Files
mrp-qrcode/lib/qr.ts
T
jason 5847a175af
Build and Push Docker Image / build (push) Successful in 1m11s
stage 5-6
2026-04-21 13:14:27 -05:00

53 lines
1.7 KiB
TypeScript

import { randomBytes } from "node:crypto";
import QRCode from "qrcode";
import { env } from "@/lib/env";
/**
* Operation QR tokens are opaque, URL-safe, high-entropy identifiers
* printed on traveler cards. 24 bytes = 192 bits of entropy, encoded
* as base64url -> 32 characters.
*/
export function generateQrToken(): string {
return randomBytes(24)
.toString("base64")
.replace(/\+/g, "-")
.replace(/\//g, "_")
.replace(/=+$/, "");
}
/**
* The payload baked into the QR image is a full absolute URL so any phone
* camera app (which opens scans in a browser) goes straight to the scan page.
* APP_URL must match the externally reachable origin — see docs/DEPLOY.md.
*/
export function scanUrlForToken(token: string): string {
const base = env.APP_URL.replace(/\/+$/, "");
return `${base}/op/scan/${token}`;
}
/**
* Render the scan URL as a data-URL PNG suitable for <img src=...> on the
* admin detail page and, later, on the printable traveler card. Error
* correction level M balances density against smudge tolerance on paper.
*/
export async function renderQrPng(token: string): Promise<string> {
return QRCode.toDataURL(scanUrlForToken(token), {
errorCorrectionLevel: "M",
margin: 1,
width: 256,
});
}
/**
* Same QR, but as a raw PNG buffer for embedding into pdf-lib documents.
* We bump width up so the vector→raster downscale at print time stays crisp;
* 512 px at 35 mm = ~370 dpi which beats any office printer we'll see.
*/
export async function renderQrPngBuffer(token: string, width = 512): Promise<Buffer> {
return QRCode.toBuffer(scanUrlForToken(token), {
errorCorrectionLevel: "M",
margin: 1,
width,
});
}