import { useEffect, useState } from 'react';
import {
  Building2,
  Check,
  Edit,
  Plus,
  Power,
  X,
} from 'lucide-react';
import toast from 'react-hot-toast';
import { tenantsApi } from '../services/api';
import type { Tenant } from '../types';
import Modal from '../components/Modal';
import ConfirmDialog from '../components/ConfirmDialog';
import SearchBar from '../components/SearchBar';
import Pagination from '../components/Pagination';
import EmptyState from '../components/EmptyState';

export default function TenantList() {
  const [tenants, setTenants] = useState<Tenant[]>([]);
  const [search, setSearch] = useState('');
  const [page, setPage] = useState(1);
  const [totalPages, setTotalPages] = useState(1);
  const [loading, setLoading] = useState(true);

  // Modal state
  const [modalOpen, setModalOpen] = useState(false);
  const [editingTenant, setEditingTenant] = useState<Tenant | null>(null);
  const [formName, setFormName] = useState('');
  const [formSlug, setFormSlug] = useState('');
  const [formActive, setFormActive] = useState(true);
  const [formSaving, setFormSaving] = useState(false);

  // Deactivate dialog
  const [deactivateTarget, setDeactivateTarget] = useState<Tenant | null>(null);
  const [deactivating, setDeactivating] = useState(false);

  useEffect(() => {
    loadTenants();
  }, [search, page]);

  const loadTenants = async () => {
    setLoading(true);
    try {
      const res = await tenantsApi.list({
        page,
        pageSize: 20,
        search: search || undefined,
      });
      setTenants(res.data);
      setTotalPages(res.totalPages);
    } catch {
      toast.error('Mandanten konnten nicht geladen werden');
    } finally {
      setLoading(false);
    }
  };

  const openCreate = () => {
    setEditingTenant(null);
    setFormName('');
    setFormSlug('');
    setFormActive(true);
    setModalOpen(true);
  };

  const openEdit = (tenant: Tenant) => {
    setEditingTenant(tenant);
    setFormName(tenant.name);
    setFormSlug(tenant.slug);
    setFormActive(tenant.active);
    setModalOpen(true);
  };

  const handleSave = async () => {
    if (!formName.trim() || !formSlug.trim()) {
      toast.error('Name und Slug sind erforderlich');
      return;
    }
    setFormSaving(true);
    try {
      if (editingTenant) {
        await tenantsApi.update(editingTenant.id, {
          name: formName,
          slug: formSlug,
          active: formActive,
        });
        toast.success('Mandant aktualisiert');
      } else {
        await tenantsApi.create({
          name: formName,
          slug: formSlug,
          active: formActive,
        });
        toast.success('Mandant erstellt');
      }
      setModalOpen(false);
      loadTenants();
    } catch {
      toast.error('Speichern fehlgeschlagen');
    } finally {
      setFormSaving(false);
    }
  };

  const handleDeactivate = async () => {
    if (!deactivateTarget) return;
    setDeactivating(true);
    try {
      await tenantsApi.update(deactivateTarget.id, {
        active: !deactivateTarget.active,
      });
      toast.success(
        deactivateTarget.active
          ? 'Mandant deaktiviert'
          : 'Mandant aktiviert'
      );
      setDeactivateTarget(null);
      loadTenants();
    } catch {
      toast.error('Aktion fehlgeschlagen');
    } finally {
      setDeactivating(false);
    }
  };

  return (
    <div className="space-y-6">
      {/* Header */}
      <div className="flex flex-col gap-4 sm:flex-row sm:items-center sm:justify-between">
        <div>
          <h1 className="text-2xl font-bold text-gray-900">Mandanten</h1>
          <p className="mt-1 text-sm text-gray-500">
            Verwalten Sie die Mandanten des Portals.
          </p>
        </div>
        <button onClick={openCreate} className="btn-primary gap-2">
          <Plus size={18} />
          Neuer Mandant
        </button>
      </div>

      {/* Search */}
      <div className="max-w-md">
        <SearchBar
          value={search}
          onChange={(val) => {
            setSearch(val);
            setPage(1);
          }}
          placeholder="Mandanten suchen..."
        />
      </div>

      {/* Table */}
      {loading ? (
        <div className="flex items-center justify-center py-16">
          <div className="h-8 w-8 animate-spin rounded-full border-4 border-primary-600 border-t-transparent" />
        </div>
      ) : tenants.length === 0 ? (
        <EmptyState
          icon={Building2}
          title="Keine Mandanten gefunden"
          description="Erstellen Sie den ersten Mandanten."
          action={
            <button onClick={openCreate} className="btn-primary gap-2">
              <Plus size={18} />
              Neuer Mandant
            </button>
          }
        />
      ) : (
        <div className="card overflow-hidden">
          <div className="overflow-x-auto">
            <table className="min-w-full divide-y divide-gray-200">
              <thead className="bg-gray-50">
                <tr>
                  <th className="px-6 py-3 text-left text-xs font-semibold uppercase tracking-wider text-gray-500">
                    Name
                  </th>
                  <th className="px-6 py-3 text-left text-xs font-semibold uppercase tracking-wider text-gray-500">
                    Slug
                  </th>
                  <th className="px-6 py-3 text-left text-xs font-semibold uppercase tracking-wider text-gray-500">
                    Status
                  </th>
                  <th className="px-6 py-3 text-right text-xs font-semibold uppercase tracking-wider text-gray-500">
                    Aktionen
                  </th>
                </tr>
              </thead>
              <tbody className="divide-y divide-gray-100 bg-white">
                {tenants.map((tenant) => (
                  <tr key={tenant.id} className="hover:bg-gray-50">
                    <td className="whitespace-nowrap px-6 py-4">
                      <div className="flex items-center gap-3">
                        <div className="flex h-9 w-9 items-center justify-center rounded-lg bg-primary-50 text-sm font-bold text-primary-700">
                          {tenant.name[0]}
                        </div>
                        <span className="font-medium text-gray-900">
                          {tenant.name}
                        </span>
                      </div>
                    </td>
                    <td className="whitespace-nowrap px-6 py-4 text-sm text-gray-500">
                      {tenant.slug}
                    </td>
                    <td className="whitespace-nowrap px-6 py-4">
                      {tenant.active ? (
                        <span className="inline-flex items-center gap-1 rounded-full bg-green-50 px-2.5 py-0.5 text-xs font-medium text-green-700 ring-1 ring-inset ring-green-300">
                          <Check size={12} />
                          Aktiv
                        </span>
                      ) : (
                        <span className="inline-flex items-center gap-1 rounded-full bg-gray-100 px-2.5 py-0.5 text-xs font-medium text-gray-600 ring-1 ring-inset ring-gray-300">
                          <X size={12} />
                          Inaktiv
                        </span>
                      )}
                    </td>
                    <td className="whitespace-nowrap px-6 py-4 text-right">
                      <div className="flex items-center justify-end gap-2">
                        <button
                          onClick={() => openEdit(tenant)}
                          className="rounded-lg p-2 text-gray-400 hover:bg-gray-100 hover:text-gray-600"
                          title="Bearbeiten"
                        >
                          <Edit size={16} />
                        </button>
                        <button
                          onClick={() => setDeactivateTarget(tenant)}
                          className="rounded-lg p-2 text-gray-400 hover:bg-gray-100 hover:text-gray-600"
                          title={tenant.active ? 'Deaktivieren' : 'Aktivieren'}
                        >
                          <Power size={16} />
                        </button>
                      </div>
                    </td>
                  </tr>
                ))}
              </tbody>
            </table>
          </div>
        </div>
      )}

      {totalPages > 1 && (
        <Pagination page={page} totalPages={totalPages} onPageChange={setPage} />
      )}

      {/* Create/Edit Modal */}
      <Modal
        open={modalOpen}
        onClose={() => setModalOpen(false)}
        title={editingTenant ? 'Mandant bearbeiten' : 'Neuer Mandant'}
      >
        <div className="space-y-4">
          <div>
            <label className="mb-1.5 block text-sm font-medium text-gray-700">
              Name *
            </label>
            <input
              type="text"
              value={formName}
              onChange={(e) => {
                setFormName(e.target.value);
                if (!editingTenant) {
                  setFormSlug(
                    e.target.value
                      .toLowerCase()
                      .replace(/[^a-z0-9]+/g, '-')
                      .replace(/(^-|-$)/g, '')
                  );
                }
              }}
              placeholder="Firmenname GmbH"
              className="input-field"
            />
          </div>
          <div>
            <label className="mb-1.5 block text-sm font-medium text-gray-700">
              Slug *
            </label>
            <input
              type="text"
              value={formSlug}
              onChange={(e) => setFormSlug(e.target.value)}
              placeholder="firmenname-gmbh"
              className="input-field"
            />
          </div>
          <label className="flex items-center gap-2">
            <input
              type="checkbox"
              checked={formActive}
              onChange={(e) => setFormActive(e.target.checked)}
              className="h-4 w-4 rounded border-gray-300 text-primary-600 focus:ring-primary-500"
            />
            <span className="text-sm text-gray-700">Aktiv</span>
          </label>
          <div className="flex justify-end gap-3 pt-2">
            <button
              onClick={() => setModalOpen(false)}
              className="btn-secondary"
            >
              Abbrechen
            </button>
            <button
              onClick={handleSave}
              disabled={formSaving}
              className="btn-primary"
            >
              {formSaving ? 'Speichern...' : 'Speichern'}
            </button>
          </div>
        </div>
      </Modal>

      {/* Deactivate Confirm */}
      <ConfirmDialog
        open={!!deactivateTarget}
        onClose={() => setDeactivateTarget(null)}
        onConfirm={handleDeactivate}
        title={
          deactivateTarget?.active
            ? 'Mandant deaktivieren?'
            : 'Mandant aktivieren?'
        }
        message={
          deactivateTarget?.active
            ? `Der Mandant "${deactivateTarget?.name}" wird deaktiviert. Benutzer des Mandanten können sich nicht mehr anmelden.`
            : `Der Mandant "${deactivateTarget?.name}" wird wieder aktiviert.`
        }
        confirmLabel={deactivateTarget?.active ? 'Deaktivieren' : 'Aktivieren'}
        variant={deactivateTarget?.active ? 'danger' : 'warning'}
        loading={deactivating}
      />
    </div>
  );
}