import { meshkeeGet, tenantPath } from "@/lib/meshkee";

export type ApiCategory = {
  id: string;
  parentId?: string | null;
  name?: string | null;
  nameFa?: string | null;
  slug?: string | null;
  sortOrder?: number | null;
  isActive?: boolean;
};

export type NavCategory = {
  id: string;
  title: string;
  href: string;
  image?: string;
  children: { id: string; title: string; href: string }[];
};

function titleOf(category: ApiCategory) {
  return category.nameFa?.trim() || category.name?.trim() || "دسته‌بندی";
}

function hrefOf(category: ApiCategory) {
  return `/products?categoryId=${encodeURIComponent(category.id)}`;
}

export async function fetchProductCategories() {
  const data = await meshkeeGet<{ items?: ApiCategory[] }>(tenantPath("/categories?entityType=product"), {
    items: [],
  });
  return (data.items ?? []).filter((category) => category.isActive !== false);
}

export function buildCategoryTree(flat: ApiCategory[]): NavCategory[] {
  const byId = new Map(flat.map((category) => [String(category.id), category]));
  const children = new Map<string, ApiCategory[]>();

  for (const category of flat) {
    const parentId = category.parentId ? String(category.parentId) : "";
    const key = parentId && byId.has(parentId) ? parentId : "root";
    const list = children.get(key) ?? [];
    list.push(category);
    children.set(key, list);
  }

  const sort = (list: ApiCategory[]) =>
    [...list].sort((a, b) => (a.sortOrder ?? 0) - (b.sortOrder ?? 0) || titleOf(a).localeCompare(titleOf(b), "fa"));

  return sort(children.get("root") ?? []).map((root) => ({
    id: String(root.id),
    title: titleOf(root),
    href: hrefOf(root),
    children: sort(children.get(String(root.id)) ?? []).map((child) => ({
      id: String(child.id),
      title: titleOf(child),
      href: hrefOf(child),
    })),
  }));
}

export async function getNavCategories() {
  return buildCategoryTree(await fetchProductCategories());
}