#include <Wire.h>
#include <LiquidCrystal_I2C.h>  // library for LCD with I2C
#include <RTClib.h> 
#include <Time.h>           // library for DS1307 RTC

const int en = 2, rw = 1, rs = 0, d4 = 4, d5 = 5, d6 = 6, d7 = 7, bl = 3;

// Define I2C Address - change if required
LiquidCrystal_I2C lcd(0x27, 16, 2);

RTC_DS1307 rtc;

#include <EEPROM.h>

const int btnChange = 2;
const int btnOK = 3;
const int btnMode = 4;
const int buzzer = 5;

int alarmHour = 12;
int alarmMinutes = 0;
boolean hourMode = 0;
boolean alarmOn = 1;
int M = 12;
int D = 31;
int Y = 2020;
int day = 7;
int h = 23;
int m = 59;

int addrH[] = {0, 1, 2, 3, 4};
int addrM[] = {5, 6, 7, 8, 9};
int addrActive[] = {10, 11, 12, 13, 14};

int mode = 1;
int submode = 1;
int slot = 0;

byte clockChar[] = {B00000, B01110, B10101, B10101, B10111, B10001, B01110, B00000};
byte alarmChar[] = {B00100, B01110, B01110, B01110, B11111, B00000, B00100, B00000};
byte dateChar[] = {B11111, B00000, B01100, B01010, B01010, B01100, B00000, B11111};

void setup() {
  pinMode(btnChange, INPUT_PULLUP);
  pinMode(btnOK, INPUT_PULLUP);
  pinMode(btnMode, INPUT_PULLUP);
  pinMode(buzzer, OUTPUT);

  lcd.begin(16, 2);         // initialize the LCD
  lcd.backlight();          // Turn on the backlight
  lcd.createChar(0, clockChar);
  lcd.createChar(1, alarmChar);
  lcd.createChar(2, dateChar);

  Wire.begin();
  rtc.begin();
  now = now();

  // Uncomment the following line if the RTC has lost power and needs to be set again
  //rtc.adjust(DateTime(2023, 6, 18, 12, 0, 0));
  rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));

  Serial.begin(9600);
}

void loop() {
  if (digitalRead(btnMode) == LOW) {
    mode++;
    Serial.println("btnMode press");
    if (mode == 4) {
      mode = 1;
    }
    submode = 0;
    lcd.clear();
    delay(200);
  }

  if (mode == 1) {
    clockDisplay();
    Serial.println(mode);
  }

  if (mode == 2) {
    alarmMode();
    Serial.println(mode);
  }

  if (mode == 3) {
    updateRTC();
    Serial.println(mode);
  }

  if (mode == 0) {
    alarm();
    Serial.println(mode);
    EEPROM.write(addrActive, 0);
  }

  DateTime now = rtc.now();
  for (int x = 0; x < 5; x++) {
    int active = EEPROM.read(addrActive[x]);
    if (active == 1) {
      int alarmHour = EEPROM.read(addrH[x]);
      int alarmMinutes = EEPROM.read(addrM[x]);
      if (now.hour() == alarmHour && now.minute() == alarmMinutes && now.second() < 2) {
        alarm();
        EEPROM.write(addrActive[x], 0);
        mode = 0;
      }
    }
  }
  delay(1000);
}

void clockDisplay() {
  lcd.setCursor(0, 0);
  lcd.print("  Current Time   ");
  lcd.setCursor(0, 1);
  lcd.print("   ");
  lcd.print(now.toString("HH:mm:ss"));
  lcd.print("   ");
}

void alarm() {
  for (int i = 0; i < 5; i++) {
    digitalWrite(buzzer, HIGH);
    lcd.setBacklight(HIGH);
    delay(500);
    digitalWrite(buzzer, LOW);
    lcd.setBacklight(LOW);
    delay(500);
  }
}

void alarmMode() {
  if (submode == 0) {
    slot++;
    if (slot == 6) {
      slot = 1;
    }
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("   Alarm Slot ");
    lcd.print(slot);
    lcd.setCursor(0, 1);
    lcd.print("Set Alarm:");
    delay(200);
    while (digitalRead(btnChange) == HIGH) {
      if (digitalRead(btnOK) == LOW) {
        submode++;
        lcd.clear();
        delay(200);
      }
    }
  }

  if (submode == 1) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("     Set Hour    ");
    lcd.setCursor(0, 1);
    lcd.print("    ");
    lcd.print(alarmHour);
    lcd.print(":");
    if (hourMode == 0) {
      lcd.print("00");
    } else {
      lcd.print("30");
    }
    lcd.print("     ");
    while (digitalRead(btnChange) == HIGH) {
      if (digitalRead(btnOK) == LOW) {
        hourMode = !hourMode;
        lcd.clear();
        delay(200);
      }
    }
    if (digitalRead(btnChange) == LOW) {
      alarmHour++;
      if (alarmHour == 13) {
        alarmHour = 1;
      }
      lcd.setCursor(0, 1);
      lcd.print("    ");
      lcd.print(alarmHour);
      lcd.print(":");
      if (hourMode == 0) {
        lcd.print("00");
      } else {
        lcd.print("30");
      }
      lcd.print("     ");
      delay(200);
    }
    if (digitalRead(btnOK) == LOW) {
      submode++;
      lcd.clear();
      delay(200);
    }
  }

  if (submode == 2) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("    Set Minute   ");
    lcd.setCursor(0, 1);
    lcd.print("    ");
    lcd.print(alarmHour);
    lcd.print(":");
    if (hourMode == 0) {
      lcd.print("00");
    } else {
      lcd.print("30");
    }
    lcd.print("     ");
    while (digitalRead(btnChange) == HIGH) {
      if (digitalRead(btnOK) == LOW) {
        hourMode = !hourMode;
        lcd.clear();
        delay(200);
      }
    }
    if (digitalRead(btnChange) == LOW) {
      alarmMinutes += 5;
      if (alarmMinutes >= 60) {
        alarmMinutes = 0;
      }
      lcd.setCursor(0, 1);
      lcd.print("    ");
      lcd.print(alarmHour);
      lcd.print(":");
      if (hourMode == 0) {
        lcd.print("00");
      } else {
        lcd.print("30");
      }
      lcd.print("     ");
      delay(200);
    }
    if (digitalRead(btnOK) == LOW) {
      submode = 0;
      lcd.clear();
      EEPROM.write(addrH[slot - 1], alarmHour);
      EEPROM.write(addrM[slot - 1], alarmMinutes);
      EEPROM.write(addrActive[slot - 1], 1);
      delay(200);
    }
  }
}

void updateRTC() {
  if (submode == 0) {
    slot++;
    if (slot == 6) {
      slot = 1;
    }
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("   Update Time   ");
    lcd.setCursor(0, 1);
    lcd.print("   ");
    lcd.print(now.toString("MM-dd-yyyy"));
    lcd.print("   ");
    delay(200);
    while (digitalRead(btnChange) == HIGH) {
      if (digitalRead(btnOK) == LOW) {
        submode++;
        lcd.clear();
        delay(200);
      }
    }
  }

  if (submode == 1) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("   Set Month   ");
    lcd.setCursor(0, 1);
    lcd.print("     ");
    lcd.print(M);
    lcd.print("      ");
    while (digitalRead(btnChange) == HIGH) {
      if (digitalRead(btnOK) == LOW) {
        lcd.clear();
        delay(200);
        submode++;
      }
    }
    if (digitalRead(btnChange) == LOW) {
      M++;
      if (M == 13) {
        M = 1;
      }
      lcd.setCursor(0, 1);
      lcd.print("     ");
      lcd.print(M);
      lcd.print("      ");
      delay(200);
    }
  }

  if (submode == 2) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("   Set Day   ");
    lcd.setCursor(0, 1);
    lcd.print("     ");
    lcd.print(D);
    lcd.print("      ");
    while (digitalRead(btnChange) == HIGH) {
      if (digitalRead(btnOK) == LOW) {
        lcd.clear();
        delay(200);
        submode++;
      }
    }
    if (digitalRead(btnChange) == LOW) {
      D++;
      if (D == 32) {
        D = 1;
      }
      lcd.setCursor(0, 1);
      lcd.print("     ");
      lcd.print(D);
      lcd.print("      ");
      delay(200);
    }
  }

  if (submode == 3) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("   Set Year   ");
    lcd.setCursor(0, 1);
    lcd.print("    ");
    lcd.print(Y);
    lcd.print("     ");
    while (digitalRead(btnChange) == HIGH) {
      if (digitalRead(btnOK) == LOW) {
        lcd.clear();
        delay(200);
        submode++;
      }
    }
    if (digitalRead(btnChange) == LOW) {
      Y++;
      if (Y == 10000) {
        Y = 1;
      }
      lcd.setCursor(0, 1);
      lcd.print("    ");
      lcd.print(Y);
      lcd.print("     ");
      delay(200);
    }
  }

  if (submode == 4) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("   Set Day   ");
    lcd.setCursor(0, 1);
    lcd.print("     ");
    lcd.print(day);
    lcd.print("      ");
    while (digitalRead(btnChange) == HIGH) {
      if (digitalRead(btnOK) == LOW) {
        lcd.clear();
        delay(200);
        submode++;
      }
    }
    if (digitalRead(btnChange) == LOW) {
      day++;
      if (day == 8) {
        day = 1;
      }
      lcd.setCursor(0, 1);
      lcd.print("     ");
      lcd.print(day);
      lcd.print("      ");
      delay(200);
    }
  }

  if (submode == 5) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("   Set Hour   ");
    lcd.setCursor(0, 1);
    lcd.print("    ");
    lcd.print(h);
    lcd.print("     ");
    while (digitalRead(btnChange) == HIGH) {
      if (digitalRead(btnOK) == LOW) {
        lcd.clear();
        delay(200);
        submode++;
      }
    }
    if (digitalRead(btnChange) == LOW) {
      h++;
      if (h == 24) {
        h = 0;
      }
      lcd.setCursor(0, 1);
      lcd.print("    ");
      lcd.print(h);
      lcd.print("     ");
      delay(200);
    }
  }

  if (submode == 6) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("  Set Minute   ");
    lcd.setCursor(0, 1);
    lcd.print("    ");
    lcd.print(m);
    lcd.print("     ");
    while (digitalRead(btnChange) == HIGH) {
      if (digitalRead(btnOK) == LOW) {
        lcd.clear();
        delay(200);
        submode++;
      }
    }
    if (digitalRead(btnChange) == LOW) {
      m++;
      if (m == 60) {
        m = 0;
      }
      lcd.setCursor(0, 1);
      lcd.print("    ");
      lcd.print(m);
      lcd.print("     ");
      delay(200);
    }
  }

  if (submode == 7) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("   Updated   ");
    lcd.setCursor(0, 1);
    lcd.print("     ");
    lcd.print(now.toString("MM-dd-yyyy"));
    lcd.print("     ");
    delay(2000);
    lcd.clear();
   rtc.adjust(DateTime(Y, M, D, h, m, 0));
    submode = 0;
  }
}