// LCD1602 to Arduino Uno connection example

#include <LiquidCrystal.h>
uint8_t number = 0, previous = 1;
LiquidCrystal lcd(12, 11, 10, 9, 8, 7);
const char* words[] = {"Led Switch", "One", "Two", "Three", "Four", "Five"}; // Array of words
const char* words2[] = {"Led Switch", "two", "pin 13 Toggle", "analogread", "Four", "Five"}; // Array of words

bool ledstate = LOW;
volatile bool goback = false;

void functionZero();

void functionOne() {
  Serial.println("Function One is called.");
  // Add code for function one here
}

void functionTwo() {
  Serial.println("Function Two is called.");
  digitalWrite(13, ledstate);
  ledstate = !ledstate;
}

void functionThree() {
  Serial.println("Function Three is called.");
  // Add code for function three here
}

void functionFour() {
  Serial.println("Function Four is called.");
  // Add code for function four here
}


void analogread() {
  char buffer[12];
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("A0: ");
  lcd.setCursor(0, 1);
  lcd.print("Voltage        V");
  float volt = 0;
  for (;;) {
    goback = false;
    lcd.setCursor(12, 0);
    sprintf(buffer, "%4d", analogRead(A0));
    lcd.print(buffer);
    lcd.setCursor(10, 1);
    volt = (analogRead(A0) * 5.0) / 1023.0;
    lcd.setCursor(11, 1);
    lcd.print(volt);
    if (goback == true) {
      delay(200);
      Serial.println("Going Back");
      goback = false;
      return;
    }
  }
}
void (*functionList2[])() = {functionOne, functionZero, functionTwo, analogread, functionFour};
void (*functionList1[])() = {functionZero, functionOne, functionTwo, functionThree, functionFour};
void callFunction(int number, void (*functionList[])()) {
  void (*selectedFunction)() = functionList[number];
  selectedFunction(); // Call the selected function
}


// Define your functions
void functionZero() {
  Serial.println("Function Zero is called.");
  goback = false;
  uint8_t number2 = 0, previous2 = 1;
  delay(100);
  for (;;) {
    menu1(words2, number2, previous2);
    getbutton(number2, previous2, functionList2);
    if (goback == true) {
      delay(200);
      Serial.println("Going Back");
      goback = false;
      return;
    }
  }

  // Add code for function one here
}







void setup() {
  Serial.begin(9600);
  pinMode(2, INPUT_PULLUP);
  pinMode(3, INPUT_PULLUP);
  pinMode(4, INPUT_PULLUP);
  pinMode(5, INPUT_PULLUP);
  pinMode(13, OUTPUT);
  attachInterrupt(digitalPinToInterrupt(2), interrupt, FALLING);
  lcd.begin(16, 2);
}

void loop() {
  menu1(words, number, previous);
  getbutton(number, previous, functionList1);
}

void menu1(char* words[], uint8_t& number, uint8_t& previous) {
  if (previous != number) {
    lcd.clear();
    if (number % 2 == 0) {
      lcd.setCursor(1, 0);
      lcd.print(words[number]);
      lcd.setCursor(1, 1);
      lcd.print(words[number + 1]);
      lcd.setCursor(0, 0);
    } else {
      lcd.setCursor(1, 0);
      lcd.print(words[number - 1]);
      lcd.setCursor(1, 1);
      lcd.print(words[number]);
      lcd.setCursor(0, 1);
    }
    lcd.write(126);
    previous = number;
  }
}

void getbutton(uint8_t& number, uint8_t& previous, void (*functionList[])()) {
  if (digitalRead(3) == LOW) {
    number++;
    if (number == 6) {
      number = 5;
    }
    delay(100);
  }
  if (digitalRead(5) == LOW) {
    number--;
    if (number == 255) {
      number = 0;
    }
    delay(100);
  }
  if (digitalRead(4) == LOW) {
    previous = 100;
    callFunction(number, functionList);
    delay(100);
  }
}

void interrupt() {
  goback = true;
}