import type { Types } from "mongoose";
import { Payout } from "@/models";
import { connectDB } from "@/lib/db";
import {
  countForQuery,
  listResult,
  resolveListSort,
  type ListResult,
} from "@/lib/api/list-query";

/**
 * Vendor payout list query.
 *
 * Shared by `GET /api/admin/payouts`, `GET /api/vendor/payouts` and the
 * payouts pages' server components so every caller reads a query string the
 * same way. The two views differ only in scope: pass `vendorId` to restrict
 * the list to one seller's payouts.
 */

export const PAYOUTS_DEFAULT_PAGE_SIZE = 20;

const SORT_FIELDS = [
  "createdAt",
  "payoutNumber",
  "status",
  "netAmount",
  "periodStart",
  "periodEnd",
];

export interface PayoutListParams {
  page: number;
  limit: number;
  search?: string;
  status?: string;
  vendorId?: string;
  sortBy?: string;
  sortOrder?: "asc" | "desc";
}

export interface PayoutListContext {
  /** Present for the vendor dashboard; absent lists every vendor's payouts. */
  vendorId?: Types.ObjectId | string;
}

export function buildPayoutListFilter(
  { search, status, vendorId: vendorFilter }: PayoutListParams,
  { vendorId }: PayoutListContext = {},
): Record<string, unknown> {
  const query: Record<string, unknown> = {};

  // The vendor dashboard is hard-scoped; the admin list may filter by vendor.
  if (vendorId) query.vendorId = vendorId;
  else if (vendorFilter && vendorFilter !== "all") query.vendorId = vendorFilter;

  const normalizedStatus = (status || "all").trim().toLowerCase();
  if (normalizedStatus !== "all") query.status = normalizedStatus;

  if (search) {
    const escaped = search.trim().replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
    if (escaped) query.payoutNumber = { $regex: escaped, $options: "i" };
  }

  return query;
}

export async function fetchPayoutList(
  params: PayoutListParams,
  context: PayoutListContext = {},
): Promise<ListResult<unknown>> {
  await connectDB();

  const { page, limit, sortBy, sortOrder } = params;
  const query = buildPayoutListFilter(params, context);
  const sort = resolveListSort({
    sortBy,
    sortOrder,
    allowed: SORT_FIELDS,
    // `payoutNumber` is unique per payout; the rest (status, amounts, period
    // bounds) tie constantly and need the `_id` tiebreaker to page cleanly.
    unique: ["createdAt", "payoutNumber"],
  });

  const [rows, total] = await Promise.all([
    Payout.find(query)
      .populate("vendorId", "storeName slug")
      .sort(sort)
      .skip((page - 1) * limit)
      .limit(limit)
      .lean(),
    countForQuery(Payout, query),
  ]);

  return listResult(rows as unknown[], page, limit, total);
}