#include <Wire.h>
#include "RTClib.h"
#include <LiquidCrystal_I2C.h>
RTC_DS1307 DS1307;
LiquidCrystal_I2C LCD(0x27,16,2);
DateTime datumCas;
byte SET = 9, UP = 10, DOWN = 11,page = 0;
long refreshLimit,blinkLimit;
bool MenuShowed = false, ON=true;

int hour,minute,day,month,year,interval = 250,del = 150;
void setup () {
  LCD.init();
  LCD.backlight();
  for(int i = 9; i <12; i++){
    pinMode(i,INPUT_PULLUP);
  }

  if (! DS1307.begin()) {
    LCD.print("NEpripojeno!");
    while (1);
  }

  if (! DS1307.isrunning()) {
    LCD.print("NEspusteny!");
  }
  DS1307.adjust(DateTime(__DATE__,__TIME__)); 
}

void loop () {
datumCas = DS1307.now();

if(((millis()-interval)>refreshLimit) && !MenuShowed){
  refreshLimit = millis();
  Show();
}

if(!digitalRead(SET) ){
  MenuShowed = true;
  page = 1;
  hour = datumCas.hour();
  minute = datumCas.minute();
  day = datumCas.day();
  year= datumCas.year();
  month=datumCas.month();
  delay(del);
}

if(MenuShowed){
    switch(page){
    case 1: Page1();break;//h
    case 2: Page2();break;//m
    case 3: Page3();break;//d
    case 4: Page4();break;//m
    case 5: Page5();break;//y
    case 6: OKScreen();break;
      }
  }
}

void Show(){
 
if((millis()-blinkLimit)>500){
  ON=!ON;
  blinkLimit = millis();
}

  LCD.setCursor(0,0);
  LCD.print("    ");
  LCD.print(datumCas.hour() < 10? "0"+String(datumCas.hour()) : datumCas.hour() );
  ON == true?LCD.print(':'): LCD.print(' ');
  LCD.print(datumCas.minute() < 10? "0"+String(datumCas.minute()) : datumCas.minute());
  ON == true?LCD.print(':'): LCD.print(' ');
  LCD.print(datumCas.second() < 10? "0"+String(datumCas.second()):datumCas.second());
  LCD.print("        ");
  LCD.setCursor(0,1);
   LCD.print("   ");
  LCD.print(datumCas.day() < 10? "0"+String(datumCas.day()):datumCas.day());
  LCD.print('.');
  LCD.print(datumCas.month()< 10? "0"+String(datumCas.month()):datumCas.month());
  LCD.print('.');
  LCD.print(datumCas.year() < 10? "0"+String(datumCas.year()):datumCas.year());
  LCD.println("     ");
}

void Page1(){
  LCD.setCursor(0,0);
  LCD.print("SET TIME: HOUR    " );
  LCD.setCursor(0,1);
  LCD.print(hour < 10? "0"+String(hour) : hour );
  LCD.print(':');
  LCD.print(minute < 10? "0"+String(minute) : minute);
  LCD.print("         ");

  if(!digitalRead(UP)){
    hour++;
    hour> 23 ? hour = 0: hour;
    hour < 0 ? hour = 23 : hour;
    delay(del);
  }

  
  if(!digitalRead(DOWN)){
    hour--;
    hour> 23 ? hour = 0: hour;
    hour < 0 ? hour = 23 : hour;
    delay(del);
  }

  if(MenuShowed && !digitalRead(SET)){
    page = 2;
    delay(250);
    Page2();    
  }
  }

  void Page2(){
  LCD.setCursor(0,0);
  LCD.print("SET TIME: MINUTE  " );
  LCD.setCursor(0,1);
  LCD.print(hour < 10? "0"+String(hour) : hour );
  LCD.print(':');
  LCD.print(minute < 10? "0"+String(minute) : minute);
  LCD.print("      ");

  if(!digitalRead(UP)){
    minute++;
    minute> 59 ? minute = 0: minute;
    minute < 0 ? minute = 59 : minute;
    delay(del);
  }
  
  if(!digitalRead(DOWN)){
    minute--;
    minute> 59 ? minute = 0: minute;
    minute < 0 ? minute = 59 : minute;
    delay(del);
  }

  if(MenuShowed && !digitalRead(SET)){

  delay(250);
  page = 3;
  Page3();
  }
}

  void Page3(){
  LCD.setCursor(0,0);
  LCD.print("SET TIME: DAY    " );
  LCD.setCursor(0,1);
  LCD.print(day < 10? "0"+String(day) : day );
  LCD.print('.');
  LCD.print(month < 10? "0"+String(month) : month);
  LCD.print('.');
  LCD.print(year < 10? "0"+String(year) : year);
  LCD.print("      ");

  if(!digitalRead(UP)){
    day++;
    day> 31 ? day = 1: day;
    day < 1 ? day = 31 : day;
    delay(del);
  }
  
  if(!digitalRead(DOWN)){
    day--;
    day> 31 ? day = 1: day;
    day < 1 ? day = 31 : day;
    delay(del);
  }

  if(MenuShowed && !digitalRead(SET)){

  delay(250);
  page = 4;
  Page4();
  }
}

 void Page4(){
  LCD.setCursor(0,0);
  LCD.print("SET TIME: MONTH  " );
  LCD.setCursor(0,1);
  LCD.print(day < 10? "0"+String(day) : day );
  LCD.print('.');
  LCD.print(month < 10? "0"+String(month) : month);
  LCD.print('.');
  LCD.print(year < 10? "0"+String(year) : year);
  LCD.print("      ");

  if(!digitalRead(UP)){
     month++;
        month> 12 ? month = 1: month;
    month < 1 ? month = 12 : month;
   
    delay(del);
  }
  
  if(!digitalRead(DOWN)){
    month--;
    month> 12 ? month = 1: month;
    month < 1 ? month = 12 : month;
    

    delay(del);
  }

  if(MenuShowed && !digitalRead(SET)){
  delay(250);
  page = 5;
  Page5();
  }
}

 void Page5(){
  LCD.setCursor(0,0);
  LCD.print("SET TIME: YEAR  " );
  LCD.setCursor(0,1);
  LCD.print(day < 10? "0"+String(day) : day );
  LCD.print('.');
  LCD.print(month < 10? "0"+String(month) : month);
    LCD.print('.');
  LCD.print(year < 10? "0"+String(year) : year);
  LCD.print("      ");

  if(!digitalRead(UP)){
    year++;
    delay(del);
  }
  
  if(!digitalRead(DOWN)){
    year--;
    delay(del);
  }

  if(MenuShowed && !digitalRead(SET)){
  delay(250);
  page = 6;
  OKScreen();
  }
}

void OKScreen(){
  LCD.clear();
  LCD.setCursor(0,0);
  LCD.print("       OK     ");
  page = 0;
  DS1307.adjust(DateTime(year, month, day, hour, minute, 0));
  delay(400);
  MenuShowed = false;
  Show();
}