/*
  https://forum.arduino.cc/t/4-buttons-to-control-4-relays/1109997
  
  https://wokwi.com/projects/360921014043806721

  =======================================
   Switch one out of four relay on/off for 3 seconds
   Block all buttons for a 2 minutes (here for test purposes 10 seconds only)
  =======================================

  2023-04-02 
  coded by ec2021


*/

constexpr byte button1Pin =  7;
constexpr byte button2Pin =  6;
constexpr byte button3Pin =  5;
constexpr byte button4Pin =  4;

constexpr byte relay1Pin  = 13;
constexpr byte relay2Pin = 12;
constexpr byte relay3Pin = 11;
constexpr byte relay4Pin = 10;

struct ButtonType {
  byte Pin;
  unsigned long lastChange = 0;
  int lastState = HIGH;
  int state     = HIGH;
  boolean released();
};

boolean ButtonType::released() {
  int actState = digitalRead(ButtonType::Pin);
  if (actState != ButtonType::lastState) {
    ButtonType::lastChange = millis();
    ButtonType::lastState = actState;
  }
  if (actState != ButtonType::state && millis() - ButtonType::lastChange > 50) {
    ButtonType::state     = actState;
    if (actState) return true;
  };
  return false;
}

ButtonType button1;
ButtonType button2;
ButtonType button3;
ButtonType button4;

constexpr int NoOfRelais = 4;
byte relayPin[NoOfRelais] = {relay1Pin, relay2Pin, relay3Pin,relay4Pin};

void setup() {
  Serial.begin(115200);
  Serial.println("Start");
  button1.Pin = button1Pin;
  button2.Pin = button2Pin;
  button3.Pin = button3Pin;
  button4.Pin = button4Pin;

  pinMode(button1.Pin, INPUT_PULLUP);
  pinMode(button2.Pin, INPUT_PULLUP);
  pinMode(button3.Pin, INPUT_PULLUP);
  pinMode(button4.Pin, INPUT_PULLUP);

  for (int i = 0; i < NoOfRelais;i++) pinMode(relayPin[i], OUTPUT);

}

constexpr unsigned long RelaySwitchTime = 3000UL;      // 3 sec = 3000 milliseconds
constexpr unsigned long ButtonBlockTime = 10000UL;    // 10 sec = 10000 milliseconds
//constexpr unsigned long ButtonBlockTime = 120000UL;  // 2 min = 120 sec = 120000 milliseconds

int SwitchNo = 0;


void loop() {
    HandleButtons();
    HandleRelaisOnOff(); 
}

void HandleButtons(){
  static boolean       BlockButtons = false;
  static unsigned long lastButtonBlockTime = 0;
  if (!BlockButtons) {
      if (button1.released()) SwitchNo = 1;
      if (button2.released()) SwitchNo = 2;
      if (button3.released()) SwitchNo = 3;
      if (button4.released()) SwitchNo = 4;
      if (SwitchNo > 0) {
         lastButtonBlockTime = millis();
         BlockButtons = true;
         Serial.println("Buttons disabled");
      }
  } else {
    if (millis() - lastButtonBlockTime > ButtonBlockTime){
      BlockButtons = false;
      Serial.println("Buttons enabled");
    }
  }

}

void HandleRelaisOnOff(){
  static int RelayOn = 0;
  static boolean RelaySwitchedOn = false;
  static unsigned long lastRelayOnTime = 0;
  if (SwitchNo) {
    lastRelayOnTime = millis();
    RelayOn = SwitchNo-1;
    SwitchNo = 0;
    digitalWrite(relayPin[RelayOn],HIGH);
    RelaySwitchedOn = true;
    Serial.println("Relay\t"+String(RelayOn+1)+ " on");

  }
  if (RelaySwitchedOn && millis() - lastRelayOnTime > RelaySwitchTime){
     digitalWrite(relayPin[RelayOn],LOW);
     RelaySwitchedOn = false;
     Serial.println("Relay\t"+String(RelayOn+1)+ " off");
  }
}