#include <Wire.h>
#include <LiquidCrystal_I2C.h>
//#include <stdio.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);

int relay = 8;
int relay2 = 9;
int buzzer = 10;
int uvSensor = A0;

String str;
int blueToothVal;
int sensorValue = 0;
float Vout = 0;
float uvIntensity = 0;

int timer_started_flag = 0;
long int total_Seconds = 0;

// Tracks the time since last event fired
unsigned long int previoussecs = 0;
unsigned long int currentsecs = 0;
unsigned long currentMillis = 0;
int interval = 1 ; // updated every 1 second

void setup()
{
  Serial.begin(9600);
  pinMode(relay, OUTPUT);
  pinMode(relay2, OUTPUT);
  pinMode(buzzer, OUTPUT);
  pinMode(uvSensor,INPUT);
  digitalWrite(relay, HIGH);// relay is OFF
  digitalWrite(relay2, HIGH);// relay is OFF
  digitalWrite(buzzer, LOW);

  lcd.init();
  lcd.init();
  lcd.backlight();

  lcd.setCursor(0, 0);
  lcd.print("UVC Kit");
  lcd.setCursor(0, 1);
  lcd.print("Intensity Sensor");
}


void loop()
{
  bluetooth();
  countdown();
}


void bluetooth()
{
  while (Serial.available() && timer_started_flag == 0)
  {
    {
      str = Serial.readStringUntil('\n');
    }

    blueToothVal = (str.toInt());
    if (blueToothVal > 30) {
      blueToothVal = 30;
    }
    total_Seconds = blueToothVal * 60;// convert to sec
    timer_started_flag = 1;
    //UVsensor(); // only take 1 reading when recieved order from bluetooth
    //Serial.write(abs(uvIntensity));
    lcd.clear();
    lcd.print("T Seconds:");
    lcd.setCursor(11, 0);
    lcd.print( total_Seconds );
    delay(1000);
  }
}


void countdown() {
  while (timer_started_flag == 1) {
    UVsensor();
    lcd.setCursor(0, 0);
    lcd.print("T Seconds:");
    lcd.setCursor(11, 0);
    lcd.print( total_Seconds );
    lcd.setCursor(0, 1);
    if ( total_Seconds > 0)
    {
      digitalWrite(relay, LOW);// turn ON relay 1
      digitalWrite(relay2, LOW);// turn ON relay 2
      //lcd.print("load ON ");
      lcd.print(abs(uvIntensity));
    }

    if ( total_Seconds <= 0)
    {
      total_Seconds = 0;
      timer_started_flag = 0;
      digitalWrite(relay, HIGH);// turn OFF Relay 1
      digitalWrite(relay2, HIGH);// turn OFF Relay 2
      //lcd.print("load OFF");
      lcd.print(abs(uvIntensity));
      //------------------------------Buzzer Tone
      digitalWrite(buzzer, HIGH);
      delay(500);
      digitalWrite(buzzer, LOW);
      delay(500);
      digitalWrite(buzzer, HIGH);
      delay(1500);
      digitalWrite(buzzer, LOW);
      delay(500);
      /////////////////////////////////////////////
    }

    currentMillis = millis();
    currentsecs = currentMillis / 1000;
    if ((unsigned long)(currentsecs - previoussecs) >= interval) {
      total_Seconds = total_Seconds - 1;
      lcd.clear();
      previoussecs = currentsecs;
    }
  }//end of while loop
}

void UVsensor(){
  int uvLevel = analogRead(uvSensor);//averageAnalogRead
  float outputVoltage = (( uvLevel * 5000 ) / 1023.0); //0-1023 --->  [x] mV
  float index = mapfloat(outputVoltage, 0.0, 1000, 0.0, 11.0);// UV index
  uvIntensity = mapfloat(outputVoltage/10, 1, 2.8, 0.0, 15.0); //Convert the voltage to a UV intensity level
}

float mapfloat(float x, float in_min, float in_max, float out_min, float out_max)
{
  if (x == 0) {
 return 0;
 }
 //mapfloat(outputVoltage/1000.0, 1, 2.8, 0.0, 15.0);
  return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
}