34784-vm/callback-google.php

<?php
ini_set('display_errors', 0); // Menonaktifkan tampilan error untuk pengguna
error_reporting(E_ALL);

session_start();
require_once __DIR__ . '/google-config.php';
require_once __DIR__ . '/db/config.php';

// Fungsi untuk menampilkan halaman error yang rapi
function showErrorPage($message) {
    http_response_code(500);
    echo "<div style='font-family: sans-serif; text-align: center; padding: 40px;'>";
    echo "<h2>Terjadi Kesalahan</h2>";
    echo "<p>Proses login dengan Google gagal. Silakan coba lagi.</p>";
    echo "<p style='color: #888; font-size: 0.9em;'>Detail: " . htmlspecialchars($message) . "</p>";
    echo "<a href='index.php'>Kembali ke Halaman Utama</a>";
    echo "</div>";
    exit;
}

// 1. Pastikan Client ID dan Secret sudah diisi
if (GOOGLE_CLIENT_ID === 'MASUKKAN_CLIENT_ID_ANDA_DISINI' || GOOGLE_CLIENT_SECRET === 'MASUKKAN_CLIENT_SECRET_ANDA_DISINI') {
    showErrorPage('Konfigurasi Google OAuth belum diatur. Silakan hubungi administrator.');
}

// 2. Ambil authorization code dari Google
if (!isset($_GET['code'])) {
    showErrorPage('Authorization code tidak ditemukan.');
}
$code = $_GET['code'];

// 3. Tukarkan code dengan access token
try {
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, 'https://oauth2.googleapis.com/token');
    curl_setopt($ch, CURLOPT_POST, true);
    curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query([
        'client_id' => GOOGLE_CLIENT_ID,
        'client_secret' => GOOGLE_CLIENT_SECRET,
        'code' => $code,
        'redirect_uri' => GOOGLE_REDIRECT_URI,
        'grant_type' => 'authorization_code'
    ]));
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    $response = curl_exec($ch);
    curl_close($ch);

    $token_data = json_decode($response, true);
    if (!isset($token_data['access_token'])) {
        showErrorPage('Gagal mendapatkan access token dari Google. ' . ($token_data['error_description'] ?? ''));
    }
    $access_token = $token_data['access_token'];

    // 4. Gunakan access token untuk mengambil data profil pengguna
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, 'https://www.googleapis.com/oauth2/v1/userinfo?alt=json');
    curl_setopt($ch, CURLOPT_HTTPHEADER, ['Authorization: Bearer ' . $access_token]);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    $profile_response = curl_exec($ch);
    curl_close($ch);

    $profile_data = json_decode($profile_response, true);
    if (!isset($profile_data['id'])) {
        showErrorPage('Gagal mengambil data profil dari Google.');
    }

    // 5. Proses data pengguna (Login atau Register)
    $google_id = $profile_data['id'];
    $email = $profile_data['email'];
    $username = $profile_data['name'];
    $avatar_url = $profile_data['picture'];

    $pdo = db();

    // Cek apakah pengguna sudah ada berdasarkan google_id
    $stmt = $pdo->prepare("SELECT * FROM users WHERE google_id = :google_id");
    $stmt->execute(['google_id' => $google_id]);
    $user = $stmt->fetch();

    if ($user) {
        // Pengguna sudah ada, langsung login
        $user_id = $user['id'];
        // Mungkin update avatar jika berubah
        $update_stmt = $pdo->prepare("UPDATE users SET avatar_url = :avatar_url WHERE id = :id");
        $update_stmt->execute(['avatar_url' => $avatar_url, 'id' => $user_id]);
    } else {
        // Pengguna baru, buat akun
        // Cek dulu apakah email sudah terdaftar (untuk linking akun)
        $stmt = $pdo->prepare("SELECT * FROM users WHERE email = :email");
        $stmt->execute(['email' => $email]);
        $existing_user_by_email = $stmt->fetch();

        if ($existing_user_by_email) {
            // Email sudah ada, tautkan akun ini dengan google_id
            $user_id = $existing_user_by_email['id'];
            $update_stmt = $pdo->prepare("UPDATE users SET google_id = :google_id, avatar_url = :avatar_url WHERE id = :id");
            $update_stmt->execute(['google_id' => $google_id, 'avatar_url' => $avatar_url, 'id' => $user_id]);
        } else {
            // Buat pengguna baru
            $insert_stmt = $pdo->prepare(
                "INSERT INTO users (username, email, google_id, avatar_url, role) VALUES (:username, :email, :google_id, :avatar_url, 'siswa')"
            );
            $insert_stmt->execute([
                'username' => $username,
                'email' => $email,
                'google_id' => $google_id,
                'avatar_url' => $avatar_url
            ]);
            $user_id = $pdo->lastInsertId();
        }
        // Ambil data pengguna yang baru dibuat/diupdate
        $stmt = $pdo->prepare("SELECT * FROM users WHERE id = :id");
        $stmt->execute(['id' => $user_id]);
        $user = $stmt->fetch();
    }

    // 6. Buat sesi login
    session_regenerate_id(true);
    $_SESSION['loggedin'] = true;
    $_SESSION['user_id'] = $user['id'];
    $_SESSION['username'] = $user['username'];
    $_SESSION['role'] = $user['role'];

    // 7. Redirect ke dashboard
    header('Location: dashboard.php');
    exit();

} catch (Exception $e) {
    // Tangkap semua jenis error (PDO, cURL, dll)
    showErrorPage($e->getMessage());
}
?>