#include <Wire.h>
#include <I2C_RTC.h>  //use lib by Manjunath CV in lib manager
#include <LiquidCrystal_I2C.h>

static DS3231 RTC; //Variable and component declaration

  LiquidCrystal_I2C lcd(0x27, 16, 2);
  const int relayPin = 2;
  const int dtbuttonPin = 3;
  const int cdbuttonPin = 4;
  const int addSecBTPin = 5;
  const int subtSecBTPin = 6;
  const int addMinBTPin = 7;
  const int subtMinBTPin = 8;
  const int addHrBTPin = 9;
  const int subtHrBTPin = 10;
  const int addDayBTPin = 11;
  const int subtDayBTPin = 12;
  unsigned long startTime = 0;
  const unsigned long duration = 10000;
  unsigned long lastDiscardTime = 0;
  const unsigned long discardInterval = 10000;
  unsigned long CDGoal = 0;
  unsigned long CDNow = 0;
  unsigned long CDTick = 0;
  unsigned long CDSeconds = 0;
  unsigned long CDMinutes = 0;
  unsigned long CDHours = 0;
  
void setup() { //Setup and initialization
  Serial.begin(9600);
  RTC.begin();
  lcd.init();
  pinMode(relayPin, OUTPUT);
  pinMode(dtbuttonPin, INPUT);
  pinMode(cdbuttonPin, INPUT);
  RTC.setHourMode(CLOCK_H24);
}

void CDGoalSet() {
  if (RTC.getWeek() == 6) {  //Friday Countdown Goal Setting
    if (RTC.getHours() < 8 && RTC.getHours() >= 0) {
          CDGoal = 28800;
    }
    if  (RTC.getHours() == 8 && RTC.getMinutes() < 10) {  //To set 8:10
          CDGoal = 29400;
    }
    if  (RTC.getHours() == 8 && RTC.getMinutes() >= 10) { //To set 9am
          CDGoal = 32400;
    }
    if  (RTC.getHours() == 9 && RTC.getMinutes() < 50) {  //To set 9:50
          CDGoal = 35400;
    }
    if  (RTC.getHours() == 9 && RTC.getMinutes() >= 50||  //To set 10:10
         RTC.getHours() == 10 && RTC.getMinutes() < 10) {
          CDGoal = 36600;
    }
    if  (RTC.getHours() == 10 && RTC.getMinutes() >= 10) { //To set 11am
          CDGoal = 39600;
    }
    if  (RTC.getHours() == 11 && RTC.getMinutes() < 50) {  //To set 11:50
          CDGoal = 42600;
    }
    if  (RTC.getHours() == 11 && RTC.getMinutes() >= 50|| //To set 12:50
         RTC.getHours() == 12 && RTC.getMinutes() < 50) {
          CDGoal = 46200;
    }
    if  (RTC.getHours() == 12 && RTC.getMinutes() >= 50|| //To set 1:40
         RTC.getHours() == 13 && RTC.getMinutes() < 40){
          CDGoal = 49200;
    }
    if  (RTC.getHours() == 13 && RTC.getMinutes() >= 40||  //To set 2:30
         RTC.getHours() == 14 && RTC.getMinutes() < 30){
          CDGoal = 52200;
    }
    if  (RTC.getHours() == 14 && RTC.getMinutes() >= 30){ //To set 3pm
          CDGoal = 54000;
    }
    if  (RTC.getHours() >= 15 && RTC.getMinutes() <= 24) {
          CDGoal = 0;
    }
  }

  if (RTC.getWeek() >= 2 && RTC.getWeek() < 6 ) { /* To set 8am */  //Monday-Thursday Countdown Goal Setting
    if (RTC.getHours() < 8 && RTC.getHours() >= 0) {
          CDGoal = 28800;
    }
    if  (RTC.getHours() == 8 && RTC.getMinutes() < 10) {  //To set 8:10
          CDGoal = 29400;
    }
    if  (RTC.getHours() == 8 && RTC.getMinutes() >= 10) { //To set 9am
          CDGoal = 32400;
    }
    if  (RTC.getHours() == 9 && RTC.getMinutes() < 50) {  //To set 9:50
          CDGoal = 35400;
    }
    if  (RTC.getHours() == 9 && RTC.getMinutes() >= 50||  //To set 10:10
         RTC.getHours() == 10 && RTC.getMinutes() < 10) {
          CDGoal = 36600;
    }
    if  (RTC.getHours() == 10 && RTC.getMinutes() >= 10) { //To set 11am
          CDGoal = 39600;
    }
    if  (RTC.getHours() == 11 && RTC.getMinutes() < 50) {  //To set 11:50
          CDGoal = 42600;
    }
    if  (RTC.getHours() == 11 && RTC.getMinutes() >= 50|| //To set 12:50
         RTC.getHours() == 12 && RTC.getMinutes() < 50) {
          CDGoal = 46200;
    }
    if  (RTC.getHours() == 12 && RTC.getMinutes() >= 50|| //To set 1:40
         RTC.getHours() == 13 && RTC.getMinutes() < 40){
          CDGoal = 49200;
    }
    if  (RTC.getHours() == 13 && RTC.getMinutes() >= 40||  //To set 2:30
         RTC.getHours() == 14 && RTC.getMinutes() < 30){
          CDGoal = 52200;
    }
    if  (RTC.getHours() == 14 && RTC.getMinutes() >= 30){ //To set 3pm
          CDGoal = 54000;
    }
    if  (RTC.getHours() >= 15 && RTC.getMinutes() <= 24) {
          CDGoal = 0;
    }
  }
}

void RingBell() { //Bell activation function
  digitalWrite(relayPin, HIGH);
  delay(1500);
  digitalWrite(relayPin, LOW);
}

void CDLcdPrint() { //Countdown LCD Function
  if  (CDSeconds == 9) {
        lcd.clear();
  }
  if (CDGoal == 0) {
  lcd.backlight();
  lcd.setCursor(3,0);
  lcd.print("COUNTDOWN");
  lcd.setCursor(0,1);
  lcd.print("School day done");
  } else  {
  lcd.backlight();
  lcd.setCursor(3,0);
  lcd.print("COUNTDOWN");
  lcd.setCursor(4,1);
  lcd.print(CDHours);
  lcd.print(":");
  lcd.print(CDMinutes);
  lcd.print(":");
  lcd.print(CDSeconds);
  }
}

void DTLcdPrint() { //Date and Time LCD Function
  if  (RTC.getSeconds() == 0)  {
        lcd.clear();
      }
  lcd.backlight();
  lcd.setCursor(0,0);
  lcd.print("DATE : ");
  lcd.print(RTC.getMonth());
  lcd.print("/");
  lcd.print(RTC.getDay());
  lcd.print("/");
  lcd.print(RTC.getYear());
  lcd.setCursor(0,1);
  lcd.print("TIME : ");
  lcd.print(RTC.getHours());
  lcd.print(":");
  lcd.print(RTC.getMinutes());
  lcd.print(":");
  lcd.print(RTC.getSeconds());  //Time
}

void SerialPrint() { //Serial Print Info

  Serial.print(RTC.getWeek()); //DOW
  Serial.print(" ");
  Serial.print(RTC.getDay());
  Serial.print("/");
  Serial.print(RTC.getMonth());
  Serial.print("/");
  Serial.print(RTC.getYear());
  Serial.print(" ");
  Serial.print(RTC.getHours());
  Serial.print(":");
  Serial.print(RTC.getMinutes());
  Serial.print(":");
  Serial.print(RTC.getSeconds());
  Serial.print(" ");
  Serial.print(digitalRead(cdbuttonPin));
  Serial.print(" ");
  Serial.print(digitalRead(dtbuttonPin));
  Serial.print(" ");
  Serial.print(CDHours);
  Serial.print(":");
  Serial.print(CDMinutes);
  Serial.print(":");
  Serial.print(CDSeconds);
  Serial.print(" ");
  Serial.print(CDGoal);
  Serial.print(" ");
  Serial.println(CDNow);

}

void discardSerialData() { //Clear serial buffer

  while (Serial.available() > 0) {
    char c = Serial.read();
   
  }
}

void ArduinoTimedReset() {
        if (RTC.getHours() == 25 && RTC.getMinutes() == 0 && RTC.getSeconds() == 0|| //test line
            RTC.getHours() == 8 && RTC.getMinutes() == 5 && RTC.getSeconds() == 0||
            RTC.getHours() == 8 && RTC.getMinutes() == 35 && RTC.getSeconds() == 0||
            RTC.getHours() == 9 && RTC.getMinutes() == 25 && RTC.getSeconds() == 0||
            RTC.getHours() == 10 && RTC.getMinutes() == 0 && RTC.getSeconds() == 0||
            RTC.getHours() == 10 && RTC.getMinutes() == 35 && RTC.getSeconds() == 0||
            RTC.getHours() == 11 && RTC.getMinutes() == 25 && RTC.getSeconds() == 0||
            RTC.getHours() == 12 && RTC.getMinutes() == 20 && RTC.getSeconds() == 0||
            RTC.getHours() == 13 && RTC.getMinutes() == 15 && RTC.getSeconds() == 0||
            RTC.getHours() == 14 && RTC.getMinutes() == 5 && RTC.getSeconds() == 0||
            RTC.getHours() == 14 && RTC.getMinutes() == 45 && RTC.getSeconds() == 0||
            RTC.getHours() >= 15 && RTC.getMinutes() == 30 && RTC.getSeconds() == 0 && RTC.getHours() <= 24||
            RTC.getHours() >= 16 && RTC.getMinutes() == 0 && RTC.getSeconds() == 0 && RTC.getHours() <= 24||
            RTC.getHours() >= 0 && RTC.getMinutes() == 0 && RTC.getSeconds() == 0 && RTC.getHours() < 8||
            RTC.getHours() >= 0 && RTC.getMinutes() == 30 && RTC.getSeconds() == 0 && RTC.getHours() < 8) {
              asm volatile ("  jmp 0");
        }      
}

void CheckBell() {
    if (RTC.getWeek() >= 2 && RTC.getWeek() < 7 ) { //When to ring bell
    if (RTC.getHours() == 8 && RTC.getMinutes() == 0 && RTC.getSeconds() == 0||
        RTC.getHours() == 8 && RTC.getMinutes() == 10 && RTC.getSeconds() == 0||
        RTC.getHours() == 9 && RTC.getMinutes() == 0 && RTC.getSeconds() == 0||
        RTC.getHours() == 9 && RTC.getMinutes() == 50 && RTC.getSeconds() == 0||
        RTC.getHours() == 10 && RTC.getMinutes() == 10 && RTC.getSeconds() == 0||
        RTC.getHours() == 11 && RTC.getMinutes() == 0 && RTC.getSeconds() == 0||
        RTC.getHours() == 11 && RTC.getMinutes() == 50 && RTC.getSeconds() == 0||
        RTC.getHours() == 12 && RTC.getMinutes() == 50 && RTC.getSeconds() == 0||
        RTC.getHours() == 13 && RTC.getMinutes() == 40 && RTC.getSeconds() == 0||
        RTC.getHours() == 14 && RTC.getMinutes() == 30 && RTC.getSeconds() == 0||
        RTC.getHours() == 15 && RTC.getMinutes() == 0 && RTC.getSeconds() == 0) {
          RingBell();
          delay(1000);
          Serial.flush();
        }
  }
}

void loop() {
  ArduinoTimedReset();

  CDGoalSet();

  CDNow = ((RTC.getHours() * 3600UL) + (RTC.getMinutes() * 60UL) + RTC.getSeconds() );

  SerialPrint();

  CDTick = CDGoal - CDNow;
  CDHours = CDTick / 3600;
  CDMinutes = (CDTick % 3600) / 60;
  CDSeconds = CDTick % 60;

  CheckBell();

  if (millis() - lastDiscardTime >= discardInterval) { //Clear serial buffer 
    discardSerialData();
    lastDiscardTime = millis();
  }


  if (digitalRead(cdbuttonPin) == 1) { //Shows cooldown on LCD for 10 seconds then turns off LCD 
        startTime = millis();
        while (millis() - startTime <= duration) {
          CDNow = ((RTC.getHours() * 3600UL) + (RTC.getMinutes() * 60UL) + RTC.getSeconds() );
          CDTick = CDGoal - CDNow;
          CDHours = CDTick / 3600;
          CDMinutes = (CDTick % 3600) / 60;
          CDSeconds = CDTick % 60;
          CDLcdPrint();
          SerialPrint();
          delay(250);
          SerialPrint();
          delay(250);
          SerialPrint();
          delay(250);
          SerialPrint();
          delay(250);


        }
        lcd.noBacklight();
        lcd.clear();
  }

  if (digitalRead(dtbuttonPin) == 1) { //Shows date and time on LCD for 10 seconds then turns off LCD
        startTime = millis();
        while (millis() - startTime <= duration) {
          DTLcdPrint();
          SerialPrint();
          delay(250);
          SerialPrint();
          delay(250);
          SerialPrint();
          delay(250);
          SerialPrint();
          delay(250);



        }
        lcd.noBacklight();
        lcd.clear();
  }

  delay(250);
}