const int controlPin1 = 2;
const int controlPin2 = 3;
const int enablePin = 9;
const int directionSwitchPin = 4;
const int onOffSwitchStateSwitchPin = 5;
const int potPin = A0;

int onOffSwitchState = 0;             
int previousOnOffSwitchState = 0;      
int directionSwitchState = 0;         
int previousDirectionSwitchState = 0; 

int motorEnabled = 0;    
int motorSpeed = 0;      
int motorDirection = 1;  

void setup() {
  pinMode(directionSwitchPin, INPUT);
  pinMode(onOffSwitchStateSwitchPin, INPUT);
  pinMode(controlPin1, OUTPUT);
  pinMode(controlPin2, OUTPUT);
  pinMode(enablePin, OUTPUT);

  digitalWrite(enablePin, LOW);
}

void loop() {
  onOffSwitchState = digitalRead(onOffSwitchStateSwitchPin);
  delay(1);
  directionSwitchState = digitalRead(directionSwitchPin);
  motorSpeed = analogRead(potPin) / 4;
  if (onOffSwitchState != previousOnOffSwitchState) {
    if (onOffSwitchState == HIGH) {
      motorEnabled = !motorEnabled;
    }
  }
  if (directionSwitchState != previousDirectionSwitchState) {
    if (directionSwitchState == HIGH) {
      motorDirection = !motorDirection;
    }
  }
  if (motorDirection == 1) {
    digitalWrite(controlPin1, HIGH);
    digitalWrite(controlPin2, LOW);
  } else {
    digitalWrite(controlPin1, LOW);
    digitalWrite(controlPin2, HIGH);
  }
  if (motorEnabled == 1) {
    analogWrite(enablePin, motorSpeed);
  } else {  
    analogWrite(enablePin, 0);
  }
  previousDirectionSwitchState = directionSwitchState;
  previousOnOffSwitchState = onOffSwitchState;
}