<?php
session_start();

if (!isset($_SESSION['user_role']) || $_SESSION['user_role'] !== 'admin') {
    header('Location: index.php');
    exit;
}

require_once __DIR__ . '/vendor/autoload.php';
require_once __DIR__ . '/db/config.php';

use ParseCsv\Csv;

if (isset($_FILES['student_file']) && $_FILES['student_file']['error'] === UPLOAD_ERR_OK) {
    $csv = new Csv();
    $csv->auto($_FILES['student_file']['tmp_name']);

    $pdo = db();

    foreach ($csv->data as $row) {
        $full_name = $row['full_name'];
        $email = $row['email'];
        
        // Generate a random password
        $password = bin2hex(random_bytes(8));
        $hashed_password = password_hash($password, PASSWORD_DEFAULT);

        try {
            $stmt = $pdo->prepare("INSERT INTO users (full_name, email, password, role) VALUES (?, ?, ?, 'student')");
            $stmt->execute([$full_name, $email, $hashed_password]);
        } catch (PDOException $e) {
            // Handle duplicate email or other errors
            // For now, we just skip the row
            continue;
        }
    }

    header('Location: admin_dashboard.php?import_success=1');
    exit;
} else {
    header('Location: admin_dashboard.php?import_error=1');
    exit;
}