// https://wokwi.com/projects/390745796014539777
// https://forum.arduino.cc/t/help-with-until-loop/1228025

const int ATOsolenoid = 3;
const int FlushSolenoid = 4;
const int lowEye = 7;
const int highEye = 8;

const int lowWater = A2;
const int highWater = A1;

#define EXE_INTERVAL_1 5000
#define EXE_INTERVAL_2 10000

void setup() {
  Serial.begin(9600);

  pinMode(ATOsolenoid, OUTPUT);
  pinMode(FlushSolenoid, OUTPUT);
  pinMode(lowEye, INPUT);
  pinMode(highEye, INPUT);

  pinMode(lowWater, OUTPUT);  
  pinMode(highWater, OUTPUT);}

unsigned long now;
enum notAnonymous {Idle, Flush, Waiting};
int state = Idle;

const unsigned int flushForTime = 20000;    // flush on duration in milliseconds
const unsigned int pauseForTime = 120000;   // wait between flushes

void loop() {

  now = millis();   // read the time for use in this loop iteration

//  bool waterIsLow = digitalRead(lowEye) == LOW;
//  bool waterIsHigh = digitalRead(highEye) == HIGH;
// proxy water level and sensors instead
  bool waterIsLow = analogRead(A0) < 128;
  bool waterIsHigh = analogRead(A0) > 896;

  digitalWrite(lowWater, waterIsLow ? HIGH : LOW);
  digitalWrite(highWater, waterIsHigh ? HIGH : LOW);

// adjust valve or pump or whatever it is
  if (waterIsLow) {
    digitalWrite(ATOsolenoid, HIGH);
  }
  if (waterIsHigh) {
    digitalWrite(ATOsolenoid, LOW);
  }

// start or continue hourly 20 second flushing

  static unsigned long flushTimer;

  switch (state) {
  case Idle :  // start flushing
    if (digitalRead(ATOsolenoid) == HIGH) {
      state = Flush;
      flushTimer = now;
      digitalWrite(FlushSolenoid, HIGH);  // Switch Solenoid ON  
    }
    break;

  case Flush :  // flush for 20 seconds 
    if (now - flushTimer >= flushForTime) {
      flushTimer = now;
      state = Waiting;
      digitalWrite(FlushSolenoid, LOW);  // Switch Solenoid OFF
    }
    else if (digitalRead(ATOsolenoid) == LOW) {
      state = Idle;
       digitalWrite(FlushSolenoid, LOW);  // Switch Solenoid OFF 
    }
    break;
      
  case Waiting :  // wait an hour, or reset the flushing machine if ATOsolenoid says
    if (now - flushTimer >= pauseForTime) {
      flushTimer = now;
      state = Flush;
      digitalWrite(FlushSolenoid, HIGH);   // Switch Solenoid ON (time to)
    }
    else if (digitalRead(ATOsolenoid) == LOW) {
      state = Idle;
      digitalWrite(FlushSolenoid, LOW);   // Switch Solenoid OFF (ATOsolenoid dropped)
    }  
    break;
  }
}

/*
// never mind
  static int pState = -1;
  if (pState != state) {
    Serial.print("state is "); Serial.println(state);
    pState = state;
  }
*/