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

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

// 按鈕腳位
#define BT1 2   // 上
#define BT2 3   // 下
#define BT3 4   // 確認
#define BT4 5   // 返回

const char* menuItems[] = {"Class", "Number", "Name"};
const int menuSize = 3;

int menuIndex = 0;
bool inSubMenu = false;

// 防彈跳處理
const unsigned long debounceDelay = 150;
unsigned long lastPressTime_BT1 = 0;
unsigned long lastPressTime_BT2 = 0;
unsigned long lastPressTime_BT3 = 0;
unsigned long lastPressTime_BT4 = 0;

bool lastBT1 = HIGH;
bool lastBT2 = HIGH;
bool lastBT3 = HIGH;
bool lastBT4 = HIGH;

void setup() {
  pinMode(BT1, INPUT_PULLUP);
  pinMode(BT2, INPUT_PULLUP);
  pinMode(BT3, INPUT_PULLUP);
  pinMode(BT4, INPUT_PULLUP);

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    for (;;);
  }

  displayBootScreen();  // 開機動畫
  displayMenu();        // 顯示主選單
}

void loop() {
  unsigned long now = millis();

  bool currentBT1 = digitalRead(BT1);
  bool currentBT2 = digitalRead(BT2);
  bool currentBT3 = digitalRead(BT3);
  bool currentBT4 = digitalRead(BT4);

  if (!inSubMenu) {
    if (lastBT1 == HIGH && currentBT1 == LOW && (now - lastPressTime_BT1 > debounceDelay)) {
      lastPressTime_BT1 = now;
      moveCursorUp();
    }

    if (lastBT2 == HIGH && currentBT2 == LOW && (now - lastPressTime_BT2 > debounceDelay)) {
      lastPressTime_BT2 = now;
      moveCursorDown();
    }

    if (lastBT3 == HIGH && currentBT3 == LOW && (now - lastPressTime_BT3 > debounceDelay)) {
      lastPressTime_BT3 = now;
      displaySubMenu();
    }
  } else {
    if (lastBT4 == HIGH && currentBT4 == LOW && (now - lastPressTime_BT4 > debounceDelay)) {
      lastPressTime_BT4 = now;
      inSubMenu = false;
      displayMenu();
    }
  }

  lastBT1 = currentBT1;
  lastBT2 = currentBT2;
  lastBT3 = currentBT3;
  lastBT4 = currentBT4;
}

void displayBootScreen() {
  for (int i = 0; i < 6; i++) { // 閃爍 6 次
    display.clearDisplay();
    if (i % 2 == 0) {
      display.setTextSize(3);
      display.setTextColor(SSD1306_WHITE);
      int16_t x, y;
      uint16_t w, h;
      display.getTextBounds("CTAS", 0, 0, &x, &y, &w, &h);
      int centerX = (SCREEN_WIDTH - w) / 2;
      int centerY = (SCREEN_HEIGHT - h) / 2;
      display.setCursor(centerX, centerY);
      display.print("CTAS");
    }
    display.display();
    delay(500);
  }
}

void moveCursorUp() {
  menuIndex--;
  if (menuIndex < 0) menuIndex = menuSize - 1;
  displayMenu();
}

void moveCursorDown() {
  menuIndex++;
  if (menuIndex >= menuSize) menuIndex = 0;
  displayMenu();
}

void displayMenu() {
  display.clearDisplay();

  // 標題 Menu（置中）
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  int16_t x, y;
  uint16_t w, h;
  display.getTextBounds("Menu", 0, 0, &x, &y, &w, &h);
  int centerX = (SCREEN_WIDTH - w) / 2;
  display.setCursor(centerX, 0);
  display.println("Menu");
  display.drawLine(0, 10, SCREEN_WIDTH, 10, SSD1306_WHITE); // 標題下劃線

  // 顯示選單（反白選項）
  for (int i = 0; i < menuSize; i++) {
    int itemY = 12 + i * 10;
    if (i == menuIndex) {
      // 黑底白字反白選項
      display.setTextColor(SSD1306_BLACK, SSD1306_WHITE);
      display.fillRect(0, itemY, SCREEN_WIDTH, 10, SSD1306_WHITE);
    } else {
      // 正常白字
      display.setTextColor(SSD1306_WHITE, SSD1306_BLACK);
    }
    display.setCursor(0, itemY);
    display.print(menuItems[i]);
  }

  display.display();
}

void displaySubMenu() {
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);

  if (menuIndex == 0) display.println("Class: I2A");
  else if (menuIndex == 1) display.println("Number: 48");
  else if (menuIndex == 2) display.println("Name: Jackson_Li");

  display.display();
  inSubMenu = true;
}
*/
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

// 按鈕腳位
#define BT1 2   // 上
#define BT2 3   // 下
#define BT3 4   // 確認
#define BT4 5   // 返回

const char* menuItems[] = {"Black tea","Green tea","Milk tea","Pearl milk tea","Winter melon lemon"};
const int menuSize = 5;

int menuIndex = 0;
bool inSubMenu = false;

// 防彈跳處理
const unsigned long debounceDelay = 150;
unsigned long lastPressTime_BT1 = 0;
unsigned long lastPressTime_BT2 = 0;
unsigned long lastPressTime_BT3 = 0;
unsigned long lastPressTime_BT4 = 0;

bool lastBT1 = HIGH;
bool lastBT2 = HIGH;
bool lastBT3 = HIGH;
bool lastBT4 = HIGH;

void setup() {
  pinMode(BT1, INPUT_PULLUP);
  pinMode(BT2, INPUT_PULLUP);
  pinMode(BT3, INPUT_PULLUP);
  pinMode(BT4, INPUT_PULLUP);

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    for (;;);
  }

  displayBootScreen();  // 開機動畫
  displayMenu();        // 顯示主選單
}

void loop() {
  unsigned long now = millis();

  bool currentBT1 = digitalRead(BT1);
  bool currentBT2 = digitalRead(BT2);
  bool currentBT3 = digitalRead(BT3);
  bool currentBT4 = digitalRead(BT4);

  if (!inSubMenu) {
    if (lastBT1 == HIGH && currentBT1 == LOW && (now - lastPressTime_BT1 > debounceDelay)) {
      lastPressTime_BT1 = now;
      moveCursorUp();
    }

    if (lastBT2 == HIGH && currentBT2 == LOW && (now - lastPressTime_BT2 > debounceDelay)) {
      lastPressTime_BT2 = now;
      moveCursorDown();
    }

    if (lastBT3 == HIGH && currentBT3 == LOW && (now - lastPressTime_BT3 > debounceDelay)) {
      lastPressTime_BT3 = now;
      displaySubMenu();
    }
  } else {
    if (lastBT4 == HIGH && currentBT4 == LOW && (now - lastPressTime_BT4 > debounceDelay)) {
      lastPressTime_BT4 = now;
      inSubMenu = false;
      displayMenu();
    }
  }

  lastBT1 = currentBT1;
  lastBT2 = currentBT2;
  lastBT3 = currentBT3;
  lastBT4 = currentBT4;
}

void displayBootScreen() {
  for (int i = 0; i < 6; i++) { // 閃爍 6 次
    display.clearDisplay();
    if (i % 2 == 0) {
      display.setTextSize(3);
      display.setTextColor(SSD1306_WHITE);
      int16_t x, y;
      uint16_t w, h;
      display.getTextBounds("E2B", 0, 0, &x, &y, &w, &h);
      int centerX = (SCREEN_WIDTH - w) / 2;
      int centerY = (SCREEN_HEIGHT - h) / 2;
      display.setCursor(centerX, centerY);
      display.println("E2B");
    }
    display.display();
    delay(500);
  }
}

void moveCursorUp() {
  menuIndex--;
  if (menuIndex < 0) menuIndex = menuSize - 1;
  displayMenu();
}

void moveCursorDown() {
  menuIndex++;
  if (menuIndex >= menuSize) menuIndex = 0;
  displayMenu();
}

void displayMenu() {
  display.clearDisplay();

  // 標題 Menu（置中）
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  int16_t x, y;
  uint16_t w, h;
  display.getTextBounds("Tea Drink", 0, 0, &x, &y, &w, &h);
  int centerX = (SCREEN_WIDTH - w) / 2;
  display.setCursor(centerX, 0);
  display.println("Tea Drink");
  display.drawLine(0, 10, SCREEN_WIDTH, 10, SSD1306_WHITE); // 標題下劃線

  // 顯示選單（反白選項）
  for (int i = 0; i < menuSize; i++) {
    int itemY = 12 + i * 10;
    if (i == menuIndex) {
      // 黑底白字反白選項
      display.setTextColor(SSD1306_BLACK, SSD1306_WHITE);
      display.fillRect(0, itemY, SCREEN_WIDTH, 10, SSD1306_WHITE);
    } else {
      // 正常白字
      display.setTextColor(SSD1306_WHITE, SSD1306_BLACK);
    }
    display.setCursor(0, itemY);
    display.print(menuItems[i]);
  }

  display.display();
}

void displaySubMenu() {
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);

  if (menuIndex == 0) display.println("Black tea-$30");
  else if (menuIndex == 1) display.println("Green tea-30");
  else if (menuIndex == 2) display.println("Milk tea-40");
  else if (menuIndex == 3) display.println("Pearl milk tea-50");
  else if (menuIndex == 4) display.println("Winter melon lemon-55");
  display.display();
  inSubMenu = true;
}