osb/app/Http/Controllers/Auth/SocialLoginController.php

<?php

namespace App\Http\Controllers\Auth;

use Illuminate\Http\Request;
use Illuminate\Support\Arr;
use Illuminate\Support\Facades\Auth;
use Illuminate\Support\Facades\Mail;
use Laravel\Socialite\Facades\Socialite;
use App\Providers\RouteServiceProvider;

use App\Http\Controllers\Controller;
use App\Mail\SocialLink;
use App\Models\Oauth;
use App\Models\AccountOauth;
use App\User;

class SocialLoginController extends Controller
{
	public function redirectToProvider($provider)
	{
		return Socialite::with($provider)->redirect();
	}

	public function handleProviderCallback($provider)
	{
		$openiduser = Socialite::with($provider)->user();

		$oo = Oauth::firstOrCreate(['name'=>$provider,'active'=>TRUE]);

		// See if this user has connected and linked previously
		$aoo = $oo->accounts->where('userid',$openiduser->id);

		if ($aoo->count() == 1)
		{
			$aoo = $aoo->first();

			if ((is_null($user=$aoo->user) AND (is_null($aoo->account) OR is_null($user=$aoo->account->user))) OR ! $user->active)
			{
				if (! $user) {
					$user = User::where('email',$openiduser->email)->first();
				}

				if (! $user OR ! $user->active)
				{
					return redirect('/login')->with('error','Invalid account, or account inactive, please contact an admin.');
				}

				return $this->link($provider,$aoo,$user);
			}

			// All Set to login
			Auth::login($user,FALSE);

		// If there are too many users, then we have a problem
		} elseif ($aoo->count() > 1) {
			return redirect('/login')->with('error','Seems you have multiple oauth IDs, please contact an admin.');

		// User is using OAUTH for the first time.
		} else {
			$uo = User::active()->where('email',$openiduser->email);

			// See if their is an account with this email address
			if ($uo->count() == 1)
			{
				$aoo = new AccountOauth;
				$aoo->userid = $openiduser->id;
				$aoo->oauth_data = $openiduser->user;
				$oo->accounts()->save($aoo);

				return $this->link($provider,$aoo,$uo->first());

				// If there are too many users, then we have a problem
			} elseif ($uo->count() > 1) {
				return redirect('/login')->with('error','Seems you have multiple accounts, please contact an admin.');

			} else {
				return redirect('/login')->with('error','Seems you dont have an account with that email, please contact an admin.');
			}
		}

		return redirect()->intended(RouteServiceProvider::HOME);
	}

	/**
	 * We have identified the user and oauth, just need them to confirm the link
	 *
	 * @param      $provider
	 * @param User $uo
	 * @return \Illuminate\Contracts\View\Factory|\Illuminate\View\View
	 */
	public function link($provider,AccountOauth $ao,User $uo)
	{
		Mail::to($uo->email)->send(new SocialLink($ao));

		return view('auth.social_link')
			->with('oauthid',$ao->id)
			->with('provider',$provider);
	}

	public function linkcomplete(Request $request,$provider)
	{
		// Load our oauth id
		$aoo = AccountOauth::findOrFail($request->post('oauthid'));

		// Check our email matches
		if (Arr::get($aoo->oauth_data,'email','invalid') !== $request->post('email'))
			return redirect('/login')->with('error','Account details didnt match to make link.');

		// Check our token matches
		if ($aoo->link_token !== $request->post('token'))
			return redirect('/login')->with('error','Token details didnt match to make link.');

		// Load our email.
		$uo = User::where('email',$request->post('email'))->firstOrFail();

		$aoo->user_id = $uo->id;
		$aoo->save();
		Auth::login($uo,FALSE);

		return redirect()->intended(RouteServiceProvider::HOME);
	}
}