# 中繼器2
###### tags: `CTBC-Lab4`

## firebase

## 程式碼
auth.services.ts

import { Injectable } from '@angular/core';
import { AngularFireAuth } from '@angular/fire/compat/auth';
import { Router } from '@angular/router';
import { LocalStorageService } from 'ngx-webstorage';
import firebase from '@firebase/app-compat';
//import { getAuth, setPersistence, inMemoryPersistence, GoogleAuthProvider, signInWithPopup, } from "firebase/auth";
import 'firebase/compat/auth';
//import { GoogleAuthProvider } from 'firebase/auth';
import 'firebase/compat/firestore';


@Injectable({
  providedIn: 'root'
})

export class AuthService {
  user: any //此變數將在login.component.ts檔使用

  constructor(
    public auth: AngularFireAuth,
    public router: Router,
    private storage: LocalStorageService,
    ) { 
      // 訂閱firebase服務提供的「登入狀態」資料流
      // authState 登入登出的狀態
      this.auth.authState.subscribe((user)=>{
        if (user) {
          this.user = user;
          this.storage.store('user',this.user); // 寫入local storage
        }
      });
    } // auth為一外部服務，需設定為public 

    // 1. 登入(email燈入)
    // .then() 為正常情況 (登入成功)
    // 1. 寫到localstore
    // 2. 轉到首頁
    // () 內可以填寫其他功能
    // () => {}
    login(mail:string,passwd:string){
      this.auth.signInWithEmailAndPassword(mail,passwd).then(
        async (uc) => {
          console.log(uc.user);
          this.router.navigate(['/student']);
        }).catch(
          (error) => {
            console.log(error)
          });
    }

    // 檢查是否已登入
    isLoggedIn(): boolean {
      const user = this.storage.retrieve('user');
      // ts檔 if else 縮寫
      return (user !== null) ? true : false;
    }

    // 2. 登出
    logout() {
      // Promise
      this.auth.signOut().then(
        () => {
          this.storage.clear('user');
          console.log('登出成功')
          this.router.navigate(['/login']); // 跳回至login頁面
        }).catch(
          error => {
            console.log('登出失敗') // 可不寫，因為登出較少失敗
          }
        )
    }

    // 使用Google登入
    loginWithGoogle() {
      //const provider = new GoogleAuthProvider();
      //firebase.auth()
      return this.auth.signInWithPopup(new firebase.auth.GoogleAuthProvider())
      .then(async(uc) => {
          console.log(uc);
          
          await this.storage.store('user',uc.user)
          this.router.navigate(['/dashboard']);
        }).catch();
    }

}