/**
 * 格式化相關工具函式
 */

/**
 * 格式化數字為千分位格式
 */
export const formatNumber = (num: number): string => {
  return num.toLocaleString();
};

/**
 * 格式化貨幣（NT$）
 */
export const formatCurrency = (num: number): string => {
  return `NT$ ${num.toLocaleString()}`;
};

/**
 * 格式化日期
 */
export const formatDate = (date: string): string => {
  if (!date) return "-";
  const datePart = date.split("T")[0].split(" ")[0];
  const parts = datePart.split("-").map(Number);
  if (parts.length < 3 || parts.some(isNaN)) return date;

  const [y, m, d] = parts;
  // Initialize at noon to avoid timezone shifting issues
  const dt = new Date(y, m - 1, d, 12, 0, 0);
  const year = dt.getFullYear();
  const month = String(dt.getMonth() + 1).padStart(2, "0");
  const day = String(dt.getDate()).padStart(2, "0");

  return `${year}/${month}/${day}`;
};

/**
 * 格式化日期並包含星期
 */
export const formatDateWithDayOfWeek = (date: string): string => {
  if (!date) return "-";
  const datePart = date.split("T")[0].split(" ")[0];
  const parts = datePart.split("-").map(Number);
  if (parts.length < 3 || parts.some(isNaN)) return date;

  const [y, m, d] = parts;
  // Initialize at noon to avoid timezone shifting issues
  const dt = new Date(y, m - 1, d, 12, 0, 0);
  const year = dt.getFullYear();
  const month = String(dt.getMonth() + 1).padStart(2, "0");
  const day = String(dt.getDate()).padStart(2, "0");
  const weekDay = dt.toLocaleDateString("zh-TW", { weekday: "short" });

  return `${year}/${month}/${day} (${weekDay})`;
};

/**
 * 格式化發票號碼
 * 例如：AB12345678 -> AB-12345678
 */
export const formatInvoiceNumber = (invoice: string | null | undefined): string => {
  if (!invoice) return "-";
  const cleanInvoice = invoice.replace(/-/g, "");
  if (/^[a-zA-Z]{2}\d+$/.test(cleanInvoice)) {
    return `${cleanInvoice.slice(0, 2).toUpperCase()}-${cleanInvoice.slice(2)}`;
  }
  return invoice;
};

/**
 * 獲取當前日期（YYYY-MM-DD 格式）
 */
export const getCurrentDate = (): string => {
  const now = new Date();
  const year = now.getFullYear();
  const month = String(now.getMonth() + 1).padStart(2, "0");
  const day = String(now.getDate()).padStart(2, "0");
  return `${year}-${month}-${day}`;
};

/**
 * 生成唯一 ID
 */
export const generateId = (): string => {
  return `${Date.now()}-${Math.random().toString(36).substring(2, 9)}`;
};

/**
 * 生成撥補單號
 */
export const generateOrderNumber = (): string => {
  return `TO${Date.now().toString().slice(-8)}`;
};

/**
 * 生成批號
 * 格式：{倉庫代碼}-{日期YYYYMMDD}-{流水號}
 * 例如：WH1-20251128-001
 */
export const generateBatchNumber = (
  warehouseId: string,
  date?: string,
  sequence?: number
): string => {
  const targetDate = date || getCurrentDate();
  const dateStr = targetDate.replace(/-/g, "");
  const seq = sequence || Math.floor(Math.random() * 1000);
  const seqStr = seq.toString().padStart(3, "0");
  return `WH${warehouseId}-${dateStr}-${seqStr}`;
};

/**
 * 獲取當前日期時間（YYYY-MM-DDTHH:mm 格式，用於 datetime-local input）
 */
export const getCurrentDateTime = (): string => {
  const now = new Date();
  const year = now.getFullYear();
  const month = String(now.getMonth() + 1).padStart(2, "0");
  const day = String(now.getDate()).padStart(2, "0");
  const hours = String(now.getHours()).padStart(2, "0");
  const minutes = String(now.getMinutes()).padStart(2, "0");
  return `${year}-${month}-${day}T${hours}:${minutes}`;
};

/**
 * 格式化日期時間顯示
 */
export const formatDateTime = (datetime: string): string => {
  if (!datetime) return "-";
  return new Date(datetime).toLocaleString("zh-TW", {
    year: "numeric",
    month: "2-digit",
    day: "2-digit",
    hour: "2-digit",
    minute: "2-digit",
    hour12: false,
  });
};