import type { CollectionConfig } from "payload";
import { isAdmin } from "@/access";

function normalizePath(value: string): string {
  // Lowercased to match the slugs it points at/from (fields/slug.ts always
  // lowercases via slugify) - without this, "/Angebote/Doula" and
  // "/angebote/doula" count as different values to the `unique` constraint
  // on fromPath, letting near-duplicate redirects coexist.
  const trimmed = value.trim().toLowerCase();
  const withSlash = trimmed.startsWith("/") ? trimmed : `/${trimmed}`;
  return withSlash.length > 1 ? withSlash.replace(/\/+$/, "") : withSlash;
}

/**
 * Simple slug-change redirect table (see lib/seo/redirects.ts). Deliberately
 * scoped to the three dynamic [slug] detail routes (Angebote/Termine/
 * Aktuelles) - that's the only place slugs actually live and can change, so
 * looking this up only there avoids adding a database lookup to every
 * single request the way a catch-all middleware would.
 */
export const Redirects: CollectionConfig = {
  slug: "redirects",
  labels: {
    singular: "Weiterleitung",
    plural: "Weiterleitungen",
  },
  admin: {
    useAsTitle: "fromPath",
    defaultColumns: ["fromPath", "toPath", "type", "enabled"],
    group: "SEO",
    description: "Leitet eine alte URL (z. B. nach einer Slug-Änderung bei Angeboten, Terminen oder Aktuelles) dauerhaft auf eine neue weiter.",
  },
  access: {
    read: () => true,
    create: isAdmin,
    update: isAdmin,
    delete: isAdmin,
  },
  fields: [
    {
      name: "fromPath",
      type: "text",
      label: "Alte URL (Pfad)",
      required: true,
      unique: true,
      index: true,
      admin: { description: "Nur der Pfad, z. B. /angebote/doula (ohne Domain)." },
      hooks: {
        beforeValidate: [({ value }) => (typeof value === "string" && value ? normalizePath(value) : value)],
      },
    },
    {
      name: "toPath",
      type: "text",
      label: "Neue URL (Pfad)",
      required: true,
      admin: { description: "Ziel-Pfad, z. B. /angebote/doula-begleitung." },
      hooks: {
        beforeValidate: [({ value }) => (typeof value === "string" && value ? normalizePath(value) : value)],
      },
    },
    {
      name: "type",
      type: "select",
      label: "Art der Weiterleitung",
      required: true,
      defaultValue: "permanent",
      options: [
        { label: "301 - Dauerhaft", value: "permanent" },
        { label: "302 - Vorübergehend", value: "temporary" },
      ],
    },
    {
      name: "enabled",
      type: "checkbox",
      label: "Aktiv",
      defaultValue: true,
    },
  ],
};