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

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

  @override
  State<LoginPage> createState() => _LoginPageState();
}

class _LoginPageState extends State<LoginPage> {
  final emailController = TextEditingController();
  final passwordController = TextEditingController();

  bool isLoading = false;
  bool obscurePassword = true;
  bool rememberMe = false;

  Future<void> loginUser() async {
    final emailText = emailController.text.trim();
    final passwordText = passwordController.text.trim();

    if (emailText.isEmpty || passwordText.isEmpty) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text("Email/Username dan Password tidak boleh kosong")),
      );
      return;
    }

    // Jika pengguna memasukkan username saja tanpa email format,
    // kita bantu tambahkan domain default agar valid sebagai email di Firebase
    String email = emailText;
    if (!emailText.contains('@')) {
      email = "$emailText@safebite.com";
    }

    setState(() => isLoading = true);

    try {
      await FirebaseAuth.instance.signInWithEmailAndPassword(
        email: email,
        password: passwordText,
      );

      if (mounted) {
        Navigator.pushReplacementNamed(context, '/dashboard');
      }
    } on FirebaseAuthException catch (e) {
      String errorMessage = "Login gagal";
      if (e.code == 'user-not-found' || e.code == 'invalid-credential') {
        errorMessage = "Email/Username atau Password salah.";
      } else if (e.code == 'wrong-password') {
        errorMessage = "Password salah.";
      } else if (e.code == 'invalid-email') {
        errorMessage = "Format email tidak valid.";
      } else {
        errorMessage = e.message ?? "Login gagal: ${e.code}";
      }
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text(errorMessage)),
        );
      }
    } catch (e) {
      debugPrint("Login 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: 60),

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

                  const SizedBox(height: 50),

                  /// ===== INPUT =====
                  FadeInUp(
                    delay: 300,
                    child: _buildTextField(
                      controller: emailController,
                      hint: "Username or Email",
                      icon: Icons.person,
                    ),
                  ),

                  const SizedBox(height: 20),

                  FadeInUp(
                    delay: 400,
                    child: _buildTextField(
                      controller: passwordController,
                      hint: "Password",
                      icon: Icons.lock,
                      isPassword: true,
                    ),
                  ),

                  const SizedBox(height: 50),

                  /// ===== LOGIN 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 : loginUser,
                        style: ElevatedButton.styleFrom(
                          backgroundColor: Colors.transparent,
                          shadowColor: Colors.transparent,
                          shape: RoundedRectangleBorder(
                            borderRadius: BorderRadius.circular(30),
                          ),
                        ),
                        child: isLoading
                            ? const CircularProgressIndicator(color: Color(0xFF1565C0))
                            : const Text(
                                "Login",
                                style: TextStyle(
                                  fontSize: 18,
                                  fontWeight: FontWeight.bold,
                                  color: Color(0xFF1565C0),
                                  letterSpacing: 1.2,
                                ),
                              ),
                      ),
                    ),
                  ),

                  const SizedBox(height: 30),

                  /// ===== REGISTER TEXT =====
                  Row(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: [
                      const Text(
                        "Don't have an account yet? ",
                        style: TextStyle(color: Colors.white70),
                      ),
                      GestureDetector(
                        onTap: () {
                          Navigator.pushNamed(context, '/signup');
                        },
                        child: const Text(
                          "Register",
                          style: TextStyle(
                            color: Colors.white,
                            fontWeight: FontWeight.bold,
                            decoration: TextDecoration.underline,
                            decorationColor: Colors.white,
                          ),
                        ),
                      ),
                    ],
                  ),

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

  /// ===== TEXTFIELD =====
  Widget _buildTextField({
    required TextEditingController controller,
    required String hint,
    required IconData icon,
    bool isPassword = 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 ? 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(
                    obscurePassword ? Icons.visibility_off : Icons.visibility,
                    color: Colors.grey,
                  ),
                  onPressed: () {
                    setState(() {
                      obscurePassword = !obscurePassword;
                    });
                  },
                )
              : null,
        ),
      ),
    );
  }
}