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

RTC_DS1307 rtc;

//  lcd object : setting register address 0x27
LiquidCrystal_I2C lcd(0x27, 20, 4);

// clock variables 
int year=0;
int month=0;
int day=0;
int hour=0;
int minute=0;
int second=0;


//  encoder variables
byte clk = 2;
byte dt = 3;
byte sw = 4;

ezButton button(sw);

//  counting rotations
int counter = 0;
int prev_counter = -1;
int flag = 1;

//String rtc_date = "";
//String rtc_time = "";

void setup() {

  Serial.begin(9600);

  //  initializing LCD
  lcd.init();  //  initialize the lcd.
  lcd.clear();  //  clears the screen and moves the cursor to the top left corner.
  lcd.backlight();  //  turn on the backlight.

  //  initial messages
  lcd.clear();
  lcd_print(0, 0, "RTC found");
  delay(1000);
  lcd_print(0, 0, "Hi i am Cuckoo!");
  delay(2000);
   if (!rtc.begin()) {
  //   Serial.println("RTC not initialised");
     while (true);
   }
  // Serial.println("RTC found");

  attachInterrupt(digitalPinToInterrupt(clk), encoder, FALLING);

  button.setDebounceTime(25);
}

void encoder() {
  prev_counter = counter;
  if (digitalRead(dt)  ==  HIGH)counter++;
  else counter--;
  counter = constrain(counter, 0, 3);
  flag = 1;
}

void mode_selector() {

  if (prev_counter != counter  &&  flag  ==  1) {
    if (counter  ==  0) {
      lcd.clear();
      lcd_print(0, 0, "Date and Time");
    }
    else if (counter  ==  1) {
      lcd.clear();
      lcd_print(0, 0, "Set Alarm");
    }
    else if (counter  ==  2) {
      lcd.clear();
      lcd_print(0, 0, "Stopwatch");
    }
    else if (counter  ==  3) {
      lcd.clear();
      lcd_print(0, 0, "Countdown Timer");
    }
    flag = 0;
  }
}



void loop() {

  button.loop();
  if (button.isPressed())
    select_mode();

  mode_selector();

  //  for better working of simulator
  delay(10);
}



void select_mode(){
 if (counter  ==  0)get_time();
 else if (counter  ==  1)set_alarm();
 else if (counter  ==  2)stopwatch();
 else countdown();
}

void get_time(){
 while(true){
  button.loop();
  if(button.isPressed()){
    lcd.clear();
    prev_counter=-1;
    flag=1;
    break;
  }
  current_time();
  String current_date="Date: "+ String(day)+"/"+ String(month)+"/"+ String(year);
  String current_time="Time: "+String(hour)+":"+String(minute)+":"+String(second);
  lcd_print(0,0,"DATE AND TIME");
  lcd_print(0,1,current_date);
  lcd_print(0,2,current_time);
  }
}
 
void set_alarm(){
 
}

void stopwatch(){
 int stopwatch_hour,stopwatch_min,stopwatch_sec=0;
 int last_second=0;
 while(true){
  button.loop();
  if(button.isPressed()){
    prev_counter=-1;
    flag=1;
    delay(5000);
    lcd.clear();
    break;
  }
  current_time();
  if(abs(second-last_second)>=1){
    last_second=second;
    String stopwatch_time= String(stopwatch_hour)+":"+String(stopwatch_min)+":"+String(stopwatch_sec);
    lcd.clear();
    lcd_print(0,0,"STOPWATCH");
    lcd_print(0,1,String(stopwatch_time));
    stopwatch_sec++;
  }
  if(stopwatch_sec>59){
    stopwatch_sec=0;
    stopwatch_min++;
  }
  else if(stopwatch_min>59){
    stopwatch_min=0;
    stopwatch_hour++;
  }
  else if(stopwatch_hour>24){
    stopwatch_min,stopwatch_sec,stopwatch_hour=0;
  }
 }
}
 
void countdown(){
 
}


void lcd_print(int x, int y, String message) {
  lcd.setCursor(x, y);
  lcd.print(message);
}

void current_time(){
  DateTime current=rtc.now();
  year=current.year();
  month=current.month();
  day=current.day();
  hour=current.hour();
  minute=current.minute();
  second=current.second();
}