/**
 * 通用的http请求类
 */
export default class Http {
  static create(configs = {}) {
    const defaultConfigs = {
      apiEnv: 'php',
    }
    configs = { ...defaultConfigs, ...configs }
    return new this(configs)
  }

  //获取头部提示信息
  static getHeaderMessage(response) {
    if (!response) {
      return ""
    }
    return response.headers.has('X-Message') ? unescape(response.headers.get('X-Message').replace(/"/g, '').replace(/\\/g, "%")) : response.statusText
  }

  //获取GET请求指定查询参数
  static getQueryParameter(parameter) {
    const url = window.location.href
    const queryIndex = url.lastIndexOf('?')
    const query = queryString.parse(url.substr(queryIndex))
    return query[parameter] ? query[parameter] : null
  }

  static getAccessToken() {
    const tokenParameter = 'access_token'
    if (Http.getQueryParameter(tokenParameter) !== null) {
      return Http.getQueryParameter(tokenParameter)
    }
    return window.localStorage.getItem('access_token')
  }

  constructor(configs) {
    this.configs = configs
  }

  async request(url, options = {}) {
    url = this._urlAddQuery(this._urlAddHost(url), options)
    //options['mode'] = 'no-cors'

    return await fetch(url, options)
      .then(this._checkStatus)
    //.catch((e) => {
    //    message.error(e, 3);
    //    return Promise.reject(e)
    //  })
  }

  get(url, options = {}) {
    const defaultOptions = {
      method: 'GET',
      headers: {
        'Accept': 'application/json',
        'Origin': 'http://localhost:8000',
      },
    }
    options = { ...defaultOptions, ...options }
    return this.request(url, options)
  }

  post(url, options = {}) {
    const defaultOptions = {
      method: 'POST',
      headers: {
        'Accept': 'application/json',
      },
    }
    defaultOptions['headers']['Content-Type'] = this._getContentType()

    options = { ...defaultOptions, ...options }
    if (options.body) {
      options.body = this._encodeBody(options.headers['Content-Type'], options.body)
    }

    return this.request(url, options)
  }

  put(url, options = {}) {
    const defaultOptions = {
      method: 'PUT',
      headers: {
        'Accept': 'application/json',
      },
    }
    defaultOptions['headers']['Content-Type'] = this._getContentType()

    options = { ...defaultOptions, ...options }
    if (options.body) {
      options.body = this._encodeBody(options.headers['Content-Type'], options.body)
    }

    return this.request(url, options)
  }

  patch(url, options = {}) {
    const defaultOptions = {
      method: 'PATCH',
      headers: {
        'Accept': 'application/json',
      },
    }
    defaultOptions['headers']['Content-Type'] = this._getContentType()

    options = { ...defaultOptions, ...options }
    if (options.body) {
      options.body = this._encodeBody(options.headers['Content-Type'], options.body)
    }

    return this.request(url, options)
  }

  remove(url, options = {}) {
    const defaultOptions = {
      method: 'DELETE',
      headers: {
        'Accept': 'application/json',
      },
    }
    defaultOptions['headers']['Content-Type'] = this._getContentType()

    options = { ...defaultOptions, ...options }
    if (options.body) {
      options.body = this._encodeBody(options.headers['Content-Type'], options.body)
    }

    return this.request(url, options)
  }

  downFile(url, options = {}) {
    let filename = ''
    let that = this
    const defaultOptions = {
      headers: {
        'Content-Type': this._getContentType(),
      },
    }

    options = { ...defaultOptions, ...options }

    if (options.body) {
      options.body = this._encodeBody(options.headers['Content-Type'], options.body)
    }
    return this.request(url, options)
      .then(function(response) {
        filename = that._getFileName(response)
        return response.blob();
      }).then(function(blob) {
        FileSaver.saveAs(blob, filename);
      })
  }

  _getApiHost() {
    const apiEnvMap = {
      php: 'host',
      java: 'javaHost',
      javaV1: 'javaHostV1',
    }
    const hostName = apiEnvMap[this.configs['apiEnv']] ? apiEnvMap[this.configs['apiEnv']] : 'javaHost'
    let hostUrl = config.api[hostName]
    //if (this.configs.port) {
    //  hostUrl += ':' + this.configs.port
    //}
    //if (this.configs.secondDir) {
    //  hostUrl += '/' + this.configs.secondDir
    //}
    return hostUrl
  }

  _getAccessToken() {
    const url = window.location.href
    const queryIndex = url.lastIndexOf('?')
    const query = queryString.parse(url.substr(queryIndex))
    if (query.access_token) {
      return query.access_token
    }
    return window.localStorage.getItem('access_token')
  }

  _urlAddHost(url) {
    if (!url.startsWith('http')) {
      url = this._getApiHost() + url
    }
    return url
  }

  _urlAddQuery(url, options) {
    if (!options.query) {
      options.query = {}
    }
    options.query.access_token = this._getAccessToken()

    const query = queryString.stringify(options.query)
    url += (url.includes('?') ? '&' : '?') + query
    return url
  }

  _getContentType() {
    return this.configs['apiEnv'] === 'php' ? 'application/x-www-form-urlencoded' : 'application/json'
  }

  _encodeBody(type, body) {
    if (type === 'application/x-www-form-urlencoded') {
      body = queryString.stringify(body)
    }
    else if (type === 'application/json') {
      body = JSON.stringify(body)
    }
    return body
  }

  _getFileName(response) {
    var filename = ""
    var disposition = response.headers.get('Content-Disposition')
    if (disposition && disposition.indexOf('attachment') !== -1) {
        var filenameRegex = /filename[^;=\n]*=((['"]).*?\2|[^;\n]*)/
        var matches = filenameRegex.exec(disposition)
        if (matches != null && matches[1]) {
          filename = matches[1].replace(/['"]/g, '')
        }
    }
    return decodeURI(filename)
  }

  _checkStatus(response) {
    if (response.status >= 200 && response.status < 300) {
      return response
    }
    const message = Http.getHeaderMessage(response)
    //message.error(message, 3);

    //token过期特殊处理
    if (response.status == 401 && response.headers.has('X-Message') && response.headers.get('X-Message').startsWith("token")) {
      router.replace('/system/login')
      const error = new Error("登录已过期请重新登录")
      throw error
    }

    const error = new Error(message)
    error.response = response
    throw error
    //return Promise.reject(message)
  }
}