#include<RTClib.h>
#include<ezButton.h>
#include <LiquidCrystal_I2C.h>
RTC_DS1307 rtc;
LiquidCrystal_I2C lcd(0x27, 20, 4);
//  encoder variables
byte clk = 2;
byte dt = 3;
byte sw = 4;
int year = 0;
int month = 0;
int day = 0;
int hour = 0;
int minute = 0;
int second = 0;
ezButton button(sw);

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

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

void setup() {

  Serial.begin(9600);
  lcd.init();
  lcd.clear();
  lcd.backlight();
  lcdPrint(0, 0, "RTC FOUND");
  delay(1000);
  lcdPrint(0, 0, "Hi Im a clock");
  delay(1000);
  // 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();
      lcdPrint(0, 0, "Date and Time");
    }
    else if (counter  ==  1) {
      lcd.clear();
      lcdPrint(0, 0, "Set Alarm");

    }
    else if (counter  ==  2) {
      lcd.clear();
      lcdPrint(0, 0, "Stopwatch");

    }
    else if (counter  ==  3) {
      lcd.clear();
      lcdPrint(0, 0, "Countdown Timer");

    }
    flag = 0;
  }
}



void loop() {

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

  //  RTC date and time
  // DateTime dt = rtc.now();
  // rtc_date = get_date(dt);
  // // Serial.println(rtc_date);
  // rtc_time = get_time(dt);
  // Serial.println(rtc_time);
  mode_selector();

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

String get_time() {
while (true){
  button.loop();
  if(button.isPressed()){
lcd.clear();
prev_counter = -1;
flag = 1;
break;
  }
 currentTime();
  String current_time = "Time : " + String(hour) + ":" + String(minute) +
                        ":" + String(second);
                        
  String current_date = "Date : " + String(day) + "/" + String(month) +
                        "/" + String(year);
  

  lcdPrint(0,0,"Date & Time");
  lcdPrint(0,1,current_date);
  lcdPrint(0,2,current_time);

   }
}

String get_date(DateTime current) {

  int year = current.year();
  int month = current.month();
  int day = current.day();

}

void select_mode() {
  if (counter  ==  0)get_time();
  else if (counter  ==  1)setAlarm();
  else if (counter  ==  2)stopwatch();
 else { countdown();}
}
void lcdPrint(int x, int y, String message) {
  lcd.setCursor(x, y);
  lcd.print(message);
}

void setAlarm(){

}

void stopwatch(){
  int lastSecond = 0;
while (true){
  button.loop();
  if (button.isPressed()){
    prev_counter = -1
    flag = 1;
    delay(5000);
    lcd.clear();
    break;
  
}
currentTime();
if (abs(second-lastSecond)>=1){
  lastSecond = second;
  String stopwatchTime =  String(stopwatchH) + ":" + String(stopwatchM) +
                        ":" + String(stopwatchS);
lcd.clear();
lcdPrint(0,0,"StopWatch");
lcdPrint(0,1,String (stopwatchTime));
stopwatchS ++;

  }
  if (stopwatchS > 59){
    stopwatchM ++;
    stopwatchS = 0;
  }
    else if (stopwatchM > 59){
    stopwatchH ++;
    stopwatchM = 0;
  }
   else if (stopwatchH > 23){
    stopwatchH = 0;
    stopwatchM = 0;
    stopwatchS = 0;
  }
 }
}

void countdown(){

}

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