Files
simple-qr/server/api/index.ts

102 lines
2.3 KiB
TypeScript

import { createCanvas, loadImage } from "canvas";
import QRCode from "qrcode";
import { z } from "zod";
import { resolve } from "path";
import sharp from "sharp";
const time = (label: string) => {
const start = performance.now();
return () => {
console.log(`${label}\t${performance.now() - start}`);
};
};
const IMAGE_FORMATS = ["jpeg", "png", "webp"] as const;
const settingsSchema = z.object({
format: z.enum(IMAGE_FORMATS).default("png"),
logo: z.string().min(1),
content: z.string().min(1),
});
export default defineEventHandler(async (event) => {
const query = getQuery(event);
const parsed = settingsSchema.safeParse(query);
if (!parsed.success) {
return createError({
status: 400,
data: {
errors: Object.fromEntries(
parsed.error.errors.map((x) => [x.path.join("."), x.message]),
),
},
});
}
const { format, logo, content } = parsed.data;
const tt = time("total");
let t;
const SIZE = 1000;
const LOGO_PADDING = 1;
t = time("render");
const canvas = createCanvas(SIZE, SIZE);
await QRCode.toCanvas(canvas, content, {
errorCorrectionLevel: "H",
width: SIZE,
margin: 1,
});
t();
t = time("count");
const qrCode = QRCode.create(content, { errorCorrectionLevel: "H" });
const moduleCount = qrCode.modules.size + 2;
t();
t = time("logo");
const logoImage = await loadImage(resolve("public", `${logo}.png`));
const moduleSize = SIZE / moduleCount;
let logoModules = Math.floor(moduleCount * 0.3);
if (logoModules % 2 !== moduleCount % 2) {
logoModules += 1;
}
const backgroundSize = logoModules * moduleSize + 1;
const backgroundPosition = (moduleSize * (moduleCount - logoModules)) / 2;
const logoSize = backgroundSize - LOGO_PADDING * 2;
const logoPosition = backgroundPosition + LOGO_PADDING;
const ctx = canvas.getContext("2d");
ctx.fillStyle = "white";
ctx.fillRect(
backgroundPosition,
backgroundPosition,
backgroundSize,
backgroundSize,
);
ctx.drawImage(logoImage, logoPosition, logoPosition, logoSize, logoSize);
t();
t = time("buffer");
let image = canvas.toBuffer();
t();
if (format !== "png") {
t = time("convert");
image = await sharp(image).toFormat(format).toBuffer();
t();
}
tt();
event.node.res.setHeader("Content-Type", `image/${format}`);
return image;
});