Initial commit

2026-09-25 15:29:54 +01:00
parent ce21e350a1
commit bd53601d8c
37 changed files with 5029 additions and 0 deletions
@@ -0,0 +1,68 @@
+import { createHash, randomBytes, timingSafeEqual } from 'node:crypto';
+
+export const nowIso = () => new Date().toISOString();
+export const randomId = (bytes = 16) => randomBytes(bytes).toString('hex');
+export const randomToken = () => `kv_${randomBytes(24).toString('base64url')}`;
+export const tokenHash = (token) => createHash('sha256').update(token).digest('hex');
+export const sha256 = (input) => createHash('sha256').update(input).digest('hex');
+
+export function safeEqualHex(a, b) {
+  if (!a || !b || a.length !== b.length) return false;
+  return timingSafeEqual(Buffer.from(a, 'hex'), Buffer.from(b, 'hex'));
+}
+
+export function cleanText(value, max = 500) {
+  if (value == null) return null;
+  const s = String(value).replace(/[\u0000-\u001f\u007f]/g, ' ').replace(/\s+/g, ' ').trim();
+  return s.slice(0, max) || null;
+}
+
+export function asInt(value, { min = 0, max = Number.MAX_SAFE_INTEGER, fallback = 0 } = {}) {
+  const n = Number(value);
+  if (!Number.isFinite(n)) return fallback;
+  const i = Math.trunc(n);
+  return Math.max(min, Math.min(max, i));
+}
+
+function validIsbn10(value) {
+  if (!/^\d{9}[\dX]$/.test(value)) return false;
+  let sum = 0;
+  for (let i = 0; i < 10; i++) {
+    const d = value[i] === 'X' ? 10 : Number(value[i]);
+    sum += d * (10 - i);
+  }
+  return sum % 11 === 0;
+}
+
+function validIsbn13(value) {
+  if (!/^97[89]\d{10}$/.test(value)) return false;
+  let sum = 0;
+  for (let i = 0; i < 12; i++) sum += Number(value[i]) * (i % 2 ? 3 : 1);
+  return (10 - (sum % 10)) % 10 === Number(value[12]);
+}
+
+/** Extract a validated ISBN from EPUB/KOReader identifier metadata.
+ * KOReader's doc_props.identifiers is commonly a newline-separated string such as
+ * `isbn:978...`, `urn:isbn:...`, `calibre:...`, `uuid:...`.
+ */
+export function extractIsbn(value) {
+  if (!value) return null;
+  const raw = String(value).toUpperCase();
+  const candidates = raw.match(/(?:97[89][\d\s-]{9,20}\d|\d[\d\s-]{7,16}[\dX])/g) || [];
+  const cleaned = [...new Set(candidates.map(x => x.replace(/[^0-9X]/g, '')))];
+  const isbn13 = cleaned.find(x => x.length === 13 && validIsbn13(x));
+  if (isbn13) return isbn13;
+  return cleaned.find(x => x.length === 10 && validIsbn10(x)) || null;
+}
+
+export function json(res, status, body, extraHeaders = {}) {
+  const payload = Buffer.from(JSON.stringify(body));
+  res.writeHead(status, {
+    'Content-Type': 'application/json; charset=utf-8',
+    'Content-Length': payload.length,
+    'Cache-Control': 'no-store',
+    'X-Content-Type-Options': 'nosniff',
+    ...extraHeaders,
+  });
+  res.end(payload);
+}