jormungandr-bite/packages/backend/src/server/proxy/proxy-media.ts
2023-01-28 18:00:08 -08:00

105 lines
2.8 KiB
TypeScript

import * as fs from "node:fs";
import type Koa from "koa";
import sharp from "sharp";
import type { IImage } from "@/services/drive/image-processor.js";
import { convertToWebp } from "@/services/drive/image-processor.js";
import { createTemp } from "@/misc/create-temp.js";
import { downloadUrl } from "@/misc/download-url.js";
import { detectType } from "@/misc/get-file-info.js";
import { StatusError } from "@/misc/fetch.js";
import { FILE_TYPE_BROWSERSAFE } from "@/const.js";
import { serverLogger } from "../index.js";
import { isMimeImage } from "@/misc/is-mime-image.js";
export async function proxyMedia(ctx: Koa.Context) {
const url = "url" in ctx.query ? ctx.query.url : `https://${ctx.params.url}`;
if (typeof url !== "string") {
ctx.status = 400;
return;
}
// Create temp file
const [path, cleanup] = await createTemp();
try {
await downloadUrl(url, path);
const { mime, ext } = await detectType(path);
const isConvertibleImage = isMimeImage(mime, "sharp-convertible-image");
let image: IImage;
if ("static" in ctx.query && isConvertibleImage) {
image = await convertToWebp(path, 996, 560);
} else if ("preview" in ctx.query && isConvertibleImage) {
image = await convertToWebp(path, 400, 400);
} else if ("badge" in ctx.query) {
if (!isConvertibleImage) {
// 画像でないなら404でお茶を濁す
throw new StatusError("Unexpected mime", 404);
}
const mask = sharp(path)
.resize(96, 96, {
fit: "inside",
withoutEnlargement: false,
})
.greyscale()
.normalise()
.linear(1.75, -(128 * 1.75) + 128) // 1.75x contrast
.flatten({ background: "#000" })
.toColorspace("b-w");
const stats = await mask.clone().stats();
if (stats.entropy < 0.1) {
// エントロピーがあまりない場合は404にする
throw new StatusError("Skip to provide badge", 404);
}
const data = sharp({
create: {
width: 96,
height: 96,
channels: 4,
background: { r: 0, g: 0, b: 0, alpha: 0 },
},
})
.pipelineColorspace("b-w")
.boolean(await mask.png().toBuffer(), "eor");
image = {
data: await data.png().toBuffer(),
ext: "png",
type: "image/png",
};
} else if (mime === "image/svg+xml") {
image = await convertToWebp(path, 2048, 2048, 1);
} else if (
!(mime.startsWith("image/") && FILE_TYPE_BROWSERSAFE.includes(mime))
) {
throw new StatusError("Rejected type", 403, "Rejected type");
} else {
image = {
data: fs.readFileSync(path),
ext,
type: mime,
};
}
ctx.set("Content-Type", image.type);
ctx.set("Cache-Control", "max-age=31536000, immutable");
ctx.body = image.data;
} catch (e) {
serverLogger.error(`${e}`);
if (e instanceof StatusError && (e.statusCode === 302 || e.isClientError)) {
ctx.status = e.statusCode;
} else {
ctx.status = 500;
}
} finally {
cleanup();
}
}