#include <I2CKeyPad.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd = LiquidCrystal_I2C(0x27, 16, 2);


I2CKeyPad keypad(0x38);
char keypad_layout[19] = "123A456B789C*0#DNF"; // N = NO_KEY, F = FAILED
int sensorInterrupt = 0;  // interrupt 0
int sensorPin       = 2; //Digital Pin 2
 int relay_motor = 12; // Digital pin 5
unsigned int SetPoint = 400; //400 milileter

/*The hall-effect flow sensor outputs pulses per second per litre/minute of flow.*/
float calibrationFactor = 90; //You can change according to your datasheet

volatile byte pulseCount =0;  

float flowRate = 0.0;
unsigned int flowMilliLitres =0;
unsigned long totalMilliLitres = 0, volume = 0;

unsigned long oldTime = 0;
//const int relay_motor = 10;
//const int mech_countr = 14;
const int roto = 11;
const int emergencyButtonPin = 13;
long code = 0 ;
int price = 10;

void setup() {
  Serial.begin(115200);
    if (!keypad.begin()) {
    Serial.print("Cannot connect to I2C.\n");
    while(1);
  }

  keypad.loadKeyMap(keypad_layout);

  pinMode(sensorPin, INPUT);
  digitalWrite(sensorPin, HIGH);

  pinMode(relay_motor, OUTPUT);
  //pinMode(mech_countr, OUTPUT);
  pinMode(roto, INPUT_PULLUP);

  pinMode(emergencyButtonPin, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(emergencyButtonPin), emergencyStop, FALLING);

  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print(    "MACHLAB"    );
  delay(4000);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Enter Amount:");
  // put your setup code here, to run once:
  Serial.println("Hello, ESP32!");
 attachInterrupt(sensorInterrupt, pulseCounter, FALLING); //you can use Rising or Falling

}

void loop() {
   char key = keypad.getChar();

 if (key>= '0' && key<= '9') {  
    //code += key;
    code = code * 10 + (key - '0');
    lcd.setCursor(0, 1);
    lcd.print(code);
    delay(100);
  }
 if (key == 'C')
    {
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Enter Amount:");
        code= 0;
        // inputIndex = 0; // Reset the input index
        // memset(inputBuffer, 0, sizeof(inputBuffer));
        delay(200);
        //code = ;
    }
  if (key == 'D') {

        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Amount: Rs.");
        lcd.print(code);

        volume = code * price;
        lcd.setCursor(0, 1);
        lcd.print("Volume = ");

        lcd.print(volume);

        lcd.print("ml");
          
 
       delay(1500);
  }


  if (totalMilliLitres < volume) {
    
    digitalWrite(relay_motor, HIGH);
       
      
        // Check the state of the fuel dispensing switch
      if (digitalRead(roto) == LOW) {
      
      // solenoidLoop();

    if ((millis() - oldTime) > 1000) {
      detachInterrupt(sensorInterrupt);
 
      flowRate = ((1000.0 / (millis() - oldTime)) * pulseCount) / calibrationFactor;
      oldTime = millis();
      flowMilliLitres = (flowRate / 60) * 1000;
      totalMilliLitres += flowMilliLitres;
 
      
      Serial.print("Flow rate :-");
      Serial.print(flowMilliLitres, DEC);
      Serial.print("mL/Second");
      Serial.print("\t");
      lcd.clear();
 
      lcd.setCursor(0, 0);
      lcd.print("Speed :");
      lcd.print(flowMilliLitres);
      lcd.print(" ml/s");
      Serial.print("Output Liquid Quantity: ");
      Serial.print(totalMilliLitres, DEC);
 
      Serial.println("mL");
      Serial.print("\t");
      lcd.setCursor(0, 1);
      lcd.print("Filled:");
      lcd.print(totalMilliLitres);
      lcd.print(" ml");
      // if (totalMilliLitres > 40) {
      //   SetSolinoidValve();
      // }
      pulseCount = 0;
      attachInterrupt(sensorInterrupt, pulseCounter, FALLING);
      
     }
     }
   else{
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("please turn on ");
    lcd.setCursor(0, 1);
    lcd.print("roto switch");
    delay(2000);
    return;
    } 
   }

  else if (totalMilliLitres = volume)  {
    digitalWrite(relay_motor, LOW);
    //saveToEEPROM(inputBuffer);
    // if(key == 'A')
    // printBill();
    // inputIndex = 0; // Reset the input index
    //    memset(inputBuffer, 0, sizeof(inputBuffer));
       volume = 0;
    //delay(4000);
    
    
    // else{
    //    inputIndex = 0; // Reset the input index
    //    memset(inputBuffer, 0, sizeof(inputBuffer));
    //    volume = 0;
    // }
  }
else {
      digitalWrite(relay_motor, LOW);
      volume = 0;
  }
}

void pulseCounter()
{
  // Increment the pulse counter
  pulseCount++;
}

void emergencyStop() {
  // Stop the liquid dispensing process and perform any necessary cleanup.
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Emergency btn");
  lcd.setCursor(0, 1);
  lcd.print("pressed");
  delay(1000);
   code= 0;
  //  inputIndex = 0; // Reset the input index
  //  memset(inputBuffer, 0, sizeof(inputBuffer));
  digitalWrite(relay_motor, HIGH);
  // digitalWrite(solenoidValve1, HIGH);
  // digitalWrite(solenoidValve2, HIGH);
  exit(0);
}