import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'package:provider/provider.dart';

import '../config.dart';
import '../services/session_manager.dart';

class LoginScreen extends StatefulWidget {
  final VoidCallback onSwitchToSignup;
  final VoidCallback onLoginSuccess;

  const LoginScreen({
    required this.onSwitchToSignup,
    required this.onLoginSuccess,
    super.key,
  });

  @override
  State<LoginScreen> createState() => _LoginScreenState();
}

class _LoginScreenState extends State<LoginScreen> {
  final _formKey = GlobalKey<FormState>();
  final _emailController = TextEditingController();
  final _passwordController = TextEditingController();

  Future<void> _login() async {
    if (_formKey.currentState!.validate()) {
      final email = _emailController.text;
      final password = _passwordController.text;

      try {
        final response = await http.post(
          Uri.parse('$apiBaseUrl/api/v1/auth/signin'),
          headers: {'Content-Type': 'application/json'},
          body: jsonEncode({'email': email, 'password': password}),
        );

        if (response.statusCode == 200) {
          final data = jsonDecode(response.body);
          final token = data['token'];
          final name = data['user']?['username'] ?? data['username'];

          await Provider.of<SessionManager>(context, listen: false).login(
            token: token,
            email: email,
            name: name,
          );

          widget.onLoginSuccess();
        } else {
          final data = jsonDecode(response.body);
          ScaffoldMessenger.of(context).showSnackBar(
            SnackBar(content: Text(data['message'] ?? 'Login failed')),
          );
        }
      } catch (e) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Login error: $e')),
        );
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Padding(
        padding: const EdgeInsets.all(24.0),
        child: Form(
          key: _formKey,
          child: SingleChildScrollView(
            child: Column(
              children: [
                const SizedBox(height: 40),
                ClipRRect(
                  borderRadius: BorderRadius.circular(20),
                  child: Image.asset(
                    'assets/icon/app_icon.png',
                    width: 100,
                    height: 100,
                  ),
                ),
                const SizedBox(height: 16),
                Text(
                  'Log in to Fuel Stats',
                  style: TextStyle(
                    fontSize: 24,
                    fontWeight: FontWeight.bold,
                  ),
                ),
                const SizedBox(height: 32),
                  TextFormField(
                    controller: _emailController,
                    decoration: InputDecoration(
                      labelText: 'Email',
                      prefixIcon: Icon(Icons.email),
                      border: OutlineInputBorder(),
                    ),
                    keyboardType: TextInputType.emailAddress,
                    validator: (value) {
                      if (value == null || value.isEmpty)
                        return 'Please enter your email';
                      if (!RegExp(r'^[^@]+@[^@]+\.[^@]+').hasMatch(value))
                        return 'Enter a valid email';
                      return null;
                    },
                  ),
                  const SizedBox(height: 16),
                  TextFormField(
                    controller: _passwordController,
                    decoration: InputDecoration(
                      labelText: 'Password',
                      prefixIcon: Icon(Icons.lock),
                      border: OutlineInputBorder(),
                    ),
                    obscureText: true,
                    validator: (value) {
                      if (value == null || value.isEmpty)
                        return 'Please enter your password';
                      if (value.length < 6)
                        return 'Password must be at least 6 characters';
                      return null;
                    },
                  ),
                  const SizedBox(height: 24),
                  ElevatedButton.icon(
                    onPressed: _login,
                    icon: Icon(Icons.login),
                    label: Text('Log In'),
                    style: ElevatedButton.styleFrom(
                      backgroundColor: Colors.green,
                      foregroundColor: Colors.white,
                      padding: EdgeInsets.symmetric(horizontal: 32, vertical: 12),
                    ),
                  ),
                  const SizedBox(height: 12),
                  TextButton(
                    onPressed: widget.onSwitchToSignup,
                    child: Text("Don't have an account? Sign up"),
                  ),
                ],
              ),
            ),
          ),
        ),
    );
  }
}