/*
   FSM assignment
*/

#include <Arduino.h>
#include <Wire.h>

enum State {
  I000, // 0
  I001, // 1
  I010, // 2
  I011, // 3
  I100, // 4
  I101, // 5
  I110, // 6
  I111, // 7
  D000, // 8
  D001, // 9
  D010, // 10
  D011, // 11
  D100, // 12
  D101, // 13
  D110, // 14
  D111 //  15
};

State state = I000;


void setup() {
  Serial.begin(9600);
}

void loop() {
  state = nextState(state);
  delay(1000);
}

State nextState (State state) {
  char input = Serial.read();
  switch (state) {
    case I000:
      Serial.println(" 0 : 000 ");
      if (checkReverse()) {
        state = I001;
      }
      else {
        state = D111;
      }
      break;
    case I001:
      Serial.println(" 1 : 001 ");
      if (checkReverse()) {
        state = I010;
      }
      else {
        state = D000;
      }
      break;
    case I010:
    Serial.println(" 2 : 010 ");
      if (checkReverse()) {
        state = I011;
      }
      else {
        state = D001;
      }
      break;
    case I011:
    Serial.println(" 3 : 011 ");
      if (checkReverse()) {
        state = I100;
      }
      else {
        state = D010;
      }
      break;
    case I100:
    Serial.println(" 4 : 100 ");
      if (checkReverse()) {
        state = I101;
      }
      else {
        state = D011;
      }
      break;
    case I101:
    Serial.println(" 5 : 101 ");
      if (checkReverse()) {
        state = I110;
      }
      else {
        state = D100;
      }
      break;
    case I110:
    Serial.println(" 6 : 110 ");
      if (checkReverse()) {
        state = I111;
      }
      else {
        state = D101;
      }
      break;
    case I111:
    Serial.println(" 7 : 111 ");
      if (checkReverse()) {
        state = I000;
      }
      else {
        state = D110;
      }
      break;
    case D000:
    Serial.println(" 0 : 000 ");
      if (checkReverse()) {
        state = D111;
      }
      else {
        state = I001;
      }
      break;
    case D111:
    Serial.println(" 7 : 111 ");
      if (checkReverse()) {
        state = D110;
      }
      else {
        state = I000;
      }
      break;
    case D110:
    Serial.println(" 6 : 110 ");
      if (checkReverse()) {
        state = D101;
      }
      else {
        state = I111;
      }
      break;
    case D101:
    Serial.println(" 5 : 101 ");
      if (checkReverse()) {
        state = D100;
      }
      else {
        state = I110;
      }
      break;
    case D100:
    Serial.println(" 4 : 100 ");
      if (checkReverse()) {
        state = D011;
      }
      else {
        state = I101;
      }
      break;
    case D011:
    Serial.println(" 3 : 011 ");
      if (checkReverse()) {
        state = D010;
      }
      else {
        state = I100;
      }
      break;
    case D010:
    Serial.println(" 2 : 010 ");
      if (checkReverse()) {
        state = D001;
      }
      else {
        state = I011;
      }
      break;
    case D001:
    Serial.println(" 1 : 001 ");
      if (checkReverse()) {
        state = D000;
      }
      else {
        state = I010;
      }
      break;
  }
  return state;
}

bool checkReverse(){ // or no inputs??
  int input = Serial.read();
  if(input != -1){
    Serial.println(" --Reverse-- ");
    return true;
  }
  return false;
}

//to do: don't use checkReverse in nextState and make checkReverse a method and use it in the loop