// To switch between modes, comment or uncomment the next line:
#define TEST_WITH_RANDOM_VALUES

// --- PIN DEFINITIONS ---
const int SENSOR_PIN = 34;
const int LED_PIN = 22;
const int BUZZER_PIN = 21;

// --- ALARM SETTINGS ---
const float HIGH_TEMP_ALARM = 38.0;
const float LOW_TEMP_ALARM = 36.0;

// --- NTC THERMISTOR CHARACTERISTICS ---
const float SERIES_RESISTOR = 10000;
const float NOMINAL_RESISTANCE = 10000;
const float B_COEFFICIENT = 3950;
const float NOMINAL_TEMPERATURE = 25;

void setup() {
  Serial.begin(115200);
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  randomSeed(analogRead(0)); 

  #ifndef TEST_WITH_RANDOM_VALUES
    // If we are in REAL SENSOR mode, print the CSV header
    Serial.println("Timestamp (ms),Temperature (C),Alarm Status");
  #endif
}

void loop() {
  int adcValue;
  unsigned long timestamp = millis();

  #ifdef TEST_WITH_RANDOM_VALUES
    // Generate a wide-range random value
    adcValue = random(900, 3800); 
  #else
    // Use the real sensor
    adcValue = analogRead(SENSOR_PIN);
  #endif
  
  // --- CALCULATIONS (Same for both modes) ---
  if (adcValue == 0) return;
  float resistance = SERIES_RESISTOR * ((4095.0 / adcValue) - 1.0);
  float steinhart = log(resistance / NOMINAL_RESISTANCE) / B_COEFFICIENT + 1.0 / (NOMINAL_TEMPERATURE + 273.15);
  float tempC = (1.0 / steinhart) - 273.15;

  // --- ALARM LOGIC (Same for both modes) ---
  String alarmStatus = "OK";
  if (tempC > HIGH_TEMP_ALARM || tempC < LOW_TEMP_ALARM) {
    digitalWrite(LED_PIN, HIGH);
    digitalWrite(BUZZER_PIN, HIGH);
    alarmStatus = "ALARM";
  } else {
    digitalWrite(LED_PIN, LOW);
    digitalWrite(BUZZER_PIN, LOW);
  }
  
  // --- OUTPUT LOGIC (This is where it changes) ---
  #ifdef TEST_WITH_RANDOM_VALUES
    // Explanatory output for test mode
    Serial.println("--- RUNNING IN WIDE-RANGE RANDOM TEST MODE ---");
    Serial.print("Timestamp: ");
    Serial.print(timestamp);
    Serial.print(" ms");
    Serial.print("\t ADC: ");
    Serial.print(adcValue);
    Serial.print("\t Temp: ");
    Serial.print(tempC);
    
    if (alarmStatus == "ALARM") {
      Serial.println(" C --- ALARM ON!");
    } else {
      Serial.println(" C --- System OK");
    }
  #else
    // Clean CSV output for real mode
    Serial.print(timestamp);
    Serial.print(",");
    Serial.print(tempC);
    Serial.print(",");
    Serial.println(alarmStatus);
  #endif
  
  delay(1000); // A 1-second delay is good for readability
}