#include <Wire.h>
#include <RTClib.h>
#include <LiquidCrystal_I2C.h>

// ----------- Objects ----------
RTC_DS1307 rtc;
LiquidCrystal_I2C lcd(0x27, 16, 2);

// ----------- Pins ----------
const int RELAY_PIN = 6;
const int BTN_MODE  = 2;
const int BTN_UP    = 3;
const int BTN_BELL  = 4;
const int BTN_FIRE  = 5;

// ----------- Bell Settings ----------
int bellHour[]={8, 8, 9, 9, 10, 10, 10, 11, 12, 12, 13, 13, 13, 14, 14, 15, 16, 16, 16, 17, 18};
int bellMinute[]={0, 40, 20, 25, 5, 45, 55, 35, 15, 20, 0, 15, 55, 35, 40, 20, 0, 10, 50, 30, 10};
int bellCount = 21;

int lastMinuteTriggered = -1;
unsigned long bellStartTime = 0;
const int BELL_DURATION = 10000;
bool isRinging = false;

// ----------- Weekdays ----------
const char* weekDays[7] = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
uint8_t hour_v, minute_v, second_v, date_v, month_v, day_v;
uint16_t year_v;
// ------------------ Functions ------------------

// 🕒 Цаг + өдөр LCD-д харуулах
void displayTime(DateTime now) {
  char buf[20];
  sprintf(buf, "%02d:%02d:%02d %s", now.hour(), now.minute(), now.second(), weekDays[now.dayOfTheWeek()]);
  lcd.setCursor(0, 0);
  lcd.print(buf);
}

// 🔔 Хонх дуугаргах
void ringBell() {
  if (digitalRead(RELAY_PIN) == LOW) { // Хонх дуугарч эхэлж байгаа үед
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("🔔 Bell Now! 🔔");
    digitalWrite(RELAY_PIN, HIGH);
    bellStartTime = millis();
}
}

// 🔥 Галын дохиолол
void fireAlarm() {
  for (int i = 0; i < 3; i++) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("!!! CAUTION !!!");
    digitalWrite(RELAY_PIN, HIGH);
    millis();
    digitalWrite(RELAY_PIN, LOW);
    lcd.clear();
    millis();
  }
}

// ⏰ Хонхны цаг шалгах
void checkBell(DateTime now) {
  if(now.dayOfTheWeek() == 0 || now.dayOfTheWeek() == 6) return;
  if (now.minute() == lastMinuteTriggered || isRinging) return;

  for (int i = 0; i < bellCount; i++) {
    if (now.hour() == bellHour[i] && now.minute() == bellMinute[i]) {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("🔔 Bell Now! 🔔");
      digitalWrite(RELAY_PIN, HIGH);
      bellStartTime = millis(); 
      isRinging = true;
      lastMinuteTriggered = now.minute();
      return;
    }
  }
}


// 🔔 Дараагийн хонхны цагийг олох
String nextBell(DateTime now) {
  if(now.dayOfTheWeek() == 0 || now.dayOfTheWeek() == 6) return "WEEKEND";
  for (int i = 0; i < bellCount; i++) {
    if (bellHour[i] > now.hour() || (bellHour[i] == now.hour() && bellMinute[i] > now.minute())) {
      char buf[6];
      sprintf(buf, "%02d:%02d", bellHour[i], bellMinute[i]);
      return String(buf);
    }
  }
  return "--:--";
}

void DS1307_display() {
  DateTime now = rtc.now();

  // Break out the components
  uint8_t hh = now.hour();
  uint8_t mm = now.minute();
  uint8_t ss = now.second();
  uint8_t dd = now.day();
  uint8_t mon = now.month();
  uint8_t wday = now.dayOfTheWeek(); // 0 = Sun
  uint16_t yy = now.year();

  // First line: time
  char line1[17];
  snprintf(line1, sizeof(line1), "%s %02u:%02u:%02u", weekDays[wday], hh, mm, ss);
  lcd.setCursor(0, 0);
  lcd.print(line1);

  // Second line: date
  char line2[17];
  // print as 2025/11/13 or yy/mm/dd if you prefer 2-digit year:
  snprintf(line2, sizeof(line2), "%04u/%02u/%02u", yy, mon, dd);
  lcd.setCursor(0, 1);
  lcd.print(line2);
}

// ---------------- small helper for blinking delay ----------------
void blink_parameter() {
  byte j = 0;
  // wait a short amount while both buttons are not pressed
  while (j < 10 && digitalRead(BTN_MODE) && digitalRead(BTN_UP)) {
    j++;
    delay(25);
  }
}

// ---------------- edit single numeric parameter on LCD ----------------
// x,y = cursor, parameter = initial value, index = which parameter (0=hour,1=min,2=year,3=month,4=date,5=day)
byte edit(byte x, byte y, byte parameter, byte index) {
  char text[4];
  // wait until MODE released if it was pressed entering edit
  while (!digitalRead(BTN_MODE)) { delay(10); }

  while (true) {
    // when UP pressed => increment
    if (!digitalRead(BTN_UP)) {
      // increment with wrapping according to index
      if (index == 0) { // hour
        parameter = (parameter + 1) % 24;
      } else if (index == 1) { // minute
        parameter = (parameter + 1) % 60;
      } else if (index == 2) { // year (we treat as two-digit 0..99 representing 2000..2099)
        parameter++;
        if (parameter > 99) parameter = 0;
      } else if (index == 3) { // month
        parameter++;
        if (parameter > 12) parameter = 1;
      } else if (index == 4) { // date
        parameter++;
        if (parameter > 31) parameter = 1;
      } 
      // show updated value
      lcd.setCursor(x, y);
      snprintf(text, sizeof(text), "%02u", parameter);
      lcd.print(text);
      delay(180); // debouncing speed
    }

    // blink effect when idle
    lcd.setCursor(x, y);
    lcd.print("  ");
    blink_parameter();
    lcd.setCursor(x, y);
    snprintf(text, sizeof(text), "%02u", parameter);
    lcd.print(text);
    blink_parameter();

    // MODE pressed => accept and move to next
    if (!digitalRead(BTN_MODE)) {
      // wait for release to avoid bouncing into next state
      while (!digitalRead(BTN_MODE)) delay(10);
      return parameter;
    }
  }
}

// ---------------- setTime() fully corrected ----------------
void setTime() {
  // get current values from RTC (so we start from sensible defaults)
  DateTime now = rtc.now();
  hour_v   = now.hour();
  minute_v = now.minute();
  second_v = now.second();
  date_v   = now.day();
  day_v    = now.dayOfTheWeek() + 1; // convert 0..6 -> 1..7 if you want 1..7 convention
  month_v  = now.month();
  year_v   = now.year(); // full year (e.g., 2025)

  // If you prefer to edit two-digit year (00..99) representing 2000..2099:
  uint8_t yearTwo = year_v % 100;

  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("SET TIME");
  delay(400);

  // i corresponds to which field we are editing; we'll step through: hour, minute, year(yy), month, date, day
  byte i = 0;

  // Edit hour
  lcd.setCursor(0,0);
  lcd.print("Hour:");
  hour_v = edit(5, 0, hour_v, 0); // place at col 5,row0

  // Edit minute
  lcd.setCursor(0,0);
  lcd.print("Min :");
  minute_v = edit(5, 0, minute_v, 1);

  // Edit year (two-digit)
  lcd.setCursor(0,0);
  lcd.print("YY   ");
  yearTwo = edit(5, 0, yearTwo, 2);

  // Edit month
  lcd.setCursor(0,0);
  lcd.print("Mon  ");
  month_v = edit(5, 0, month_v, 3);

  // Edit date (day of month)
  lcd.setCursor(0,0);
  lcd.print("Date ");
  date_v = edit(5, 0, date_v, 4);

  // If you want to allow editing seconds too, add similar step.

  // Now compose full year
  year_v = 2000 + yearTwo; // assuming 2000..2099 range

  // Write to RTC using RTClib DateTime - pass (year, month, day, hour, minute, second)
  rtc.adjust(DateTime((uint16_t)year_v, (uint8_t)month_v, (uint8_t)date_v,
                      (uint8_t)hour_v, (uint8_t)minute_v, (uint8_t)second_v));

  lcd.clear();
  lcd.print("Time Saved!");
  delay(1000);
  lcd.clear();
}


// 🔁 Өдөр бүр ресет хийх
/*void autoReset(DateTime now) {
  int savedResetDay = EEPROM.read(RESET_ADDR);

  // өдөр 03:00 болсон, мөн өмнөхөд энэ өдөр ресет хийгдээгүй бол
  if (now.hour() == 3 && now.minute() == 0 && now.second() < 10 && savedResetDay != now.day()) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Daily Reset...");
    delay(2000);
    lcd.clear();

    // тухайн өдрийг EEPROM-д бичнэ
    EEPROM.write(RESET_ADDR, now.day());

    // RTC-г өөрчлөхгүй — зөвхөн Arduino-г restart хийх
    void (*resetFunc)(void) = 0; // safer reset
    resetFunc();
  }
}*/

// ------------------ Setup ------------------
void setup() {
  Serial.begin(9600);
  Wire.begin();
  lcd.init();
  lcd.backlight();

  pinMode(RELAY_PIN, OUTPUT); //D6 pin
  digitalWrite(RELAY_PIN, LOW);

  pinMode(BTN_MODE, INPUT_PULLUP); //D5 pin
  pinMode(BTN_UP, INPUT_PULLUP); //D4 pin
  pinMode(BTN_BELL, INPUT_PULLUP); //D3 pin
  pinMode(BTN_FIRE, INPUT_PULLUP); //D2 pin

  if (!rtc.begin()) {
    lcd.print("RTC not found!");
    while (1);
  }
  

  lcd.setCursor(0, 0);
  lcd.print("Automatic Bell");
  lcd.setCursor(0, 1);
  lcd.print("Loading Memory...");
  delay(1500);

  //loadFromEEPROM();

  lcd.clear();
  lcd.print("System Ready!");
  delay(1000);
  lcd.clear();
}

// ------------------ Loop ------------------
void loop() {
  DateTime now = rtc.now();
  displayTime(now);
  if (isRinging && millis() - bellStartTime >= BELL_DURATION) {
    digitalWrite(RELAY_PIN, LOW);
    isRinging = false;
    lcd.clear();
  }
  // LCD-д дараагийн хонхны цаг харуулах
  lcd.setCursor(0,1);
  lcd.print("Next: " + nextBell(now) + "   "); 

  if (!digitalRead(BTN_FIRE)) fireAlarm();
  if (!digitalRead(BTN_MODE)) setTime();

  checkBell(now);
  //autoReset(now);

  delay(200);
}