<?php
require 'config.php';
header('Content-Type: application/json');
if (!isset($_SESSION['authenticated']) || $_SESSION['authenticated'] !== true ||
    !isset($_SESSION['isAdmin']) || $_SESSION['isAdmin'] !== true) {
    echo json_encode(["error" => "Unauthorized"]);
    exit;
}
$usersFile = USERS_DIR . USERS_FILE;
$users = [];
if (file_exists($usersFile)) {
    $lines = file($usersFile, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
    foreach ($lines as $line) {
        $parts = explode(':', trim($line));
        if (count($parts) >= 3) {
            // Optionally, validate username format:
            if (preg_match('/^[A-Za-z0-9_\- ]+$/', $parts[0])) {
                $users[] = ["username" => $parts[0]];
            }
        }
    }
}
echo json_encode($users);
?>