function isEmpty(val) {
  return typeof val === 'undefined' || val === '' || val === null
}

function formateDate(datetime) {
  if (isEmpty(datetime)) {
    return ''
  }
  var date = getDate(datetime.trim())
  var today = getDate()
  var week = ''
  if (date.toString().substring(0, 15) === today.toString().substring(0, 15)) {
    week = '(今天)'
  } else if (date.getTime() > today.getTime()) {
    week = '(明天)'
  }
  return week + datetime
}

function formateText(text, length) {
  if (!text) {
    return ''
  }
  if (text.length <= length) {
    return text
  }
  return text.substring(0, length)
}

function colorText(price) {
  if(!price || price == 0){
    return 'text-gray'
  }
  if(price > 0){
    return 'text-red'
  }
  if(price < 0){
    return 'text-green'
  }
}

function floatImage(price) {
  if(!price || price == 0){
    return 'text-gray'
  }
  if(price > 0){
    return '/assets/image/icon-up.png'
  }
  if(price < 0){
    return '/assets/image/icon-down.png'
  }
}

module.exports = {
  formateDate: formateDate,
  formateText: formateText,
  colorText: colorText,
  floatImage: floatImage
}