// TODO: P2-F20 — Replace hardcoded AVAILABLE_EVENTS with backend config
/**
 * SettingsWebhooks page — Webhook management.
 *
 * Features:
 * - Table listing all webhooks with URL, events, status toggle, test/edit/delete buttons
 * - Create/edit modal: URL, events (multi-select checkboxes), secret, retry_count, timeout
 * - Test button sends test payload, shows result
 */

import React, { useState, useCallback } from 'react';
import { useTranslation } from 'react-i18next';
import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
import clsx from 'clsx';
import { Plus, Pencil, Trash2, AlertTriangle, Send, Webhook as WebhookIcon, CheckCircle, XCircle } from 'lucide-react';
import {
  fetchWebhooks,
  createWebhook,
  updateWebhook,
  deleteWebhook,
  testWebhook,
  useWebhooks,
  useCreateWebhook,
  useUpdateWebhook,
  useDeleteWebhook,
  useTestWebhook,
  type Webhook,
  type CreateWebhookPayload,
  type UpdateWebhookPayload,
  type WebhookTestResult,
} from '@/api/webhooks';
import { Card } from '@/components/ui/Card';
import { Button } from '@/components/ui/Button';
import { Modal } from '@/components/ui/Modal';
import { Input } from '@/components/ui/Input';

// ─── Available Events ───────────────────────────────────────────────────────

const AVAILABLE_EVENTS = [
  'contact.created',
  'contact.updated',
  'contact.deleted',
  'company.created',
  'company.updated',
  'company.deleted',
  'user.created',
  'user.updated',
  'deal.created',
  'deal.updated',
  'deal.deleted',
  'task.created',
  'task.updated',
  'task.deleted',
  'note.created',
  'note.updated',
  'note.deleted',
];

// ─── Webhook Form Modal (shared for create & edit) ───────────────────────────

interface WebhookFormModalProps {
  open: boolean;
  onClose: () => void;
  webhook?: Webhook | null;
  onSubmit: (data: CreateWebhookPayload | UpdateWebhookPayload) => void;
  isSubmitting: boolean;
  error?: string | null;
}

function WebhookFormModal({ open, onClose, webhook, onSubmit, isSubmitting, error }: WebhookFormModalProps) {
  const { t } = useTranslation();
  const isEdit = !!webhook;

  const [url, setUrl] = useState(webhook?.url ?? '');
  const [events, setEvents] = useState<string[]>(webhook?.events ?? []);
  const [secret, setSecret] = useState(webhook?.secret ?? '');
  const [retryCount, setRetryCount] = useState(webhook?.retry_count ?? 3);
  const [timeoutSeconds, setTimeoutSeconds] = useState(webhook?.timeout_seconds ?? 30);

  // Reset form when modal opens or webhook changes
  React.useEffect(() => {
    if (open) {
      setUrl(webhook?.url ?? '');
      setEvents(webhook?.events ?? []);
      setSecret(webhook?.secret ?? '');
      setRetryCount(webhook?.retry_count ?? 3);
      setTimeoutSeconds(webhook?.timeout_seconds ?? 30);
    }
  }, [open, webhook]);

  const toggleEvent = useCallback((event: string) => {
    setEvents((prev) =>
      prev.includes(event)
        ? prev.filter((e) => e !== event)
        : [...prev, event]
    );
  }, []);

  const handleSubmit = useCallback(
    (e: React.FormEvent) => {
      e.preventDefault();
      const trimmedUrl = url.trim();
      if (!trimmedUrl || events.length === 0) return;
      const data: CreateWebhookPayload | UpdateWebhookPayload = {
        url: trimmedUrl,
        events,
        secret: secret.trim() || null,
        retry_count: retryCount,
        timeout_seconds: timeoutSeconds,
      };
      if (!isEdit) {
        (data as CreateWebhookPayload).is_active = true;
      }
      onSubmit(data);
    },
    [url, events, secret, retryCount, timeoutSeconds, isEdit, onSubmit]
  );

  return (
    <Modal
      open={open}
      onClose={onClose}
      title={isEdit ? t('webhooks.editTitle', 'Webhook bearbeiten') : t('webhooks.createTitle', 'Neuer Webhook')}
      size="lg"
    >
      <form onSubmit={handleSubmit} className="space-y-4">
        {/* URL */}
        <Input
          label={t('webhooks.url', 'URL')}
          value={url}
          onChange={(e) => setUrl(e.target.value)}
          required
          placeholder={t('webhooks.urlPlaceholder', 'https://example.com/webhook')}
          autoFocus
          data-testid="webhook-form-url"
        />

        {/* Events multi-select */}
        <div>
          <label className="block text-sm font-medium text-secondary-700 mb-1.5">
            {t('webhooks.events', 'Events')}
          </label>
          <div className="grid grid-cols-2 gap-2 max-h-48 overflow-y-auto border border-secondary-200 rounded-md p-2">
            {AVAILABLE_EVENTS.map((event) => (
              <label
                key={event}
                className={clsx(
                  'flex items-center gap-2 px-2 py-1.5 rounded cursor-pointer text-sm',
                  'hover:bg-secondary-50 transition-colors',
                  events.includes(event) ? 'bg-primary-50 text-primary-700' : 'text-secondary-700'
                )}
              >
                <input
                  type="checkbox"
                  checked={events.includes(event)}
                  onChange={() => toggleEvent(event)}
                  className="rounded border-secondary-300 text-primary-600 focus:ring-primary-500"
                />
                <span>{event}</span>
              </label>
            ))}
          </div>
          {events.length === 0 && (
            <p className="text-xs text-danger-600 mt-1">
              {t('webhooks.eventsRequired', 'Mindestens ein Event erforderlich')}
            </p>
          )}
        </div>

        {/* Secret */}
        <Input
          label={t('webhooks.secret', 'Secret (optional)')}
          value={secret}
          onChange={(e) => setSecret(e.target.value)}
          placeholder={t('webhooks.secretPlaceholder', 'HMAC-Signing Secret')}
          type="password"
          data-testid="webhook-form-secret"
        />

        {/* Retry Count & Timeout */}
        <div className="grid grid-cols-2 gap-4">
          <Input
            label={t('webhooks.retryCount', 'Retry Count')}
            value={String(retryCount)}
            onChange={(e) => setRetryCount(parseInt(e.target.value) || 3)}
            type="number"
            min={0}
            max={10}
            data-testid="webhook-form-retry"
          />
          <Input
            label={t('webhooks.timeout', 'Timeout (s)')}
            value={String(timeoutSeconds)}
            onChange={(e) => setTimeoutSeconds(parseInt(e.target.value) || 30)}
            type="number"
            min={1}
            max={120}
            data-testid="webhook-form-timeout"
          />
        </div>

        {/* Error */}
        {error && (
          <div className="rounded-md bg-danger-50 border border-danger-200 px-3 py-2 text-sm text-danger-700">
            {error}
          </div>
        )}

        {/* Actions */}
        <div className="flex items-center justify-end gap-2 pt-2">
          <Button type="button" variant="ghost" onClick={onClose}>
            {t('common.cancel', 'Abbrechen')}
          </Button>
          <Button
            type="submit"
            variant="primary"
            isLoading={isSubmitting}
            disabled={!url.trim() || events.length === 0}
            icon={<Plus className="h-4 w-4" />}
            data-testid="webhook-form-submit"
          >
            {isEdit ? t('common.save', 'Speichern') : t('webhooks.create', 'Erstellen')}
          </Button>
        </div>
      </form>
    </Modal>
  );
}

// ─── Delete Confirmation Modal ──────────────────────────────────────────────

interface DeleteModalProps {
  open: boolean;
  webhook: Webhook | null;
  onConfirm: () => void;
  onCancel: () => void;
  isDeleting: boolean;
}

function DeleteModal({ open, webhook, onConfirm, onCancel, isDeleting }: DeleteModalProps) {
  const { t } = useTranslation();

  return (
    <Modal open={open} onClose={onCancel} title={t('webhooks.deleteTitle', 'Webhook löschen')} size="sm">
      <div className="space-y-4">
        <div className="flex items-start gap-3">
          <div className="flex-shrink-0 rounded-full bg-danger-100 p-2">
            <AlertTriangle className="h-5 w-5 text-danger-600" aria-hidden="true" />
          </div>
          <div>
            <p className="text-sm text-secondary-700">
              {t('webhooks.deleteConfirm', 'Möchten Sie den Webhook')}{' '}
              <span className="font-semibold text-secondary-900 break-all">{webhook?.url}</span>{' '}
              {t('webhooks.deleteConfirmEnd', 'wirklich löschen?')}
            </p>
          </div>
        </div>
        <div className="flex items-center justify-end gap-2 pt-2">
          <Button type="button" variant="ghost" onClick={onCancel} disabled={isDeleting}>
            {t('common.cancel', 'Abbrechen')}
          </Button>
          <Button
            type="button"
            variant="danger"
            onClick={onConfirm}
            isLoading={isDeleting}
            data-testid="webhook-delete-confirm"
          >
            {t('webhooks.delete', 'Löschen')}
          </Button>
        </div>
      </div>
    </Modal>
  );
}

// ─── Test Result Modal ──────────────────────────────────────────────────────

interface TestResultModalProps {
  open: boolean;
  result: WebhookTestResult | null;
  onClose: () => void;
}

function TestResultModal({ open, result, onClose }: TestResultModalProps) {
  const { t } = useTranslation();

  if (!result) return null;

  return (
    <Modal open={open} onClose={onClose} title={t('webhooks.testResult', 'Test-Ergebnis')} size="sm">
      <div className="space-y-4">
        <div className={clsx(
          'flex items-start gap-3',
          result.success ? 'text-success-700' : 'text-danger-700'
        )}>
          <div className={clsx(
            'flex-shrink-0 rounded-full p-2',
            result.success ? 'bg-success-100' : 'bg-danger-100'
          )}>
            {result.success
              ? <CheckCircle className="h-5 w-5" aria-hidden="true" />
              : <XCircle className="h-5 w-5" aria-hidden="true" />
            }
          </div>
          <div>
            <p className="text-sm font-medium">
              {result.success
                ? t('webhooks.testSuccess', 'Webhook erfolgreich gesendet')
                : t('webhooks.testFailed', 'Webhook fehlgeschlagen')
              }
            </p>
            {result.status_code && (
              <p className="text-sm mt-1">
                {t('webhooks.statusCode', 'Status-Code')}: {result.status_code}
              </p>
            )}
            {result.error && (
              <p className="text-sm mt-1">
                {t('webhooks.error', 'Fehler')}: {result.error}
              </p>
            )}
          </div>
        </div>
        <div className="flex items-center justify-end pt-2">
          <Button type="button" variant="ghost" onClick={onClose}>
            {t('common.close', 'Schließen')}
          </Button>
        </div>
      </div>
    </Modal>
  );
}

// ─── Main Page Component ─────────────────────────────────────────────────────

export function SettingsWebhooksPage() {
  const { t } = useTranslation();
  const queryClient = useQueryClient();

  const { data: webhooks = [], isLoading, error } = useWebhooks();
  const createMutation = useCreateWebhook();
  const updateMutation = useUpdateWebhook();
  const deleteMutation = useDeleteWebhook();
  const testMutation = useTestWebhook();

  // Modal state
  const [formModalOpen, setFormModalOpen] = useState(false);
  const [editingWebhook, setEditingWebhook] = useState<Webhook | null>(null);
  const [deleteModalOpen, setDeleteModalOpen] = useState(false);
  const [deletingWebhook, setDeletingWebhook] = useState<Webhook | null>(null);
  const [testResultModalOpen, setTestResultModalOpen] = useState(false);
  const [testResult, setTestResult] = useState<WebhookTestResult | null>(null);
  const [formError, setFormError] = useState<string | null>(null);

  // Handlers
  const handleCreate = useCallback(() => {
    setEditingWebhook(null);
    setFormError(null);
    setFormModalOpen(true);
  }, []);

  const handleEdit = useCallback((webhook: Webhook) => {
    setEditingWebhook(webhook);
    setFormError(null);
    setFormModalOpen(true);
  }, []);

  const handleFormSubmit = useCallback(
    (data: CreateWebhookPayload | UpdateWebhookPayload) => {
      setFormError(null);
      if (editingWebhook) {
        updateMutation.mutate(
          { id: editingWebhook.id, data: data as UpdateWebhookPayload },
          {
            onSuccess: () => {
              setFormModalOpen(false);
              setEditingWebhook(null);
            },
            onError: (err: any) => {
              setFormError(err?.message || t('webhooks.updateError', 'Fehler beim Aktualisieren'));
            },
          }
        );
      } else {
        createMutation.mutate(data as CreateWebhookPayload, {
          onSuccess: () => {
            setFormModalOpen(false);
          },
          onError: (err: any) => {
            setFormError(err?.message || t('webhooks.createError', 'Fehler beim Erstellen'));
          },
        });
      }
    },
    [editingWebhook, createMutation, updateMutation, t]
  );

  const handleDeleteClick = useCallback((webhook: Webhook) => {
    setDeletingWebhook(webhook);
    setDeleteModalOpen(true);
  }, []);

  const handleDeleteConfirm = useCallback(() => {
    if (!deletingWebhook) return;
    deleteMutation.mutate(deletingWebhook.id, {
      onSuccess: () => {
        setDeleteModalOpen(false);
        setDeletingWebhook(null);
      },
    });
  }, [deletingWebhook, deleteMutation]);

  const handleTest = useCallback(
    (webhook: Webhook) => {
      testMutation.mutate(webhook.id, {
        onSuccess: (result) => {
          setTestResult(result);
          setTestResultModalOpen(true);
        },
        onError: (err: any) => {
          setTestResult({ success: false, status_code: null, error: err?.message || 'Unknown error' });
          setTestResultModalOpen(true);
        },
      });
    },
    [testMutation]
  );

  const handleToggleActive = useCallback(
    (webhook: Webhook) => {
      updateMutation.mutate({
        id: webhook.id,
        data: { is_active: !webhook.is_active },
      });
    },
    [updateMutation]
  );

  return (
    <div className="space-y-6">
      {/* Header */}
      <div className="flex items-center justify-between">
        <div>
          <h1 className="text-2xl font-semibold text-secondary-900">
            {t('webhooks.title', 'Webhooks')}
          </h1>
          <p className="mt-1 text-sm text-secondary-500">
            {t('webhooks.description', 'Verwalten Sie ausgehende Webhook-Abonnements für Ereignisbenachrichtigungen')}
          </p>
        </div>
        <Button
          variant="primary"
          onClick={handleCreate}
          icon={<Plus className="h-4 w-4" />}
          data-testid="webhook-create-btn"
        >
          {t('webhooks.add', '+ Neuer Webhook')}
        </Button>
      </div>

      {/* Loading */}
      {isLoading && (
        <div className="flex items-center justify-center py-12">
          <div className="h-8 w-8 animate-spin rounded-full border-2 border-primary-500 border-t-transparent" />
        </div>
      )}

      {/* Error */}
      {error && (
        <Card>
          <div className="p-4 text-center text-danger-600">
            {t('webhooks.loadError', 'Fehler beim Laden der Webhooks')}
          </div>
        </Card>
      )}

      {/* Empty state */}
      {!isLoading && !error && webhooks.length === 0 && (
        <Card>
          <div className="flex flex-col items-center justify-center py-12 text-center">
            <WebhookIcon className="h-12 w-12 text-secondary-300 mb-4" />
            <h3 className="text-lg font-medium text-secondary-900">
              {t('webhooks.noWebhooks', 'Keine Webhooks')}
            </h3>
            <p className="mt-1 text-sm text-secondary-500 max-w-sm">
              {t('webhooks.noWebhooksDesc', 'Erstellen Sie Ihren ersten Webhook, um Ereignisbenachrichtigungen an externe Dienste zu senden.')}
            </p>
            <Button
              variant="primary"
              className="mt-4"
              onClick={handleCreate}
              icon={<Plus className="h-4 w-4" />}
            >
              {t('webhooks.createFirst', 'Ersten Webhook erstellen')}
            </Button>
          </div>
        </Card>
      )}

      {/* Webhook list */}
      {!isLoading && !error && webhooks.length > 0 && (
        <div className="space-y-3">
          {webhooks.map((webhook) => (
            <Card key={webhook.id}>
              <div className="p-4">
                <div className="flex items-start justify-between">
                  <div className="flex-1 min-w-0">
                    <div className="flex items-center gap-2">
                      <span
                        className={clsx(
                          'inline-block w-2 h-2 rounded-full',
                          webhook.is_active ? 'bg-success-500' : 'bg-secondary-300'
                        )}
                        aria-hidden="true"
                      />
                      <span className="text-sm font-medium text-secondary-900 break-all">
                        {webhook.url}
                      </span>
                    </div>
                    <div className="mt-1 flex flex-wrap gap-1.5">
                      {webhook.events.slice(0, 5).map((event) => (
                        <span
                          key={event}
                          className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-primary-50 text-primary-700"
                        >
                          {event}
                        </span>
                      ))}
                      {webhook.events.length > 5 && (
                        <span className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-secondary-100 text-secondary-600">
                          +{webhook.events.length - 5}
                        </span>
                      )}
                    </div>
                    <div className="mt-1 text-xs text-secondary-400">
                      {t('webhooks.retryCount', 'Retries')}: {webhook.retry_count} |{' '}
                      {t('webhooks.timeout', 'Timeout')}: {webhook.timeout_seconds}s
                    </div>
                  </div>
                  <div className="flex items-center gap-1 ml-4 flex-shrink-0">
                    {/* Toggle active */}
                    <button
                      type="button"
                      onClick={() => handleToggleActive(webhook)}
                      className={clsx(
                        'relative inline-flex h-6 w-10 flex-shrink-0 cursor-pointer rounded-full border-2 border-transparent transition-colors duration-200 ease-in-out focus:outline-none focus-visible:ring-2 focus-visible:ring-primary-500 focus-visible:ring-offset-2',
                        webhook.is_active ? 'bg-success-500' : 'bg-secondary-200'
                      )}
                      role="switch"
                      aria-checked={webhook.is_active}
                      aria-label={t('webhooks.toggleActive', 'Aktiv/Inaktiv umschalten')}
                    >
                      <span
                        className={clsx(
                          'pointer-events-none inline-block h-5 w-5 transform rounded-full bg-white shadow ring-0 transition duration-200 ease-in-out',
                          webhook.is_active ? 'translate-x-4' : 'translate-x-0'
                        )}
                      />
                    </button>

                    {/* Test */}
                    <button
                      type="button"
                      onClick={() => handleTest(webhook)}
                      className="p-1.5 rounded-md text-secondary-400 hover:text-primary-600 hover:bg-primary-50 transition-colors"
                      title={t('webhooks.test', 'Testen')}
                      data-testid="webhook-test-btn"
                    >
                      <Send className="h-4 w-4" />
                    </button>

                    {/* Edit */}
                    <button
                      type="button"
                      onClick={() => handleEdit(webhook)}
                      className="p-1.5 rounded-md text-secondary-400 hover:text-secondary-600 hover:bg-secondary-100 transition-colors"
                      title={t('common.edit', 'Bearbeiten')}
                      data-testid="webhook-edit-btn"
                    >
                      <Pencil className="h-4 w-4" />
                    </button>

                    {/* Delete */}
                    <button
                      type="button"
                      onClick={() => handleDeleteClick(webhook)}
                      className="p-1.5 rounded-md text-secondary-400 hover:text-danger-600 hover:bg-danger-50 transition-colors"
                      title={t('common.delete', 'Löschen')}
                      data-testid="webhook-delete-btn"
                    >
                      <Trash2 className="h-4 w-4" />
                    </button>
                  </div>
                </div>
              </div>
            </Card>
          ))}
        </div>
      )}

      {/* Modals */}
      <WebhookFormModal
        open={formModalOpen}
        onClose={() => { setFormModalOpen(false); setEditingWebhook(null); setFormError(null); }}
        webhook={editingWebhook}
        onSubmit={handleFormSubmit}
        isSubmitting={createMutation.isPending || updateMutation.isPending}
        error={formError}
      />

      <DeleteModal
        open={deleteModalOpen}
        webhook={deletingWebhook}
        onConfirm={handleDeleteConfirm}
        onCancel={() => { setDeleteModalOpen(false); setDeletingWebhook(null); }}
        isDeleting={deleteMutation.isPending}
      />

      <TestResultModal
        open={testResultModalOpen}
        result={testResult}
        onClose={() => { setTestResultModalOpen(false); setTestResult(null); }}
      />
    </div>
  );
}

export default SettingsWebhooksPage;