#include <LiquidCrystal_I2C.h>
#include <RTClib.h>


RTC_DS1307 rtc;
char daysOfTheWeek[7][24] = {
  "Sunday",
  "Monday",
  "Tuesday",
  "Wednesday",
  "Thursday",
  "Friday",
  "Saturday"
};

const int ATOtime = 21;
const int ATOduration = 30;
const int AWCday = 6;
const int AWCtime = 12;
const int AWCduration = 30;

LiquidCrystal_I2C lcd(0x27, 20, 4); 

/* 
  HIGH ena = drive dissabled
  LOW ena = drive enabled
  HIGH dir = CCW = tank drain
  LOW dir = CW = tank fill
  tankHigh and tankLow are normally LOW; HIGH indicates no water at that level --> external pull-up
  wasteHigh is normally HIGH; LOW indicates waste tank is full --> internal pull-up
  freshLow is normally HIGH; LOW indicates fresh water tank is empty --> internal pull-up
*/
#define ena_1 2
#define dir_1 3
#define ena_2 4
#define dir_2 5
#define tankHigh 6
#define tankLow 7
#define freshLow 8
#define wasteHigh 9
#define purgeFill 10
#define purgeDrain 11
#define purgeChem 12
// #define txEnable 13
#define light 14 // K4
#define filter 15 // K3
#define heater 16 // K2
#define alarm 17 // K1

int state;
unsigned int a;
int blink;
long offTime = 1000;
long onTime = 1000;
unsigned long previousMillis = 0;

// Timer_2 variables
int trigger;
int cycle;
const long duration_2 = 10000; // milliseconds
long offset_2;

void setup() {

  Serial.begin(9600);
  lcd.init();
  lcd.backlight();

  pinMode(ena_1, OUTPUT);
  pinMode(dir_1, OUTPUT);
  pinMode(ena_2, OUTPUT);
  pinMode(dir_2, OUTPUT);
  pinMode(light, OUTPUT);
  pinMode(filter, OUTPUT);
  pinMode(heater, OUTPUT);
  pinMode(alarm, OUTPUT);

  pinMode(tankHigh, INPUT);
  pinMode(tankLow, INPUT);
  pinMode(freshLow, INPUT_PULLUP);
  pinMode(wasteHigh, INPUT_PULLUP);

  // pinMode(purgeFill, INPUT);
  // pinMode(purgeDrain, INPUT);
  // pinMode(purgeChem, INPUT);
  pinMode(purgeFill, INPUT_PULLUP);
  pinMode(purgeDrain, INPUT_PULLUP);
  pinMode(purgeChem, INPUT_PULLUP);

  if (! rtc.begin()) {
    lcd.setCursor(0,1);
    lcd.print("Couldn't find RTC");
    while (1);
  }
  else { 
    lcd.setCursor(0,1);
    lcd.print("                    ");
  }
  // rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  DateTime now = rtc.now();

  state = 0;
  a = LOW;
  blink = 0;

}

void loop() {

  while(state == 0) {
    DateTime now = rtc.now();
    clock();
    State();
    if(state != 0) {
      break;
    }
    lcd.setCursor(0,1);
    lcd.print("OK   ");
    digitalWrite(alarm, LOW);

    if((now.hour() == ATOtime) && (0 < now.minute()) && (now.minute() < ATOduration)) {
      digitalWrite(dir_2, HIGH);
      digitalWrite(ena_2, HIGH);

      if(digitalRead(tankHigh) == HIGH) {
        digitalWrite(dir_1, LOW);
        digitalWrite(ena_1, LOW);
        lcd.setCursor(0,2);
        lcd.print("ATO  ");
      }
      else if(digitalRead(tankHigh) == LOW) {
        digitalWrite(dir_1, HIGH);
        digitalWrite(ena_1, HIGH);
        lcd.setCursor(0,2);
        lcd.print("READY");
      }
    }
    else if((digitalRead(purgeDrain) == LOW) && (digitalRead(purgeFill) == HIGH) && (digitalRead(purgeChem) == HIGH)) {
      digitalWrite(dir_1, HIGH);
      digitalWrite(ena_1, LOW);
      lcd.setCursor(0,2);
      lcd.print("DRAIN");
    }
    else if((digitalRead(purgeDrain) == HIGH) && (digitalRead(purgeFill) == LOW) && (digitalRead(purgeChem) == HIGH)) {
      digitalWrite(dir_1, LOW);
      digitalWrite(ena_1, LOW);
      lcd.setCursor(0,2);
      lcd.print("FILL ");
    }
    else if((digitalRead(purgeDrain) == HIGH) && (digitalRead(purgeFill) == HIGH) && (digitalRead(purgeChem) == LOW)) {
      digitalWrite(dir_2, LOW);
      digitalWrite(ena_2, LOW);
      lcd.setCursor(0,2);
      lcd.print("CHEM ");
    }
    else if((digitalRead(purgeDrain) == HIGH) && (digitalRead(purgeFill) == LOW) && (digitalRead(purgeChem) == LOW)) {
      delay(20);
      State();
    }
    else {
      digitalWrite(dir_1, HIGH);
      digitalWrite(ena_1, HIGH);
      digitalWrite(dir_2, HIGH);
      digitalWrite(ena_2, HIGH);
      lcd.setCursor(0,2);
      lcd.print("IDLE ");
    }
  }

  while(state == 1) {
    clock();
    State();
    if(state != 1) {
      break;
    }
    lcd.setCursor(0,1);
    lcd.print("FRESH");
    lcd.setCursor(0,2);
    lcd.print("*****");
    digitalWrite(dir_1, HIGH);
    digitalWrite(ena_1, HIGH);
    digitalWrite(dir_2, HIGH);
    digitalWrite(ena_2, HIGH);
    digitalWrite(alarm, HIGH);
  }

  while(state == 2) {
    clock();
    State();
    if(state != 2) {
      break;
    }
    lcd.setCursor(0,1);
    lcd.print("WASTE");
    lcd.setCursor(0,2);
    lcd.print("*****");
    digitalWrite(dir_1, LOW);
    digitalWrite(ena_1, HIGH);
    digitalWrite(dir_2, LOW);
    digitalWrite(ena_2, HIGH);
    digitalWrite(alarm, HIGH);
  }

  while(state == 3) {
    clock();
    State();
    timer_1();
    if(state != 3) {
      break;
    }
    lcd.setCursor(0,1);
    lcd.print("ERROR");
    lcd.setCursor(0,2);
    lcd.print("*****");
    digitalWrite(dir_1, LOW);
    digitalWrite(ena_1, HIGH);
    digitalWrite(dir_2, LOW);
    digitalWrite(ena_2, HIGH);
    if(blink == 0) {
      digitalWrite(alarm, LOW);
      digitalWrite(LED_BUILTIN, LOW);
    }
    else if(blink == 1) {
      digitalWrite(alarm, HIGH);
      digitalWrite(LED_BUILTIN, HIGH);
    }
  }

  while(state == 4) {
    clock();
    trigger = 0;
    timer_2();
    
    if(digitalRead(purgeFill) == LOW || digitalRead(purgeDrain) == LOW || digitalRead(purgeChem) == LOW) {
      trigger = 0;
      timer_2();
    }
    if(cycle == 0) {
      lcd.clear();
      state = 0;
      break;
    }
    else if(cycle == 1) {
      lcd.setCursor(0,1);
      lcd.print("CONFIG");
      lcd.setCursor(0,2);
      lcd.print("------");
    }
  }


}

void clock() {
  DateTime now = rtc.now();
  lcd.setCursor(0,0);
  if(now.month() < 10) {
    lcd.print("0");
    lcd.print(now.month());
  }
  else {
    lcd.print(now.month());
  }
  lcd.print("/");
  if(now.day() < 10) {
    lcd.print("0");
    lcd.print(now.day());
  }
  else {
    lcd.print(now.day());
  }
  lcd.print("/");
  lcd.print(now.year());
  lcd.print("  ");
  if(now.hour() < 10) {
    lcd.print("0");
    lcd.print(now.hour());
  }
  else {
    lcd.print(now.hour());
  }
  lcd.print(":");
  if(now.minute() < 10) {
    lcd.print("0");
    lcd.print(now.minute());
  }
  else {
    lcd.print(now.minute());
  }
  lcd.print(":");
  if(now.second() < 10) {
    lcd.print("0");
    lcd.print(now.second());
  }
  else {
    lcd.print(now.second());
  }
}

void State() {
  if((digitalRead(freshLow) == HIGH) && (digitalRead(wasteHigh) == HIGH)) {
    state = 0;
  }
  else if((digitalRead(freshLow) == LOW) && (digitalRead(wasteHigh) == HIGH)) {
    state = 1;
  }
  else if((digitalRead(freshLow) == HIGH) && (digitalRead(wasteHigh) == LOW)) {
    state = 2;
  }
  else if((digitalRead(freshLow) == LOW) && (digitalRead(wasteHigh) == LOW)) {
    state = 3;
  }
  else if((digitalRead(purgeFill) == LOW) && (digitalRead(purgeChem) == LOW)) {
    delay(1000);
    state = 4;
  }
}
void timer_1() {
  long 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;
  }

}

void timer_2() {
  long currentMillis = millis();

  if(trigger == 1) {
    offset_2 = currentMillis;
    trigger = 0;
  }
  if(currentMillis < (offset_2 + duration_2)) {
    cycle = 1;
  }
  if(currentMillis > (offset_2 + duration_2)) {
    cycle = 0;
  }

}