//-------------DISCLAIMER-------------
//iam not a good programator, nor is the english my language so sorry for some mistakes :D

#include <LiquidCrystal_I2C.h>
#include <SHT2x.h>
#include <Wire.h>


#define I2C_ADDR    0x27                    //address of the 
#define LCD_COLUMNS 16
#define LCD_LINES   2

//-------------CONSTANTS-------------

const int ledRead = 4;                      //GREEN LED signaling when the sensor is reading
const int ledError = 2;                     //RED LED signaling when error with sensor ocured
const int ledWaiting = 3;                   //YELLOW LED signaling when its waiting for input or interval run out (see interval for interval change)
const int ledRUN = 5;                       //GREEN LED signaling when the program runs (constant on)
const int buttonLight = 6;                  //Button for lightninh the screen with back light
const int buttonYellow = 7;                 //Button which is not implemented yet (probably for restart or instant read)

//-------------variables-------------

float temperature = 0;                       //variable for storing temperature
float humidity = 0;                          //variable for storing humidity
bool digitalSwitch = false;                  //boolean for storing ON OFF state of back light
unsigned long errorCode = 0;                 //variable for storing current error code
unsigned long errorCodeBefore = 0;           //variable for storing previous error code
unsigned long previousMillis = 0;            //variable that stores time at the start of the timer (waiting period)
const long interval = 2500;                  //<----- you can customize the interval of the waiting period 

SHT2x sht;                                   //sht is the sensor (currently not in simulation)
LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);  //lcd is for the LCD I2C screen 


void setup() {
  pinMode(ledRUN, OUTPUT);
  digitalWrite(ledRUN, HIGH);
  Wire.begin();
  sht.begin();
  Serial.begin(115200);
  lcd.init();
  pinMode(ledRead, OUTPUT);
  pinMode(ledError, OUTPUT);
  pinMode(ledWaiting, OUTPUT);
  pinMode(ledWaiting, OUTPUT);
  pinMode(buttonLight, INPUT);
  pinMode(buttonYellow, INPUT);
  

  //lcd.backlight();
  //lcd.setCursor(0, 0);
  //lcd.print("Hello, world!");
  //lcd.noBacklight();
}


void loop() {
  digitalWrite(ledRead, HIGH);
  delay(500);
  sht.read();
  digitalWrite(ledRead, LOW);
  errorCode = sht.getError();
  if (errorCode != errorCodeBefore) {
    if (errorCode == 0) {
      errorCodeBefore = errorCode;
      digitalWrite(ledError, LOW);
      temperature = sht.getTemperature();
      humidity = sht.getHumidity();
      lcd.clear();
      lcd.setCursor(0,0);
      lcd.print("Temp: " + String(temperature));
      lcd.setCursor(0,1);
      lcd.print("Humi: " + String(humidity));

    } else if (errorCode == 130) {
      errorCodeBefore = errorCode;
      digitalWrite(ledError, HIGH);
      lcd.clear();
      lcd.setCursor(0,0);
      lcd.print("----ERR:0x" + String(errorCode,HEX) + "----");
      lcd.setCursor(0,1);
      lcd.print("---READ ERROR---");

    } else {
      errorCodeBefore = errorCode;
      digitalWrite(ledError, HIGH);
      lcd.clear();
      lcd.setCursor(0,0);
      lcd.print("----ERR:0x" + String(errorCode,HEX) + "----");
      lcd.setCursor(0,1);
      lcd.print("----DIFFERENT----");

    }
  } else if (errorCode == 0) {

    temperature = sht.getTemperature();
    humidity = sht.getHumidity();
    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("Temp: " + String(temperature));
    lcd.setCursor(0,1);
    lcd.print("Humi: " + String(humidity));

  }
  previousMillis = millis();
  digitalWrite(ledWaiting, HIGH);
  while (digitalRead(buttonLight) == LOW && digitalRead(buttonYellow) == LOW) {
    unsigned long currentMillis = millis();
     if (currentMillis - previousMillis >= interval) {
        break;
     }
  }
  digitalWrite(ledWaiting, LOW);
  if (digitalRead(buttonLight) == HIGH) {
    digitalSwitch = !digitalSwitch;
  }

  if (digitalSwitch) {
      lcd.backlight();
    } else {
      lcd.noBacklight();
  }
}