import fetch from 'isomorphic-unfetch'; 
import store from '../store'; 
import getUrl from '../../util/getUrl'; 

// define action types
export const SET_USER = 'SET_USER'; 
export const LOGIN_PENDING = 'LOGIN_PENDING'; 
export const LOGIN_FAILED = 'LOGIN_FAILED'; 
export const LOGOUT = 'LOGOUT'; 

export const setUser = user => {
  store.dispatch({
    type: SET_USER,
    data: user
  }); 
}; // setUser

export const doLogout = () => {
  if(typeof window !== 'undefined') {
    window.localStorage.removeItem('jwt'); 
    document.cookie = 'jwt=; expires=Thu, 01 Jan 1970 00:00:01 GMT;path=/;'; 
  }
  store.dispatch({ type: LOGOUT }); 
}; // doLogout

export async function doLogin (creds, jwt, noPend) {
  !noPend && store.dispatch({ type: LOGIN_PENDING });
  const authReqOpts = { method: 'POST', credentials: 'include' }; 
  const authReqHead = { headers: jwt ? { Authorization: jwt } : { 
    'Content-Type': 'application/json' } 
  }; 
  const authReqBody = jwt ? null : { 
    body: JSON.stringify({...creds, strategy: 'local'}) 
  }; 
  const authReq = new Request(getUrl('auth'), {
    ...authReqOpts, ...authReqHead, ...authReqBody
  }); 
  const authRes = await fetch(authReq).catch(err => {
    store.dispatch({ type: LOGIN_FAILED, data: err.message });
  }); 
  if(!authRes.ok) {
    let error; 
    try {
      error = await authRes.json();
      error = error.message;  
    }
    catch (err) {
      error = authRes.status === 429 
        ? 'Max login attempts reached'
        : 'An error occurred during login';
    }
    return store.dispatch({
      type: LOGIN_FAILED, 
      data: error
    }); 
  }
  const { accessToken } = await authRes.json(); 
  const payload = accessToken.split('.')[1]; 
  const { userId } = JSON.parse(atob(payload)); 
  const userReq = new Request(getUrl(`/users/${userId}`), {
    headers: {
      Authorization: accessToken
    }
  });
  const userRes = await fetch(userReq); 
  if(!userRes.ok) {
    return store.dispatch({
      type: LOGIN_FAILED,
      data: 'failed to get user'
    }); 
  }
  window.localStorage.setItem('jwt', accessToken); 
  setUser(await userRes.json()); 
} // doLogin