#define S3 0
#define S1 1
#define S2 2
#define V1 3 // Flow restrictor bypass
#define Y 4 // Chiller call for refrigeration
#define V2 5 // RO membrane flush 
#define V3 6 // Recirculation
#define LH 7 // High water level switch
#define LL 8 // Low water level switch
#define V4 9 // Tank fill valve
#define V5 10 // RO membrane bypass (pre-filtered)
#define LM 11 // Minimum water level switch (Safety cut-out)
#define PS 12 // Leaving water pressure switch
#define DV 13 // Tank drain valve
#define SV 14 // RO system supply valve
#define PP 15 // leaving water pressure pump
#define PY 16 // Chiller circulation pump
#define B1 17 // Button
#define HB 18 // Heart beat indicator
#define EST_NTC A6
#define CWT_NTC A7

float EST;
float CWT;
const int setpoint  = 38;

int page;
int paragraph;
int sentence;
int verb[10];
int noun;

// global variables
unsigned long currentMillis;

// defrost variables
int triggerDefrost;
int cycleDefrost;
unsigned long durDefrost; // milliseconds
long ofstDefrost;

// Timer_1 variables
int state;
unsigned int a;
int blink;
long offTime = 1000;
long onTime = 1000;
unsigned long previousMillis;

// timer_2 variables
int trigger_2;
int cycle_2;
unsigned long dur_2; // milliseconds
long ofst_2;

// timer_3 variables
int trigger_3;
int cycle_3;
unsigned long dur_3; // milliseconds
long ofst_3;

void setup() {
  pinMode(S3, INPUT_PULLUP);
  pinMode(S1, INPUT_PULLUP);
  pinMode(S2, INPUT_PULLUP);
  pinMode(LH, INPUT_PULLUP);
  pinMode(LL, INPUT_PULLUP);
  pinMode(LM, INPUT_PULLUP);
  pinMode(PS, INPUT_PULLUP);
  pinMode(B1, INPUT_PULLUP);

  pinMode(V1, OUTPUT);
  pinMode(Y, OUTPUT);
  pinMode(V2, OUTPUT);
  pinMode(V3, OUTPUT);
  pinMode(V4, OUTPUT);
  pinMode(V5, OUTPUT);
  pinMode(DV, OUTPUT);
  pinMode(SV, OUTPUT);
  pinMode(PP, OUTPUT);
  pinMode(PY, OUTPUT);
  pinMode(HB, OUTPUT);

  analogWrite(V1, 0);
  digitalWrite(Y, LOW);
  analogWrite(V2, 0);
  analogWrite(V3, 0);
  analogWrite(V4, 0);
  analogWrite(V5, 0);
  digitalWrite(DV, LOW);
  digitalWrite(SV, LOW);
  digitalWrite(PP, LOW);
  digitalWrite(PY, LOW);
  digitalWrite(HB, HIGH);

  delay(1000);

  digitalWrite(HB, LOW);

  triggerDefrost = 0;
  cycleDefrost = 0;
  trigger_2 = 0;
  cycle_2 = 0;
  trigger_3 = 0;
  cycle_3 = 0;

  currentMillis = millis(); 

}

void loop() {
  while(page == 0) { // System Off
    analogWrite(V1, 0);
    digitalWrite(Y, LOW);
    analogWrite(V2, 0);
    analogWrite(V3, 0);
    analogWrite(V4, 0);
    analogWrite(V5, 0);
    digitalWrite(DV, LOW);
    digitalWrite(SV, LOW);
    digitalWrite(PP, LOW);
    digitalWrite(PY, LOW);

    inputs();
    if(page != 0)  {
      break;
    }
    delay(1000);
  }
  while(page == 1) { // Normal Operation
    inputs();

    timer_1();
    digitalWrite(HB, a);

    NTC();
    defrost();
    if(cycleDefrost == 0) {
      if(EST > 32) {
        if(CWT >= (setpoint + 2)) {
          digitalWrite(PY, HIGH);
          digitalWrite(Y, HIGH);
        }
        else if(CWT <= setpoint) {
          digitalWrite(PY, LOW);
          digitalWrite(Y, LOW);
        }
      }
      else if(EST <= 32) {
        digitalWrite(PY, LOW);
        digitalWrite(Y, LOW);
        triggerDefrost = 1;
        durDefrost = 300000;
      }
    }
    else {
      digitalWrite(PY, LOW);
      digitalWrite(Y, LOW);
    }

    timer_2();
    if(digitalRead(PS) == HIGH) {
      digitalWrite(PP, LOW);
      verb[0] = 0;
    }
    else if(digitalRead(PS) == LOW) {
      if(verb[0] == 0) {
        trigger_2 = 1;
        dur_2 = 2000;
        verb[0] = 1;
      }
      else if(verb[0] == 1) {
        if(cycle_2 == 1) {
          digitalWrite(PP, LOW);
        }
        else if(cycle_2 == 0) {
          digitalWrite(PP, HIGH);
        }
      }
    }

    if((digitalRead(LL) == LOW) && (digitalRead(LH) == LOW)) {
      verb[1] = 0;
      analogWrite(V4, 0);
      digitalWrite(SV, LOW);
    }
    else if((digitalRead(LL) == LOW) && (digitalRead(LH) == HIGH)) {
      
    }
    else if((digitalRead(LL) == HIGH) && (digitalRead(LH) == HIGH)) {
      if(verb[1] == 0) {
        digitalWrite(SV, HIGH);
        analogWrite(V4, 255);
        delay(1000);
        for(int i = 255; i > 80; i--) {
          analogWrite(V4, i);
        }
        verb[1] = 1;
      }
    }



  }
  while(page == 2) { // Membrane Flush
    while(paragraph == 1) {
      analogWrite(V1, 0);
      digitalWrite(Y, LOW);
      analogWrite(V2, 0);
      analogWrite(V3, 0);
      analogWrite(V4, 0);
      analogWrite(V5, 0);
      digitalWrite(DV, LOW);
      digitalWrite(SV, LOW);
      digitalWrite(PP, LOW);
      digitalWrite(PY, LOW);
      digitalWrite(HB, HIGH);
      paragraph = 2;
    }
    while( paragraph == 2) {
      timer_1();
      digitalWrite(HB, a);

      if(noun == 1) {
        dur_2 = 300000;
        dur_3 = 420000;
        trigger_2 = 1;
        trigger_3 = 1;
        analogWrite(V1, 255);
        analogWrite(V2, 255);
        delay(1000);
        for(int i = 255; i > 80; i--) {
          analogWrite(V1, i);
          analogWrite(V2, i);
        }
        digitalWrite(SV, HIGH);
        noun = 2;
      }
      timer_2();
      timer_3();
      if(cycle_2 == 0) {
        analogWrite(V1, 0);
      }
      if(cycle_3 == 0) {
        analogWrite(V2, 0);
      }
      if((cycle_2 == 0) && (cycle_3 == 0)) {
        digitalWrite(SV, LOW);
        digitalWrite(HB, HIGH);
        paragraph = 3;
      }
    }
    while(paragraph == 3) {
      inputs();
      if(page == 0) {
        break;
      }
      else if(page == 1) {
        paragraph = 0;
        sentence = 0;
        noun = 0;
        for(int i = 0; i < 10; i++) {
          verb[i] = 0;
        }
        break;
      }
    }
  }
  while(page == 3) { // Cleaning Cycle
    // set all outputs LOW
    while(paragraph == 1) {
      analogWrite(V1, 0);
      digitalWrite(Y, LOW);
      analogWrite(V2, 0);
      analogWrite(V3, 0);
      analogWrite(V4, 0);
      analogWrite(V5, 0);
      digitalWrite(DV, LOW);
      digitalWrite(SV, LOW);
      digitalWrite(PP, LOW);
      digitalWrite(PY, LOW);
      digitalWrite(HB, HIGH);
      paragraph = 2;
    }
    // Drain
    while(paragraph == 2) {
      if(digitalRead(LM) == HIGH) {
        digitalWrite(DV, LOW);
        digitalWrite(HB, LOW);
        delay(1000);
        paragraph = 3;
        verb[2] = 1;
      }
      else if(digitalRead(LM) == LOW) {
        digitalWrite(DV, HIGH);
        digitalWrite(HB, HIGH);
      }
    }
    // First fill (pre-filtered water)
    while(paragraph == 3) {
      if(digitalRead(LL) == HIGH) {
        timer_1();
        digitalWrite(HB, a);
        if(verb[2] == 1) {
          analogWrite(V4, 255);
          analogWrite(V5, 255);
          delay(1000);
          for(int i = 255; i > 80; i--) {
            analogWrite(V4, i);
            analogWrite(V5, i);
          }
          verb[2] = 2;
        }
        digitalWrite(SV, HIGH);
      }
      else if(digitalRead(LL) == LOW) {
        digitalWrite(SV, LOW);
        analogWrite(V4, 0);
        analogWrite(V5, 0);
        verb[2] = 1;
        paragraph = 4;
        sentence = 1;
      }
    }
    // Wash cycle
    while(paragraph == 4) {
      while(sentence == 1) {
        trigger_3 = 1;
        dur_3 = 10000; // 900000 (15 minutes)
        sentence = 2;
        timer_3();
      }
      while(sentence == 2) {
        timer_3();
        timer_1();
        digitalWrite(HB, a);

        if(cycle_3 == 1) {
          if(verb[2] == 1) {
            analogWrite(V3, 255);
            delay(1000);
            for(int i = 255; i > 80; i--) {
              analogWrite(V3, i);
            }
            verb[2] = 2;
          }

          digitalWrite(PY, HIGH);

          timer_2();
          if(digitalRead(PS) == HIGH) {
            digitalWrite(PP, LOW);
            verb[0] = 0;
          }
          else if(digitalRead(PS) == LOW) {
            if(verb[0] == 0) {
              trigger_2 = 1;
              dur_2 = 2000;
              verb[0] = 1;
            }
            else if(verb[0] == 1) {
              if(cycle_2 == 1) {
                digitalWrite(PP, LOW);
              }
              else if(cycle_2 == 0) {
                digitalWrite(PP, HIGH);
              }
            }
          }
        }
        else if(cycle_3 == 0) {
          analogWrite(V3, 0);
          digitalWrite(PY, LOW);
          digitalWrite(PP, LOW);
          digitalWrite(HB, LOW);
          verb[2] = 1;
          sentence = 1;
          paragraph = 5;
        }
      }
    }
    // Drain 2
    while(paragraph == 5) {
      if(digitalRead(LM) == HIGH) {
        digitalWrite(DV, LOW);
        digitalWrite(HB, LOW);
        delay(1000);
        paragraph = 6;
        verb[2] = 1;
      }
      else if(digitalRead(LM) == LOW) {
        digitalWrite(DV, HIGH);
        digitalWrite(HB, HIGH);
      }
    }
    // Second fill (RO water)
    while(paragraph == 6) {
      if(digitalRead(LL) == HIGH) {
        timer_1();
        digitalWrite(HB, a);
        if(verb[2] == 1) {
          analogWrite(V4, 255);
          delay(1000);
          for(int i = 255; i > 80; i--) {
            analogWrite(V4, i);
          }
          verb[2] = 2;
        }
        digitalWrite(SV, HIGH);
      }
      else if(digitalRead(LL) == LOW) {
        digitalWrite(SV, LOW);
        analogWrite(V4, 0);
        verb[2] = 1;
        paragraph = 7;
        sentence = 1;
      }
    }
    // DONE! Wait for mode switch to return to NORMAL or OFF
    while(paragraph == 7) {
      inputs();
      if(page == 0) {
        break;
      }
      else if(page == 1) {
        paragraph = 0;
        sentence = 0;
        noun = 0;
        for(int i = 0; i < 10; i++) {
          verb[i] = 0;
        }
        break;
      }
      else {
        digitalWrite(HB, HIGH);
      }
    }

  }
  while(page == 4) {

  }

}

void NTC() {
  const int beta = 3950;
  float read_1;
  float read_2;
  float celsius;

  read_1 = 0.0;
  read_2 = 0.0;

  for(int i = 0; i < 10; i++) {
    read_1 = (read_1 + analogRead(A6));
    delay(5);
  }
  float average_1 = (read_1 / 10);

  for(int i = 0; i < 10; i++) {
    read_2 = read_2 + analogRead(A7);
    delay(5);
  }
  float average_2 = (read_2 / 10);

  celsius = 1 / (log(1 / (1023.0 / average_1 - 1)) / beta + 1.0 / 298.15) - 273.15;
  EST = ((celsius * 1.8) + 32);

  celsius = 1 / (log(1 / (1023.0 / average_2 - 1)) / beta + 1.0 / 298.15) - 273.15;
  CWT = ((celsius * 1.8) + 32);
}

void inputs() {
  if((digitalRead(S1) == HIGH) && (digitalRead(S2) == HIGH) && (digitalRead(S3) == HIGH)) {
    page = 0;
  }
  else if((digitalRead(S1) == LOW) && (digitalRead(S2) == HIGH) && (digitalRead(S3) == HIGH)) {
    page = 1;
  }
  else if((digitalRead(S1) == HIGH) && (digitalRead(S2) == LOW) && (digitalRead(S3) == HIGH)) {
    page = 2;
    if(paragraph != 3) {
      paragraph = 1;
      noun = 1;
      verb[1] = 0;
    }
    else if(paragraph == 3) {
      paragraph = 3;
    }
  }
  else if((digitalRead(S1) == LOW) && (digitalRead(S2) == HIGH) && (digitalRead(S3) == LOW)) {
    page = 3;
    if(paragraph != 7) {
      paragraph = 1;
    }
    else if(paragraph == 7) {
      paragraph = 7;
    }
  }
  else if((digitalRead(S1) == HIGH) && (digitalRead(S2) == LOW) && (digitalRead(S3) == LOW)) {
    page = 4;
  }
  
}

void defrost() {
  currentMillis = millis();

  if(triggerDefrost == 1) {
    ofstDefrost = currentMillis;
    triggerDefrost = 0;
  }
  if(currentMillis < (ofstDefrost + durDefrost)) {
    cycleDefrost = 1;
  }
  if(currentMillis > (ofstDefrost + durDefrost)) {
    cycleDefrost = 0;
  }
}

void timer_3() {
  currentMillis = millis();

  if(trigger_3 == 1) {
    ofst_3 = currentMillis;
    trigger_3 = 0;
  }
  if(currentMillis < (ofst_3 + dur_3)) {
    cycle_3 = 1;
  }
  if(currentMillis > (ofst_3 + dur_3)) {
    cycle_3 = 0;
  }
}

void timer_2() {
  currentMillis = millis();

  if(trigger_2 == 1) {
    ofst_2 = currentMillis;
    trigger_2 = 0;
  }
  if(currentMillis < (ofst_2 + dur_2)) {
    cycle_2 = 1;
  }
  if(currentMillis > (ofst_2 + dur_2)) {
    cycle_2 = 0;
  }
}

void timer_1() {
  currentMillis = millis(); 

  if ((a == HIGH) && (currentMillis - previousMillis >= offTime)) {
    a = LOW;
    previousMillis = currentMillis;
    blink = 1;
  }
  else if((a == LOW) && (currentMillis - previousMillis >= onTime)) {
    a = HIGH;
    previousMillis = currentMillis;
    blink = 0;
  }
}