"use client";

import { NEXT_PUBLIC_API_URL } from "@/config/api";
import { buildItemCodePasteRequestBody } from './parseItemCodeTokens';
import { clientAuthFetch } from "@/app/utils/clientAuthFetch";
import {
  exportChartToXlsx,
  exportMultiSheetToXlsx,
} from "@/app/(main)/chart/_components/exportChartToXlsx";
import { reportExcelT as tx } from "./reportI18n";
import type { TFunction } from "i18next";

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;
  /** PO line unit price (purchase_order_line.up) */
  unitPrice?: number;
  /** unitPrice × acceptedQty */
  lineAmount?: number;
  /** PO currency code (currency.code) */
  currencyCode?: string;
  /** M18 AN document code from m18_goods_receipt_note_log.grn_code */
  grnCode?: string;
  /** M18 record id (m18_record_id) */
  grnId?: number | string;
  /** From purchase_order.m18CreatedUId; e.g. "2569 (legato)" */
  poM18CreatorDisplay?: string;
  [key: string]: unknown;
}

/** Sheet "已上架PO金額": totals grouped by receipt date + currency / PO (ADMIN-only data from API). */
export interface ListedPoAmounts {
  currencyTotals: {
    receiptDate?: string;
    currencyCode?: string;
    totalAmount?: number;
  }[];
  byPurchaseOrder: {
    receiptDate?: string;
    poCode?: string;
    currencyCode?: string;
    totalAmount?: number;
    grnCodes?: string;
  }[];
}

export interface GrnReportResponse {
  rows: GrnReportRow[];
  listedPoAmounts?: ListedPoAmounts;
}

/**
 * Fetch GRN (Goods Received Note) report data by date range.
 * Backend: POST /report/grn-report  { receiptDateStart, receiptDateEnd, itemCodes }
 */
export async function fetchGrnReportData(
  criteria: Record<string, string>
): Promise<{ rows: GrnReportRow[]; listedPoAmounts?: ListedPoAmounts }> {
  const url = `${NEXT_PUBLIC_API_URL}/report/grn-report`;

  const response = await clientAuthFetch(url, {
    method: "POST",
    headers: {
      Accept: "application/json",
      "Content-Type": "application/json",
    },
    body: JSON.stringify(buildItemCodePasteRequestBody(criteria, "itemCode")),
  });

  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[];
  if (Array.isArray(data)) {
    return { rows: data };
  }
  const body = data as GrnReportResponse;
  return {
    rows: body.rows ?? [],
    listedPoAmounts: body.listedPoAmounts,
  };
}

/** Coerce API JSON (number or numeric string) to a finite number. */
function coerceToFiniteNumber(value: unknown): number | null {
  if (value === null || value === undefined) return null;
  if (typeof value === "number" && Number.isFinite(value)) return value;
  if (typeof value === "string") {
    const t = value.trim();
    if (t === "") return null;
    const n = Number(t);
    return Number.isFinite(n) ? n : null;
  }
  return null;
}

/**
 * Cell value for money columns: numeric when possible so Excel export can apply `#,##0.00` (see exportChartToXlsx).
 */
function moneyCellValue(v: unknown): number | string {
  const n = coerceToFiniteNumber(v);
  if (n === null) return "";
  return n;
}

/** Thousands separator for quantities (up to 4 decimal places, trims trailing zeros). */
const formatQty = (n: number | undefined | null): string => {
  if (n === undefined || n === null || Number.isNaN(Number(n))) return "";
  return new Intl.NumberFormat("en-US", {
    minimumFractionDigits: 0,
    maximumFractionDigits: 4,
  }).format(Number(n));
};

function grnLabels(t?: TFunction) {
  return {
    sheetDetail: tx(t, "excel.grn.sheetDetail", "PO入倉記錄"),
    sheetListedPo: tx(t, "excel.grn.sheetListedPo", "已上架PO金額"),
    poNo: tx(t, "excel.grn.poNo", "訂單編號"),
    deliveryNoteNo: tx(t, "excel.grn.deliveryNoteNo", "送貨單編號"),
    receiptDate: tx(t, "excel.grn.receiptDate", "收貨日期"),
    itemCode: tx(t, "excel.grn.itemCode", "物料編號"),
    itemName: tx(t, "excel.grn.itemName", "物料名稱"),
    qty: tx(t, "excel.grn.qty", "數量"),
    demandQty: tx(t, "excel.grn.demandQty", "訂單數量"),
    uom: tx(t, "excel.grn.uom", "單位"),
    supplierLotNo: tx(t, "excel.grn.supplierLotNo", "供應商批次"),
    expiryDate: tx(t, "excel.grn.expiryDate", "到期日"),
    supplierCode: tx(t, "excel.grn.supplierCode", "供應商編號"),
    supplier: tx(t, "excel.grn.supplier", "供應商"),
    status: tx(t, "excel.grn.status", "入倉狀態"),
    unitPrice: tx(t, "excel.grn.unitPrice", "單價"),
    currency: tx(t, "excel.grn.currency", "貨幣"),
    amount: tx(t, "excel.grn.amount", "金額"),
    grnCode: tx(t, "excel.grn.grnCode", "M18 入倉單號"),
    grnId: tx(t, "excel.grn.grnId", "M18 記錄編號"),
    poCreator: tx(t, "excel.grn.poCreator", "PO建立者(M18)"),
    note: tx(t, "excel.grn.note", "備註"),
    category: tx(t, "excel.grn.category", "類別"),
    totalAmount: tx(t, "excel.grn.totalAmount", "金額"),
    grnCodes: tx(t, "excel.grn.grnCodes", "M18 入倉單號"),
    noCompletedPo: tx(t, "excel.grn.noCompletedPo", "（篩選範圍內無已完成之 PO 行）"),
    categoryCurrencyTotal: tx(t, "excel.grn.categoryCurrencyTotal", "貨幣小計"),
    categoryPo: tx(t, "excel.grn.categoryPo", "訂單"),
  };
}

function toExcelRow(
  r: GrnReportRow,
  includeFinancialColumns: boolean,
  t?: TFunction,
): Record<string, string | number | undefined> {
  const L = grnLabels(t);
  const base: Record<string, string | number | undefined> = {
    [L.poNo]: r.poCode ?? "",
    [L.deliveryNoteNo]: r.deliveryNoteNo ?? "",
    [L.receiptDate]: r.receiptDate ?? "",
    [L.itemCode]: r.itemCode ?? "",
    [L.itemName]: r.itemName ?? "",
    [L.qty]: formatQty(r.acceptedQty ?? r.receivedQty ?? undefined),
    [L.demandQty]: formatQty(r.demandQty),
    [L.uom]: r.uom ?? r.purchaseUomDesc ?? r.stockUomDesc ?? "",
    [L.supplierLotNo]: r.productLotNo ?? "",
    [L.expiryDate]: r.expiryDate ?? "",
    [L.supplierCode]: r.supplierCode ?? "",
    [L.supplier]: r.supplier ?? "",
    [L.status]: r.status ?? "",
  };
  if (includeFinancialColumns) {
    base[L.unitPrice] = moneyCellValue(r.unitPrice);
    base[L.currency] = r.currencyCode ?? "";
    base[L.amount] = moneyCellValue(r.lineAmount);
  }
  base[L.grnCode] = r.grnCode ?? "";
  base[L.grnId] = r.grnId ?? "";
  base[L.poCreator] = r.poM18CreatorDisplay ?? "";
  return base;
}

function buildListedPoAmountSheetRows(
  listed: ListedPoAmounts | undefined,
  t?: TFunction,
): Record<string, string | number | undefined>[] {
  const L = grnLabels(t);
  if (
    !listed ||
    (listed.currencyTotals.length === 0 &&
      listed.byPurchaseOrder.length === 0)
  ) {
    return [{ [L.note]: L.noCompletedPo }];
  }
  const out: Record<string, string | number | undefined>[] = [];
  for (const c of listed.currencyTotals) {
    out.push({
      [L.category]: L.categoryCurrencyTotal,
      [L.receiptDate]: c.receiptDate ?? "",
      [L.poNo]: "",
      [L.currency]: c.currencyCode ?? "",
      [L.totalAmount]: moneyCellValue(c.totalAmount),
      [L.grnCodes]: "",
    });
  }
  for (const p of listed.byPurchaseOrder) {
    out.push({
      [L.category]: L.categoryPo,
      [L.receiptDate]: p.receiptDate ?? "",
      [L.poNo]: p.poCode ?? "",
      [L.currency]: p.currencyCode ?? "",
      [L.totalAmount]: moneyCellValue(p.totalAmount),
      [L.grnCodes]: p.grnCodes ?? "",
    });
  }
  return out;
}

/**
 * Generate and download GRN report as Excel.
 * Sheet "已上架PO金額" is included only when `includeFinancialColumns` is true (ADMIN).
 */
export async function generateGrnReportExcel(
  criteria: Record<string, string>,
  reportTitle: string = "PO 入倉記錄",
  /** Only users with ADMIN authority should pass true (must match backend). */
  includeFinancialColumns: boolean = false,
  t?: TFunction,
): Promise<void> {
  const { rows, listedPoAmounts } = await fetchGrnReportData(criteria);
  const excelRows = rows.map((r) => toExcelRow(r, includeFinancialColumns, t));
  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}`;
  const L = grnLabels(t);

  if (includeFinancialColumns) {
    const sheet2 = buildListedPoAmountSheetRows(listedPoAmounts, t);
    exportMultiSheetToXlsx(
      [
        { name: L.sheetDetail, rows: excelRows as Record<string, unknown>[] },
        { name: L.sheetListedPo, rows: sheet2 as Record<string, unknown>[] },
      ],
      filename
    );
  } else {
    exportChartToXlsx(excelRows as Record<string, unknown>[], filename, L.sheetDetail);
  }
}