/**
 * 通用工具函数
 */

/**
 * 生成唯一 ID
 */
export function uniqueId(prefix = ''): string {
  const id = Date.now().toString(36) + Math.random().toString(36).slice(2, 8);
  return prefix ? `${prefix}_${id}` : id;
}

/**
 * 简易深拷贝(基于 JSON,适用于纯数据对象)
 */
export function deepClone<T>(value: T): T {
  return JSON.parse(JSON.stringify(value));
}

/**
 * 防抖
 */
export function debounce<T extends (...args: any[]) => any>(fn: T, wait = 300) {
  let timer: ReturnType<typeof setTimeout> | null = null;
  const debounced = (...args: Parameters<T>) => {
    if (timer) clearTimeout(timer);
    timer = setTimeout(() => fn(...args), wait);
  };
  debounced.cancel = () => {
    if (timer) clearTimeout(timer);
    timer = null;
  };
  return debounced;
}

/**
 * 节流
 */
export function throttle<T extends (...args: any[]) => any>(fn: T, wait = 300) {
  let lastTime = 0;
  return (...args: Parameters<T>) => {
    const now = Date.now();
    if (now - lastTime >= wait) {
      lastTime = now;
      fn(...args);
    }
  };
}

/**
 * 格式化日期
 */
export function formatDate(date: Date | string | number, format = 'YYYY-MM-DD HH:mm:ss'): string {
  const d = new Date(date);
  if (Number.isNaN(d.getTime())) return '';

  const pad = (n: number) => String(n).padStart(2, '0');
  const map: Record<string, string> = {
    YYYY: String(d.getFullYear()),
    MM: pad(d.getMonth() + 1),
    DD: pad(d.getDate()),
    HH: pad(d.getHours()),
    mm: pad(d.getMinutes()),
    ss: pad(d.getSeconds()),
  };

  return format.replace(/YYYY|MM|DD|HH|mm|ss/g, (match) => map[match]);
}

/**
 * 树形数据扁平化
 */
export interface TreeNode {
  id: string | number;
  children?: TreeNode[];
  [key: string]: any;
}

export function flattenTree<T extends TreeNode>(tree: T[]): T[] {
  const result: T[] = [];
  const stack = [...tree].reverse();
  while (stack.length) {
    const node = stack.pop() as T;
    result.push(node);
    if (node.children?.length) {
      stack.push(...(node.children as T[]).reverse());
    }
  }
  return result;
}