/*
  A Group of several objects
   a simple on/off relay
   a retriggerable Monoflop
   a button to read

  https://forum.arduino.cc/t/delay-turning-led-off-after-button-press/1105635/
  2023-03-25 by noiasca
  to be deleted: 2023-06
  refactored to composition
*/

constexpr uint8_t noPin = 255;  // unused dummy GPIO
void release(uint8_t);          // only a prototype - just the signature of a function implemented later in the code

// a simple button read in OOP
class Button {
    const uint8_t pin;
    const uint8_t active = LOW;
  public:
    Button(uint8_t pin) : pin{pin} {}

    void begin() {
      pinMode(pin, INPUT_PULLUP);
    }

    uint8_t getPin() {
      return pin;
    }

    bool isPressed()  {
      if (digitalRead(pin) == active ) return true; else return false;
    }
};

// a simple on/off output
class OnOff {
    const uint8_t pin;                 // the ouput pin
    const uint8_t active = HIGH;
    const uint8_t inactive = LOW;
  public:
    OnOff(uint8_t pin) : pin{pin}
    {}

    void begin() {
      pinMode(pin, OUTPUT);
    }

    void on() {
      digitalWrite(pin, active);
    }

    void off() {
      digitalWrite(pin, inactive);
    }
};

// a class to "switch off a pin" after a certain time
class Monoflop {
    const uint8_t pin;                     // the output GPIO, active HIGH
    bool state = false;                    // timer is running or not
    uint32_t previousMillis = 0;           // time management
  public:
    Monoflop(uint8_t pin) : pin{pin}
    {}

    void begin() {                         // to be called in setup()
      pinMode(pin, OUTPUT);
    }

    void on(uint32_t currentMillis = millis()) {
      previousMillis = currentMillis;
      digitalWrite(pin, HIGH);
      state = true;
    }

    void off() {                           // handles switching off
      digitalWrite(pin, LOW);
      state = false;
    }

    void update(uint32_t currentMillis = millis()) {   // to be called in loop()
      if (state && currentMillis - previousMillis > 3000) {
        off();
      }
    }
};
 
// composite serveral harware belonging together
// a class for one button, one LED, one Relay
class Group {
    Button button;
    Monoflop led;
    OnOff relay;
  public:
    Group(uint8_t buttonPin, uint8_t ledPin, uint8_t relayPin)
      : button(buttonPin), led(ledPin), relay(relayPin)
    {};

    void begin() {
      button.begin();
      led.begin();
      relay.begin();
    }

    void off() {
      led.off();
      relay.off();
    }

    uint8_t getButtonPin() {
      return button.getPin();
    }

    void update(uint32_t currentMillis = millis()) {
      if (button.isPressed()) {
        release(button.getPin());  // call release with the current pressed button
        led.on();
        relay.on();
      }
      led.update(currentMillis);   // the led needs to be updated;
    }
};

//create 3 instances (each with one button, one LED, one relay)
Group amplifier[] {
  {A2, 12, 7},  // buttonPin, ledPin, relayPin
  {A1, 11, 8},
  {A0, 10, 9},
};

Button offButton(A3); // a master off button

void release(uint8_t currentPin = noPin) {
  for (auto &i : amplifier)  {
    if (currentPin != i.getButtonPin())
      i.off();
  }
}

void setup() {
  Serial.begin(115200);
  for (auto &i : amplifier) i.begin();
  offButton.begin();
}

void loop() {
  if (offButton.isPressed()) release();
  for (auto &i : amplifier) i.update();
}