'use client';

import { useCallback, useEffect, useState } from 'react';
import { useTranslations } from 'next-intl';
import { useAuthStore } from '@/lib/stores/auth-store';

const API_URL = process.env.NEXT_PUBLIC_API_URL || 'http://localhost:3001';

interface FieldMapping {
  id: string;
  ldapField: string;
  tesseraField: string;
  isDefault: boolean;
}

interface LdapConfig {
  id: string;
  tenantId: string;
  serverUrl: string;
  baseDn: string;
  bindDn: string;
  bindPassword: string;
  searchFilter: string;
  syncIntervalMin: number;
  isActive: boolean;
  tlsRejectUnauthorized: boolean;
  groupFilterDns: string[];
  userExcludeList: string[];
  lastSyncAt: string | null;
  fieldMappings: FieldMapping[];
}

interface LdapDirectoryEntry {
  dn: string;
  name: string;
  type: 'group' | 'ou';
  alreadyImported?: boolean;
}

interface LdapUserSearchResult {
  dn: string;
  username: string;
  displayName: string;
  email: string;
  alreadyImported: boolean;
}

interface UserImportResult {
  created: number;
  updated: number;
  skipped: number;
  errors: string[];
}

interface GroupImportResult {
  imported: number;
  skipped: number;
  nameCollisions: string[];
  errors: string[];
}

interface SyncResult {
  created: number;
  updated: number;
  deactivated: number;
  errors: string[];
}

/**
 * LDAP Configuration admin page (D-14, D-16, D-17, D-18).
 * Only visible to ADMIN and SUPER_ADMIN roles.
 */
export default function AdminLdapPage() {
  const t = useTranslations('admin.ldap');
  const tCommon = useTranslations('common');
  const currentUser = useAuthStore((s) => s.user);

  const [config, setConfig] = useState<LdapConfig | null>(null);
  const [loading, setLoading] = useState(true);
  const [saving, setSaving] = useState(false);
  const [testResult, setTestResult] = useState<{
    success: boolean;
    error?: string;
  } | null>(null);
  const [syncResult, setSyncResult] = useState<SyncResult | null>(null);
  const [syncing, setSyncing] = useState(false);

  // Form state for connection settings.
  const [formData, setFormData] = useState({
    serverUrl: '',
    baseDn: '',
    bindDn: '',
    bindPassword: '',
    searchFilter: '(objectClass=person)',
    syncIntervalMin: 0,
    isActive: true,
    tlsRejectUnauthorized: true,
  });

  // New mapping form
  const [newMapping, setNewMapping] = useState({ ldapField: '', tesseraField: '' });
  const [showMappingForm, setShowMappingForm] = useState(false);

  // Group/OU import filter (selective sync)
  const [groupFilterDns, setGroupFilterDns] = useState<string[]>([]);
  const [discovered, setDiscovered] = useState<LdapDirectoryEntry[] | null>(null);
  const [discovering, setDiscovering] = useState(false);
  const [manualDn, setManualDn] = useState('');
  const [savingFilter, setSavingFilter] = useState(false);
  const [discoverSearch, setDiscoverSearch] = useState('');

  // Per-user exclude/denylist (individual usernames never imported)
  const [userExcludeList, setUserExcludeList] = useState<string[]>([]);
  const [newExcludeUser, setNewExcludeUser] = useState('');
  const [savingExclude, setSavingExclude] = useState(false);

  // Individual user search & import
  const [userSearchQuery, setUserSearchQuery] = useState('');
  const [userSearchResults, setUserSearchResults] = useState<
    LdapUserSearchResult[] | null
  >(null);
  const [userSearching, setUserSearching] = useState(false);
  const [selectedUserDns, setSelectedUserDns] = useState<string[]>([]);
  const [importingUsers, setImportingUsers] = useState(false);
  const [userImportResult, setUserImportResult] =
    useState<UserImportResult | null>(null);

  // AD group import (SC-1/SC-2, D-01/D-02) — own state, own discovery call,
  // independent of Section 2.5's groupFilterDns picker (different purpose).
  const [groupImportCandidates, setGroupImportCandidates] = useState<
    LdapDirectoryEntry[] | null
  >(null);
  const [groupImportSearch, setGroupImportSearch] = useState('');
  const [discoveringGroupImport, setDiscoveringGroupImport] = useState(false);
  const [selectedImportDns, setSelectedImportDns] = useState<string[]>([]);
  const [importingGroups, setImportingGroups] = useState(false);
  const [groupImportResult, setGroupImportResult] =
    useState<GroupImportResult | null>(null);
  const [groupImportError, setGroupImportError] = useState<string | null>(
    null,
  );

  const filteredGroupImportCandidates = groupImportCandidates?.filter(
    (entry) => {
      const q = groupImportSearch.trim().toLowerCase();
      if (!q) return true;
      return (
        entry.name.toLowerCase().includes(q) ||
        entry.dn.toLowerCase().includes(q)
      );
    },
  );

  const filteredDiscovered = discovered?.filter((entry) => {
    const q = discoverSearch.trim().toLowerCase();
    if (!q) return true;
    return (
      entry.name.toLowerCase().includes(q) || entry.dn.toLowerCase().includes(q)
    );
  });

  const hasAccess =
    currentUser?.role === 'ADMIN' || currentUser?.role === 'SUPER_ADMIN';

  const fetchConfig = useCallback(async () => {
    try {
      const res = await fetch(`${API_URL}/ldap/config`, {
        credentials: 'include',
      });
      if (res.ok) {
        const data = await res.json();
        if (data) {
          setConfig(data);
          setFormData({
            serverUrl: data.serverUrl || '',
            baseDn: data.baseDn || '',
            bindDn: data.bindDn || '',
            bindPassword: '',
            searchFilter: data.searchFilter || '(objectClass=person)',
            syncIntervalMin: data.syncIntervalMin ?? 60,
            isActive: data.isActive ?? true,
            tlsRejectUnauthorized: data.tlsRejectUnauthorized ?? true,
          });
          setGroupFilterDns(data.groupFilterDns ?? []);
          setUserExcludeList(data.userExcludeList ?? []);
        }
      }
    } catch {
      // silently fail
    } finally {
      setLoading(false);
    }
  }, []);

  useEffect(() => {
    if (hasAccess) {
      fetchConfig();
    } else {
      setLoading(false);
    }
  }, [hasAccess, fetchConfig]);

  const handleSave = async (e: React.FormEvent) => {
    e.preventDefault();
    setSaving(true);
    setTestResult(null);

    try {
      const method = config ? 'PATCH' : 'POST';
      const body: Record<string, unknown> = { ...formData };

      // Don't send empty password on update (keeps existing)
      if (config && !formData.bindPassword) {
        delete body.bindPassword;
      }

      const res = await fetch(`${API_URL}/ldap/config`, {
        method,
        headers: { 'Content-Type': 'application/json' },
        credentials: 'include',
        body: JSON.stringify(body),
      });

      if (res.ok) {
        await fetchConfig();
      }
    } catch {
      // silently fail
    } finally {
      setSaving(false);
    }
  };

  const handleTestConnection = async () => {
    setTestResult(null);
    try {
      // Send the currently entered values so a connection can be validated
      // before ever saving a config. bindPassword is omitted when blank so
      // the backend falls back to the saved config's password (masked
      // fields never get re-sent once a config already exists).
      const body: Record<string, unknown> = {};
      if (formData.serverUrl) body.serverUrl = formData.serverUrl;
      if (formData.bindDn) body.bindDn = formData.bindDn;
      if (formData.bindPassword) body.bindPassword = formData.bindPassword;
      // Always send the current TLS-verification choice so the test reflects it.
      body.tlsRejectUnauthorized = formData.tlsRejectUnauthorized;

      const res = await fetch(`${API_URL}/ldap/test-connection`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        credentials: 'include',
        body: JSON.stringify(body),
      });
      const data = await res.json();
      if (res.ok) {
        setTestResult(data);
      } else {
        setTestResult({ success: false, error: data.message || 'Test failed' });
      }
    } catch {
      setTestResult({ success: false, error: 'Network error' });
    }
  };

  const handleSync = async () => {
    setSyncing(true);
    setSyncResult(null);
    try {
      const res = await fetch(`${API_URL}/ldap/sync`, {
        method: 'POST',
        credentials: 'include',
      });
      if (res.ok) {
        const data = await res.json();
        setSyncResult(data);
        await fetchConfig();
      }
    } catch {
      setSyncResult({ created: 0, updated: 0, deactivated: 0, errors: ['Network error'] });
    } finally {
      setSyncing(false);
    }
  };

  const handleAddMapping = async (e: React.FormEvent) => {
    e.preventDefault();
    if (!newMapping.ldapField || !newMapping.tesseraField) return;

    try {
      const res = await fetch(`${API_URL}/ldap/config/mappings`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        credentials: 'include',
        body: JSON.stringify(newMapping),
      });
      if (res.ok) {
        setNewMapping({ ldapField: '', tesseraField: '' });
        setShowMappingForm(false);
        await fetchConfig();
      }
    } catch {
      // silently fail
    }
  };

  const handleRemoveMapping = async (mappingId: string) => {
    try {
      const res = await fetch(`${API_URL}/ldap/config/mappings/${mappingId}`, {
        method: 'DELETE',
        credentials: 'include',
      });
      if (res.ok) {
        await fetchConfig();
      }
    } catch {
      // silently fail
    }
  };

  const handleDiscoverGroups = async () => {
    setDiscovering(true);
    try {
      const res = await fetch(`${API_URL}/ldap/groups`, {
        credentials: 'include',
      });
      if (res.ok) {
        const data = await res.json();
        setDiscovered(data);
      }
    } catch {
      // silently fail
    } finally {
      setDiscovering(false);
    }
  };

  const toggleGroupFilterDn = (dn: string) => {
    setGroupFilterDns((prev) =>
      prev.includes(dn) ? prev.filter((d) => d !== dn) : [...prev, dn],
    );
  };

  const handleAddManualDn = () => {
    const dn = manualDn.trim();
    if (!dn || groupFilterDns.includes(dn)) return;
    setGroupFilterDns((prev) => [...prev, dn]);
    setManualDn('');
  };

  const handleRemoveGroupFilterDn = (dn: string) => {
    setGroupFilterDns((prev) => prev.filter((d) => d !== dn));
  };

  const handleSaveGroupFilter = async () => {
    setSavingFilter(true);
    try {
      const res = await fetch(`${API_URL}/ldap/config`, {
        method: 'PATCH',
        headers: { 'Content-Type': 'application/json' },
        credentials: 'include',
        body: JSON.stringify({ groupFilterDns }),
      });
      if (res.ok) {
        await fetchConfig();
      }
    } catch {
      // silently fail
    } finally {
      setSavingFilter(false);
    }
  };

  const handleAddExcludeUser = () => {
    const name = newExcludeUser.trim().toLowerCase();
    if (!name || userExcludeList.includes(name)) return;
    setUserExcludeList((prev) => [...prev, name]);
    setNewExcludeUser('');
  };

  const handleRemoveExcludeUser = (name: string) => {
    setUserExcludeList((prev) => prev.filter((u) => u !== name));
  };

  const handleSearchUsers = async () => {
    const q = userSearchQuery.trim();
    if (!q) return;
    setUserSearching(true);
    setUserImportResult(null);
    try {
      const res = await fetch(
        `${API_URL}/ldap/users/search?q=${encodeURIComponent(q)}`,
        { credentials: 'include' },
      );
      if (res.ok) {
        const data = await res.json();
        setUserSearchResults(data);
        setSelectedUserDns([]);
      }
    } catch {
      // silently fail
    } finally {
      setUserSearching(false);
    }
  };

  const toggleUserDn = (dn: string) => {
    setSelectedUserDns((prev) =>
      prev.includes(dn) ? prev.filter((d) => d !== dn) : [...prev, dn],
    );
  };

  const handleImportUsers = async (dns: string[]) => {
    if (dns.length === 0) return;
    setImportingUsers(true);
    setUserImportResult(null);
    try {
      const res = await fetch(`${API_URL}/ldap/users/import`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        credentials: 'include',
        body: JSON.stringify({ dns }),
      });
      if (res.ok) {
        const data = await res.json();
        setUserImportResult(data);
        setSelectedUserDns([]);
        // Re-run the search so alreadyImported flags refresh.
        await handleSearchUsers();
      }
    } catch {
      // silently fail
    } finally {
      setImportingUsers(false);
    }
  };

  const handleDiscoverGroupsToImport = async () => {
    setDiscoveringGroupImport(true);
    setGroupImportError(null);
    try {
      const res = await fetch(`${API_URL}/ldap/groups`, {
        credentials: 'include',
      });
      if (res.ok) {
        const data: LdapDirectoryEntry[] = await res.json();
        // Only AD groups are importable — OUs are not selectable here.
        setGroupImportCandidates(data.filter((entry) => entry.type === 'group'));
      } else {
        setGroupImportError(t('groupImport.discoverError'));
      }
    } catch {
      setGroupImportError(t('groupImport.discoverError'));
    } finally {
      setDiscoveringGroupImport(false);
    }
  };

  const toggleImportDn = (dn: string) => {
    setSelectedImportDns((prev) =>
      prev.includes(dn) ? prev.filter((d) => d !== dn) : [...prev, dn],
    );
  };

  const handleImportGroups = async () => {
    if (selectedImportDns.length === 0) return;
    setImportingGroups(true);
    setGroupImportError(null);
    try {
      const res = await fetch(`${API_URL}/ldap/groups/import`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        credentials: 'include',
        body: JSON.stringify({ dns: selectedImportDns }),
      });
      if (res.ok) {
        const data: GroupImportResult = await res.json();
        setGroupImportResult(data);
        setSelectedImportDns([]);
        // Re-run discovery so alreadyImported flags refresh immediately.
        await handleDiscoverGroupsToImport();
      } else {
        setGroupImportError(t('groupImport.importError'));
      }
    } catch {
      setGroupImportError(t('groupImport.importError'));
    } finally {
      setImportingGroups(false);
    }
  };

  const handleSaveExcludeList = async () => {
    setSavingExclude(true);
    try {
      const res = await fetch(`${API_URL}/ldap/config`, {
        method: 'PATCH',
        headers: { 'Content-Type': 'application/json' },
        credentials: 'include',
        body: JSON.stringify({ userExcludeList }),
      });
      if (res.ok) {
        await fetchConfig();
      }
    } catch {
      // silently fail
    } finally {
      setSavingExclude(false);
    }
  };

  if (!hasAccess) {
    return (
      <div className="flex items-center justify-center min-h-[60vh]">
        <p className="text-lg text-muted-foreground">{tCommon('accessDenied')}</p>
      </div>
    );
  }

  if (loading) {
    return (
      <div className="flex items-center justify-center min-h-[60vh]">
        <p className="text-muted-foreground">{tCommon('loading')}</p>
      </div>
    );
  }

  return (
    <div className="space-y-8">
      <h1 className="text-2xl font-bold text-foreground">{t('title')}</h1>

      {/* Section 1: Connection Settings */}
      <section className="rounded-lg border border-border p-6">
        <h2 className="text-lg font-semibold text-foreground mb-4">
          {t('connectionTitle')}
        </h2>
        <form onSubmit={handleSave} className="space-y-4">
          <div className="grid gap-4 md:grid-cols-2">
            <div className="space-y-2">
              <label className="text-sm font-medium text-foreground">
                {t('serverUrl')}
              </label>
              <input
                type="text"
                value={formData.serverUrl}
                onChange={(e) => setFormData({ ...formData, serverUrl: e.target.value })}
                placeholder="ldap://ldap.example.com"
                className="flex h-10 w-full rounded-md border border-input bg-background px-3 py-2 text-sm"
                required
              />
            </div>
            <div className="space-y-2">
              <label className="text-sm font-medium text-foreground">
                {t('baseDn')}
              </label>
              <textarea
                value={formData.baseDn}
                onChange={(e) => setFormData({ ...formData, baseDn: e.target.value })}
                placeholder={'dc=example,dc=com\nou=extern,dc=example,dc=com'}
                rows={3}
                className="flex min-h-20 w-full rounded-md border border-input bg-background px-3 py-2 text-sm"
                required
              />
              <p className="text-xs text-muted-foreground">{t('baseDnHint')}</p>
            </div>
            <div className="space-y-2">
              <label className="text-sm font-medium text-foreground">
                {t('bindDn')}
              </label>
              <input
                type="text"
                value={formData.bindDn}
                onChange={(e) => setFormData({ ...formData, bindDn: e.target.value })}
                placeholder="cn=admin,dc=example,dc=com (leer = anonymous bind)"
                className="flex h-10 w-full rounded-md border border-input bg-background px-3 py-2 text-sm"
              />
            </div>
            <div className="space-y-2">
              <label className="text-sm font-medium text-foreground">
                {t('bindPassword')}
              </label>
              <input
                type="password"
                value={formData.bindPassword}
                onChange={(e) => setFormData({ ...formData, bindPassword: e.target.value })}
                placeholder={config?.bindPassword ? '********' : ''}
                className="flex h-10 w-full rounded-md border border-input bg-background px-3 py-2 text-sm"
              />
            </div>
          </div>
          <div className="space-y-2">
            <label className="text-sm font-medium text-foreground">
              {t('searchFilter')}
            </label>
            <input
              type="text"
              value={formData.searchFilter}
              onChange={(e) => setFormData({ ...formData, searchFilter: e.target.value })}
              className="flex h-10 w-full rounded-md border border-input bg-background px-3 py-2 text-sm"
            />
          </div>

          <div className="space-y-1">
            <label className="flex items-center gap-2 text-sm text-foreground">
              <input
                type="checkbox"
                checked={!formData.tlsRejectUnauthorized}
                onChange={(e) =>
                  setFormData({
                    ...formData,
                    tlsRejectUnauthorized: !e.target.checked,
                  })
                }
              />
              {t('tlsSkip.label')}
            </label>
            <p className="text-xs text-muted-foreground">{t('tlsSkip.hint')}</p>
          </div>

          <div className="flex items-center gap-4 pt-2">
            <button
              type="submit"
              disabled={saving}
              className="rounded-md bg-primary px-4 py-2 text-sm font-medium text-primary-foreground hover:opacity-90 transition-opacity disabled:opacity-50"
            >
              {saving ? tCommon('loading') : t('save')}
            </button>
            <button
              type="button"
              onClick={handleTestConnection}
              disabled={!config && !formData.serverUrl}
              className="rounded-md border border-border px-4 py-2 text-sm font-medium text-foreground hover:bg-muted transition-colors disabled:opacity-50"
            >
              {t('testConnection')}
            </button>
          </div>

          {testResult && (
            <div
              className={`mt-2 rounded-md px-4 py-2 text-sm ${
                testResult.success
                  ? 'bg-green-100 text-green-700 dark:bg-green-900/30 dark:text-green-400'
                  : 'bg-red-100 text-red-700 dark:bg-red-900/30 dark:text-red-400'
              }`}
            >
              {testResult.success ? t('testSuccess') : `${t('testFailed')}: ${testResult.error}`}
            </div>
          )}
        </form>
      </section>

      {/* Section 2: Field Mapping (D-16, D-17) */}
      {config && (
        <section className="rounded-lg border border-border p-6">
          <div className="flex items-center justify-between mb-4">
            <h2 className="text-lg font-semibold text-foreground">
              {t('fieldMapping.title')}
            </h2>
            <button
              onClick={() => setShowMappingForm(true)}
              className="rounded-md bg-primary px-3 py-1.5 text-xs font-medium text-primary-foreground hover:opacity-90 transition-opacity"
            >
              {t('fieldMapping.add')}
            </button>
          </div>

          <div className="overflow-x-auto rounded-md border border-border">
            <table className="w-full text-sm">
              <thead className="bg-muted/50">
                <tr>
                  <th className="px-4 py-3 text-left font-medium text-muted-foreground">
                    {t('fieldMapping.ldapField')}
                  </th>
                  <th className="px-4 py-3 text-left font-medium text-muted-foreground">
                    {t('fieldMapping.tesseraField')}
                  </th>
                  <th className="px-4 py-3 text-left font-medium text-muted-foreground">
                    {t('fieldMapping.default')}
                  </th>
                  <th className="px-4 py-3 text-right font-medium text-muted-foreground">
                    {tCommon('actions')}
                  </th>
                </tr>
              </thead>
              <tbody className="divide-y divide-border">
                {config.fieldMappings.map((mapping) => (
                  <tr key={mapping.id} className="hover:bg-muted/30 transition-colors">
                    <td className="px-4 py-3 font-mono text-foreground">
                      {mapping.ldapField}
                    </td>
                    <td className="px-4 py-3 font-mono text-foreground">
                      {mapping.tesseraField}
                    </td>
                    <td className="px-4 py-3">
                      {mapping.isDefault && (
                        <svg
                          xmlns="http://www.w3.org/2000/svg"
                          width="16"
                          height="16"
                          viewBox="0 0 24 24"
                          fill="none"
                          stroke="currentColor"
                          strokeWidth="2"
                          strokeLinecap="round"
                          strokeLinejoin="round"
                          className="text-muted-foreground"
                        >
                          <rect x="3" y="11" width="18" height="11" rx="2" ry="2" />
                          <path d="M7 11V7a5 5 0 0 1 10 0v4" />
                        </svg>
                      )}
                    </td>
                    <td className="px-4 py-3 text-right">
                      {!mapping.isDefault && (
                        <button
                          onClick={() => handleRemoveMapping(mapping.id)}
                          className="rounded px-2 py-1 text-xs text-destructive hover:bg-destructive/10 transition-colors"
                        >
                          {t('fieldMapping.remove')}
                        </button>
                      )}
                    </td>
                  </tr>
                ))}
              </tbody>
            </table>
          </div>

          {/* Add mapping form */}
          {showMappingForm && (
            <form onSubmit={handleAddMapping} className="mt-4 flex items-end gap-3">
              <div className="space-y-1">
                <label className="text-xs font-medium text-muted-foreground">
                  {t('fieldMapping.ldapField')}
                </label>
                <input
                  type="text"
                  value={newMapping.ldapField}
                  onChange={(e) => setNewMapping({ ...newMapping, ldapField: e.target.value })}
                  className="flex h-9 w-40 rounded-md border border-input bg-background px-3 py-1 text-sm"
                  required
                />
              </div>
              <div className="space-y-1">
                <label className="text-xs font-medium text-muted-foreground">
                  {t('fieldMapping.tesseraField')}
                </label>
                <input
                  type="text"
                  value={newMapping.tesseraField}
                  onChange={(e) => setNewMapping({ ...newMapping, tesseraField: e.target.value })}
                  className="flex h-9 w-40 rounded-md border border-input bg-background px-3 py-1 text-sm"
                  required
                />
              </div>
              <button
                type="submit"
                className="h-9 rounded-md bg-primary px-3 text-xs font-medium text-primary-foreground hover:opacity-90 transition-opacity"
              >
                {tCommon('save')}
              </button>
              <button
                type="button"
                onClick={() => setShowMappingForm(false)}
                className="h-9 rounded-md border border-border px-3 text-xs text-foreground hover:bg-muted transition-colors"
              >
                {tCommon('cancel')}
              </button>
            </form>
          )}
        </section>
      )}

      {/* Section 2.5: Group/OU import filter (selective sync) */}
      {config && (
        <section className="rounded-lg border border-border p-6">
          <h2 className="text-lg font-semibold text-foreground mb-2">
            {t('groupFilter.title')}
          </h2>
          <p className="text-sm text-muted-foreground mb-4">
            {t('groupFilter.description')}
          </p>

          <div className="flex items-center gap-3 mb-4">
            <button
              type="button"
              onClick={handleDiscoverGroups}
              disabled={discovering}
              className="rounded-md border border-border px-4 py-2 text-sm font-medium text-foreground hover:bg-muted transition-colors disabled:opacity-50"
            >
              {discovering ? tCommon('loading') : t('groupFilter.discover')}
            </button>
          </div>

          {discovered && discovered.length > 0 && (
            <div className="mb-4 space-y-2">
              <input
                type="text"
                value={discoverSearch}
                onChange={(e) => setDiscoverSearch(e.target.value)}
                placeholder={t('groupFilter.searchPlaceholder')}
                className="flex h-9 w-full rounded-md border border-input bg-background px-3 py-1 text-sm"
              />
              <div className="max-h-64 overflow-y-auto rounded-md border border-border divide-y divide-border">
                {filteredDiscovered && filteredDiscovered.length > 0 ? (
                  filteredDiscovered.map((entry) => (
                    <label
                      key={entry.dn}
                      className="flex items-center gap-3 px-4 py-2 text-sm hover:bg-muted/30 cursor-pointer"
                    >
                      <input
                        type="checkbox"
                        checked={groupFilterDns.includes(entry.dn)}
                        onChange={() => toggleGroupFilterDn(entry.dn)}
                      />
                      <span className="rounded bg-muted px-1.5 py-0.5 text-xs font-medium text-muted-foreground">
                        {entry.type === 'ou' ? t('groupFilter.typeOu') : t('groupFilter.typeGroup')}
                      </span>
                      <span className="font-medium text-foreground">{entry.name}</span>
                      <span className="font-mono text-xs text-muted-foreground truncate">
                        {entry.dn}
                      </span>
                    </label>
                  ))
                ) : (
                  <p className="px-4 py-3 text-sm text-muted-foreground">
                    {t('groupFilter.noMatches')}
                  </p>
                )}
              </div>
            </div>
          )}

          {discovered && discovered.length === 0 && (
            <p className="mb-4 text-sm text-muted-foreground">{t('groupFilter.noneFound')}</p>
          )}

          <div className="flex items-end gap-3 mb-4">
            <div className="flex-1 space-y-1">
              <label className="text-xs font-medium text-muted-foreground">
                {t('groupFilter.manualDn')}
              </label>
              <input
                type="text"
                value={manualDn}
                onChange={(e) => setManualDn(e.target.value)}
                placeholder="CN=Beispiel,OU=Gruppen,DC=ctl,DC=local"
                className="flex h-9 w-full rounded-md border border-input bg-background px-3 py-1 text-sm font-mono"
              />
            </div>
            <button
              type="button"
              onClick={handleAddManualDn}
              className="h-9 rounded-md border border-border px-3 text-xs font-medium text-foreground hover:bg-muted transition-colors"
            >
              {t('groupFilter.addDn')}
            </button>
          </div>

          <div className="mb-4">
            <p className="text-xs font-medium text-muted-foreground mb-2">
              {t('groupFilter.selected')}
            </p>
            {groupFilterDns.length === 0 ? (
              <p className="text-sm text-muted-foreground">{t('groupFilter.emptyMeansAll')}</p>
            ) : (
              <ul className="space-y-1">
                {groupFilterDns.map((dn) => (
                  <li
                    key={dn}
                    className="flex items-center justify-between gap-3 rounded-md border border-border px-3 py-1.5 text-sm"
                  >
                    <span className="font-mono text-xs text-foreground truncate">{dn}</span>
                    <button
                      type="button"
                      onClick={() => handleRemoveGroupFilterDn(dn)}
                      className="shrink-0 rounded px-2 py-1 text-xs text-destructive hover:bg-destructive/10 transition-colors"
                    >
                      {t('fieldMapping.remove')}
                    </button>
                  </li>
                ))}
              </ul>
            )}
          </div>

          <button
            type="button"
            onClick={handleSaveGroupFilter}
            disabled={savingFilter}
            className="rounded-md bg-primary px-4 py-2 text-sm font-medium text-primary-foreground hover:opacity-90 transition-opacity disabled:opacity-50"
          >
            {savingFilter ? tCommon('loading') : t('groupFilter.save')}
          </button>
        </section>
      )}

      {/* Section 2.52: AD group import (SC-1/SC-2, D-01/D-02) */}
      {config && (
        <section className="rounded-lg border border-border p-6">
          <h2 className="text-lg font-semibold text-foreground mb-2">
            {t('groupImport.title')}
          </h2>
          <p className="text-sm text-muted-foreground mb-4">
            {t('groupImport.description')}
          </p>

          <div className="flex items-center gap-3 mb-4">
            <button
              type="button"
              onClick={handleDiscoverGroupsToImport}
              disabled={discoveringGroupImport}
              className="rounded-md border border-border px-4 py-2 text-sm font-medium text-foreground hover:bg-muted transition-colors disabled:opacity-50"
            >
              {discoveringGroupImport
                ? tCommon('loading')
                : t('groupImport.discover')}
            </button>
          </div>

          {groupImportError && (
            <div className="mb-4 rounded-md border border-destructive/50 bg-destructive/10 p-3 text-sm text-destructive">
              {groupImportError}
            </div>
          )}

          {groupImportCandidates && groupImportCandidates.length > 0 && (
            <div className="mb-4 space-y-2">
              <input
                type="text"
                value={groupImportSearch}
                onChange={(e) => setGroupImportSearch(e.target.value)}
                placeholder={t('groupImport.searchPlaceholder')}
                className="flex h-9 w-full rounded-md border border-input bg-background px-3 py-1 text-sm"
              />
              <div className="max-h-64 overflow-y-auto rounded-md border border-border divide-y divide-border">
                {filteredGroupImportCandidates &&
                filteredGroupImportCandidates.length > 0 ? (
                  filteredGroupImportCandidates.map((entry) => (
                    <label
                      key={entry.dn}
                      className={`flex items-center gap-3 px-4 py-2 text-sm ${
                        entry.alreadyImported
                          ? 'opacity-60'
                          : 'hover:bg-muted/30 cursor-pointer'
                      }`}
                    >
                      <input
                        type="checkbox"
                        disabled={entry.alreadyImported}
                        checked={selectedImportDns.includes(entry.dn)}
                        onChange={() => toggleImportDn(entry.dn)}
                      />
                      <span className="font-medium text-foreground">
                        {entry.name}
                      </span>
                      <span className="font-mono text-xs text-muted-foreground truncate">
                        {entry.dn}
                      </span>
                      {entry.alreadyImported && (
                        <span className="ml-auto shrink-0 rounded bg-muted px-1.5 py-0.5 text-xs font-medium text-muted-foreground">
                          {t('groupImport.alreadyImported')}
                        </span>
                      )}
                    </label>
                  ))
                ) : (
                  <p className="px-4 py-3 text-sm text-muted-foreground">
                    {t('groupImport.noMatches')}
                  </p>
                )}
              </div>
            </div>
          )}

          {groupImportCandidates && groupImportCandidates.length === 0 && (
            <p className="mb-4 text-sm text-muted-foreground">
              {t('groupImport.noneFound')}
            </p>
          )}

          {groupImportCandidates && groupImportCandidates.length > 0 && (
            <button
              type="button"
              onClick={handleImportGroups}
              disabled={importingGroups || selectedImportDns.length === 0}
              className="rounded-md bg-primary px-4 py-2 text-sm font-medium text-primary-foreground hover:opacity-90 transition-opacity disabled:opacity-50"
            >
              {importingGroups
                ? tCommon('loading')
                : `${t('groupImport.importSelected')} (${selectedImportDns.length})`}
            </button>
          )}

          {groupImportResult && (
            <div className="mt-3">
              <p className="text-sm text-muted-foreground">
                {t('groupImport.resultSummary', {
                  imported: groupImportResult.imported,
                  skipped: groupImportResult.skipped,
                  errors:
                    groupImportResult.errors.length +
                    groupImportResult.nameCollisions.length,
                })}
              </p>
              {groupImportResult.nameCollisions.length > 0 && (
                <div className="mt-2 space-y-1">
                  {groupImportResult.nameCollisions.map((name, i) => (
                    <p key={`collision-${i}`} className="text-xs text-destructive">
                      {t('groupImport.nameCollisionError', { name })}
                    </p>
                  ))}
                </div>
              )}
              {groupImportResult.errors.length > 0 && (
                <div className="mt-2 space-y-1">
                  {groupImportResult.errors.map((err, i) => (
                    <p key={`error-${i}`} className="text-xs text-destructive">
                      {err}
                    </p>
                  ))}
                </div>
              )}
              <p className="mt-2 text-xs text-muted-foreground">
                {t('groupImport.membershipHint')}
              </p>
            </div>
          )}
        </section>
      )}

      {/* Section 2.55: Individual user search & import */}
      {config && (
        <section className="rounded-lg border border-border p-6">
          <h2 className="text-lg font-semibold text-foreground mb-2">
            {t('userSearch.title')}
          </h2>
          <p className="text-sm text-muted-foreground mb-4">
            {t('userSearch.description')}
          </p>

          <div className="flex items-end gap-3 mb-4">
            <div className="flex-1 space-y-1">
              <input
                type="text"
                value={userSearchQuery}
                onChange={(e) => setUserSearchQuery(e.target.value)}
                onKeyDown={(e) => {
                  if (e.key === 'Enter') handleSearchUsers();
                }}
                placeholder={t('userSearch.placeholder')}
                className="flex h-9 w-full rounded-md border border-input bg-background px-3 py-1 text-sm"
              />
            </div>
            <button
              type="button"
              onClick={handleSearchUsers}
              disabled={userSearching || !userSearchQuery.trim()}
              className="h-9 rounded-md border border-border px-4 text-sm font-medium text-foreground hover:bg-muted transition-colors disabled:opacity-50"
            >
              {userSearching ? tCommon('loading') : t('userSearch.search')}
            </button>
          </div>

          {userSearchResults && userSearchResults.length > 0 && (
            <div className="mb-4 max-h-64 overflow-y-auto rounded-md border border-border divide-y divide-border">
              {userSearchResults.map((u) => (
                <label
                  key={u.dn}
                  className={`flex items-center gap-3 px-4 py-2 text-sm ${
                    u.alreadyImported
                      ? 'opacity-60'
                      : 'hover:bg-muted/30 cursor-pointer'
                  }`}
                >
                  <input
                    type="checkbox"
                    disabled={u.alreadyImported}
                    checked={selectedUserDns.includes(u.dn)}
                    onChange={() => toggleUserDn(u.dn)}
                  />
                  <span className="font-medium text-foreground">
                    {u.displayName || u.username}
                  </span>
                  <span className="text-xs text-muted-foreground">
                    {u.username}
                  </span>
                  {u.email && (
                    <span className="truncate text-xs text-muted-foreground">
                      {u.email}
                    </span>
                  )}
                  {u.alreadyImported && (
                    <span className="ml-auto shrink-0 rounded bg-muted px-1.5 py-0.5 text-xs font-medium text-muted-foreground">
                      {t('userSearch.alreadyImported')}
                    </span>
                  )}
                </label>
              ))}
            </div>
          )}

          {userSearchResults && userSearchResults.length === 0 && (
            <p className="mb-4 text-sm text-muted-foreground">
              {t('userSearch.noResults')}
            </p>
          )}

          {userSearchResults && userSearchResults.length > 0 && (
            <button
              type="button"
              onClick={() => handleImportUsers(selectedUserDns)}
              disabled={importingUsers || selectedUserDns.length === 0}
              className="rounded-md bg-primary px-4 py-2 text-sm font-medium text-primary-foreground hover:opacity-90 transition-opacity disabled:opacity-50"
            >
              {importingUsers
                ? tCommon('loading')
                : `${t('userSearch.importSelected')} (${selectedUserDns.length})`}
            </button>
          )}

          {userImportResult && (
            <p className="mt-3 text-sm text-muted-foreground">
              {userImportResult.created} {t('userSearch.created')},{' '}
              {userImportResult.skipped} {t('userSearch.skipped')}
              {userImportResult.errors.length > 0 && (
                <>
                  , {userImportResult.errors.length} {t('userSearch.errors')}
                </>
              )}
            </p>
          )}
        </section>
      )}

      {/* Section 2.6: Per-user exclude/denylist */}
      {config && (
        <section className="rounded-lg border border-border p-6">
          <h2 className="text-lg font-semibold text-foreground mb-2">
            {t('userExclude.title')}
          </h2>
          <p className="text-sm text-muted-foreground mb-4">
            {t('userExclude.description')}
          </p>

          <div className="flex items-end gap-3 mb-4">
            <div className="flex-1 space-y-1">
              <label className="text-xs font-medium text-muted-foreground">
                {t('userExclude.username')}
              </label>
              <input
                type="text"
                value={newExcludeUser}
                onChange={(e) => setNewExcludeUser(e.target.value)}
                onKeyDown={(e) => {
                  if (e.key === 'Enter') {
                    e.preventDefault();
                    handleAddExcludeUser();
                  }
                }}
                placeholder="administrator, krbtgt, guest, ldap$ ..."
                className="flex h-9 w-full rounded-md border border-input bg-background px-3 py-1 text-sm font-mono"
              />
            </div>
            <button
              type="button"
              onClick={handleAddExcludeUser}
              className="h-9 rounded-md border border-border px-3 text-xs font-medium text-foreground hover:bg-muted transition-colors"
            >
              {t('userExclude.add')}
            </button>
          </div>

          <div className="mb-4">
            <p className="text-xs font-medium text-muted-foreground mb-2">
              {t('userExclude.excluded')}
            </p>
            {userExcludeList.length === 0 ? (
              <p className="text-sm text-muted-foreground">{t('userExclude.empty')}</p>
            ) : (
              <ul className="flex flex-wrap gap-2">
                {userExcludeList.map((name) => (
                  <li
                    key={name}
                    className="flex items-center gap-2 rounded-md border border-border px-3 py-1.5 text-sm"
                  >
                    <span className="font-mono text-xs text-foreground">{name}</span>
                    <button
                      type="button"
                      onClick={() => handleRemoveExcludeUser(name)}
                      className="shrink-0 rounded px-1.5 py-0.5 text-xs text-destructive hover:bg-destructive/10 transition-colors"
                    >
                      {t('fieldMapping.remove')}
                    </button>
                  </li>
                ))}
              </ul>
            )}
          </div>

          <button
            type="button"
            onClick={handleSaveExcludeList}
            disabled={savingExclude}
            className="rounded-md bg-primary px-4 py-2 text-sm font-medium text-primary-foreground hover:opacity-90 transition-opacity disabled:opacity-50"
          >
            {savingExclude ? tCommon('loading') : t('userExclude.save')}
          </button>
        </section>
      )}

      {/* Section 3: Sync Settings (D-14) */}
      {config && (
        <section className="rounded-lg border border-border p-6">
          <h2 className="text-lg font-semibold text-foreground mb-4">
            {t('sync.title')}
          </h2>

          <div className="space-y-4">
            {/* Sync interval */}
            <div className="flex items-center gap-4">
              <div className="space-y-1">
                <label className="text-sm font-medium text-foreground">
                  {t('sync.interval')}
                </label>
                <div className="flex items-center gap-2">
                  <input
                    type="number"
                    min={0}
                    value={formData.syncIntervalMin}
                    onChange={(e) =>
                      setFormData({ ...formData, syncIntervalMin: parseInt(e.target.value, 10) || 0 })
                    }
                    className="flex h-10 w-24 rounded-md border border-input bg-background px-3 py-2 text-sm"
                  />
                  <span className="text-sm text-muted-foreground">min</span>
                  {formData.syncIntervalMin === 0 && (
                    <span className="text-xs text-muted-foreground">
                      ({t('sync.intervalDisabled')})
                    </span>
                  )}
                </div>
              </div>
            </div>

            {/* Enable/Disable toggle */}
            <div className="flex items-center gap-3">
              <label className="relative inline-flex items-center cursor-pointer">
                <input
                  type="checkbox"
                  checked={formData.isActive}
                  onChange={(e) => setFormData({ ...formData, isActive: e.target.checked })}
                  className="sr-only peer"
                />
                <div className="w-11 h-6 bg-gray-200 peer-focus:outline-none rounded-full peer dark:bg-gray-700 peer-checked:after:translate-x-full rtl:peer-checked:after:-translate-x-full peer-checked:after:border-white after:content-[''] after:absolute after:top-[2px] after:start-[2px] after:bg-white after:border-gray-300 after:border after:rounded-full after:h-5 after:w-5 after:transition-all dark:border-gray-600 peer-checked:bg-primary" />
              </label>
              <span className="text-sm font-medium text-foreground">
                {formData.isActive ? t('enable') : t('disable')}
              </span>
            </div>

            {/* Save interval changes */}
            <button
              onClick={handleSave}
              disabled={saving}
              className="rounded-md bg-primary px-4 py-2 text-sm font-medium text-primary-foreground hover:opacity-90 transition-opacity disabled:opacity-50"
            >
              {t('save')}
            </button>

            {/* Last sync info */}
            <div className="border-t border-border pt-4">
              <p className="text-sm text-muted-foreground">
                {t('sync.lastSync')}:{' '}
                <span className="font-medium text-foreground">
                  {config.lastSyncAt
                    ? new Date(config.lastSyncAt).toLocaleString()
                    : t('sync.neverSynced')}
                </span>
              </p>
            </div>

            {/* Manual sync button (D-14) */}
            <button
              onClick={handleSync}
              disabled={syncing}
              className="rounded-md bg-primary px-4 py-2 text-sm font-medium text-primary-foreground hover:opacity-90 transition-opacity disabled:opacity-50"
            >
              {syncing ? t('sync.syncing') : t('sync.trigger')}
            </button>

            {/* Sync result display */}
            {syncResult && (
              <div className="rounded-md border border-border bg-muted/30 p-4">
                <p className="text-sm font-medium text-foreground mb-2">
                  {t('sync.result', {
                    created: syncResult.created,
                    updated: syncResult.updated,
                    deactivated: syncResult.deactivated,
                  })}
                </p>
                {syncResult.errors.length > 0 && (
                  <div className="mt-2 space-y-1">
                    {syncResult.errors.map((err, i) => (
                      <p key={i} className="text-xs text-destructive">
                        {err}
                      </p>
                    ))}
                  </div>
                )}
              </div>
            )}
          </div>
        </section>
      )}
    </div>
  );
}