/**
 * generate-secrets.mjs — FamilySync bootstrap secret generator (SETUP-03 / D-05).
 *
 * Generates all secrets required for a first-time FamilySync deployment:
 *   - SESSION_SECRET          (AES-256-GCM session signing key, 32 random bytes / 64 hex chars)
 *   - APP_PASSWORD_ENCRYPTION_KEY (AES-256-GCM encryption key, 32 random bytes / 64 hex chars)
 *   - VAPID_PUBLIC_KEY        (EC P-256 public key, base64url, ~87 chars)
 *   - VAPID_PRIVATE_KEY       (EC P-256 private scalar, base64url, ~43 chars)
 *
 * Security contract (SC-3):
 *   - Prints to stdout ONLY — never writes any file, never touches the DB, never calls any API.
 *   - The operator is responsible for pasting the output into docker-compose.yml and keeping it safe.
 *   - These values CANNOT be recovered if lost (VAPID key rotation invalidates push subscriptions).
 *
 * Usage:
 *   node scripts/generate-secrets.mjs
 *   # or via pnpm script:
 *   pnpm generate-secrets
 */

// IN-03: use Node.js built-in crypto to generate VAPID keys — avoids importing
// web-push via its private source tree (../apps/api/node_modules/web-push/src/index.js)
// which breaks if web-push restructures internally or workspace hoisting moves the package.
// createECDH('prime256v1') + getPublicKey()/getPrivateKey() produces the same
// base64url-encoded keys as web-push.generateVAPIDKeys().
import { randomBytes, createECDH } from 'node:crypto';

const sessionSecret = randomBytes(32).toString('hex');
const encKey = randomBytes(32).toString('hex');
// Phase 19 (D-05): LOCAL_SESSION_SECRET signs the local-auth JWT session cookie.
// Must be >= 32 chars. 32 random bytes encoded as base64 = 44 chars (safe, distinct from hex keys).
const localSessionSecret = randomBytes(32).toString('base64');

// VAPID key generation (P-256 / prime256v1 — same curve as web-push)
const ecdhCurve = createECDH('prime256v1');
ecdhCurve.generateKeys();
// Pad raw buffers to the expected lengths, matching web-push defensive padding
// (https://github.com/web-push-libs/web-push/issues/295)
let pubBuffer = ecdhCurve.getPublicKey();
let privBuffer = ecdhCurve.getPrivateKey();
if (privBuffer.length < 32) {
  privBuffer = Buffer.concat([Buffer.alloc(32 - privBuffer.length), privBuffer]);
}
if (pubBuffer.length < 65) {
  pubBuffer = Buffer.concat([Buffer.alloc(65 - pubBuffer.length), pubBuffer]);
}
const vapid = {
  publicKey: pubBuffer.toString('base64url'),
  privateKey: privBuffer.toString('base64url'),
};

console.log(`# FamilySync Bootstrap Secrets — generated ${new Date().toISOString()}
# Paste into your docker-compose.yml environment block under the 'api' service.
# Keep this output safe — these values cannot be recovered if lost.
# VAPID key rotation will invalidate all existing push subscriptions.

SESSION_SECRET=${sessionSecret}
APP_PASSWORD_ENCRYPTION_KEY=${encKey}
VAPID_PUBLIC_KEY=${vapid.publicKey}
VAPID_PRIVATE_KEY=${vapid.privateKey}
# Phase 19 (D-05): Signs local-auth JWT session cookies. Required when not using DEV_AUTH_BYPASS.
LOCAL_SESSION_SECRET=${localSessionSecret}
`);