// home version

const byte ON = HIGH;
const byte OFF = LOW;

const byte OPEN = HIGH;
const byte CLOSED = LOW;

const byte WaterAvailable = LOW;

const byte tankFull = HIGH;  // a HIGH reading of the upper sensor == tank is full

const byte tankEmpty = HIGH;  // a HIGH reading of the lower sensor == tank is empty

const byte lowLevel1_Pin = 3;
const byte highLevel1_Pin = 4;

const byte sump_Pin = 5;             // Sump Level

const byte lowLevel2_Pin = 6;
const byte highLevel2_Pin = 7;

const byte lowLevel3_Pin = 8;
const byte highLevel3_Pin = 9;

const byte motor_Pin = 12;  // thirteen is unlucky.
const byte valve1_Pin = A0;
const byte valve2_Pin = 10;
const byte valve3_Pin = 11;

void setup() {

  // INPUTS
  pinMode(lowLevel1_Pin, INPUT_PULLUP);
  pinMode(highLevel1_Pin, INPUT_PULLUP);
  pinMode(lowLevel2_Pin, INPUT_PULLUP);
  pinMode(highLevel2_Pin, INPUT_PULLUP);
  pinMode(lowLevel3_Pin, INPUT_PULLUP);
  pinMode(highLevel3_Pin, INPUT_PULLUP);

  pinMode(sump_Pin, INPUT_PULLUP);

  // OUTPUTS
  digitalWrite(motor_Pin,OFF); 
  digitalWrite(valve1_Pin,CLOSED);
  digitalWrite(valve2_Pin,CLOSED);
  digitalWrite(valve3_Pin,CLOSED);

  pinMode(motor_Pin, OUTPUT);
  pinMode(valve1_Pin, OUTPUT);
  pinMode(valve2_Pin, OUTPUT);
  pinMode(valve3_Pin, OUTPUT);

//  delay(1000);  // why?
}

void loop() {

delay(125);  // no need for speed here

//  static bool pumpState = OFF;

// alternate state variables
static bool tank1Needs, tank2Needs, tank3Needs; 

//  static bool valveState = CLOSED;

/* real world section input
  bool tank1Full = digitalRead(highLevel1_Pin);
  bool tank2Full = digitalRead(highLevel2_Pin);
  bool tank3Full = digitalRead(highLevel3_Pin);
  
  bool tank1Empty = digitalRead(lowLevel1_Pin);
  bool tank2Empty = digitalRead(lowLevel2_Pin);
  bool tank3Empty = digitalRead(lowLevel3_Pin);
*/

/* simpulated input section */

  analogRead(A1);
  int tank1Level =  analogRead(A1);

  analogRead(A2);
  int tank2Level =  analogRead(A2);
 
  analogRead(A3);
  int tank3Level =  analogRead(A3);

  bool tank1Full = tank1Level > 923;
  bool tank2Full = tank2Level > 923;
  bool tank3Full = tank3Level > 923;

  bool tank1Empty = tank1Level < 100;  
  bool tank2Empty = tank2Level < 100;
  bool tank3Empty = tank3Level < 100;

/* end of simulated tank sensor input */

// basic hysteresis
  if (tank1Empty) tank1Needs = true;
  if (tank2Empty) tank2Needs = true;
  if (tank3Empty) tank3Needs = true;

  if (tank1Full) tank1Needs = false;
  if (tank2Full) tank2Needs = false;
  if (tank3Full) tank3Needs = false;

// might as well top off the other tanks
  if (tank1Empty || tank2Empty || tank3Empty) {
    if (!tank1Full) tank1Needs = true;
    if (!tank2Full) tank2Needs = true;
    if (!tank3Full) tank3Needs = true;
  }

// only in case the sump has enough water for pumping
  if (digitalRead(sump_Pin) != WaterAvailable) {
    digitalWrite(valve1_Pin, CLOSED);
    digitalWrite(valve2_Pin, CLOSED);
    digitalWrite(valve3_Pin, CLOSED);

    digitalWrite(motor_Pin, OFF);

    return;  // no water available, all done
  }

  digitalWrite(valve1_Pin, tank1Needs ? OPEN : CLOSED);
  digitalWrite(valve2_Pin, tank2Needs ? OPEN : CLOSED);
  digitalWrite(valve3_Pin, tank3Needs ? OPEN : CLOSED);


  digitalWrite(motor_Pin, (tank1Needs || tank2Needs || tank3Needs) ? ON : OFF);
}