#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 20, 4);

int continuousPin = 6, automaticPin = 4; //Wahlschalter für manuelles Schweißen und Schweißen mit Timer
int startPin = 5; //Start Taster
int relaisPin = 7; //Solid-State-Relais Ausgang
int delayPin = A0; //Poti für Schweißzeit
int ledPinCont = 11, ledPinAuto = 13, ledPinWelding = 12;

bool oldMode = 0;
int weldingMS = 0;

void setup() {
  Serial.begin(9600);
  pinMode(continuousPin, INPUT_PULLUP);
  pinMode(automaticPin, INPUT_PULLUP);
  pinMode(startPin, INPUT_PULLUP);
  pinMode(delayPin, INPUT);
  pinMode(relaisPin, OUTPUT);

  lcd.init();
  lcd.backlight();
  // lcd.setCursor(Zeichen, Zeile);
}

void loop() {
  bool continuous = digitalRead(continuousPin);
  bool automatic = digitalRead(automaticPin);
  int time = map(analogRead(delayPin), 0, 1023, 0, 100) * 50;
  if(time != weldingMS) {
    weldingMS = time;
  }
  
  if (digitalRead(startPin) != LOW) {
    lcd.setCursor(0, 0);
    lcd.print("Current Mode:       ");
    lcd.setCursor(0, 1);
    if(continuous) {
      lcd.print("Continuous / Manual ");
      lcd.setCursor(0, 2);
      lcd.print("                    ");
      lcd.setCursor(0, 3);
      lcd.print("Ready to Weld!      ");
    } else if (automatic) {
      lcd.print("Automatic / Timer   ");
      lcd.setCursor(0, 2);
      lcd.print("Welding time:       ");
      lcd.setCursor(14, 2);
      lcd.print(weldingMS);
      lcd.setCursor(0, 3);
      lcd.print("Ready to Weld!      ");
    }
  }

  if(continuous && !automatic) {
    if(oldMode != 0) {
      oldMode = 0;
    }
    weldContinuous();
  } else if(!continuous && automatic) {
    if(oldMode != 1) {
      oldMode = 1;
    }
    weldWithTimer(weldingMS);
  }
  delay(10);
}

void weldWithTimer(int timerMS) {
  if(!digitalRead(startPin)) {

    lcd.setCursor(0, 0);
    lcd.print("Welding!!!          ");
    lcd.setCursor(0, 1);
    lcd.print("                    ");
    lcd.setCursor(0, 2);
    lcd.print("Time remaining:     ");
    lcd.setCursor(0, 3);
    lcd.print("                    ");

    digitalWrite(relaisPin, HIGH);

    for(int i = timerMS; i > 0; i -= 50) {

      lcd.setCursor(0, 1);
      lcd.print("                    ");
      lcd.print((i));
      if(i < 1000) {
        lcd.setCursor(3, 3);
        lcd.print("ms               ");
      } else if(i >= 1000) {
        lcd.setCursor(4, 3);
        lcd.print("ms              ");
      }
      
      delay(50);
    }
    digitalWrite(relaisPin, LOW);
  }
}

void weldContinuous() {
  if (digitalRead(startPin) != LOW) {
    digitalWrite(relaisPin, LOW);
  } else {
    
    lcd.setCursor(0, 0);
    lcd.print("Welding!!!          ");
    lcd.setCursor(0, 1);
    lcd.print("                    ");
    lcd.setCursor(0, 2);
    lcd.print("                    ");
    lcd.setCursor(0, 3);
    lcd.print("                    ");

    digitalWrite(relaisPin, HIGH);
  }
}