#include <LiquidCrystal.h>
#include <DallasTemperature.h>
#include <OneWire.h>

#define CHNG_TEMP 6
#define TEMP_INC 5
#define TEMP_DEC 4
#define RELAY 3
#define DELAY 300
#define DISPLAY_DELAY 100
#define TEMP_DELAY 100
#define ARROW_BLINK_DELAY 500

#define RS 12
#define E 11
#define D4 10
#define D5 9
#define D6 8
#define D7 7
#define DS18B20 2

LiquidCrystal lcd(RS, E, D4, D5, D6, D7);
OneWire ds(DS18B20);

uint8_t circle[8] = 
{
  0b01100,
  0b10010,
  0b10010,
  0b01100,
  0b00000,
  0b00000,
  0b00000,
  0b00000,
};

void setup() 
{
  lcd.begin(16, 2);
  lcd.createChar(3, circle);
  pinMode(DS18B20, INPUT);
  pinMode(RELAY, OUTPUT);
  pinMode(CHNG_TEMP, INPUT);
  pinMode(TEMP_INC, INPUT);
  pinMode(TEMP_DEC, INPUT);
}

float temperature = 0;
float referenceTemp = 0;
float deadzone = 0;
bool enableChngOfTemp = false;
bool BUTT = false;
bool BUTT_FLAG = false;
bool ARROW_BLINK_FLAG = true;
bool FIRST_START = true;

static uint32_t buttTimer = millis();
static uint32_t buttTimer_2 = millis();
static uint32_t displayTimer = millis();
static uint32_t arrowBlink_timer = millis();

void loop() 
{
  static uint32_t timer = millis();
  byte data[2];
  
  ds.reset();
  ds.write(0xCC);
  ds.write(0x44);

  oneClick(CHNG_TEMP, buttTimer);
  changeRefTemp(enableChngOfTemp, buttTimer_2);
  
  if((millis() - timer) >= TEMP_DELAY)
  {
    timer = millis();

    ds.reset();
    ds.write(0xCC); 
    ds.write(0xBE);
    data[0] = ds.read();
    data[1] = ds.read();
    temperature =  ((data[1] << 8) | data[0]) * 0.5;
  }

  if(temperature != 0 && FIRST_START == true)
  {
    referenceTemp = temperature;
    FIRST_START = false;
  }

  referenceTemp = constrain(referenceTemp, -55, 60);

  if((millis() - displayTimer) >= DISPLAY_DELAY)
  {
    lcd.setCursor(0,0);
    lcd.print("Temp:");
    lcd.print(temperature);
    lcd.print("C\x03");

    if(enableChngOfTemp)
    {
      int analog = analogRead(A0);
      deadzone = map(analog, 0, 1023, 0, 300);
      deadzone /= 100;

      lcd.setCursor(14, 0);
      lcd.print("DZ");
      lcd.setCursor(13, 1);
      lcd.print(deadzone);

      lcd.setCursor(0,1);
      if((millis() - arrowBlink_timer) >= ARROW_BLINK_DELAY)
      {
        if(ARROW_BLINK_FLAG)
        {
          lcd.print(">");
          ARROW_BLINK_FLAG = !ARROW_BLINK_FLAG;
        }
        else
        {
          lcd.print(" ");
          ARROW_BLINK_FLAG = !ARROW_BLINK_FLAG;
        }
        arrowBlink_timer = millis();
      }
      lcd.setCursor(1,1);
      lcd.print("RefT:");
      lcd.print(referenceTemp);
      lcd.print("C\x03");
    }
    else
    {
      lcd.setCursor(0,1);
      lcd.print("RefT:");
      lcd.print(referenceTemp);
      lcd.print("C\x03      ");

      lcd.setCursor(14, 0);
      lcd.print("  ");
    }
    displayTimer = millis();
  }

  if(temperature >= (referenceTemp + deadzone))
    digitalWrite(RELAY, LOW);
  else if(temperature <= (referenceTemp - deadzone))
    digitalWrite(RELAY, HIGH);
}

void oneClick(short BUTTON_PIN, uint32_t timer)
{
  BUTT = digitalRead(BUTTON_PIN); 

  if((millis() - timer) >= DELAY)
  {
    if(!BUTT_FLAG && BUTT)
    {
      BUTT_FLAG = true; 
      enableChngOfTemp = !enableChngOfTemp;
    }
    buttTimer = millis();
  }

  if(!BUTT && BUTT_FLAG)
  {
    BUTT_FLAG = false;
  }
}

void changeRefTemp(bool buttEnable, uint32_t timer)
{
  if(buttEnable)
  {
    if((millis() - timer) >= DELAY)
    {
      if(digitalRead(TEMP_INC))
        referenceTemp = referenceTemp + 0.5;

      if(digitalRead(TEMP_DEC))
        referenceTemp = referenceTemp - 0.5;
      buttTimer_2 = millis();
    }
  }
}