/* 基础小工具，可通用于服务端和用户端
 */

const fs = require('fs')
const path = require('path')

module.exports = {
  sleep: (ms) => new Promise((resolve, reject) => setTimeout(resolve, ms)),

  parseJsonPossible(value) {
    try {
      return JSON.parse(value)
    } catch (e) {
      return value
    }
  },

  sortAndFilterJson({ fields, entity, exclude = [] } = {}) {
    const newEntity = {}
    for (let key of Object.keys(fields).sort()) {
      if (typeof (entity[key] !== 'undefined') && !Number.isNaN(entity[key]) && entity[key] !== Infinity) {
        newEntity[key] = entity[key]
      }
    }
    for (let exkey of exclude) {
      delete newEntity[exkey]
    }
    return JSON.stringify(newEntity)
  },

  getDynamicConfig(dynamicConfigFile='ConfigDynamic.js') { // dynamicConfigFile should be absolute or relative to the node process's dir.
    const fullpath = path.join(process.cwd(), dynamicConfigFile)
    if (fs.existsSync(fullpath)) {
      delete require.cache[require.resolve(fullpath)] // delete require.cache[fullpath] 不起作用
      return require(fullpath)
    } else {
      return {}
    }
  },

}