const decode = require('jsonwebtoken/decode')
const app = require('./app')
app.service('api', function($http, $location, $mdToast) {
  window.api = this
  this.opts = {
    headers: {},
    withCredentials: true
  }
  this.claims = {}
  this.postProcess = (res) => res.data
  this.get = (path, opts = {}) => $http.get(path, Object.assign({}, opts, this.opts)).then(this.postProcess)
  this.post = (path, data, opts = {}) => $http.post(path, data, Object.assign({}, opts, this.opts)).then(this.postProcess)
  this.put = (path, data, opts = {}) => $http.put(path, data, Object.assign({}, opts, this.opts)).then(this.postProcess)
  this.patch = (path, data, opts = {}) => $http.patch(path, data, Object.assign({}, opts, this.opts)).then(this.postProcess)
  this.delete = (path, opts = {}) => $http.delete(path, Object.assign({}, opts, this.opts)).then(this.postProcess)

  const setUser = (user, token) => {
    const decoded = decode(token)
    this.token = token
    this.user = user
    this.claims = decoded
    this.opts.headers.authentication = `Bearer ${token}`
    localStorage.setItem('token', token)
    localStorage.setItem('user', JSON.stringify(user))
  }

  const clearUser = () => {
    this.token = null
    this.user = null
    this.claims = {}
    delete this.opts.headers.authentication
    localStorage.removeItem('token')
    localStorage.removeItem('user')
  }

  this.login = async data => {
    const res = await this.post('/api/auth/login', data)
    setUser(res.user, res.token)
  }
  this.logout = async () => {
    clearUser()
  }

  this.renew = async () => {
    console.info('Renewing session...')
    const res = await this.post('/api/auth/renew', {})
    setUser(res.user, res.token)
  }

  this.checkRenew = async () => {
    if (!this.user) {
      throw new Error('Not logged in')
    }
    try {
      await this.renew()
    } catch (e) {
      clearUser()
      throw e
    }
  }

  this.restore = () => {
    const token = localStorage.getItem('token')
    const userJson = localStorage.getItem('user')
    if (token && userJson) {
      try {
        const user = JSON.parse(userJson)
        setUser(user, token)
      } catch (err) {
        console.warn(`Unable to restore login:`, err)
      }
    }
  }

  this.restore()

  const renewTimer = () => {
    if (this.user) {
      this.renew().catch(err => {
          console.warn('Login session could not be renewed:', err)
          $mdToast.show(
            $mdToast.simple()
              .textContent(`You are not logged in: ${err.statusText || err.message}.`)
              .action('Return to login page')
              .hideDelay(60000)
              .position('top middle')
              .highlightAction(true)
              .highlightClass('md-warn')
          )
            .then(res => {
              if (res === 'ok') {
                clearUser()
                $location.url('/login')
              }
            })
      })
    }
  }

  setInterval(renewTimer, 15000)
  renewTimer()

  this.crud = (apiPrefix) => ({
    list: () => this.get(apiPrefix),
    create: data => this.post(apiPrefix, data),
    read: id => this.get(`${apiPrefix}/${id}`),
    update: (id, data) => this.patch(`${apiPrefix}/${id}`, data),
    delete: (id) => this.delete(`${apiPrefix}/${id}`),
    trash: () => this.get(`${apiPrefix}/trash`),
    undelete: (id) => this.delete(`${apiPrefix}/trash/${id}`),
    autocomplete: (searchText) => this.get(apiPrefix, { params: { q: searchText } }),
    lookup: (ids) => this.get(apiPrefix, { params: { ids: ids.join(',')}})
  })

})