<?php
session_start();

$loggedin = isset($_SESSION['neptune_loggedin']) && $_SESSION['neptune_loggedin'] === true;
if (!$loggedin) {
    http_response_code(401);
    echo 'Unauthorized';
    exit;
}

$file = $_GET['file'] ?? '';
$mode = $_GET['mode'] ?? 'download';

if (!$file || preg_match('/[^a-zA-Z0-9_\.\-]/', $file)) {
    http_response_code(400);
    echo 'Invalid file';
    exit;
}

$path = '/var/www/uploads/' . basename($file);
if (!file_exists($path)) {
    http_response_code(404);
    echo 'File not found';
    exit;
}

require_once __DIR__ . '/config/database.php';
$db = getDbConnection();
$stmt = $db->prepare("SELECT original_name, mime_type FROM file_attachments WHERE stored_name = ?");
$stmt->execute([basename($file)]);
$att = $stmt->fetch(PDO::FETCH_ASSOC);

$originalName = $att ? $att['original_name'] : basename($file);
$mimeType = $att && $att['mime_type'] ? $att['mime_type'] : mime_content_type($path);

$ext = strtolower(pathinfo($originalName, PATHINFO_EXTENSION));
$viewable = in_array($ext, ['txt', 'md', 'pdf', 'csv']);

if ($mode === 'view' && $viewable) {
    header('Content-Disposition: inline; filename="' . $originalName . '"');
    header('Content-Type: ' . $mimeType);
    header('Content-Length: ' . filesize($path));
    header('X-File-Name: ' . $originalName);
    header('X-File-Viewable: 1');
    readfile($path);
    exit;
}

header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename="' . $originalName . '"');
header('Content-Length: ' . filesize($path));
header('Cache-Control: no-cache');
readfile($path);