import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';
import '../../../../core/i18n/locale_utils.dart';
import '../../../../core/services/auth_proxy_service.dart';
import '../../../../core/services/auth_token_store.dart';

class ApproveQrScreen extends StatefulWidget {
  final String? pendingRef;
  const ApproveQrScreen({super.key, this.pendingRef});

  @override
  State<ApproveQrScreen> createState() => _ApproveQrScreenState();
}

class _ApproveQrScreenState extends State<ApproveQrScreen> {
  bool _isLoading = false;
  String? _message;
  bool _success = false;
  bool _isCheckingSession = false;
  bool _redirectingToLogin = false;
  bool _autoApproveTriggered = false;

  @override
  void initState() {
    super.initState();
    _bootstrapCookieSession().then((_) {
      _redirectIfNotLoggedIn();
      _maybeAutoApprove();
    });
  }

  Future<bool> _bootstrapCookieSession() async {
    if (AuthTokenStore.usesCookie()) {
      return true;
    }
    if (_isCheckingSession) {
      return false;
    }
    setState(() => _isCheckingSession = true);
    try {
      await AuthProxyService.checkCookieSession();
      AuthTokenStore.setCookieMode(provider: 'ory');
      return true;
    } catch (_) {
      return false;
    } finally {
      if (mounted) {
        setState(() => _isCheckingSession = false);
      }
    }
  }

  void _redirectIfNotLoggedIn() {
    if (_redirectingToLogin || !mounted) return;
    final hasStoredToken = AuthTokenStore.getToken()?.isNotEmpty ?? false;
    final usesCookie = AuthTokenStore.usesCookie();
    final isLoggedIn = hasStoredToken || usesCookie;
    if (!isLoggedIn) {
      _redirectingToLogin = true;
      WidgetsBinding.instance.addPostFrameCallback((_) {
        if (!mounted) return;
        final target = buildLocalizedSigninPath(Uri.base);
        context.go('$target?notice=qr_login_required');
      });
    }
  }

  void _maybeAutoApprove() {
    if (!mounted || _autoApproveTriggered) return;
    if (widget.pendingRef == null || widget.pendingRef!.trim().isEmpty) {
      if (_message == null) {
        WidgetsBinding.instance.addPostFrameCallback((_) {
          if (!mounted) return;
          setState(() {
            _message = 'Error: pendingRef is missing.';
          });
        });
      }
      return;
    }

    final hasStoredToken = AuthTokenStore.getToken()?.isNotEmpty ?? false;
    final usesCookie = AuthTokenStore.usesCookie();
    final isLoggedIn = hasStoredToken || usesCookie || _isCheckingSession;
    if (!isLoggedIn || _isLoading || _success) {
      return;
    }

    _autoApproveTriggered = true;
    _handleApprove();
  }

  Future<void> _handleApprove() async {
    if (widget.pendingRef == null) return;

    final storedToken = AuthTokenStore.getToken();
    final usesCookie = AuthTokenStore.usesCookie();
    var hasCookie = usesCookie;
    if (storedToken == null && !hasCookie) {
      hasCookie = await _bootstrapCookieSession();
    }
    if (storedToken == null && !hasCookie) {
      if (mounted) {
        final target = buildLocalizedSigninPath(Uri.base);
        context.go('$target?notice=qr_login_required');
      }
      return;
    }

    setState(() {
      _isLoading = true;
      _message = null;
    });
    // jwt 유효성 확인
    try {
      final token = storedToken ?? '';
      await AuthProxyService.approveQrLogin(
        widget.pendingRef!,
        token: token,
        withCredentials: hasCookie,
      );
      setState(() {
        _success = true;
        _message = "Login Approved! Your browser should now be logged in.";
      });

      // Automatically go to dashboard after a short delay
      Future.delayed(const Duration(seconds: 1), () {
        if (mounted) context.go(buildLocalizedHomePath(Uri.base));
      });
    } catch (e) {
      setState(() => _message = "Error: $e");
    } finally {
      setState(() => _isLoading = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    final hasStoredToken = AuthTokenStore.getToken()?.isNotEmpty ?? false;
    final usesCookie = AuthTokenStore.usesCookie();
    final isLoggedIn = hasStoredToken || usesCookie || _isCheckingSession;

    if (!isLoggedIn && !_redirectingToLogin) {
      _redirectIfNotLoggedIn();
    }
    if (isLoggedIn && !_success && !_isLoading) {
      _maybeAutoApprove();
    }

    return Scaffold(
      appBar: AppBar(title: const Text("QR Login Approval")),
      body: Center(
        child: Padding(
          padding: const EdgeInsets.all(24.0),
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              const Icon(Icons.phonelink_lock, size: 80, color: Colors.blue),
              const SizedBox(height: 24),
              const Text(
                "Web Login Request",
                style: TextStyle(fontSize: 22, fontWeight: FontWeight.bold),
              ),
              const SizedBox(height: 16),
              Text(
                "A computer is trying to log in using this QR code.",
                textAlign: TextAlign.center,
                style: TextStyle(color: Colors.grey.shade600),
              ),
              const SizedBox(height: 40),

              if (_message != null)
                Padding(
                  padding: const EdgeInsets.only(bottom: 20),
                  child: Text(
                    _message!,
                    style: TextStyle(
                      color: _success ? Colors.green : Colors.red,
                      fontWeight: FontWeight.bold,
                    ),
                    textAlign: TextAlign.center,
                  ),
                ),

              if (_isLoading)
                const Padding(
                  padding: EdgeInsets.only(bottom: 16),
                  child: CircularProgressIndicator(),
                ),

              if (!_success && !_isLoading)
                Text(
                  "Approving login request automatically...",
                  textAlign: TextAlign.center,
                  style: TextStyle(color: Colors.grey.shade700),
                ),

              if (!isLoggedIn && !_success)
                Padding(
                  padding: const EdgeInsets.only(top: 16),
                  child: TextButton(
                    onPressed: () =>
                        context.go(buildLocalizedSigninPath(Uri.base)),
                    child: const Text("Login on this device first"),
                  ),
                ),

              if (!_success && !_isLoading && _message != null)
                FilledButton.icon(
                  onPressed: !isLoggedIn
                      ? null
                      : () {
                          _autoApproveTriggered = false;
                          _handleApprove();
                        },
                  icon: const Icon(Icons.refresh),
                  label: const Text("Retry Approval"),
                ),

              if (_success)
                FilledButton(
                  onPressed: () => context.go(buildLocalizedHomePath(Uri.base)),
                  child: const Text("Go to My Dashboard"),
                ),
            ],
          ),
        ),
      ),
    );
  }
}