#include <Wire.h>

String inputString = "";         // a string to hold incoming data
boolean startGame = false;
boolean stopGame = false;
boolean readSensors = false;

boolean sensor_1_tripped = false;
boolean sensor_2_tripped = false;
boolean sensor_3_tripped = false;
boolean sensor_4_tripped = false;
boolean sensor_5_tripped = false;
boolean sensor_6_tripped = false;

#define SENSOR_1 2
#define SENSOR_2 3
#define SENSOR_3 21
#define SENSOR_4 20
#define SENSOR_5 19
#define SENSOR_6 18

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);

  pinMode(SENSOR_1, INPUT_PULLUP);
  pinMode(SENSOR_2, INPUT_PULLUP);
  pinMode(SENSOR_3, INPUT_PULLUP);
  pinMode(SENSOR_4, INPUT_PULLUP);
  pinMode(SENSOR_5, INPUT_PULLUP);
  pinMode(SENSOR_6, INPUT_PULLUP);

  // reserve 200 bytes for the inputString:
  inputString.reserve(200);
}

void loop() {
  while (Serial.available()) {
    // get the new byte:
    char inChar = (char)Serial.read();
    // add it to the inputString:
    inputString += inChar;
    // if the incoming character is a newline, set a flag
    // so the main loop can do something about it:
    if (inputString == "start") {
      startGame = true;
      stopGame = false;
      readSensors = true;
      Serial.write("STARTED");
      inputString = "";
      return;
    }
    if (inputString == "stop") {
      stopGame = true;
      startGame = false;
      readSensors = false;
      return;
    }
  }

  while (startGame) {
    while(readSensors) {

      attachInterrupt(digitalPinToInterrupt(SENSOR_1), sensor_1_callback, FALLING);
      attachInterrupt(digitalPinToInterrupt(SENSOR_2), sensor_2_callback, FALLING);
      attachInterrupt(digitalPinToInterrupt(SENSOR_3), sensor_3_callback, FALLING);
      attachInterrupt(digitalPinToInterrupt(SENSOR_4), sensor_4_callback, FALLING);
      attachInterrupt(digitalPinToInterrupt(SENSOR_5), sensor_5_callback, FALLING);
      attachInterrupt(digitalPinToInterrupt(SENSOR_6), sensor_6_callback, FALLING);

      if(Serial.available()) {
        char inChar = (char)Serial.read();
        inputString += inChar;
        if (inputString == "stop") {
          stopGame = true;
          startGame = false;
          readSensors = false;
          inputString = "";
          Serial.write("STOPPED");
          break;
        }
      }

      if(sensor_1_tripped == true) {
        sensor_1_tripped = false;
        Serial.write("1");
      }
      if(sensor_2_tripped == true) {
        sensor_2_tripped = false;
        Serial.write("2");
      }
      if(sensor_3_tripped == true) {
        sensor_3_tripped = false;
        Serial.write("3");
      }
      if(sensor_4_tripped == true) {
        sensor_4_tripped = false;
        Serial.write("4");
      }
      if(sensor_5_tripped == true) {
        sensor_5_tripped = false;
        Serial.write("5");
      }
      if(sensor_6_tripped == true) {
        sensor_6_tripped = false;
        Serial.write("6");
      }
    }
  }
}

void sensor_1_callback() {
  sensor_1_tripped = true;
}
void sensor_2_callback() {
  sensor_2_tripped = true;
}
void sensor_3_callback() {
  sensor_3_tripped = true;
}
void sensor_4_callback() {
  sensor_4_tripped = true;
}
void sensor_5_callback() {
  sensor_5_tripped = true;
}
void sensor_6_callback() {
  sensor_6_tripped = true;
}