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

// OLED 設定
#define I2C_MASTER_SCL_IO    10    /*!< gpio number for I2C master clock */
#define I2C_MASTER_SDA_IO    9     /*!< gpio number for I2C master data */
#define OLED_ADDR            0x3C  /*!< SSD1306 I2C address */
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

// Keypad 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] = {21, 20, 19, 18};
byte colPins[COLS] = {17, 16, 15, 14};
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

// 密碼相關設定
String correctPassword = "1234";
String inputPassword = "";
int attempts = 0;

// 蜂鳴器
#define BUZZER_PIN 13

void setup() {
  Serial.begin(115200);

  // 初始化 Wire (I2C)
  Wire.begin(SDA_PIN, SCL_PIN);
  if (!display.begin(SSD1306_SWITCHCAPVCC, OLED_ADDR, &Wire, -1)) {
    Serial.println("SSD1306 初始化失敗！");
    for (;;);
  }
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.println("密碼鎖系統啟動");
  display.display();
  delay(2000);
  display.clearDisplay();

  // 初始化蜂鳴器
  pinMode(BUZZER_PIN, OUTPUT);
  digitalWrite(BUZZER_PIN, LOW);
}

void loop() {
  char key = keypad.getKey(); // 讀取按鍵
  if (key) {
    handleKeyPress(key);
  }
}

void handleKeyPress(char key) {
  if (key == '#') { // # 作為確認鍵
    if (inputPassword == correctPassword) {
      unlock();
    } else {
      attempts++;
      if (attempts >= 3) {
        triggerAlarm();
      } else {
        displayMessage("密碼錯誤！");
      }
    }
    inputPassword = ""; // 清空輸入
  } else if (key == '*') { // * 作為清除鍵
    inputPassword = "";
    displayMessage("密碼已清除");
  } else { // 數字鍵輸入
    inputPassword += key;
    updatePasswordDisplay();
  }
}

void updatePasswordDisplay() {
  display.clearDisplay();
  display.setCursor(0, 0);
  display.print("輸入密碼: ");
  for (size_t i = 0; i < inputPassword.length(); i++) {
    display.print("*"); // 顯示星號代替密碼
  }
  display.display();
}

void unlock() {
  display.clearDisplay();
  display.setCursor(0, 0);
  display.println("密碼正確！系統解鎖");
  display.display();
  digitalWrite(BUZZER_PIN, HIGH);
  delay(1000);
  digitalWrite(BUZZER_PIN, LOW);
  delay(2000);
  attempts = 0; // 重置錯誤次數
}

void triggerAlarm() {
  display.clearDisplay();
  display.setCursor(0, 0);
  display.println("密碼錯誤次數過多！");
  display.display();
  for (int i = 0; i < 5; i++) {
    digitalWrite(BUZZER_PIN, HIGH);
    delay(500);
    digitalWrite(BUZZER_PIN, LOW);
    delay(500);
  }
  attempts = 0; // 重置錯誤次數
}

void displayMessage(String message) {
  display.clearDisplay();
  display.setCursor(0, 0);
  display.println(message);
  display.display();
  delay(2000);
}