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

#define TEMP_PIN 13
#define HEATER   2
#define BUZZER   5

OneWire oneWire(TEMP_PIN);
DallasTemperature sensor(&oneWire);

void setup() {
  Serial.begin(115200);
  sensor.begin();
  pinMode(HEATER, OUTPUT);
  pinMode(BUZZER, OUTPUT);
  digitalWrite(HEATER, LOW);
  noTone(BUZZER);
}

void loop() {
  sensor.requestTemperatures();
  float t = sensor.getTempCByIndex(0);

  // Ignore invalid or out-of-range readings
  if (t == -127.0 || t == 85.0 || t < -50 || t > 125) {
    Serial.println("Invalid temperature reading. Skipping...");
    noTone(BUZZER);
    digitalWrite(HEATER, LOW);
    delay(1000);
    return;
  }

  String state;

  if (t >= 50) { // OVERHEAT
    state = "OVERHEAT";
    digitalWrite(HEATER, LOW);
    tone(BUZZER, 1000); // Beep sound
    delay(500);
    noTone(BUZZER);
    delay(500);
    return; // Keep beeping loop
  } 
  else if (t >= 45) { // TARGET
    state = "TARGET";
    digitalWrite(HEATER, LOW);
    noTone(BUZZER);
  } 
  else if (t >= 40) { // STABILIZING
    state = "STABILIZING";
    digitalWrite(HEATER, HIGH);
    noTone(BUZZER);
  } 
  else if (t >= 10) { // HEATING
    state = "HEATING";
    digitalWrite(HEATER, HIGH);
    noTone(BUZZER);
  } 
  else if (t<10){ // IDLE
    state = "IDLE";
    digitalWrite(HEATER, LOW);
    noTone(BUZZER);
  }

  Serial.print("Temp: ");
  Serial.print(t);
  Serial.print(" °C | State: ");
  Serial.println(state);

  delay(500);
}