'use strict';

// 随机长度字符串
const randomString = len => {
  len = len || 10;
  const chars = 'abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
  const maxPos = chars.length;
  let str = '';
  for (let i = 0; i < len; i++) {
    str += chars.charAt(Math.floor(Math.random() * maxPos));
  }
  return str;
};

const getSuffix = fileName => {
  const arr = fileName.split('.');
  let suffix = '';
  if (arr.length >= 2) {
    suffix = arr[arr.length - 1];
  }
  if (suffix) suffix = `.${suffix}`;
  return suffix;
};

const getFilePath = type => {
  const now = new Date();
  const fullYears = now.getFullYear();
  const Month = now.getMonth();
  let typeStr = '';
  switch (type) {
    case 'blog':
      typeStr = 'blog';
      break;
    default:
      typeStr = 'media';
      break;
  }
  const path = `${typeStr}/${fullYears}/${Month}/`;
  return path;
};

module.exports = {
  randomString,
  getSuffix,
  getFilePath,
};