/*
   Forum: 
   Wokwi: https://wokwi.com/projects/439190575651317761

  2025/08/13
  ec2021

  Two signal lights synchronized by time
  The signals are for cars and pedestrians moving in the same or opposite direction
  * left: Car signals
  * right: Pedestrian signals 
  
  The timing of both signal lights makes sure that signal A changes to YELLOWRED when signal B is RED and vice versa

*/


constexpr unsigned long durationYellowRed {2000};
constexpr unsigned long durationYellow {4000};
constexpr unsigned long durationGreen {4000};
constexpr unsigned long durationRed = durationYellowRed+durationYellow+durationGreen;


struct signalPins {
  uint8_t Red;
  uint8_t Yellow;
  uint8_t Green;
};


enum signalState {RED, YELLOWRED, GREEN, YELLOW};

class SignalLightClass {
  private:
    signalPins carPin;
    signalPins persPin;
    signalState carState;
    unsigned long startTime = 0;
    unsigned long duration;
    void handleState(boolean useStartTime) {
      if (millis()-startTime > duration || !useStartTime){
        startTime = millis();
        switch (carState) {
          case RED:
            carState = YELLOWRED;
            setSignal(HIGH, HIGH, LOW, HIGH, LOW);
            duration = durationYellowRed;
            break;
          case YELLOWRED:
            carState = GREEN;
            setSignal(LOW, LOW, HIGH, LOW, HIGH);
            duration = durationGreen;
            break;
          case GREEN:
            carState = YELLOW;
            setSignal(LOW, HIGH, LOW, HIGH, LOW);
            duration = durationYellow;
            break;
          case YELLOW:
            carState = RED;
            setSignal(HIGH, LOW, LOW, HIGH, LOW);
            duration = durationRed;
            break;
        }
      };  
    };
    void setSignal(byte Red, byte Yellow, byte Green, byte pRed, byte pGreen) {
      digitalWrite(carPin.Red, Red);
      digitalWrite(carPin.Yellow, Yellow);
      digitalWrite(carPin.Green, Green);
      digitalWrite(persPin.Red, pRed);
      digitalWrite(persPin.Green, pGreen);
    };

  public:
    SignalLightClass(signalPins cPins, signalPins pPins) : carPin(cPins), persPin(pPins) {};
    void init(signalState startState) {
      pinMode(carPin.Red, OUTPUT);
      pinMode(carPin.Yellow, OUTPUT);
      pinMode(carPin.Green, OUTPUT);
      pinMode(persPin.Red, OUTPUT);
      pinMode(persPin.Green, OUTPUT);
      switch (startState) {
        case RED:
          carState = YELLOW;
          break;
        case YELLOW:
          carState = GREEN;
          break;
        case GREEN:
          carState = YELLOWRED;
          break;
        case YELLOWRED:
          carState = RED;
          break;
      }
      handleState(false);
    };
    void run() {
      handleState(true);
    };
};

SignalLightClass signal1 = {{11, 12, 13}, {9, 0, 10}};
SignalLightClass signal2 = {{17, 16, 15}, {19, 0, 18}};

void setup() {
  signal1.init(RED);
  signal2.init(YELLOWRED);

}

void loop() {
  signal1.run();
  signal2.run();

}