/**
 * AutomationTemplatesView
 *
 * View for managing automation templates (CRUD).
 * System templates (isSystem=true) are read-only for non-SysAdmin, with duplicate option.
 * Instance templates can be managed by instance admins/editors.
 */

import React, { useState, useMemo, useEffect } from 'react';
import { useAutomationTemplates, type AutomationTemplate } from '../../../hooks/useAutomations';
import { FormGeneratorTable } from '../../../components/FormGenerator/FormGeneratorTable';
import { AutomationEditor } from '../../../components/AutomationEditor';
import { FaSync, FaPlus, FaFileAlt, FaLock } from 'react-icons/fa';
import { useToast } from '../../../contexts/ToastContext';
import { useCurrentUser } from '../../../hooks/useUsers';
import styles from '../../admin/Admin.module.css';

export const AutomationTemplatesView: React.FC = () => {
  const {
    templates,
    attributes,
    loading,
    error,
    permissions,
    refetch,
    fetchTemplates,
    pagination,
    createTemplate,
    updateTemplate,
    deleteTemplate,
    duplicateTemplate,
    getTemplate,
  } = useAutomationTemplates();
  const { user: currentUser } = useCurrentUser();
  const isSysAdmin = currentUser?.isSysAdmin || false;
  const { showSuccess, showError } = useToast();

  const [showEditor, setShowEditor] = useState(false);
  const [editingTemplate, setEditingTemplate] = useState<AutomationTemplate | null>(null);
  const [saving, setSaving] = useState(false);

  useEffect(() => { refetch(); }, []);

  const canCreate = permissions?.create !== 'n';
  const canUpdate = permissions?.update !== 'n';
  const canDelete = permissions?.delete !== 'n';

  const columns = useMemo(() => [
    { key: 'label', label: 'Label', type: 'string' as const, sortable: true, searchable: true, width: 200 },
    { key: 'overview', label: 'Beschreibung', type: 'string' as const, width: 300 },
    { key: 'isSystem', label: 'Typ', type: 'boolean' as const, width: 100, formatter: (value: any) =>
      value ? <span style={{ display: 'inline-flex', alignItems: 'center', gap: 4, fontSize: '0.75rem', padding: '0.125rem 0.5rem', borderRadius: 10, background: 'var(--info-color, #3182ce)', color: '#fff' }}><FaLock style={{ fontSize: '0.625rem' }} /> System</span>
        : <span style={{ fontSize: '0.75rem', padding: '0.125rem 0.5rem', borderRadius: 10, background: 'var(--success-color, #38a169)', color: '#fff' }}>Instanz</span>
    },
    { key: '_createdByUserName', label: 'Erstellt von', type: 'string' as const, width: 150 },
  ], []);

  const handleEditClick = async (template: AutomationTemplate) => {
    const fullTemplate = await getTemplate(template.id);
    setEditingTemplate(fullTemplate || template);
    setShowEditor(true);
  };

  const handleCreateClick = () => {
    setEditingTemplate(null);
    setShowEditor(true);
  };

  const handleEditorSave = async (data: Partial<AutomationTemplate>) => {
    setSaving(true);
    try {
      if (editingTemplate) {
        await updateTemplate(editingTemplate.id, data);
        showSuccess('Vorlage aktualisiert');
      } else {
        await createTemplate(data as any);
        showSuccess('Vorlage erstellt');
      }
      setShowEditor(false);
      setEditingTemplate(null);
      await refetch();
    } catch (err: any) {
      showError(`Fehler: ${err.message}`);
    } finally {
      setSaving(false);
    }
  };

  const handleEditorCancel = () => {
    setShowEditor(false);
    setEditingTemplate(null);
  };

  const handleDelete = async (templateId: string): Promise<boolean> => {
    try {
      await deleteTemplate(templateId);
      showSuccess('Vorlage gelöscht');
      return true;
    } catch (err: any) {
      showError(`Fehler: ${err.message}`);
      return false;
    }
  };

  const handleDuplicate = async (template: AutomationTemplate) => {
    try {
      await duplicateTemplate(template.id);
      showSuccess('Vorlage dupliziert');
      await refetch();
    } catch (err: any) {
      showError(`Fehler beim Duplizieren: ${err.message}`);
    }
  };

  if (error) {
    return (
      <div className={styles.adminPage}>
        <div className={styles.errorContainer}>
          <span className={styles.errorIcon}>⚠️</span>
          <p className={styles.errorMessage}>Fehler beim Laden der Vorlagen: {error}</p>
          <button className={styles.secondaryButton} onClick={() => refetch()}><FaSync /> Erneut versuchen</button>
        </div>
      </div>
    );
  }

  return (
    <div className={`${styles.adminPage} ${styles.adminPageFill}`}>
      <div className={styles.pageHeader}>
        <div>
          <h1 className={styles.pageTitle}>Automation-Vorlagen</h1>
          <p className={styles.pageSubtitle}>Verwalten Sie Ihre Workflow-Vorlagen</p>
        </div>
        <div className={styles.headerActions}>
          <button className={styles.secondaryButton} onClick={() => refetch()} disabled={loading}>
            <FaSync className={loading ? 'spinning' : ''} /> Aktualisieren
          </button>
          {canCreate && (
            <button className={styles.primaryButton} onClick={handleCreateClick}>
              <FaPlus /> Neue Vorlage
            </button>
          )}
        </div>
      </div>

      <div className={styles.tableContainer}>
        {loading && (!templates || templates.length === 0) ? (
          <div className={styles.loadingContainer}>
            <div className={styles.spinner} />
            <span>Lade Vorlagen...</span>
          </div>
        ) : !templates || templates.length === 0 ? (
          <div className={styles.emptyState}>
            <FaFileAlt className={styles.emptyIcon} />
            <h3 className={styles.emptyTitle}>Keine Vorlagen vorhanden</h3>
            <p className={styles.emptyDescription}>Erstellen Sie eine neue Vorlage für Ihre Workflows.</p>
            {canCreate && (
              <button className={styles.primaryButton} onClick={handleCreateClick}>
                <FaPlus /> Vorlage erstellen
              </button>
            )}
          </div>
        ) : (
          <FormGeneratorTable
            data={templates as any[]}
            columns={columns}
            apiEndpoint="/api/automation-templates"
            loading={loading}
            pagination={true}
            pageSize={25}
            searchable={true}
            filterable={true}
            sortable={true}
            selectable={false}
            actionButtons={[
              { type: 'copy' as const, title: 'Duplizieren', onAction: handleDuplicate },
              { type: 'edit' as const, onAction: handleEditClick, title: 'Bearbeiten', disabled: (row: any) => row.isSystem && !isSysAdmin ? { disabled: true, message: 'System-Vorlagen können nur vom SysAdmin bearbeitet werden' } : !canUpdate ? { disabled: true, message: 'Keine Berechtigung' } : false },
              { type: 'delete' as const, title: 'Löschen', disabled: (row: any) => row.isSystem && !isSysAdmin ? { disabled: true, message: 'System-Vorlagen können nur vom SysAdmin gelöscht werden' } : !canDelete ? { disabled: true, message: 'Keine Berechtigung' } : false },
            ]}
            onDelete={(template) => handleDelete(template.id)}
            hookData={{ refetch: fetchTemplates, pagination, handleDelete, attributes }}
            emptyMessage="Keine Vorlagen gefunden"
          />
        )}
      </div>

      {showEditor && (
        <AutomationEditor
          mode="template"
          initialData={editingTemplate}
          onSave={handleEditorSave}
          onCancel={handleEditorCancel}
          saving={saving}
        />
      )}
    </div>
  );
};