#define CMD_START_RECORDING 's'
#define CMD_DISPLAY_AVERAGES 'd'

int sensor = 27;
int sampleCount = 0;
int totalSum = 0;
unsigned long measurementPeriod = 1000;  // 1 second
unsigned long lastMeasurement = 0;
int lowest = 100;  // start with the maximum possible percentage
int highest = 0;  // start with the minimum possible percentage
int tenSecs[6] = {0, 0, 0, 0, 0, 0};
int intervalCount = 0;
bool recordingMode = false;
String outputBuffer = "";

void setup() {
  Serial.begin(9600);
  Serial.println("Program starting...");
}

void loop() {
  if (Serial.available() > 0) {
    char cmd = Serial.read();
    if (cmd == CMD_START_RECORDING) {
      recordingMode = true;
      sampleCount = 0;
      totalSum = 0;
      lastMeasurement = millis();
      lowest = 100;
      highest = 0;
      memset(tenSecs, 0, sizeof(tenSecs));
      intervalCount = 0;
      outputBuffer = "";
    } else if (cmd == CMD_DISPLAY_AVERAGES) {
      recordingMode = false;
      calculateAndDisplayAverages();
    }
  }

  if (recordingMode) {
    unsigned long currentMillis = millis();
    if (currentMillis - lastMeasurement >= measurementPeriod) {
      int soil = analogRead(sensor);
      int soilPercent = map(soil, 4095, 2076, 0, 100);
      soilPercent = constrain(soilPercent, 0, 100);

      totalSum += soilPercent;
      sampleCount++;
      if (soilPercent > highest) highest = soilPercent;
      if (soilPercent < lowest) lowest = soilPercent;
      outputBuffer += String((currentMillis - lastMeasurement) / 1000) + "," + String(soilPercent) + "\n";

      tenSecs[intervalCount] += soilPercent;
      if (sampleCount % 10 == 0) intervalCount++;

      if (soilPercent >= 80) {
        Serial.println("Enough water for plant.");
      } else if (soilPercent <= 40) {
        Serial.println("Water level is low.");
      } else {
        Serial.println("Water level is OK.");
      }

      Serial.print("Raw Soil Moisture: ");
      Serial.println(soil);
      Serial.print("Soil Moisture Percentage: ");
      Serial.println(soilPercent);

      lastMeasurement = currentMillis;
    }
  }
}

void calculateAndDisplayAverages() {
  Serial.println("Sample,10 sec interval average (%)");
  for (int i = 0; i < 6; i++) {
    int intervalAverage = tenSecs[i] / 10;
    Serial.println("Interval " + String(i + 1) + "," + String(intervalAverage));
  }

  int average = totalSum / sampleCount;
  Serial.println("Highest Value: " + String(highest));
  Serial.println("Lowest Value: " + String(lowest));
  Serial.println("Overall Average: " + String(average));
}