<?php
session_start();

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

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

$month = date('Y-m');
$filename = "leave_report_{$month}.csv";

header('Content-Type: text/csv');
header('Content-Disposition: attachment; filename="' . $filename . '"');

$output = fopen('php://output', 'w');

fputcsv($output, ['Student Name', 'Leave Type', 'Start Date', 'End Date', 'Reason', 'Status']);

try {
    $pdo = db();
    $stmt = $pdo->prepare("SELECT users.full_name AS student_name, leave_requests.* FROM leave_requests JOIN users ON leave_requests.student_id = users.id WHERE DATE_FORMAT(leave_requests.created_at, '%Y-%m') = ?");
    $stmt->execute([$month]);
    
    while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
        fputcsv($output, [
            $row['student_name'],
            $row['leave_type'],
            $row['start_date'],
            $row['end_date'],
            $row['reason'],
            $row['status']
        ]);
    }
} catch (PDOException $e) {
    // handle error
}

fclose($output);
exit;