#include "U8g2lib.h"

// Initialize the U8G2 library for the SSD1306 OLED display with I²C
U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/U8X8_PIN_NONE);

#define BUTTON1_PIN 32  // Button for Screen 0
#define BUTTON2_PIN 33  // Button for Screen 1
#define BUTTON3_PIN 25  // Button to toggle screens

int current_screen = 0; // 0: initial screen, 1: Screen 0, 2: Screen 1, 3: Screen 2

void setup() {
    // Initialize pins for buttons
    pinMode(BUTTON1_PIN, INPUT_PULLUP);
    pinMode(BUTTON2_PIN, INPUT_PULLUP);
    pinMode(BUTTON3_PIN, INPUT_PULLUP);

    // Initialize the OLED display
    u8g2.begin();
}

void loop() {
    // Button logic to change screens
    if (digitalRead(BUTTON1_PIN) == LOW) {
        current_screen = (current_screen == 1) ? 0 : 1; // Toggle Screen 0
        delay(200); // Debounce delay
    } else if (digitalRead(BUTTON2_PIN) == LOW) {
        current_screen = (current_screen == 2) ? 0 : 2; // Toggle Screen 1
        delay(200); // Debounce delay
    } else if (digitalRead(BUTTON3_PIN) == LOW) {
        current_screen = (current_screen + 1) % 4; // Toggle through screens
        delay(200); // Debounce delay
    }

    // Display logic
    u8g2.firstPage();
    do {
        if (current_screen == 0) {
            // Initial screen with options
            u8g2.setFont(u8g2_font_ncenB08_tr);
            u8g2.drawStr(10, 20, "Select a Screen:");
            u8g2.drawStr(10, 40, "1: Screen 0");
            u8g2.drawStr(10, 60, "2: Screen 1");
            u8g2.drawStr(10, 80, "3: Screen 2");
        } else if (current_screen == 1) {
            // Screen 0
            u8g2.setFont(u8g2_font_ncenB08_tr);
            u8g2.drawStr(30, 30, "Screen 0");
        } else if (current_screen == 2) {
            // Screen 1
            u8g2.setFont(u8g2_font_ncenB08_tr);
            u8g2.drawStr(30, 30, "Screen 1");
        } else if (current_screen == 3) {
            // Screen 2 (QR Code Display)
            u8g2.setFont(u8g2_font_ncenB08_tr);
            u8g2.drawStr(30, 30, "Screen 2: QR Code");
            // Placeholder for QR Code: replace with actual QR Code generation
            u8g2.drawBox(40, 40, 50, 50); // Placeholder box
        }
    } while (u8g2.nextPage());
}