import logo from './logo.svg';
import './App.css';
import React, { useState, Component, useEffect, useRef } from "react";
import {Provider, connect}   from 'react-redux';
import thunk  from 'redux-thunk';
import {createStore, combineReducers,applyMiddleware } from 'redux';
import Form from './components/Form';





const getGQL = url => 
    (query, variables) =>
        fetch(url, {
            method: 'POST',
            headers: {
                "content-type": "application/json",
                ...(localStorage.authToken ? {Authorization: "Bearer " + localStorage.authToken} : {})
            },
            body: JSON.stringify({query, variables})
        }).then(res => res.json())

    let gql = getGQL("http://snippet.asmer.fs.a-level.com.ua/graphql")

function promiseReducer(state , {type, name ,status , payload, error}) {
  if (!state){
      return {} //{status , payload , error}
  }
  if (type === 'PROMISE') {
      return {
          ...state,
          [name]: [status,payload , error]
      }
  }
  return state
}

let reg = async(login,password) => {
  let query = `mutation reg($l:String! , $p:String!) {
      createUser(login:$l,password:$p){
  _id
}
}`

    let qVariables = {
      "l": login,
      "p": password
    }
    let result = await gql(query,qVariables)
    return result
  }

  let log = async(login , password) => {
    let query = ` query log($l:String!,$p:String!) {
      login(login:$l,password:$p)
    }`
let qVariables = {
    "l": login,
    "p": password 
}
let result = await gql(query,qVariables)
console.log(result)
localStorage.authToken = result.data.login
}

const actionPending = name =>            ({type: "PROMISE" ,status:"PENDING", name})
const actionResolved = (name,payload) => ({type: "PROMISE" ,status:"RESOLVED", name,payload})
const actionRejected = (name,error) =>   ({type: "PROMISE" ,status:"REJECTED", name,error})

const actionPromise = (name, promise) => 
  async dispatch => {
      dispatch(actionPending(name))
      try {
          let payload = await promise
          dispatch(actionResolved(name , payload))
          return payload
      }
      catch(error){
          dispatch(actionRejected(name , error))
      }
  }

  function authReducer(state, action){ //....
    if (state === undefined){
        if (!localStorage.authToken){
            return {}
        }
        action.token = localStorage.authToken
        action.type = 'LOGIN'
        // добавить в action token из localStorage, и проимитировать LOGIN 
    }
    if (action.type === 'LOGIN'){
        console.log('ЛОГИН')
        localStorage.authToken = action.token
        console.log(action.token)
        function jwt_decode (token) {
            var start64Url = token.split('.')[1]
            return JSON.parse(atob(start64Url))
        }
        return {token: action.token, payload: jwt_decode(action.token)}
    }
    if (action.type === 'LOGOUT'){
        console.log('ЛОГАУТ')
        localStorage.removeItem("authToken")
        //вернуть пустой объект
        return {}
    }
    return state
}

const actionAuthLogin = token => ({type:'LOGIN', token})
const actionAuthLogout = () => ({type:'LOGOUT'})
const actionFullLogin = (login , password) => async dispatch => {
  let result = await dispatch(actionPromise("login",log(login,password)))
  if (result.data.login !== null){
  dispatch(actionAuthLogin(result.data.login))
  }
  else {
      alert ('такого пользователя не существует')
  }
}
const actionRegister = (login,password) => async dispatch => {
  return await dispatch (actionPromise('register' , reg(login,password)))
}

const actionFullRegister = (login,password) => async dispatch => {
  let result =  await dispatch (actionRegister(login,password))
  if (result.errors === undefined) {
      await dispatch (actionFullLogin(login,password))
  }
  else { 
      alert("Такой пользователь уже есть")

  }
}


let reducers = {
    promise:promiseReducer,
    auth:authReducer
}

const store = createStore(combineReducers(reducers), applyMiddleware(thunk))





const LoginForm = ({ onLogin }) => {
  const [login, setLogin] = useState("");
  const [password, setPassword] = useState("");
  //надо тип инпуту
  //надо проверку на пустоту инпутов и запрет кнопки (disabled)
  //надо при кнопке отправить в onLogin login и пароль. onLogin - это функция-колбэк
  return (
    <>
      <input value={login} onChange={(e) => setLogin(e.target.value)} />
      <input
        type="password"
        value={password}
        onChange={(e) => setPassword(e.target.value)}
      />
      <button
        onClick={() => onLogin(login, password)}
        disabled={!login || !password}
      >
        Sign in
      </button>
      
    </>
  );
};


const ConnectedLoginForm = connect(null, {onLogin: actionAuthLogin})(LoginForm)

const unsubscribe = store.subscribe(() => console.log('result here',store.getState()))



const NickName =  ({nick}) => {
  return (
    <p></p>,
    <a href = '#'>{nick || 'anon'}</a>
    )
  }
  
  
  
  const ConnectedNick = connect(state => ({nick:state?.auth?.payload?.sub?.login }))(NickName)
  
  const LogOut = connect ((state) => ({children:'Logout' , disabled:!state.auth.token }) , ({onClick:actionAuthLogout}))('button')


function App() {
  return (
    <div className="App">
      <Provider store = {store}>
        <ConnectedNick/> <br/>
      <ConnectedLoginForm/>
        <LogOut/>
        {/* <Form/> */}
      </Provider>
     
    </div>
  );
}

export default App;