#include <DHT.h>

#define DHTPIN 2
#define DHTTYPE DHT22
#define HEATER_PIN 3
#define LED_PIN 13

DHT dht(DHTPIN, DHTTYPE);

enum HeaterState {
  IDLE,
  HEATING,
  STABILIZING,
  TARGET_REACHED,
  OVERHEAT
};

HeaterState currentState = IDLE;

void setup() {
  Serial.begin(9600);
  pinMode(HEATER_PIN, OUTPUT);
  pinMode(LED_PIN, OUTPUT);
  dht.begin();
}

void loop() {
  float temp = dht.readTemperature();

  if (isnan(temp)) {
    Serial.println("Failed to read temperature!");
    return;
  }

  if (temp < 25) currentState = IDLE;
  else if (temp < 45) currentState = HEATING;
  else if (temp < 48) currentState = STABILIZING;
  else if (temp <= 50) currentState = TARGET_REACHED;
  else currentState = OVERHEAT;

  switch (currentState) {
    case IDLE:
      digitalWrite(HEATER_PIN, LOW);
      digitalWrite(LED_PIN, LOW);
      Serial.print("State: IDLE | ");
      break;
    case HEATING:
      digitalWrite(HEATER_PIN, HIGH);
      digitalWrite(LED_PIN, HIGH);
      Serial.print("State: HEATING | ");
      break;
    case STABILIZING:
      digitalWrite(HEATER_PIN, HIGH);
      digitalWrite(LED_PIN, HIGH);
      Serial.print("State: STABILIZING | ");
      break;
    case TARGET_REACHED:
      digitalWrite(HEATER_PIN, LOW);
      digitalWrite(LED_PIN, LOW);
      Serial.print("State: TARGET REACHED | ");
      break;
    case OVERHEAT:
      digitalWrite(HEATER_PIN, LOW);
      digitalWrite(LED_PIN, LOW);
      Serial.print("State: OVERHEAT! | ");
      break;
  }

  Serial.print("Temp: ");
  Serial.print(temp);
  Serial.println(" °C");

  delay(2000);
}