		int rotRef = rand.nextInt(26);
		int ring1 = rand.nextInt(26);
		int ring2 = rand.nextInt(26);
		int ring3 = rand.nextInt(26);
		int ringRef = rand.nextInt(26);

		this.rotor1.setRotation(rot1).setRingSetting(ring1);
		this.rotor2.setRotation(rot2).setRingSetting(ring2);
		this.rotor3.setRotation(rot3).setRingSetting(ring3);

		this.reflector.setRotation(rotRef).setRingSetting(ringRef)
				.setConfiguration(Plugboard.seedToReflectorConfiguration(rand));
	}

	@Override
	public char encryptChar(char k)
	{
		nextState();
		int x = ((int) k)-65;   //Cast to int and remove Unicode Offset (A=65 in Unicode.)
		//Encryption
		//forward direction
		x = entryWheel.encryptForward(x);
		x = rotor1.normalize(x + rotor1.getRotation() - rotor1.getRingSetting());
		x = rotor1.encryptForward(x);
		x = rotor1.normalize(x - rotor1.getRotation() + rotor1.getRingSetting() + rotor2.getRotation() - rotor2.getRingSetting());
		x = rotor2.encryptForward(x);
		x = rotor1.normalize(x - rotor2.getRotation() + rotor2.getRingSetting() + rotor3.getRotation() - rotor3.getRingSetting());
		x = rotor3.encryptForward(x);
		x = rotor1.normalize(x - rotor3.getRotation() + rotor3.getRingSetting() + reflector.getRotation() - reflector.getRingSetting());
		//backward direction
		x = reflector.encrypt(x);
		x = rotor1.normalize(x + rotor3.getRotation() - rotor3.getRingSetting() - reflector.getRotation() + reflector.getRingSetting());
		x = rotor3.encryptBackward(x);
		x = rotor1.normalize(x + rotor2.getRotation() - rotor2.getRingSetting() - rotor3.getRotation() + rotor3.getRingSetting());
		x = rotor2.encryptBackward(x);
		x = rotor1.normalize(x + rotor1.getRotation() - rotor1.getRingSetting() - rotor2.getRotation() + rotor2.getRingSetting());
		x = rotor1.encryptBackward(x);
		x = rotor1.normalize(x - rotor1.getRotation() + rotor1.getRingSetting());
		x = entryWheel.encryptBackward(x);
		return (char) (x + 65);     //Add Offset again, cast back to char and return
	}

	@Override
	public void setState(EnigmaStateBundle state)
	{
		this.entryWheel = getEntryWheel(state.getTypeEntryWheel());
		this.rotor1 = getRotor(state.getTypeRotor1(), state.getRotationRotor1(), state.getRingSettingRotor1());
		this.rotor2 = getRotor(state.getTypeRotor2(), state.getRotationRotor2(), state.getRingSettingRotor2());
		this.rotor3 = getRotor(state.getTypeRotor3(), state.getRotationRotor3(), state.getRingSettingRotor3());
		this.reflector = getReflector(state.getTypeReflector(),
									  state.getRotationReflector(),
									  state.getRingSettingReflector())
				.setConfiguration(state.getConfigurationReflector());
	}

	@Override
	public EnigmaStateBundle getState()
	{
		EnigmaStateBundle state = new EnigmaStateBundle();

		state.setTypeEntryWheel(entryWheel.getIndex());

		state.setTypeRotor1(rotor1.getIndex());
		state.setTypeRotor2(rotor2.getIndex());
		state.setTypeRotor3(rotor3.getIndex());

		state.setRotationRotor1(rotor1.getRotation());
		state.setRotationRotor2(rotor2.getRotation());
		state.setRotationRotor3(rotor3.getRotation());

		state.setRingSettingRotor1(rotor1.getRingSetting());
		state.setRingSettingRotor2(rotor2.getRingSetting());
		state.setRingSettingRotor3(rotor3.getRingSetting());

		state.setTypeReflector(reflector.getIndex());
		state.setRotationReflector(reflector.getRotation());
		state.setRingSettingReflector(reflector.getRingSetting());
		state.setConfigurationReflector(reflector.getConfiguration());

		return state;
	}

	@Override
	public void restoreState(BigInteger s, int protocol_version)
	{
		switch(protocol_version)
		{
			case 1:
				int rot1 = getValue(s, 26);
				s = removeDigit(s, 26);
				int ring1 = getValue(s, 26);
				s = removeDigit(s, 26);
				int rot2 = getValue(s, 26);
				s = removeDigit(s, 26);
				int ring2 = getValue(s, 26);
				s = removeDigit(s, 26);
				int rot3 = getValue(s, 26);
				s = removeDigit(s, 26);
				int ring3 = getValue(s, 26);
				s = removeDigit(s, 26);
				int rotRef = getValue(s, 26);
				s = removeDigit(s, 26);
				int ringRef = getValue(s, 26);
				s = removeDigit(s, 26);

				this.rotor1 = getRotor(0, rot1, ring1);
				this.rotor2 = getRotor(1, rot2, ring2);
				this.rotor3 = getRotor(2, rot3, ring3);
				this.reflector = getReflector(0, rotRef, ringRef);
				this.reflector.setConfiguration(s);
				break;

			default: Log.e(MainActivity.APP_ID, "Unsupported protocol version "+protocol_version);
		}
	}

	@Override
	public BigInteger getEncodedState(int protocol_version) {
		BigInteger s = Plugboard.configurationToBigInteger(reflector.getConfiguration());
		s = addDigit(s, reflector.getRingSetting(), 26);
		s = addDigit(s, reflector.getRotation(), 26);
		s = addDigit(s, rotor3.getRingSetting(), 26);
		s = addDigit(s, rotor3.getRotation(), 26);
		s = addDigit(s, rotor2.getRingSetting(), 26);
		s = addDigit(s, rotor2.getRotation(), 26);
		s = addDigit(s, rotor1.getRingSetting(), 26);
		s = addDigit(s, rotor1.getRotation(), 26);

		s = addDigit(s, 6, 20); //Machine #6
		s = addDigit(s, protocol_version, MainActivity.max_protocol_version);
		return s;
	}
}