import type { CollectionBeforeDeleteHook } from 'payload'

import { APIError } from 'payload'

/**
 * Blocks deletion of a page assigned a System Page role (homepage,
 * privacyPolicy, cookiePolicy, termsOfService). An editor deleting the privacy
 * policy or homepage by accident would break routing and compliance links; this
 * stops it with a clear error. They must unassign the role first (deliberate).
 *
 * Reads the role assignments from SiteSettings (which page holds which role).
 *
 *   hooks: { beforeDelete: [buildPreventDeleteSystemPage({ settingsSlug: 'site-settings' })] }
 */
export function buildPreventDeleteSystemPage(
  args: { roleFields?: string[]; settingsSlug?: string } = {},
): CollectionBeforeDeleteHook {
  const settingsSlug = args.settingsSlug ?? 'site-settings'
  const roleFields = args.roleFields ?? [
    'homepage',
    'privacyPolicy',
    'cookiePolicy',
    'termsOfService',
  ]

  return async ({ id, req }) => {
    const settings = (await req.payload
      .findGlobal({ slug: settingsSlug as never, depth: 0 })
      .catch(() => null)) as null | Record<string, unknown>
    if (!settings) {return}

    for (const field of roleFields) {
      const assigned = settings[field]
      const assignedId =
        assigned && typeof assigned === 'object' ? (assigned as { id?: unknown }).id : assigned
      if (assignedId != null && String(assignedId) === String(id)) {
        throw new APIError(
          `Nie można usunąć strony przypisanej do roli systemowej "${field}". ` +
            `Najpierw odłącz rolę w Site Settings.`,
          400,
        )
      }
    }
  }
}