#include <Streaming.h>
Print& cout {Serial};

// Automatically define a suitable data type for millis()
using Millis_t = decltype(millis());

constexpr Millis_t gcBlinkInterval {500};

class Timer {
public:
  void start() { timeStamp = millis(); }
  bool operator()(const Millis_t duration) const { return (millis() - timeStamp >= duration); }

private:
  Millis_t timeStamp {0};
};

// Define new own data type for moisture sensor
struct SensorDevice {
  const uint8_t pin;
  const int threshold;
  const Millis_t delay_ms;
};

// Define new own data type for a watering pump
struct PumpDevice {
  const uint8_t pin;
  const Millis_t delay_ms;
  bool isRunning;
};

SensorDevice sensor {A0, 500, 15000};   // Init. sensor default data (pinnr, moisture threshold, measurement interval)
PumpDevice pump {5, 8000, false};   // Init. pump default data (pinnr, pump interval, on (true) / off (false) state )

// Timer objects for handling the different time intervals
Timer timerSensor;
Timer timerPump;
Timer blinkTimer;

void blink() {
  if (blinkTimer(gcBlinkInterval)) {
    blinkTimer.start();
    digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN));
  }
}

// Returns true if the measured sensor value is above the specified threshold else it returns false
bool checkSensor(SensorDevice& dev, Timer& wait) {
  bool result {false};

  if (wait(dev.delay_ms)) {
    wait.start();
    cout << F("Read Sensor Data: ");
    result = analogRead(dev.pin) > dev.threshold;
    (result) ? cout << F("Soil too dry\n") : cout << F("Soil moist enough\n");
  }
  return result;
}

void enablePump(PumpDevice& dev, Timer& wait) {
  if (dev.isRunning) { return; }   // Return if device is already on

  cout << F("Start pump\n");
  digitalWrite(dev.pin, HIGH);
  dev.isRunning = true;
  wait.start();
}

void disablePump(PumpDevice& dev, Timer& wait) {
  if (!wait(dev.delay_ms)) { return; }   // Return if interval has not elapsed

  cout << F("Pump interval over. Stop pump\n");
  digitalWrite(dev.pin, LOW);
  dev.isRunning = false;
}

void setup() {
  Serial.begin(115200);
  cout << F("Start...\n");
  cout << F("Wait ") << sensor.delay_ms << F(" milliseconds until the first sensor measurement.\n");
  pinMode(pump.pin, OUTPUT);
  pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
  blink();   // Does nothing in particular except flash away
  // if checksensor returns true, enable the pump
  if (checkSensor(sensor, timerSensor)) { enablePump(pump, timerPump); }
  // When the pump is on, Switch off the pump when the specified pumping time interval has elapsed.
  if (pump.isRunning) { disablePump(pump, timerPump); }
}