#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <OneWire.h>
#include <DallasTemperature.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

const int buttonStart = 2;
const int buttonStop = 3;
const int buttonAddTime = 4;
const int oneWireBus = 5;  // DS18B20 pripojený na pin 5
OneWire oneWire(oneWireBus);
DallasTemperature sensors(&oneWire);

int cookingTime = 0;
bool isCooking = false;
unsigned long previousMillis = 0;
unsigned long previousCookingMillis = 0;
const long interval = 1000;

void setup() {
  // Nastavenie pinov pre tlačidlá pomocou registrov
  DDRD &= ~(1 << PD2); // buttonStart ako vstup (PD2)
  PORTD |= (1 << PD2); // zapnutie vnútorného pull-up rezistora pre PD2
  DDRD &= ~(1 << PD3); // buttonStop ako vstup (PD3)
  PORTD |= (1 << PD3); // zapnutie vnútorného pull-up rezistora pre PD3
  DDRD &= ~(1 << PD4); // buttonAddTime ako vstup (PD4)
  PORTD |= (1 << PD4); // zapnutie vnútorného pull-up rezistora pre PD4

  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.print("Smart Microwave");
  display.display();
  
  sensors.begin();
}

void loop() {
  unsigned long currentMillis = millis();

  // Kontrola tlačidiel
  if (!(PIND & (1 << PD4))) { // buttonAddTime je stlačené
    if (currentMillis - previousMillis >= 200) {
      previousMillis = currentMillis;
      cookingTime += 30;  // pridá 30 sekúnd
    }
  }

  if (!(PIND & (1 << PD2)) && cookingTime > 0) { // buttonStart je stlačené
    isCooking = true;
  }

  if (!(PIND & (1 << PD3))) { // buttonStop je stlačené
    isCooking = false;
    cookingTime = 0;
  }

  // Aktualizácia času varenia
  if (isCooking && currentMillis - previousCookingMillis >= interval) {
    previousCookingMillis = currentMillis;
    if (cookingTime > 0) {
      cookingTime--;
    } else {
      isCooking = false;
    }
  }

  sensors.requestTemperatures();
  float temperature = sensors.getTempCByIndex(0);

  display.clearDisplay();
  display.setCursor(0, 0);
  display.print("Time: ");
  display.print(cookingTime);
  display.print(" s");
  display.setCursor(0, 20);
  display.print("Temp: ");
  display.print(temperature);
  display.print(" C");
  display.setCursor(0, 40);
  display.print(isCooking ? "Cooking..." : "Stopped");
  display.display();
}