#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Keypad.h>

#define PIR_PIN 13
#define OLED_ADDR 0x3C
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

// 初始化 LCD 顯示（兩個 LCD 使用不同 I2C 位址）
LiquidCrystal_I2C lcd1(0x27, 16, 2);  // LCD1：帳號密碼輸入
LiquidCrystal_I2C lcd2(0x26, 16, 2);  // LCD2：PIR 偵測結果

// 初始化 OLED 顯示
Adafruit_SSD1306 oled(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

// 鍵盤設定
const byte ROWS = 4;
const byte COLS = 4;
char keys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};
byte rowPins[ROWS] = {2, 4, 5, 18};
byte colPins[COLS] = {19, 23, 33, 32};
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

// 預設帳號與密碼
String correctUsername = "1234";
String correctPassword = "5678";

String input = "";
String username = "";
String password = "";
bool enteringUsername = true;

void setup() {
  pinMode(PIR_PIN, INPUT);

  lcd1.begin(16, 2);
  lcd1.backlight();
  lcd2.begin(16, 2);
  lcd2.backlight();

  oled.begin(SSD1306_SWITCHCAPVCC, OLED_ADDR);
  oled.clearDisplay();
  oled.setTextSize(1);
  oled.setTextColor(SSD1306_WHITE);
  oled.setCursor(0, 0);
  oled.print("System Start");
  oled.display();

  lcd1.setCursor(0, 0);
  lcd1.print("Enter username:");
  lcd2.setCursor(0, 0);
  lcd2.print("No intrusion");
}

void loop() {
  char key = keypad.getKey();
  if (key) {
    if (key >= '0' && key <= '9') {
      input += key;
    } else if (key == 'C') {
      input = "";
    } else if (key == 'D') {
      if (enteringUsername) {
        username = input;
        input = "";
        enteringUsername = false;
        lcd1.clear();
        lcd1.print("Enter password:");
      } else {
        password = input;
        input = "";
        validateLogin();
      }
    }

    // 顯示輸入中內容
    lcd1.setCursor(0, 1);
    lcd1.print("                "); // 清空第二行
    lcd1.setCursor(0, 1);
    lcd1.print(input);
  }

  // PIR 偵測顯示（只更新狀態改變時才清除/更新內容）
  static bool previousState = false;
  bool motionDetected = digitalRead(PIR_PIN);

  if (motionDetected != previousState) {
    previousState = motionDetected;
    lcd2.clear();
    lcd2.setCursor(0, 0);
    if (motionDetected) {
      lcd2.print("Intrusion");
      lcd2.setCursor(0, 1);
      lcd2.print("Detected!");
    } else {
      lcd2.print("No intrusion");
    }
  }

  delay(100);
}

void validateLogin() {
  lcd1.clear();
  if (username == correctUsername && password == correctPassword) {
    lcd1.print("Access granted");
  } else {
    lcd1.print("Invalid login");
    delay(2000);
    input = "";
    username = "";
    password = "";
    enteringUsername = true;
    lcd1.clear();
    lcd1.print("Enter username:");
  }
}