<?php

namespace App\Http\Controllers\Auth;

use App\Http\Controllers\Controller;
use App\Models\User;
use App\Models\DeviceIp;
use Carbon\Carbon;
use Illuminate\Support\Facades\Auth;
use Illuminate\Support\Facades\Session;
use Illuminate\Support\Facades\Mail;
use Laravel\Socialite\Facades\Socialite;
use Exception;

class GoogleAuthController extends Controller
{
    /**
     * Redirect to Google OAuth
     */
    public function redirect()
    {
        try {
            return Socialite::driver('google')->redirect();
        } catch (Exception $e) {
            Session::flash('error', get_phrase('Google authentication is currently unavailable. Please try again later.'));
            return redirect()->route('login');
        }
    }

    /**
     * Handle Google OAuth callback
     */
    public function callback()
    {
        try {
            $googleUser = Socialite::driver('google')->user();

            // Validate required data
            if (!$googleUser->getEmail()) {
                Session::flash('error', get_phrase('Google account email is required. Please ensure your Google account has an email address.'));
                return redirect()->route('login');
            }

            // Find existing user by email
            $existingUser = User::where('email', $googleUser->getEmail())->first();

            if ($existingUser) {
                // Update existing user with Google data if missing
                if (!$existingUser->google_id) {
                    $existingUser->update([
                        'google_id' => $googleUser->getId(),
                        'photo' => $googleUser->getAvatar() ?? $existingUser->avatar,
                    ]);
                }

                Auth::login($existingUser);
                return $this->handlePostLogin($existingUser);

            } else {
                // Create new user with your existing field structure
                $newUser = User::create([
                    'name' => $googleUser->getName() ?? $this->generateNameFromEmail($googleUser->getEmail()),
                    'email' => $googleUser->getEmail(),
                    'google_id' => $googleUser->getId(),
                    'password' => null, // No password for Google-authenticated users
                    'role' => 'student',
                    'status' => 1,
                    'photo' => $googleUser->getAvatar(),
                    ]);

                if (get_settings('student_email_verification') != 1) {
                    $user_data['email_verified_at'] = Carbon::now();
                }

                Auth::login($newUser);
                Session::flash('success', get_phrase('Account created successfully! Welcome to our platform.'));
                return $this->handlePostLogin($newUser);
            }

        } catch (Exception $e) {
            Session::flash('error', get_phrase('Authentication failed. Please try again or use another method.'));
            return redirect()->route('login');
        }
    }

    /**
     * Handle post-login logic (device tracking, etc.)
     */
    private function handlePostLogin($user)
    {
        request()->session()->regenerate();

        // Track device limitation (same as your existing login)
        if (Auth::check() && $user->role != 'admin') {
            $current_ip = request()->getClientIp();
            $session_id = request()->session()->getId();
            $current_user_agent = base64_encode($user->id . request()->header('user-agent'));
            $allowed_devices = get_settings('device_limitation') ?? 1;
            $logged_in_devices = DeviceIp::where('user_id', $user->id)->get();

            if ($logged_in_devices->where('user_agent', '!=', $current_user_agent)->count() < $allowed_devices) {
                if ($logged_in_devices->where('user_agent', $current_user_agent)->count() == 0) {
                    DeviceIp::insert([
                        'user_id'    => $user->id,
                        'ip_address' => $current_ip,
                        'session_id' => $session_id,
                        'user_agent' => $current_user_agent,
                        'created_at' => now(),
                        'updated_at' => now(),
                    ]);
                } else {
                    DeviceIp::where('user_id', $user->id)
                            ->where('user_agent', $current_user_agent)
                            ->update([
                                'session_id' => $session_id,
                                'updated_at' => now(),
                            ]);
                }
            } else {
                $logged_in_oldest_row = DeviceIp::where('user_id', $user->id)->orderBy('id', 'desc')->first();
                $data = [
                    'verification_link' => route('login', ['user_agent' => $logged_in_oldest_row->user_agent])
                ];

                try {
                    Mail::send('email.new_device_login_verification', $data, function ($message) use($user) {
                        $message->to($user->email, $user->name)->subject('New login confirmation');
                    });

                    Auth::guard('web')->logout();
                    request()->session()->invalidate();
                    request()->session()->regenerateToken();

                    Session::flash('success', get_phrase('A confirmation email has been sent. Please check your inbox to confirm access to this account from this device.'));
                    return redirect(route('login'));
                } catch (\Swift_TransportException $e) {
                    Session::flash('error', 'We could not send the email. Please try again later.');
                } catch (Exception $e) {
                    Session::flash('error', 'Something went wrong. Please try again.');
                }

                Auth::guard('web')->logout();
                request()->session()->invalidate();
                request()->session()->regenerateToken();
                return redirect(route('login'));
            }
        }

        return redirect()->intended('/dashboard');
    }

    /**
     * Generate a name from email if Google name is not available
     */
    private function generateNameFromEmail($email)
    {
        $name = strstr($email, '@', true);
        return ucfirst(str_replace(['.', '_'], ' ', $name));
    }
}