import type { Category, CategoryTreeNode, GuestCartLine } from "@/lib/meshkee/types";

export function slugifyFa(value: string | null | undefined): string {
  const raw = (value ?? "").trim().toLowerCase();
  if (!raw) return "item";
  return raw
    .replace(/\s+/g, "-")
    .replace(/[^\u0600-\u06FFa-z0-9-]+/g, "")
    .replace(/-+/g, "-")
    .replace(/^-|-$/g, "") || "item";
}

export function formatPrice(value: number | null | undefined): string {
  const amount = Number(value ?? 0);
  return `${new Intl.NumberFormat("fa-IR").format(amount)} تومان`;
}

export function formatDate(value: string | null | undefined): string {
  if (!value) return "";
  try {
    return new Intl.DateTimeFormat("fa-IR", {
      year: "numeric",
      month: "long",
      day: "numeric",
    }).format(new Date(value));
  } catch {
    return value;
  }
}

export function displayName(user: {
  firstName?: string | null;
  lastName?: string | null;
}): string {
  const first = user.firstName?.trim();
  if (first) return first;
  const last = user.lastName?.trim();
  if (last) return last;
  return "کاربر";
}

export function buildCategoryTree(categories: Category[]): CategoryTreeNode[] {
  const map = new Map<string, CategoryTreeNode>();
  for (const category of categories) {
    if (category.isActive === false) continue;
    map.set(category.id, { ...category, children: [] });
  }

  const roots: CategoryTreeNode[] = [];
  for (const node of map.values()) {
    if (node.parentId && map.has(node.parentId)) {
      map.get(node.parentId)!.children.push(node);
    } else {
      roots.push(node);
    }
  }

  const sortNodes = (nodes: CategoryTreeNode[]) => {
    nodes.sort((a, b) => (a.sortOrder ?? 0) - (b.sortOrder ?? 0));
    nodes.forEach((node) => sortNodes(node.children));
  };
  sortNodes(roots);
  return roots;
}

export function categoryLabel(category: Category): string {
  return category.nameFa?.trim() || category.name;
}

export function storeItemName(item: {
  productNameFa?: string | null;
  productTitle?: string | null;
  label?: string | null;
}): string {
  return item.productNameFa?.trim() || item.productTitle?.trim() || "محصول";
}

export function storeItemPrice(item: {
  price: number;
  discountedPrice?: number | null;
}): number {
  return item.discountedPrice != null && item.discountedPrice > 0
    ? item.discountedPrice
    : item.price;
}

export function normalizeGuestLines(items: GuestCartLine[]): GuestCartLine[] {
  const result: GuestCartLine[] = [];
  for (const item of items) {
    const id = (item.id || "").trim();
    if (!id) continue;
    result.push({
      id,
      name: item.name || "محصول",
      slug: item.slug,
      price: Number(item.price) || 0,
      image: item.image ?? null,
      quantity: Math.max(1, Math.floor(item.quantity) || 1),
    });
  }
  return result;
}