sxchnge/frontend/app/lib/verification/page.dart

import 'package:flutter/material.dart';

import 'package:go_router/go_router.dart';

import 'package:provider/provider.dart';

import 'package:sxchnge_auth/sxchnge_auth.dart';

import '../auth/brand_panel.dart';
import '../auth/validation.dart';
import '../routing/routes.dart';
import '../widgets/locale.dart';

import '../generated/i18n/app_localizations.dart';

class VerificationPage extends StatefulWidget {
  const VerificationPage({super.key, this.email, this.token});
  final String? email;
  final String? token;

  @override
  State<VerificationPage> createState() => _VerificationPageState();
}

class _VerificationPageState extends State<VerificationPage> {
  final _form = GlobalKey<FormState>();
  late final _email = TextEditingController(text: widget.email);
  late final _provider = VerificationProvider(
    context.read<VerificationService>(),
  );
  bool _initialized = false;
  bool _lastWasSend = false;
  bool _validated = false;

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    if (!_initialized) {
      _initialized = true;
      WidgetsBinding.instance.addPostFrameCallback((_) {
        if (!mounted) return;
        if (widget.token != null) {
          _provider.confirm(widget.token!);
        } else if (_email.text.isNotEmpty) {
          _send();
        }
      });
    } else if (_validated) {
      WidgetsBinding.instance.addPostFrameCallback((_) {
        if (mounted) _form.currentState?.validate();
      });
    }
  }

  @override
  void didUpdateWidget(covariant VerificationPage oldWidget) {
    super.didUpdateWidget(oldWidget);
    if (oldWidget.token == widget.token) return;
    _provider.reset();
    _lastWasSend = false;
    _validated = false;
    _email.clear();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (mounted && widget.token != null) _provider.confirm(widget.token!);
    });
  }

  void _send() {
    if (_provider.state.isLoading) return;
    _validated = true;
    if (!(_form.currentState?.validate() ?? false)) return;
    _lastWasSend = true;
    _provider.send(
      email: _email.text,
      locale: Localizations.localeOf(context).languageCode,
    );
  }

  @override
  void dispose() {
    _provider.dispose();
    _email.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) => ListenableBuilder(
    listenable: _provider,
    builder: (context, _) {
      final l = AppLocalizations.of(context)!;
      final theme = Theme.of(context);
      final colors = theme.colorScheme;
      final state = _provider.state;
      final status = state.status;
      final failed = [
        VerificationStatus.expired,
        VerificationStatus.invalid,
        VerificationStatus.error,
      ].contains(status);
      final verified = status == VerificationStatus.verified;
      final demo =
          _provider.service is DummyVerificationService || state.isSimulated;
      final title = switch (status) {
        VerificationStatus.sent => l.checkInbox,
        VerificationStatus.sending => l.verificationSending,
        VerificationStatus.checking => l.verificationChecking,
        VerificationStatus.verified => l.verificationVerified,
        VerificationStatus.expired => l.verificationExpired,
        VerificationStatus.invalid => l.verificationInvalid,
        VerificationStatus.error => l.verificationInternal,
        VerificationStatus.idle =>
          widget.token != null ? l.verificationChecking : l.verificationRequest,
      };
      final body = switch (status) {
        VerificationStatus.sent => l.verificationSent,
        VerificationStatus.verified => l.verificationVerifiedBody,
        VerificationStatus.expired => l.verificationExpiredBody,
        VerificationStatus.invalid => l.verificationInvalidBody,
        VerificationStatus.error => l.verificationInternalBody,
        _ => null,
      };
      return Scaffold(
        body: SafeArea(
          child: SingleChildScrollView(
            padding: const EdgeInsets.all(24),
            child: Center(
              child: ConstrainedBox(
                constraints: const BoxConstraints(maxWidth: 520),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.stretch,
                  children: [
                    const Align(
                      alignment: Alignment.centerRight,
                      child: LocaleSelector(),
                    ),
                    const Align(
                      alignment: Alignment.centerLeft,
                      child: BrandWordmark(),
                    ),
                    const SizedBox(height: 48),
                    Align(
                      alignment: Alignment.centerLeft,
                      child: Container(
                        padding: const EdgeInsets.all(20),
                        decoration: BoxDecoration(
                          color: failed
                              ? colors.errorContainer
                              : colors.primaryContainer,
                          borderRadius: BorderRadius.circular(24),
                        ),
                        child: state.isLoading
                            ? const SizedBox(
                                width: 32,
                                height: 32,
                                child: CircularProgressIndicator(),
                              )
                            : Icon(
                                verified
                                    ? Icons.mark_email_read_outlined
                                    : failed
                                    ? Icons.error_outline
                                    : Icons.mark_email_unread_outlined,
                                size: 32,
                                color: failed
                                    ? colors.onErrorContainer
                                    : colors.onPrimaryContainer,
                              ),
                      ),
                    ),
                    const SizedBox(height: 28),
                    Text(
                      l.verificationStep,
                      style: theme.textTheme.labelLarge?.copyWith(
                        color: colors.primary,
                      ),
                    ),
                    const SizedBox(height: 12),
                    Semantics(
                      liveRegion: true,
                      child: Text(
                        title,
                        key: ValueKey('verification-${status.name}'),
                        style: theme.textTheme.displaySmall,
                      ),
                    ),
                    if (body != null) ...[
                      const SizedBox(height: 20),
                      Text(
                        body,
                        style: theme.textTheme.bodyLarge?.copyWith(
                          color: colors.onSurfaceVariant,
                        ),
                      ),
                    ],
                    if (status == VerificationStatus.sent) ...[
                      const SizedBox(height: 16),
                      Text(
                        l.verificationHint,
                        style: theme.textTheme.bodyMedium,
                      ),
                    ],
                    if (!verified && status != VerificationStatus.checking) ...[
                      const SizedBox(height: 28),
                      Form(
                        key: _form,
                        child: TextFormField(
                          key: const ValueKey('verification-email'),
                          controller: _email,
                          enabled: !state.isLoading,
                          keyboardType: TextInputType.emailAddress,
                          autofillHints: const [AutofillHints.email],
                          textInputAction: TextInputAction.send,
                          validator: (value) => AuthValidation.email(value, l),
                          onFieldSubmitted: (_) => _send(),
                          decoration: InputDecoration(
                            labelText: l.email,
                            hintText: l.emailHint,
                            errorMaxLines: 3,
                            prefixIcon: const Icon(Icons.alternate_email),
                          ),
                        ),
                      ),
                      const SizedBox(height: 16),
                      FilledButton(
                        key: const ValueKey('verification-resend'),
                        onPressed: state.isLoading ? null : _send,
                        child: Text(
                          state.isLoading
                              ? l.authWorking
                              : status == VerificationStatus.sent
                              ? l.verificationResend
                              : l.verificationRequest,
                          textAlign: TextAlign.center,
                        ),
                      ),
                    ],
                    if (status == VerificationStatus.error &&
                        !_lastWasSend &&
                        widget.token != null) ...[
                      const SizedBox(height: 12),
                      OutlinedButton(
                        key: const ValueKey('verification-retry'),
                        onPressed: () => _provider.confirm(widget.token!),
                        child: Text(l.verificationRetry),
                      ),
                    ],
                    const SizedBox(height: 16),
                    TextButton(
                      onPressed: () => context.goNamed(AppRoutes.login),
                      child: Text(l.verificationBack),
                    ),
                    if (demo) ...[
                      const SizedBox(height: 24),
                      Text(
                        l.verificationDemo,
                        style: theme.textTheme.bodySmall?.copyWith(
                          color: colors.onSurfaceVariant,
                        ),
                      ),
                      if (status == VerificationStatus.sent)
                        TextButton(
                          key: const ValueKey('demo-confirmation'),
                          onPressed: () => context.goNamed(
                            AppRoutes.verifyEmail,
                            queryParameters: {'token': 'demo-valid'},
                          ),
                          child: Text(l.verificationDemoLink),
                        ),
                    ],
                  ],
                ),
              ),
            ),
          ),
        ),
      );
    },
  );
}