// Type inference (Dart รู้ type เอง)
var name = "John";
var age = 25;
var isActive = true;

// Explicit type
String email = "john@example.com";
int count = 10;
double price = 99.99;
bool isDark = false;

// Final (กำหนดค่าได้ครั้งเดียว)
final userId = "123";

// Const (ค่าคงที่ตอน compile)
const apiUrl = "https://api.example.com";

// Function with return type
String greet(String name) {
  return "Hello, $name!";
}

// Arrow function (สำหรับ expression เดียว)
String greet(String name) => "Hello, $name!";

// Optional parameters
void printInfo(String name, {int? age, String? city}) {
  print("Name: $name");
  if (age != null) print("Age: $age");
  if (city != null) print("City: $city");
}

// Usage
printInfo("John", age: 25);
printInfo("Jane", city: "Bangkok");

// Non-nullable (ห้ามเป็น null)
String name = "John";
// name = null; // ❌ Error!

// Nullable (อนุญาตให้เป็น null)
String? email; // email เป็น null ได้
email = "test@example.com";
email = null; // ✅ OK

// Null-aware operators
String? username;
print(username ?? "Guest"); // ถ้า username เป็น null ใช้ "Guest"

String? displayName;
print(displayName?.toUpperCase()); // ถ้า displayName เป็น null จะไม่เรียก toUpperCase()

// List (Array)
List<String> fruits = ["Apple", "Banana", "Orange"];
fruits.add("Mango");
print(fruits[0]); // Apple
print(fruits.length); // 4

// Map (Dictionary/Object)
Map<String, dynamic> user = {
  "name": "John",
  "age": 25,
  "email": "john@example.com"
};
print(user["name"]); // John

// Set (ไม่มีค่าซ้ำ)
Set<int> numbers = {1, 2, 3, 3, 4};
print(numbers); // {1, 2, 3, 4}

class User {
  String name;
  int age;
  
  // Constructor
  User(this.name, this.age);
  
  // Named constructor
  User.guest() : name = "Guest", age = 0;
  
  // Method
  void introduce() {
    print("Hi, I'm $name, $age years old");
  }
}

// Usage
var user1 = User("John", 25);
user1.introduce(); // Hi, I'm John, 25 years old

var guest = User.guest();
guest.introduce(); // Hi, I'm Guest, 0 years old

import 'package:flutter/material.dart';
import 'package:google_fonts/google_fonts.dart';
import 'screens/splash_screen.dart';
import 'services/theme_controller.dart';
import 'services/language_controller.dart';
import 'theme/app_theme.dart';

void main() {
  WidgetsFlutterBinding.ensureInitialized();
  runApp(const QuomApp());
}

class QuomApp extends StatelessWidget {
  const QuomApp({super.key});

  @override
  Widget build(BuildContext context) {
    return ValueListenableBuilder<ThemeMode>(
      valueListenable: ThemeController.instance.themeMode,
      builder: (context, mode, child) {
        return ValueListenableBuilder<Locale>(
          valueListenable: LanguageController.instance.locale,
          builder: (context, locale, child) {
            return MaterialApp(
              debugShowCheckedModeBanner: false,
              title: 'QUOM',
              theme: _enhanceWithFonts(AppTheme.light()),
              darkTheme: _enhanceWithFonts(AppTheme.dark()),
              themeMode: mode,
              locale: locale,
              home: const SplashScreen(),
            );
          },
        );
      },
    );
  }
}

class QuomApp extends StatelessWidget {
  const QuomApp({super.key});

@override
Widget build(BuildContext context) {
  return MaterialApp(...);
}

return MaterialApp(
  debugShowCheckedModeBanner: false,
  title: 'QUOM',
  theme: _enhanceWithFonts(AppTheme.light()),
  darkTheme: _enhanceWithFonts(AppTheme.dark()),
  themeMode: mode,
  locale: locale,
  home: const SplashScreen(),
);

return ValueListenableBuilder<ThemeMode>(
  valueListenable: ThemeController.instance.themeMode,
  builder: (context, mode, child) {
    // UI จะ rebuild เมื่อ themeMode เปลี่ยน
    return MaterialApp(
      themeMode: mode,
      ...
    );
  },
);

ThemeData _enhanceWithFonts(ThemeData theme) {
  final textTheme = GoogleFonts.promptTextTheme(theme.textTheme);
  
  return theme.copyWith(
    textTheme: textTheme.copyWith(
      displayLarge: GoogleFonts.prompt(
        color: theme.colorScheme.onSurface,
        fontWeight: FontWeight.bold,
      ),
      titleLarge: GoogleFonts.prompt(
        color: theme.colorScheme.onSurface,
        fontWeight: FontWeight.w700,
      ),
      bodyLarge: GoogleFonts.prompt(
        color: theme.colorScheme.onSurface,
        height: 1.5,
      ),
    ),
  );
}

class GreetingWidget extends StatelessWidget {
  final String name;
  
  const GreetingWidget({required this.name, super.key});
  
  @override
  Widget build(BuildContext context) {
    return Text("Hello, $name!");
  }
}

// Usage
GreetingWidget(name: "John")

class CounterWidget extends StatefulWidget {
  const CounterWidget({super.key});
  
  @override
  State<CounterWidget> createState() => _CounterWidgetState();
}

class _CounterWidgetState extends State<CounterWidget> {
  int count = 0;
  
  void increment() {
    setState(() {
      count++;
    });
  }
  
  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        Text("Count: $count"),
        ElevatedButton(
          onPressed: increment,
          child: Text("Increment"),
        ),
      ],
    );
  }
}

MaterialApp
  └─ SplashScreen
       └─ Scaffold
            ├─ AppBar
            │    └─ Text
            └─ Body
                 └─ Center
                      └─ Column
                           ├─ Image
                           ├─ Text
                           └─ CircularProgressIndicator

Text(
  "Hello, World!",
  style: TextStyle(
    fontSize: 24,
    fontWeight: FontWeight.bold,
    color: Colors.blue,
  ),
)

Container(
  width: 200,
  height: 100,
  padding: EdgeInsets.all(16),
  margin: EdgeInsets.symmetric(vertical: 8),
  decoration: BoxDecoration(
    color: Colors.blue,
    borderRadius: BorderRadius.circular(16),
    boxShadow: [
      BoxShadow(
        color: Colors.black.withOpacity(0.2),
        blurRadius: 10,
        offset: Offset(0, 4),
      ),
    ],
  ),
  child: Text("Container"),
)

// Column (แนวตั้ง)
Column(
  mainAxisAlignment: MainAxisAlignment.center,
  crossAxisAlignment: CrossAxisAlignment.start,
  children: [
    Text("Item 1"),
    Text("Item 2"),
    Text("Item 3"),
  ],
)

// Row (แนวนอน)
Row(
  mainAxisAlignment: MainAxisAlignment.spaceBetween,
  children: [
    Icon(Icons.home),
    Icon(Icons.search),
    Icon(Icons.settings),
  ],
)

ElevatedButton(
  onPressed: () {
    print("Button pressed!");
  },
  style: ElevatedButton.styleFrom(
    backgroundColor: Colors.blue,
    padding: EdgeInsets.symmetric(horizontal: 32, vertical: 16),
    shape: RoundedRectangleBorder(
      borderRadius: BorderRadius.circular(12),
    ),
  ),
  child: Text("Click Me"),
)

TextField(
  controller: emailController,
  keyboardType: TextInputType.emailAddress,
  decoration: InputDecoration(
    labelText: "Email",
    hintText: "Enter your email",
    prefixIcon: Icon(Icons.email),
    border: OutlineInputBorder(
      borderRadius: BorderRadius.circular(12),
    ),
  ),
)

// TODO: สร้าง ProfileCard widget ที่รับ name และ email
// แสดงเป็น Card พร้อม Icon, ชื่อ, และ email

// TODO: สร้าง TodoItem widget ที่มี checkbox
// เมื่อกด checkbox ให้ขีดฆ่าข้อความ

// TODO: สร้างหน้า Login ที่มี:
// - Logo (Image)
// - Email TextField
// - Password TextField
// - Login Button
// ใช้ Column, Container, และ TextField