var {handleResponse} = require('.utils')

var {setErrorMessages} = require('./messages')

var CHECK_TOKEN = 'auth/CHECK_TOKEN'
var CHECK_TOKEN_FAILURE = 'auth/CHECK_TOKEN_FAILURE'
var CHECK_TOKEN_SUCCESS = 'auth/CHECK_TOKEN_SUCCESS'

var LOGIN = 'auth/LOGIN'
var LOGIN_FAILURE = 'auth/LOGIN_FAILURE'
var LOGIN_SUCCESS = 'auth/LOGIN_SUCCESS'

var SHOWED_WELCOME = 'auth/SHOWED_WELCOME'

var LOGOUT = 'auth/LOGOUT'

var json = window.localStorage.auth
var initialState = json ? JSON.parse(json) : {token: null, user: null}

function auth(state={ // eslint-disable-line space-infix-ops
  ...initialState,
  checkingToken: false,
  loggingIn: false,
  showWelcome: false
}, action) {
  switch (action.type) {
    case CHECK_TOKEN:
      return {...state, checkingToken: true}
    case CHECK_TOKEN_FAILURE:
    case CHECK_TOKEN_SUCCESS:
      return {...state, checkingToken: false}
    case LOGIN:
      return {...state, loggingIn: true}
    case LOGIN_FAILURE:
      return {...state, loggingIn: false}
    case LOGIN_SUCCESS:
      window.localStorage.auth = JSON.stringify(action.payload)
      return {...state, loggingIn: false, showWelcome: true, ...action.payload}
    case SHOWED_WELCOME:
      return {...state, showWelcome: false}
    case LOGOUT:
      delete window.localStorage.auth
      return {...state, token: null, user: null}
  }
  return state
}

auth.checkToken = () => (dispatch, getState) => {
  dispatch({type: CHECK_TOKEN})
  window.fetch('/api/check-token', {
    headers: {
      'Content-Type': 'application/json'
    },
    method: 'POST',
    body: JSON.stringify({token: getState().auth.token})
  })
  .then(handleResponse)
  .then(({valid}) => {
    if (!valid) {
      dispatch(auth.logout())
      dispatch(setErrorMessages(['Login expired - please log in again.']))
    }
    dispatch({type: CHECK_TOKEN_SUCCESS})
  })
  .catch(error => {
    dispatch(setErrorMessages([`Error checking authentication token: ${error.message}`]))
    dispatch({type: CHECK_TOKEN_FAILURE})
  })
}

auth.login = (username, password) => dispatch => {
  dispatch({type: LOGIN})
  window.fetch('/api/authenticate', {
    headers: {
      'Content-Type': 'application/json'
    },
    method: 'POST',
    body: JSON.stringify({username, password})
  })
  .then(handleResponse)
  .then(payload => dispatch({type: LOGIN_SUCCESS, payload}))
  .catch(error => {
    dispatch(setErrorMessages([`Error logging in: ${error.message}`]))
    dispatch({type: LOGIN_FAILURE})
  })
}

auth.logout = () => ({type: LOGOUT})

auth.showedWelcome = () => ({type: SHOWED_WELCOME})

auth.LOGOUT = LOGOUT

module.exports = auth