// Pin number for the thermistor
const int thermistorPin = 35;

// Thermistor parameters
const double thermistorNominal = 10000.0;
const double temperatureNominal = 25.0;
const double betaCoefficient = 3950.0;
const double seriesResistor = 10000.0;

// Duration settings
const unsigned long timerDuration = 14400000;   // 4 hours in milliseconds
const unsigned long rollingAverageDuration = 600000;   // 10 minutes in milliseconds

// Variables for tracking time
unsigned long startTime;
unsigned long lastAverageTime;
unsigned long lastPrintedTime;
unsigned long currentTime;
unsigned long elapsedTime;

// Array to store temperature readings
int temperatureData[240 * 60]; // Store 1 value per second for 4 hours
int dataCount = 0;

// Variables for temperature statistics
double maxTemperature = -273.15;  // Initialize to absolute zero
double minTemperature = 1000.0;   // Initialize to a high value
double totalTemperature = 0.0;    // Initialize the sum of temperatures

void setup() {
  // Initialize serial communication
  Serial.begin(38400);

  // Record the start time
  startTime = millis();
  
  // Initialize the last recorded average time and last printed time
  lastAverageTime = startTime;
  lastPrintedTime = startTime;
}

// Function to calculate the rolling average of temperature
double calculateRollingAverage() {
  double allData = 0;
  int numSamples = dataCount;

  // Limit the number of samples for the rolling average
  if (numSamples > rollingAverageDuration / 1000) {
    numSamples = rollingAverageDuration / 1000;
  }

  // Calculate the sum of the selected samples
  for (int i = 0; i < numSamples; ++i) {
    allData += temperatureData[dataCount - 1 - i];
  }

  // Calculate the average
  double average = allData / numSamples;
  return average;
}

void loop() {
  // Get the current time and elapsed time
  currentTime = millis();
  elapsedTime = currentTime - startTime;

  // Check if the 4-hour duration has been reached
  if (elapsedTime >= timerDuration) {
    // 4-hour duration reached, stop the program

    // Print highest temperature
    Serial.print("Highest temperature: ");
    Serial.println(maxTemperature);

    // Print lowest temperature
    Serial.print("Lowest temperature: ");
    Serial.println(minTemperature);

    // Calculate and print overall average temperature
    double averageTemperature = totalTemperature / dataCount;
    Serial.print("Overall average temperature: ");
    Serial.println(averageTemperature);

    // Exit the loop and end the program
    return;
  }

  // Check if it's time to calculate the rolling average
  if (currentTime - lastAverageTime >= rollingAverageDuration) {
    // Time to calculate rolling average
    double rollingAvg = calculateRollingAverage();

    // Print the rolling average
    Serial.print("10-minute Rolling average: ");
    Serial.println(rollingAvg);

    // Update the last recorded average time
    lastAverageTime = currentTime;
  }

  // Check if it's time to record and print a new temperature reading
  if (currentTime - lastPrintedTime >= 1000 && dataCount < (timerDuration / 1000)) {
    // Read and record temperature every second

    // Read the raw value from the thermistor
    int rawValue = analogRead(thermistorPin);

    // Calculate the resistance of the thermistor
    double resistance = seriesResistor * (4095.0 / rawValue - 1.0);

    // Calculate the temperature using the Steinhart-Hart equation
    double steinhart;
    steinhart = resistance / thermistorNominal;
    steinhart = log(steinhart);
    steinhart /= betaCoefficient;
    steinhart += 1.0 / (temperatureNominal + 273.15);
    steinhart = 1.0 / steinhart;
    steinhart = steinhart - 273.15;
    steinhart = steinhart * 1.80;

    // Convert the temperature to Celsius
    double temperature = steinhart + 30.0;

    // Update the maximum temperature if needed
    if (temperature > maxTemperature) {
      maxTemperature = temperature;
    }

    // Update the minimum temperature if needed
    if (temperature < minTemperature) {
      minTemperature = temperature;
    }

    // Add the temperature to the total sum
    totalTemperature += temperature;

    // Store the temperature reading in the array
    temperatureData[dataCount] = temperature;
    ++dataCount;

    // Print the current temperature
    Serial.println(temperature);

    // Update the last printed time
    lastPrintedTime = currentTime;
  }
}