#include<LiquidCrystal_I2C.h>
#include <RTClib.h>
#include <TimerOne.h>
#include <Keypad.h>

LiquidCrystal_I2C lcd(0x27,20,4);
RTC_DS1307 rtc;

const uint8_t ROWS = 4;
const uint8_t COLS = 3;
char key[ROWS][COLS] = {
  {'1','2','3'},
  {'4','5','6'},
  {'7','8','9'},
  {'*','0','#'}
};

uint8_t colPins[COLS] = {5,4,3};
uint8_t rowPins[ROWS] = {9,8,7,6};

Keypad keypad1(makeKeymap(key),rowPins,colPins,ROWS,COLS);

void setup() {
  Serial.begin(9600);
  rtc.begin();
  lcd.init();
  
  // 最初閃爍三次
  for (int i=0 ; i<2 ; i++)
  {
    lcd.backlight();
    delay(500);
    lcd.noBacklight();
    delay(500);
  }
  lcd.backlight();
  delay(500);

  lcd.print("myClock: S1152009");

  Timer1.initialize(10000);
  Timer1.attachInterrupt(setTime);
}

bool _update = false;
int millisec = 99;
int _hour = 23;
int _min = 59;
int _sec = 59;

// Emerge > 0 時顯示冒號，反之使冒號消失
void colonEmerge(int Emerge)
{
  if (Emerge)
  {
    lcd.setCursor(2,3);
    lcd.print(":");
    lcd.setCursor(5,3);
    lcd.print(":");
  }
  else
  {
    lcd.setCursor(2,3);
    lcd.print(" ");
    lcd.setCursor(5,3);
    lcd.print(" ");
  }
}

int mode = 1; // 1為正常倒數 2為分號消失 3為分號顯現
int cnt=0; // 數setTimeOrFlash 被呼叫幾次

void setTime()
{
  if (mode == 1)
  {
    if (millisec > 0) millisec--;
    else 
    {
      millisec = 99;
      if (_sec > 0) _sec--;
      else
      {
        _sec = 59;
        if (_min > 0) _min--;
        else
        {
          _min=59;
          if (_hour > 0) _hour--;
          else
          {
            millisec = 0;
            _hour = 0;
            _min = 0;
            _sec = 0;
          }
        }
      }
    }  
    _update = true;
  }
  else if (mode == 2 || mode == 3)
    cnt++;
}

int numOfInput = 0;

void loop() {
  DateTime now = rtc.now();

  char key = keypad1.getKey();

  if (key != NO_KEY)
  {
    if (key == '#')
      mode = 2;
    else if (key == '*')
    {
      mode = 1;
      
      lcd.setCursor(2,3);
      lcd.print(":");
      lcd.setCursor(5,3);
      lcd.print(":");
    }
    else
    {
      if (numOfInput == 0) // 先將小時、分、秒歸零
      {
        _hour = 0;
        _min = 0;
        _sec = 0;
      }

      if (numOfInput < 2)
      {
        lcd.setCursor(numOfInput,3);
        lcd.print(key);
        _hour += ((int)key - 48)*(numOfInput%2 == 0 ? 10 : 1);
      }
      else if (numOfInput < 4)
      {
        lcd.setCursor(numOfInput+1,3);
        lcd.print(key);
        _min += ((int)key - 48)*(numOfInput%2 == 0 ? 10 : 1);
      }
      else if (numOfInput < 6)
      {
        lcd.setCursor(numOfInput+2,3);
        lcd.print(key);
        _sec += ((int)key - 48)*(numOfInput%2 == 0 ? 10 : 1);
      }
      numOfInput++;

      numOfInput = (numOfInput == 6) ? 0 : numOfInput;
    }
    
  }

// 分號閃爍
  if (cnt >= 50)
  {
    if (mode == 2)
    {
      colonEmerge(0);
      mode = 3;
    } 
    else if (mode == 3)
    {
      colonEmerge(1);
      mode = 2;
    }
    cnt = 0; // 重新計時
  }

  lcd.setCursor(0,1);
  lcd.print(now.year());
  lcd.print('/');
  lcd.print((now.month() >= 10) ? "" : "0");
  lcd.print(now.month());
  lcd.print('/');
  lcd.print((now.day() >= 10) ? "" : "0");
  lcd.print(now.day());

  lcd.setCursor(0,2);
  lcd.print((now.hour() >= 10) ? "" : "0");
  lcd.print(now.hour());
  lcd.print(':');
  lcd.print((now.minute() >= 10) ? "" : "0");
  lcd.print(now.minute());
  lcd.print(':');
  lcd.print((now.second() >= 10) ? "" : "0");
  lcd.print(now.second());

  if (_update)
  {
    lcd.setCursor(0,3);
    lcd.print((_hour >= 10) ? "" : "0");
    lcd.print(_hour);
    lcd.print(':');
    lcd.print((_min >= 10) ? "" : "0");
    lcd.print(_min);
    lcd.print(':');
    lcd.print((_sec >= 10) ? "" : "0");
    lcd.print(_sec);
    lcd.print('.');
    lcd.print((millisec >= 10) ? "" : "0");
    // lcd.setCursor(11,3);
    // lcd.print(" ");
    lcd.setCursor(9,3);
    lcd.print(millisec);

    _update = false;
  }
}