/**
 *
 * @authors yutent (yutent.io@gmail.com)
 * @date    2016-11-26 16:35:45
 *
 */

export const toS = Object.prototype.toString
export const encode = encodeURIComponent
export const decode = decodeURIComponent

/**
 * 表单序列化
 */
function serialize(p, obj, query) {
  var k
  if (Array.isArray(obj)) {
    obj.forEach(function (it, i) {
      k = p ? `${p}[${Array.isArray(it) ? i : ''}]` : i
      if (typeof it === 'object') {
        serialize(k, it, query)
      } else {
        query(k, it)
      }
    })
  } else {
    for (let i in obj) {
      k = p ? `${p}[${i}]` : i
      if (typeof obj[i] === 'object') {
        serialize(k, obj[i], query)
      } else {
        query(k, obj[i])
      }
    }
  }
}

export const Format = {
  parseForm(form) {
    let data = {}
    let hasAttach = false
    for (let i = 0, field; (field = form.elements[i++]); ) {
      switch (field.type) {
        case 'select-one':
        case 'select-multiple':
          if (field.name.length && !field.disabled) {
            for (let j = 0, opt; (opt = field.options[j++]); ) {
              if (opt.selected) {
                data[field.name] = opt.value || opt.text
              }
            }
          }
          break
        case 'file':
          if (field.name.length && !field.disabled) {
            data[field.name] = field.files[0]
            hasAttach = true
          }
          break
        case undefined:
        case 'submit':
        case 'reset':
        case 'button':
          break //按钮啥的, 直接忽略
        case 'radio':
        case 'checkbox':
          // 只处理选中的
          if (!field.checked) break
        default:
          if (field.name.length && !field.disabled) {
            data[field.name] = field.value
          }
      }
    }
    // 如果有附件, 改为FormData
    if (hasAttach) {
      return this.mkFormData(data)
    } else {
      return data
    }
  },
  mkFormData(data) {
    let form = new FormData()
    for (let i in data) {
      let el = data[i]
      if (Array.isArray(el)) {
        el.forEach(function (it) {
          form.append(i + '[]', it)
        })
      } else {
        form.append(i, data[i])
      }
    }
    return form
  },
  param(obj) {
    if (!obj || typeof obj === 'string' || typeof obj === 'number') {
      return obj
    }

    let arr = []
    let query = function (k, v) {
      if (/native code/.test(v)) {
        return
      }

      v = typeof v === 'function' ? v() : v
      v = toS.call(v) === '[object File]' || toS.call(v) === '[object Blob]' ? v : encode(v)

      arr.push(encode(k) + '=' + v)
    }

    if (typeof obj === 'object') {
      serialize('', obj, query)
    }

    return arr.join('&')
  }
}