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

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
#define OLED_RESET -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// Keypad setup
const byte ROWS = 4; // Four rows
const byte COLS = 4; // Four columns
char keys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};
byte rowPins[ROWS] = {9, 8, 7, 6}; // Connect to the row pinouts of the keypad
byte colPins[COLS] = {5, 4, 3, 2}; // Connect to the column pinouts of the keypad
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

void setup() {
  Serial.begin(9600);

  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3C for 128x64
    Serial.println(F("SSD1306 allocation failed"));
    for (;;); // Don't proceed, loop forever
  }

  display.clearDisplay();
  display.setTextSize(1); // Normal 1:1 pixel scale
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.println("Keypad Test");
  display.display();
}

void loop() {
  char key = keypad.getKey();

  if (key) {
    display.clearDisplay();
    display.setCursor(0, 0);
    display.setTextSize(2); // Set text size larger for better readability

    switch (key) {
      case 'A':
        display.println("Welcome");
        break;
      case 'B':
        display.println("Safe is");
        display.setCursor(0, 15);
        display.println("Unlocked");
        break;
      case 'C':
        display.println("Set");
        display.setCursor(0, 15);
        display.println("Password");
        break;
      case 'D':
        display.println("Locked");
        break;
      default:
        display.println("KeyPressed:");
        display.setCursor(10, 20);
        display.print(key);
        break;
    }

    display.display();
  }
}