#include <RTClib.h>
#include <ezButton.h>
 
byte CLK = 2;
byte DT = 3;
byte SW = 4;
int prev_count = 0;
int counter = 0;
int flag = 0;
ezButton button(SW);

RTC_DS1307 rtc;
String rtc_date = "";
String rtc_time = ""; 

void setup() {
  Serial.begin(9600);
  if (!rtc.begin()){
    //Serial.println("RTC has not been initialised");
    while(1);
  }
  //Serial.println("RTC found");
  attachInterrupt(digitalPinToInterrupt(CLK), encoder, FALLING);
  button.setDebounceTime(25);
  
}

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

void mode_selector(){
  if (flag == 1 && prev_count != counter){
    if (counter == 0){
      Serial.println("Date and Time");
    }
    else if (counter == 1){
      Serial.println("Set Alarm");
    }
    else if (counter == 2){
      Serial.println("Stopwatch");
    }
    else if (counter == 3){
      Serial.println("Timer");
    }

    flag = 0;
  }
}

void loop() {
  if (button.isPressed()) select_mode();
  //DateTime dt = rtc.now();
  //rtc_date = get_date(dt);
  //rtc_time = get_time(dt);
  //Serial.println(rtc_date);
  //Serial.println(rtc_time);
  mode_selector();
  delay(100);
}

void select_mode(){
  if (counter == 0) Serial.println("Date and Time");
  if (counter == 1) Serial.println("Set Alarm");
  if (counter == 2) Serial.println("Stopwatch");
  if (counter == 3) Serial.println("Timer");
}

String get_date(DateTime dt){
  int day = dt.day();
  int month = dt.month();
  int year = dt.year();
  String current_date = "Date : " + String(day) + "/" + String(month) + "/" + String(year);
  return current_date;
}

String get_time(DateTime dt){
  int hour = dt.hour();
  int minute = dt.minute();
  int second = dt.second();
  String current_time = "Time : " + String(hour) + ":" + String(minute) + ":" + String(second);
  return current_time;
}