import { createWriteStream } from 'node:fs';
import { randomBytes, createHash } from 'node:crypto';
import { mkdir, stat } from 'node:fs/promises';
import { join, basename, extname } from 'node:path';
export interface SavedFileInfo {
absolutePath: string;
originalName: string;
size: number;
sha256: string;
ext: string;
}
export async function ensureDir(dir: string) {
try { await stat(dir); } catch { await mkdir(dir, { recursive: true }); }
}
export function safeBaseName(original: string) {
// Remove any directory parts, keep only last segment
const base = basename(original).replace(/[^A-Za-z0-9._-]/g, '_');
return base.length ? base : 'file';
}
export function randomFileName(ext: string) {
return randomBytes(16).toString('hex') + ext.toLowerCase();
}
export function hashBuffer(buf: Buffer) {
return createHash('sha256').update(buf).digest('hex');
}
export async function saveStreamToFile(opts: {
stream: NodeJS.ReadableStream;
uploadDir: string;
originalName: string;
maxBytes: number;
}): Promise<SavedFileInfo> {
await ensureDir(opts.uploadDir);
const ext = extname(opts.originalName) || '';
const finalName = randomFileName(ext);
const absolutePath = join(opts.uploadDir, finalName);
let size = 0;
const chunks: Buffer[] = [];
const sha = createHash('sha256');
await new Promise<void>((resolve, reject) => {
const ws = createWriteStream(absolutePath, { flags: 'wx' });
opts.stream.on('data', (chunk: Buffer) => {
size += chunk.length;
if (size > opts.maxBytes) {
ws.destroy();
reject(new Error('File too large'));
return;
}
sha.update(chunk);
chunks.push(chunk);
ws.write(chunk);
});
opts.stream.on('end', () => {
ws.end();
});
ws.on('close', () => resolve());
ws.on('error', reject);
opts.stream.on('error', reject);
});
return {
absolutePath,
originalName: opts.originalName,
size,
sha256: sha.digest('hex'),
ext
};
}
