// Read-only view of the hub's authentication policy (T4/T5):
// which token validator is active, whether anonymous calls are
// accepted, and the configured tokens with their scope grants —
// surfaced in Settings → Security so security administration is
// inspectable without opening config.yaml. Editing stays in the
// operator config on purpose (secrets live in env vars, the file
// carries only names); the panel says so and offers the live
// reload that applies a rotation without a daemon restart.

import 'package:flutter/material.dart';

import '../data/hub.dart';
import '../l10n/app_localizations.dart';
import '../theme/tokens.dart';
import 'chain_error_box.dart';

class HubAuthPolicyPanel extends StatefulWidget {
  /// Test seam: replaces the live [HubService.authStatus] call.
  @visibleForTesting
  final Future<HubAuthPolicy> Function()? loader;

  /// Test seam: replaces the live [HubService.reloadHubAuth] call.
  @visibleForTesting
  final Future<int> Function()? reloader;

  /// Bumped by the parent whenever an adjacent action changed the
  /// connection's auth state (token saved or cleared in the panel
  /// above) — the policy view reloads instead of showing a stale
  /// "store an admin token" hint next to the just-stored token.
  final int reloadTick;

  const HubAuthPolicyPanel({
    super.key,
    this.loader,
    this.reloader,
    this.reloadTick = 0,
  });

  @override
  State<HubAuthPolicyPanel> createState() => _HubAuthPolicyPanelState();
}

class _HubAuthPolicyPanelState extends State<HubAuthPolicyPanel> {
  HubAuthPolicy? _policy;
  Object? _error;
  bool _loading = true;
  bool _reloading = false;
  String? _reloadNote;

  @override
  void initState() {
    super.initState();
    _load();
  }

  @override
  void didUpdateWidget(covariant HubAuthPolicyPanel oldWidget) {
    super.didUpdateWidget(oldWidget);
    if (widget.reloadTick != oldWidget.reloadTick) {
      _load();
    }
  }

  Future<void> _load() async {
    setState(() {
      _loading = true;
      _error = null;
    });
    try {
      final load = widget.loader ?? HubService.instance.authStatus;
      final p = await load();
      if (!mounted) return;
      setState(() {
        _policy = p;
        _loading = false;
      });
    } catch (e) {
      if (!mounted) return;
      setState(() {
        _error = e;
        _loading = false;
      });
    }
  }

  Future<void> _reload() async {
    final l = AppLocalizations.of(context)!;
    setState(() {
      _reloading = true;
      _reloadNote = null;
    });
    try {
      final reload = widget.reloader ?? HubService.instance.reloadHubAuth;
      final n = await reload();
      if (!mounted) return;
      setState(() {
        _reloading = false;
        _reloadNote = l.authPolicyReloadDone(n);
      });
      await _load();
    } catch (e) {
      if (!mounted) return;
      setState(() {
        _reloading = false;
        _error = e;
      });
    }
  }

  /// True when the failure is the hub refusing the caller —
  /// either no/invalid token (UNAUTHENTICATED) or a token
  /// without the admin scope (PERMISSION_DENIED). Both get the
  /// same plain-language fix: store an admin token above.
  bool _isPermissionDenied(Object e) {
    final s = e.toString();
    return s.contains('PERMISSION_DENIED') ||
        s.contains('code: 7') ||
        s.contains('UNAUTHENTICATED') ||
        s.contains('code: 16');
  }

  /// True when the hub predates the AuthStatus RPC (skew: Studio
  /// newer than the hub) — gets an update hint, not a raw error.
  bool _isUnimplemented(Object e) {
    final s = e.toString();
    return s.contains('UNIMPLEMENTED') || s.contains('code: 12');
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final l = AppLocalizations.of(context)!;
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(
          l.authPolicyHeader,
          style: theme.textTheme.labelSmall?.copyWith(
            color: theme.colorScheme.onSurfaceVariant,
            letterSpacing: 0.6,
            fontSize: 10,
          ),
        ),
        const SizedBox(height: 2),
        Text(
          l.authPolicyBlurb,
          style: theme.textTheme.bodySmall?.copyWith(
            color: theme.colorScheme.onSurfaceVariant,
          ),
        ),
        const SizedBox(height: ChainSpace.sm),
        if (_loading)
          const Padding(
            padding: EdgeInsets.symmetric(vertical: ChainSpace.md),
            child: Center(
              child: SizedBox(
                width: 18,
                height: 18,
                child: CircularProgressIndicator(strokeWidth: 2),
              ),
            ),
          )
        else if (_error != null) ...[
          if (_isPermissionDenied(_error!))
            _hintRow(theme, Icons.lock_outline, l.authPolicyNeedsAdmin)
          else if (_isUnimplemented(_error!))
            _hintRow(theme, Icons.update, l.authPolicyHubTooOld)
          else
            ChainErrorBox(error: _error!, isError: true, maxHeight: 160),
          const SizedBox(height: ChainSpace.xs),
          Align(
            alignment: Alignment.centerLeft,
            child: OutlinedButton.icon(
              onPressed: _load,
              icon: const Icon(Icons.refresh, size: 16),
              label: Text(l.authPolicyRetry),
            ),
          ),
        ] else if (_policy != null)
          ..._policyView(theme, l, _policy!),
      ],
    );
  }

  List<Widget> _policyView(ThemeData theme, AppLocalizations l, HubAuthPolicy p) {
    final isJwt = p.validator == 'jwt-rs256';
    return [
      Row(
        children: [
          Icon(
            Icons.verified_user_outlined,
            size: 16,
            color: theme.colorScheme.primary,
          ),
          const SizedBox(width: ChainSpace.xs),
          Expanded(
            child: Text(
              isJwt ? l.authPolicyValidatorJwt : l.authPolicyValidatorStatic,
              style: theme.textTheme.bodyMedium?.copyWith(
                fontWeight: FontWeight.w600,
              ),
            ),
          ),
        ],
      ),
      if (p.anonymousAllowed) ...[
        const SizedBox(height: ChainSpace.xs),
        _hintRow(
          theme,
          Icons.warning_amber_outlined,
          l.authPolicyAnonymous,
          color: theme.colorScheme.tertiary,
        ),
      ],
      if (p.reloadRequired) ...[
        const SizedBox(height: ChainSpace.xs),
        _hintRow(
          theme,
          Icons.sync_problem_outlined,
          l.authPolicyReloadRequired,
          color: theme.colorScheme.tertiary,
        ),
      ],
      if (p.tokens.isNotEmpty) ...[
        const SizedBox(height: ChainSpace.sm),
        for (final t in p.tokens) _tokenRow(theme, l, t),
      ],
      if (isJwt && p.jwt != null) ...[
        const SizedBox(height: ChainSpace.sm),
        _kvRow(theme, l.authPolicyJwtKeySource, p.jwt!.keySource),
        _kvRow(
          theme,
          l.authPolicyJwtAudience,
          p.jwt!.audience.isEmpty ? l.authPolicyNotChecked : p.jwt!.audience,
        ),
        _kvRow(
          theme,
          l.authPolicyJwtIssuer,
          p.jwt!.issuer.isEmpty ? l.authPolicyNotChecked : p.jwt!.issuer,
        ),
        _kvRow(theme, l.authPolicyJwtScopeClaim, p.jwt!.scopeClaim),
      ],
      const SizedBox(height: ChainSpace.sm),
      Text(
        l.authPolicyEditHint,
        style: theme.textTheme.bodySmall?.copyWith(
          color: theme.colorScheme.onSurfaceVariant,
        ),
      ),
      const SizedBox(height: ChainSpace.xs),
      Row(
        children: [
          OutlinedButton.icon(
            onPressed: _reloading ? null : _reload,
            icon: _reloading
                ? const SizedBox(
                    width: 14,
                    height: 14,
                    child: CircularProgressIndicator(strokeWidth: 2),
                  )
                : const Icon(Icons.refresh, size: 16),
            label: Text(l.authPolicyReload),
          ),
          if (_reloadNote != null) ...[
            const SizedBox(width: ChainSpace.sm),
            Flexible(
              child: Text(
                _reloadNote!,
                style: theme.textTheme.bodySmall?.copyWith(
                  color: theme.colorScheme.primary,
                ),
              ),
            ),
          ],
        ],
      ),
    ];
  }

  Widget _tokenRow(ThemeData theme, AppLocalizations l, HubAuthTokenEntry t) {
    return Padding(
      padding: const EdgeInsets.only(bottom: ChainSpace.sm),
      child: Container(
        width: double.infinity,
        padding: const EdgeInsets.symmetric(
          horizontal: ChainSpace.sm,
          vertical: ChainSpace.xs,
        ),
        decoration: BoxDecoration(
          color: theme.colorScheme.surfaceContainerHighest,
          borderRadius: BorderRadius.circular(ChainRadius.sm),
          border: Border.all(color: theme.colorScheme.outlineVariant),
        ),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              children: [
                Expanded(
                  child: Text(
                    t.name,
                    style: theme.textTheme.bodyMedium?.copyWith(
                      fontWeight: FontWeight.w600,
                    ),
                  ),
                ),
                if (t.rateLimitPerMinute > 0)
                  Text(
                    l.authPolicyRateLimit(t.rateLimitPerMinute),
                    style: theme.textTheme.bodySmall?.copyWith(
                      color: theme.colorScheme.onSurfaceVariant,
                    ),
                  ),
              ],
            ),
            const SizedBox(height: 4),
            Wrap(
              spacing: 4,
              runSpacing: 4,
              children: [
                for (final s in t.scopes)
                  Container(
                    padding: const EdgeInsets.symmetric(
                      horizontal: 6,
                      vertical: 1,
                    ),
                    decoration: BoxDecoration(
                      color: theme.colorScheme.primary.withValues(alpha: 0.10),
                      borderRadius: BorderRadius.circular(ChainRadius.sm),
                    ),
                    child: Text(
                      s,
                      style: theme.textTheme.labelSmall?.copyWith(
                        color: theme.colorScheme.primary,
                      ),
                    ),
                  ),
              ],
            ),
            const SizedBox(height: 4),
            Row(
              children: [
                Icon(
                  t.envSet ? Icons.check_circle : Icons.error_outline,
                  size: 13,
                  color: t.envSet
                      ? theme.colorScheme.primary
                      : theme.colorScheme.error,
                ),
                const SizedBox(width: 4),
                Expanded(
                  child: Text(
                    t.envSet
                        ? l.authPolicyEnvSet(t.tokenEnv)
                        : l.authPolicyEnvMissing(t.tokenEnv),
                    style: theme.textTheme.bodySmall?.copyWith(
                      color: t.envSet
                          ? theme.colorScheme.onSurfaceVariant
                          : theme.colorScheme.error,
                    ),
                  ),
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }

  Widget _kvRow(ThemeData theme, String label, String value) {
    return Padding(
      padding: const EdgeInsets.only(bottom: 2),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          SizedBox(
            width: 140,
            child: Text(
              label,
              style: theme.textTheme.bodySmall?.copyWith(
                color: theme.colorScheme.onSurfaceVariant,
              ),
            ),
          ),
          Expanded(
            child: SelectableText(
              value,
              style: theme.textTheme.bodySmall,
            ),
          ),
        ],
      ),
    );
  }

  Widget _hintRow(
    ThemeData theme,
    IconData icon,
    String text, {
    Color? color,
  }) {
    final c = color ?? theme.colorScheme.onSurfaceVariant;
    return Row(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Icon(icon, size: 16, color: c),
        const SizedBox(width: 6),
        Expanded(
          child: Text(
            text,
            style: theme.textTheme.bodySmall?.copyWith(color: c),
          ),
        ),
      ],
    );
  }
}