"use client";

import { NEXT_PUBLIC_API_URL } from "@/config/api";
import { clientAuthFetch } from "@/app/utils/clientAuthFetch";
import { exportChartToXlsx } from "@/app/(main)/chart/_components/exportChartToXlsx";

export interface GrnReportRow {
  poCode?: string;
  deliveryNoteNo?: string;
  receiptDate?: string;
  itemCode?: string;
  itemName?: string;
  acceptedQty?: number;
  receivedQty?: number;
  demandQty?: number;
  uom?: string;
  purchaseUomDesc?: string;
  stockUomDesc?: string;
  productLotNo?: string;
  expiryDate?: string;
  supplierCode?: string;
  supplier?: string;
  status?: string;
   grnId?: number | string;
  [key: string]: unknown;
}

export interface GrnReportResponse {
  rows: GrnReportRow[];
}

/**
 * Fetch GRN (Goods Received Note) report data by date range.
 * Backend: GET /report/grn-report?receiptDateStart=&receiptDateEnd=&itemCode=
 */
export async function fetchGrnReportData(
  criteria: Record<string, string>
): Promise<GrnReportRow[]> {
  const queryParams = new URLSearchParams(criteria).toString();
  const url = `${NEXT_PUBLIC_API_URL}/report/grn-report?${queryParams}`;

  const response = await clientAuthFetch(url, {
    method: "GET",
    headers: { Accept: "application/json" },
  });

  if (response.status === 401 || response.status === 403)
    throw new Error("Unauthorized");
  if (!response.ok)
    throw new Error(`HTTP error! status: ${response.status}`);

  const data = (await response.json()) as GrnReportResponse | GrnReportRow[];
  const rows = Array.isArray(data) ? data : (data as GrnReportResponse).rows ?? [];
  return rows;
}

/** Excel column headers (bilingual) for GRN report */
function toExcelRow(r: GrnReportRow): Record<string, string | number | undefined> {
  return {
    "PO No. / 訂單編號": r.poCode ?? "",
    "Supplier Code / 供應商編號": r.supplierCode ?? "",
    "Delivery Note No. / 送貨單編號": r.deliveryNoteNo ?? "",
    "Receipt Date / 收貨日期": r.receiptDate ?? "",
    "Item Code / 物料編號": r.itemCode ?? "",
    "Item Name / 物料名稱": r.itemName ?? "",
    "Qty / 數量": r.acceptedQty ?? r.receivedQty ?? "",
    "Demand Qty / 訂單數量": r.demandQty ?? "",
    "UOM / 單位": r.uom ?? r.purchaseUomDesc ?? r.stockUomDesc ?? "",
    "Product Lot No. / 批次": r.productLotNo ?? "",
    "Expiry Date / 到期日": r.expiryDate ?? "",
    "Supplier / 供應商": r.supplier ?? "",
    "Status / 狀態": r.status ?? "",
    "GRN Id / M18 單號": r.grnId ?? "",
  };
}

/**
 * Generate and download GRN report as Excel.
 */
export async function generateGrnReportExcel(
  criteria: Record<string, string>,
  reportTitle: string = "PO 入倉記錄"
): Promise<void> {
  const rows = await fetchGrnReportData(criteria);
  const excelRows = rows.map(toExcelRow);
  const start = criteria.receiptDateStart;
  const end = criteria.receiptDateEnd;
  let datePart: string;
  if (start && end && start === end) {
    datePart = start;
  } else if (start || end) {
    datePart = `${start || ""}_to_${end || ""}`;
  } else {
    datePart = new Date().toISOString().slice(0, 10);
  }
  const safeDatePart = datePart.replace(/[^\d\-_/]/g, "");
  const filename = `${reportTitle}_${safeDatePart}`;
  exportChartToXlsx(excelRows, filename, "GRN");
}