import 'package:flutter/material.dart';
import 'package:flutter/foundation.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:firebase_database/firebase_database.dart';
import '../widgets/fade_in_up.dart';

class RegisterPage extends StatefulWidget {
  const RegisterPage({super.key});

  @override
  State<RegisterPage> createState() => _RegisterPageState();
}

class _RegisterPageState extends State<RegisterPage> {
  final usernameController = TextEditingController();
  final emailController = TextEditingController();
  final passwordController = TextEditingController();
  final confirmPasswordController = TextEditingController();

  bool isLoading = false;
  bool obscurePassword = true;
  bool obscureConfirm = true;

  Future<void> registerUser() async {
    final username = usernameController.text.trim();
    final emailText = emailController.text.trim();
    final password = passwordController.text.trim();
    final confirmPassword = confirmPasswordController.text.trim();

    if (username.isEmpty || emailText.isEmpty || password.isEmpty || confirmPassword.isEmpty) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text("Semua kolom harus diisi")),
      );
      return;
    }

    if (password != confirmPassword) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text("Password dan Konfirmasi Password tidak cocok")),
      );
      return;
    }

    // Jika user memasukkan username sebagai email (tidak mengandung @)
    String email = emailText;
    if (!emailText.contains('@')) {
      email = "$emailText@safebite.com";
    }

    setState(() => isLoading = true);

    try {
      // 1. Create Firebase Auth user
      final userCredential = await FirebaseAuth.instance.createUserWithEmailAndPassword(
        email: email,
        password: password,
      );

      // 2. Update display name
      await userCredential.user?.updateDisplayName(username);

      // 3. Save user profile to Realtime Database under users/<uid>
      final db = FirebaseDatabase.instance.ref();
      await db.child("users").child(userCredential.user!.uid).set({
        "username": username,
        "email": email,
        "createdAt": DateTime.now().millisecondsSinceEpoch,
      });

      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text("Pendaftaran berhasil! Silakan login.")),
        );
        Navigator.pushReplacementNamed(context, '/login');
      }
    } on FirebaseAuthException catch (e) {
      String errorMessage = "Pendaftaran gagal";
      if (e.code == 'email-already-in-use') {
        errorMessage = "Email atau Username sudah terdaftar.";
      } else if (e.code == 'weak-password') {
        errorMessage = "Password terlalu lemah (minimal 6 karakter).";
      } else if (e.code == 'invalid-email') {
        errorMessage = "Format email tidak valid.";
      } else {
        errorMessage = e.message ?? "Pendaftaran gagal: ${e.code}";
      }
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text(errorMessage)),
        );
      }
    } catch (e) {
      debugPrint("Register Error: $e");
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text("Terjadi kesalahan: $e")),
        );
      }
    } finally {
      if (mounted) {
        setState(() => isLoading = false);
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Container(
        width: double.infinity,
        height: double.infinity,
        decoration: const BoxDecoration(
          gradient: LinearGradient(
            colors: [Colors.white, Color(0xFFE3F2FD), Color(0xFF42A5F5), Color(0xFF1565C0)],
            begin: Alignment.topLeft,
            end: Alignment.bottomRight,
            stops: [0.1, 0.4, 0.8, 1.0],
          ),
        ),
        child: SafeArea(
          child: Padding(
            padding: const EdgeInsets.symmetric(horizontal: 30),
            child: SingleChildScrollView(
              child: Column(
                children: [
                  const SizedBox(height: 50),

                  /// ===== LOGO =====
                  FadeInUp(
                    delay: 200,
                    child: Hero(
                      tag: 'app_logo',
                      child: Image.asset('assets/images/logo_formalin.png', height: 160),
                    ),
                  ),

                  const SizedBox(height: 40),

                  /// ===== INPUT =====
                  FadeInUp(
                    delay: 300,
                    child: Column(
                      children: [
                        _buildTextField(usernameController, "Username", Icons.person),
                        const SizedBox(height: 15),

                        _buildTextField(emailController, "Email", Icons.email),
                        const SizedBox(height: 15),

                        _buildTextField(
                          passwordController,
                          "Password",
                          Icons.lock,
                          isPassword: true,
                          isConfirm: false,
                        ),
                        const SizedBox(height: 15),

                        _buildTextField(
                          confirmPasswordController,
                          "Confirm Password",
                          Icons.lock,
                          isPassword: true,
                          isConfirm: true,
                        ),
                      ],
                    ),
                  ),

                  const SizedBox(height: 40),

                  /// ===== BUTTON =====
                  FadeInUp(
                    delay: 500,
                    child: Container(
                      width: double.infinity,
                      height: 55,
                      decoration: BoxDecoration(
                        color: Colors.white,
                        borderRadius: BorderRadius.circular(30),
                        boxShadow: [
                          BoxShadow(
                            color: const Color(0xFF1565C0).withOpacity(0.3),
                            blurRadius: 15,
                            offset: const Offset(0, 8),
                          ),
                        ],
                      ),
                      child: ElevatedButton(
                        onPressed: isLoading ? null : registerUser,
                        style: ElevatedButton.styleFrom(
                          backgroundColor: Colors.transparent,
                          shadowColor: Colors.transparent,
                          shape: RoundedRectangleBorder(
                            borderRadius: BorderRadius.circular(30),
                          ),
                        ),
                        child: isLoading
                            ? const CircularProgressIndicator(color: Color(0xFF1565C0))
                            : const Text(
                                "Sign Up",
                                style: TextStyle(
                                  fontSize: 18,
                                  fontWeight: FontWeight.bold,
                                  color: Color(0xFF1565C0),
                                  letterSpacing: 1.2,
                                ),
                              ),
                      ),
                    ),
                  ),

                  const SizedBox(height: 25),

                  /// ===== LOGIN TEXT =====
                  Row(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: [
                      const Text(
                        "Already have an Account? ",
                        style: TextStyle(color: Colors.white70),
                      ),
                      GestureDetector(
                        onTap: () {
                          Navigator.pushNamed(context, '/login');
                        },
                        child: const Text(
                          "Login",
                          style: TextStyle(
                            color: Colors.white,
                            decoration: TextDecoration.underline,
                            decorationColor: Colors.white,
                          ),
                        ),
                      ),
                    ],
                  ),

                  const SizedBox(height: 30),
                ],
              ),
            ),
          ),
        ),
      ),
    );
  }

  /// ===== TEXTFIELD =====
  Widget _buildTextField(
    TextEditingController controller,
    String hint,
    IconData icon, {
    bool isPassword = false,
    bool isConfirm = false,
  }) {
    return Container(
      decoration: BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.circular(25),
        boxShadow: [
          BoxShadow(
            color: const Color(0xFF1565C0).withOpacity(0.15),
            blurRadius: 15,
            offset: const Offset(0, 8),
          ),
        ],
      ),
      child: TextField(
        controller: controller,
        obscureText: isPassword
            ? (isConfirm ? obscureConfirm : obscurePassword)
            : false,
        decoration: InputDecoration(
          prefixIcon: Icon(icon, color: const Color(0xFF1565C0)),
          hintText: hint,
          hintStyle: const TextStyle(color: Colors.grey),
          border: InputBorder.none,
          contentPadding: const EdgeInsets.symmetric(vertical: 20),
          suffixIcon: isPassword
              ? IconButton(
                  icon: Icon(
                    (isConfirm ? obscureConfirm : obscurePassword)
                        ? Icons.visibility_off
                        : Icons.visibility,
                    color: Colors.grey,
                  ),
                  onPressed: () {
                    setState(() {
                      if (isConfirm) {
                        obscureConfirm = !obscureConfirm;
                      } else {
                        obscurePassword = !obscurePassword;
                      }
                    });
                  },
                )
              : null,
        ),
      ),
    );
  }
}