#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Wire.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, & Wire, OLED_RESET);
const int buttonUpPin = 25; // Pin untuk tombol Up
const int buttonDownPin = 26; // Pin untuk tombol Down
const int buttonCoinPin = 27; // Pin untuk tombol Coin
const int buttonNextPin = 14; // Pin untuk tombol Next
const int buttonBackPin = 12; // Pin untuk tombol Back

int menu=0;
int flag_coffee=0, flag_milk=0, flag_tea=0;
int pay_coffee=0, pay_milk=0, pay_tea=0;
int price_coffee=0, price_milk=0, price_tea=0;
unsigned long previousMillis = 0;
const unsigned long timeoutPeriod = 80000;

void setup() {
    pinMode(buttonUpPin, INPUT_PULLUP);
    pinMode(buttonDownPin, INPUT_PULLUP);
    pinMode(buttonCoinPin, INPUT_PULLUP);
    pinMode(buttonNextPin, INPUT_PULLUP);
    pinMode(buttonBackPin, INPUT_PULLUP);

    display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
    Serial.begin(19200);
    display.clearDisplay();
    display.setTextSize(2);
    display.setTextColor(SSD1306_WHITE);
    display.setCursor(18,13);
    display.println("VenDrink");
    display.setCursor(18,28);
    display.println("Machine");
    display.display();
    flag_coffee=0;
    flag_milk=0;
    flag_tea=0;  
    delay(2000);
}

void loop() {
unsigned long currentMillis = millis();
static unsigned long previousTimeoutMillis = 0;
if ((pay_coffee == 1 || pay_milk == 1 || pay_tea == 1) && ((currentMillis - previousTimeoutMillis) >= timeoutPeriod))
{
  pay_coffee=0;
  pay_milk=0;
  pay_tea=0;
  menu = 10;
  previousTimeoutMillis = currentMillis;
  previousMillis = currentMillis;
}
if(digitalRead(buttonDownPin)==0){
  delay(200);
  menu++;
  if(menu>2){
    menu=2;
    }
}
if(digitalRead(buttonUpPin)==0){
  delay(200);
  menu--;
  if(menu<0){
    menu=0;
    }
}
if(digitalRead(buttonBackPin)==0){
  delay(200);
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(18,13);
  display.println("VenDrink");
  display.setCursor(18,28);
  display.println("Machine");
  display.display();
  flag_coffee=0;
  flag_milk=0;
  flag_tea=0;
  pay_coffee=0;
  pay_milk=0;
  pay_tea=0;
  price_coffee=0;
  price_milk=0;
  price_tea=0;
  delay(2000);
  menu=0;
}

/////////////// Pilih Menu ////////////////////
if(flag_coffee==1 && digitalRead(buttonNextPin)==0) delay(200), pay_coffee=1;
if(pay_coffee==1) menu=3;
if(flag_milk==1 && digitalRead(buttonNextPin)==0) delay(200), pay_milk=1;
if(pay_milk==1) menu=4;
if(flag_tea==1 && digitalRead(buttonNextPin)==0) delay(200), pay_tea=1;
if(pay_tea==1) menu=5;

/////////////// Payment ////////////////////
if(flag_coffee==1 && digitalRead(buttonCoinPin)==0) {
  delay(200);
  price_coffee++;
  if(price_coffee>3) price_coffee=3;
  pay_coffee=0;
  menu=5+price_coffee;
}
if(flag_milk==1 && digitalRead(buttonCoinPin)==0) {
  delay(200);
  price_milk++;
  if(price_milk>2) price_milk=2;
  pay_milk=0;
  menu=5+price_milk;
}

if(flag_tea==1 && digitalRead(buttonCoinPin)==0) {
delay(200);
price_tea++;
if(price_tea>1) price_tea=1;
pay_tea=0;
menu=5+price_tea;
}

/////////////// Double Cek ////////////////////
if(price_coffee==3){
  delay(200);
  menu=9;
}
if(price_milk==2){
  delay(200);
  menu=9;
}
if(price_tea==1){
  delay(200);
  menu=9;
}

switch (menu) {
  case 0: //Coffee
  display.clearDisplay();
  display.setTextSize(1.5);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(10,5);
  display.println("List Menu :");
  display.setCursor(10,20);
  display.setTextSize(1);
  display.println(">>> 1. Coffee");
  display.setCursor(15,30);
  display.println("2. Milk");
  display.setCursor(15,40);
  display.println("3. Tea");
  display.setCursor(100,50);
  display.println("OK");
  display.setCursor(0,50);
  display.println("Back");
  display.display();
  flag_coffee=1;
  flag_milk=0;
  flag_tea=0;
  break;

  case 1: //Milk
  display.clearDisplay();
  display.setTextSize(1.5);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(10,5);
  display.println("List Menu :");
  display.setCursor(10,20);
  display.setTextSize(1);
  display.println("1. Coffee");
  display.setCursor(15,30);
  display.println(">>> 2. Milk");
  display.setCursor(15,40);
  display.println("3. Tea");
  display.setCursor(100,50);
  display.println("OK");
  display.setCursor(0,50);
  display.println("Back");
  display.display();
  flag_coffee=0;
  flag_milk=1;
  flag_tea=0;
  break;

  case 2: //Tea
  display.clearDisplay();
  display.setTextSize(1.5);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(10,5);
  display.println("List Menu :");
  display.setCursor(10,20);
  display.setTextSize(1);
  display.println("1. Coffee");
  display.setCursor(15,30);
  display.println("2. Milk");
  display.setCursor(15,40);
  display.println(">>> 3. Tea");
  display.setCursor(100,50);
  display.println("OK");
  display.setCursor(0,50);
  display.println("Back");
  display.display();
  flag_coffee=0;
  flag_milk=0;
  flag_tea=1;
  break;

  case 3: // Payment Kopi
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(18,0);
  display.println("PRICE");
  display.setTextSize(1.5);
  display.setCursor(38,22);
  display.println("$3");
  display.display();
  if (digitalRead(buttonNextPin) == 0)
  {
  delay(250);
  previousMillis = currentMillis;
  pay_coffee = 1;
  }
  break;

  case 4: // Payment Susu
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(18,0);
  display.println("PRICE");
  display.setTextSize(1.5);
  display.setCursor(38,22);
  display.println("$2");
  display.display();
  if (digitalRead(buttonNextPin) == 0)
  {
  delay(250);
  previousMillis = currentMillis;
  pay_milk = 1;
  }
  break;

  case 5: // Payment Teh
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(18,0);
  display.println("PRICE");
  display.setTextSize(1.5);
  display.setCursor(38,22);
  display.println("$1");
  display.display();
  if (digitalRead(buttonNextPin) == 0)
  {
  delay(250);
  previousMillis = currentMillis;
  pay_tea = 1;
  }
  break;

  case 6: // 3000
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0,0);
  display.println("Your Coin");
  display.setTextSize(1.5);
  display.setCursor(38,22);
  display.println("$1");
  display.display();
  break;

  case 7: // 2000
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0,0);
  display.println("Your Coin");
  display.setTextSize(1.5);
  display.setCursor(38,22);
  display.println("$2");
  display.display();
  break;

  case 8: // 1000
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0,0);
  display.println("Your Coin");
  display.setTextSize(1.5);
  display.setCursor(38,22);
  display.println("$3");
  display.display();
  break;

  case 9: // Diterima
  display.clearDisplay();
  display.setTextSize(1.5);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(10,0);
  display.println("Your Payment");
  display.setCursor(12,15);
  display.println("Accepted");
  display.display();
  delay(2000);
  flag_coffee = 0;
  flag_milk = 0;
  flag_tea = 0;
  pay_coffee = 0;
  pay_milk = 0;
  pay_tea = 0;
  price_coffee = 0;
  price_milk = 0;
  price_tea = 0;
  menu = 0;
  break;

  case 10: // Timeout
  display.clearDisplay();
  display.setTextSize(1.5);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(10,0);
  display.println("TIMEOUT");
  display.setCursor(12,15);
  display.println("Try Again");
  display.display();
  delay(2000);
  menu = 0;
  // previousMillis = 0;
  // currentMillis = 0;
  // previousTimeoutMillis = 0;
  break;
}
}