/**
   Arduino Calculator

   Copyright (C) 2020, Uri Shaked.
   Released under the MIT License.
*/

#include <LiquidCrystal.h>
#include <Keypad.h>
#include <Servo.h>
#include <MsTimer2.h>

/* Display */
LiquidCrystal lcd(12, 11, 10, 9, 8, 7);

/* Keypad setup */
const byte KEYPAD_ROWS = 4;
const byte KEYPAD_COLS = 4;
byte rowPins[KEYPAD_ROWS] = {5, 4, 3, 2};
byte colPins[KEYPAD_COLS] = {A3, A2, A1, A0};
char keys[KEYPAD_ROWS][KEYPAD_COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'h', '0', 'm', 's'}
};

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, KEYPAD_ROWS, KEYPAD_COLS);

bool timerPaused = true;
bool timerChange = false;
unsigned long long setTime = 0;
unsigned long long startTime;
unsigned long long Time = 0;
unsigned long long pausedTime=0;
unsigned long long psTime;
unsigned long long pfTime;
int h=0;
int m=0;
int s=0;
int x=0;
int y=0;
int count=0;

void showSpalshScreen() {
  lcd.print("LiuJingwen");
  lcd.setCursor(0, 1);
  String message = "20232241308";
  for (byte i = 0; i < message.length(); i++) {
    lcd.print(message[i]);
    delay(50);
  }
  delay(1000);
  lcd.clear();
}

void setup() {
  Serial.begin(9600);
  lcd.begin(16, 2);
  showSpalshScreen();
  MsTimer2::set(1000, timerInterrupt); // 1 second interrupt
  // MsTimer2::start();
}

void loop() {
  char key = keypad.getKey();
  if (key != NO_KEY) {
    handleKeyPress(key);
  }
  if(!timerPaused&&Time>0){
    updateDisplay();
  }
  else if(0==Time){
    lcd.setCursor(0, 0);
    lcd.print("Timer Time is up!");
    lcd.setCursor(0, 1);
    lcd.print("Reset ");
  }
}

void timerInterrupt() {
  unsigned long long curTime = millis();
  Time = setTime-(curTime-startTime-pausedTime);
  if(Time==0){
    timerPaused=true;
  }
}

void handleKeyPress(char key) {
  if (key == 'A') {
    if(setTime>0&&!timerChange&&timerPaused){
      pfTime=millis();
      timerPaused=false;
      pausedTime+=pfTime-psTime-1;
      pfTime=0;
      psTime=0;
      MsTimer2::start();
    }
    if(timerChange){
      setTime=1000ULL*(3600*h+60*m+s);
      startTime = millis();
      MsTimer2::start();
      h=0;
      m=0;
      s=0;
      lcd.setCursor(0, 1);
      lcd.print("Reset        ");
      lcd.setCursor(6, 1);
      timerPaused=false;
      timerChange=false;
    }
  } 
  else if (key == 'B') {
    if(!timerPaused){
      timerPaused=true;
      psTime=millis();
      MsTimer2::stop();
    }
  } 
  else if (key == 'C') {
    setTime=0;
    Time=0;
    x=0;
    y=0;
    pausedTime=0;
    timerPaused=true;
    lcd.setCursor(0, 1);
    lcd.print("Reset        ");
    lcd.setCursor(6, 1);
  } 
  else if (key == 'h') {
    if(count){
      h=10*x+y;
      x=0;
      y=0;
      timerChange=true;
      count=0;
    }
  } 
  else if (key == 'm') {
    if(count){
      m=10*x+y;
      x=0;
      y=0;
      timerChange=true;
      count=0;
    }
  } 
  else if (key == 's') {
    if(count){
      s=10*x+y;
      x=0;
      y=0;
      timerChange=true;
      count=0;
    }
  } 
  else {
    if(count<2){
      lcd.setCursor(6+count++, 1);
      lcd.print(key);
      x=y;
      y=key-'0';
    }
  }
}

void updateDisplay() {
  // if(Time>=1ULL){
    int hours = (Time /3600000) ;
    int minutes = (Time % 3600000)/60000;
    int seconds = (Time -hours*3600000-minutes*60000) / 1000;
    lcd.setCursor(0, 0);
    lcd.print("Timer ");
    if (hours < 10) 
      lcd.print("0");
    lcd.print(hours);
    lcd.print(":");
    if (minutes < 10) 
      lcd.print("0");
    lcd.print(minutes);
    lcd.print(":");
    if (seconds < 10) 
      lcd.print("0");
    lcd.print(seconds);
    lcd.print("  ");
}