import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:google_fonts/google_fonts.dart';
import 'package:descope/descope.dart';
import 'package:go_router/go_router.dart';

class LoginScreen extends ConsumerStatefulWidget {
  const LoginScreen({super.key});

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

class _LoginScreenState extends ConsumerState<LoginScreen>
    with SingleTickerProviderStateMixin {
  late TabController _tabController;
  final TextEditingController _emailController = TextEditingController();
  final TextEditingController _passwordController = TextEditingController();
  final TextEditingController _phoneController = TextEditingController();

  @override
  void initState() {
    super.initState();
    _tabController = TabController(length: 2, vsync: this);
  }

  @override
  void dispose() {
    _tabController.dispose();
    _emailController.dispose();
    _passwordController.dispose();
    _phoneController.dispose();
    super.dispose();
  }

  Future<void> _handleEmailLogin() async {
    final email = _emailController.text.trim();
    if (email.isEmpty) return;

    // Determine if it's Password or Enchanted Link flow
    // For this PoC, we'll try Enchanted Link as primary for 'Email' tab per requirements,
    // but the UI has a password field. Let's support both based on input.
    // However, PRD says Primary is Email/Password.

    final password = _passwordController.text;
    if (password.isNotEmpty) {
      // Email + Password Flow
      try {
        final authResponse = await Descope.auth.password.signIn(
          loginId: email,
          password: password,
        );
        final session = DescopeSession.fromAuthenticationResponse(authResponse);
        Descope.sessionManager.manageSession(session);
        if (mounted) context.go('/dashboard');
      } catch (e) {
        _showError("Email/Password Login Failed: $e");
      }
    } else {
      // Enchanted Link Flow (Passwordless)
      try {
        // Start Enchanted Link
        final response = await Descope.auth.enchantedLink.signUpOrIn(
          loginId: email,
          uri: "baronsso://auth", // Deep link for the 'Clicked' device
        );

        // Show Polling Dialog
        if (mounted) {
          showDialog(
            context: context,
            barrierDismissible: false,
            builder: (context) => AlertDialog(
              title: const Text("Check your Email"),
              content: Column(
                mainAxisSize: MainAxisSize.min,
                children: [
                  Text("We sent an email to $email"),
                  const SizedBox(height: 16),
                  const LinearProgressIndicator(),
                  const SizedBox(height: 16),
                  Text("Link: ${response.linkId}"), // Display for debug/PoC
                ],
              ),
            ),
          );

          // Poll for completion
          final authResponse = await Descope.auth.enchantedLink.poll(
            response.pendingRef,
          );
          final session = DescopeSession.fromAuthenticationResponse(
            authResponse,
          );
          Descope.sessionManager.manageSession(session);

          if (mounted) {
            Navigator.of(context).pop(); // Close Dialog
            context.go('/dashboard');
          }
        }
      } catch (e) {
        if (mounted) Navigator.of(context).pop(); // Close dialog if open
        _showError("Enchanted Link Failed: $e");
      }
    }
  }

  Future<void> _handleSmsLogin() async {
    final phone = _phoneController.text.trim();
    if (phone.isEmpty) return;

    try {
      // Enchanted Link via SMS (Polling)
      // Note: This assumes Descope project is configured to send SMS for this loginId
      final response = await Descope.auth.enchantedLink.signUpOrIn(
        loginId: phone,
        uri: "baronsso://auth", // Link for the device that receives SMS
      );

      if (mounted) {
        showDialog(
          context: context,
          barrierDismissible: false,
          builder: (context) => AlertDialog(
            title: const Text("Check your Messages"),
            content: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                Text("We sent a message to $phone"),
                const SizedBox(height: 16),
                const LinearProgressIndicator(),
                const SizedBox(height: 16),
                // Text("Link: ${response.linkId}"), // Debug
              ],
            ),
          ),
        );

        // Poll for completion
        final authResponse = await Descope.auth.enchantedLink.poll(
          response.pendingRef,
        );
        final session = DescopeSession.fromAuthenticationResponse(authResponse);
        Descope.sessionManager.manageSession(session);

        if (mounted) {
          Navigator.of(context).pop(); // Close Dialog
          context.go('/dashboard');
        }
      }
    } catch (e) {
      if (mounted && Navigator.canPop(context)) Navigator.of(context).pop();
      _showError("SMS Enchanted Link Failed: $e");
    }
  }

  void _showError(String message) {
    if (!mounted) return;
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(content: Text(message), backgroundColor: Colors.red),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Container(
          constraints: const BoxConstraints(maxWidth: 400),
          padding: const EdgeInsets.all(24),
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              Text(
                "Baron SSO",
                style: GoogleFonts.outfit(
                  fontSize: 32,
                  fontWeight: FontWeight.bold,
                ),
                textAlign: TextAlign.center,
              ),
              const SizedBox(height: 40),

              // Tab Bar
              TabBar(
                controller: _tabController,
                tabs: const [
                  Tab(text: "Email"),
                  Tab(text: "Phone (SMS)"),
                ],
              ),
              const SizedBox(height: 24),

              // Tab View Content
              SizedBox(
                height: 300, // Slightly increased height for content
                child: TabBarView(
                  controller: _tabController,
                  children: [
                    // Email/Password Form
                    Column(
                      children: [
                        TextField(
                          controller: _emailController,
                          decoration: const InputDecoration(
                            labelText: "Email",
                            border: OutlineInputBorder(),
                            prefixIcon: Icon(Icons.email_outlined),
                          ),
                        ),
                        const SizedBox(height: 16),
                        TextField(
                          controller: _passwordController,
                          obscureText: true,
                          decoration: const InputDecoration(
                            labelText: "Password",
                            border: OutlineInputBorder(),
                            prefixIcon: Icon(Icons.lock_outline),
                          ),
                        ),
                        const SizedBox(height: 24),
                        FilledButton(
                          onPressed: _handleEmailLogin,
                          style: FilledButton.styleFrom(
                            minimumSize: const Size.fromHeight(50),
                          ),
                          child: const Text("Sign In"),
                        ),
                      ],
                    ),

                    // Phone/SMS Form
                    Column(
                      children: [
                        TextField(
                          controller: _phoneController,
                          decoration: const InputDecoration(
                            labelText: "Phone Number",
                            hintText: "+82 10-1234-5678",
                            border: OutlineInputBorder(),
                            prefixIcon: Icon(Icons.phone_android),
                          ),
                        ),
                        const SizedBox(height: 24),
                        FilledButton(
                          onPressed: _handleSmsLogin,
                          style: FilledButton.styleFrom(
                            minimumSize: const Size.fromHeight(50),
                          ),
                          child: const Text("Send Login Link"),
                        ),
                      ],
                    ),
                  ],
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}