#include <LiquidCrystal_I2C.h>  
#include <Countimer.h>          
#include <EEPROM.h>

// ===== CALLS THE FOLLOWING LIBRARY AND MODULES ====== //
LiquidCrystal_I2C lcd(0x27, 16, 2);  // LCD HEX address 0x3F -- change according to yours
Countimer tdown;

// ===== 🔠 DEFINE THE VARIABLES FOR EACH FUNCTIONS ====== //
//Define for the Tact Switches
#define bt_set 2
#define bt_up 3
#define bt_down 4
#define bt_start 5

//Constants for Date and Time
int time_s = 0;
int time_m = 0;
int time_h = 0;

int set = 0;
int flag1 = 0, flag2 = 0;

int relay = 7;
int buzzer = 8;

// ===== ✅ INITIALIZE THE FUNCTION AND STARTUP ====== //
void setup() {
  Serial.begin(9600);
  lcd.init();          // initialize lcd
  lcd.backlight();     // switch-on lcd backlight
  lcd.clear();         //clear all the previous display

  //Set the 4 Tact Switch in different modes: Set, Up, Down, Start
  pinMode(bt_set, INPUT_PULLUP);
  pinMode(bt_up, INPUT_PULLUP);
  pinMode(bt_down, INPUT_PULLUP);
  pinMode(bt_start, INPUT_PULLUP);

  //Set the Pin Output for the Relay and Buzzer
  pinMode(relay, OUTPUT);
  pinMode(buzzer, OUTPUT);

  //START-UP DISPLAY
  lcd.setCursor(0, 0);
  lcd.print("    ARDUINO     ");
  lcd.setCursor(0, 1);
  lcd.print("TMR CTRL RELAY");
  delay(2000);
  lcd.clear();  
 

  tdown.setInterval(print_time, 999);
  eeprom_read();
  delay(1000);
}

// ===== FUNCTION FOR THE PRINT TIME ===== //
void print_time() {
  time_s = time_s - 1;
  if (time_s < 0) {
    time_s = 59;
    time_m = time_m - 1;
  }
  if (time_m < 0) {
    time_m = 59;
    time_h = time_h - 1;
  }
}

// ===== FUNCTION FOR TIMER COOLDOWN COMPLETE ===== //
void tdownComplete() {
  Serial.print("ok");
}

//tdown.stop();

// ===== MAIN LOOP FUNCTION FOR THE PROGRAM ===== //
void loop() {
  tdown.run();

  if (digitalRead(bt_set) == 0) {
    if (flag1 == 0 && flag2 == 0) {
      flag1 = 1;
      set = set + 1;
      if (set > 3) { set = 0; }
      delay(100);
    }
  } else {
    flag1 = 0;
  }

  if (digitalRead(bt_up) == 0) {
    if (set == 0) {
      tdown.start();
      flag2 = 1;
    }
    if (set == 1) { time_s++; }
    if (set == 2) { time_m++; }
    if (set == 3) { time_h++; }
    if (time_s > 59) { time_s = 0; }
    if (time_m > 59) { time_m = 0; }
    if (time_h > 99) { time_h = 0; }
    if (set > 0) { eeprom_write(); }
    delay(200);  
  }

  if (digitalRead(bt_down) == 0) {
    if (set == 0) {
      tdown.stop();
      flag2 = 0;
    }
    if (set == 1) { time_s--; }
    if (set == 2) { time_m--; }
    if (set == 3) { time_h--; }
    if (time_s < 0) { time_s = 59; }
    if (time_m < 0) { time_m = 59; }
    if (time_h < 0) { time_h = 99; }
    if (set > 0) { eeprom_write(); }
    delay(200);
  }

  if (digitalRead(bt_start) == 0) {
    flag2 = 1;
    eeprom_read();
    digitalWrite(relay, HIGH);
    tdown.restart();
    tdown.start();
  }

  lcd.setCursor(0, 0);
  if (set == 0) { lcd.print("      Timer     "); }
  if (set == 1) { lcd.print("  Set Timer SS  "); }
  if (set == 2) { lcd.print("  Set Timer MM  "); }
  if (set == 3) { lcd.print("  Set Timer HH  "); }

  lcd.setCursor(4, 1);
  if (time_h <= 9) { lcd.print("0"); }
  lcd.print(time_h);
  lcd.print(":");
  if (time_m <= 9) { lcd.print("0"); }
  lcd.print(time_m);
  lcd.print(":");
  if (time_s <= 9) { lcd.print("0"); }
  lcd.print(time_s);
  lcd.print("   ");

  if (time_s == 0 && time_m == 0 && time_h == 0 && flag2 == 1) {
    flag2 = 0;
    tdown.stop();
    digitalWrite(relay, HIGH);
    digitalWrite(buzzer, HIGH);
    delay(300);
    digitalWrite(buzzer, LOW);
    delay(200);
    digitalWrite(buzzer, HIGH);
    delay(300);
    digitalWrite(buzzer, LOW);
    delay(200);
    digitalWrite(buzzer, HIGH);
    delay(300);
    digitalWrite(buzzer, LOW);
  }

  if (flag2 == 1) {
    digitalWrite(relay, LOW);
  } else {
    digitalWrite(relay, HIGH);
  }

  delay(1);
}

// ===== FUNCTION FOR EEPROM WRITE ===== //
void eeprom_write() {
  EEPROM.write(1, time_s);
  EEPROM.write(2, time_m);
  EEPROM.write(3, time_h);
}

// ===== FUNCTION FOR EEPROM READ ===== //
void eeprom_read() {
  time_s = EEPROM.read(1);
  time_m = EEPROM.read(2);
  time_h = EEPROM.read(3);
}