Add image handler by id with quality control

api/src/controllers/images.ts

@@ -0,0 +1,119 @@
+import { stat } from "node:fs/promises";
+import type { BunFile } from "bun";
+import Elysia, { t } from "elysia";
+import { KError } from "~/models/error";
+import { imageDir } from "./seed/images";
+
+export const imagesH = new Elysia({ prefix: "/images", tags: ["images"] }).get(
+	":id",
+	async ({ params: { id }, query: { quality }, headers: reqHeaders }) => {
+		const path = `${imageDir}/${id}.${quality}.jpg`;
+		const file = Bun.file(path);
+
+		const etag = await generateETag(file);
+		if (await isCached(reqHeaders, etag, path))
+			return new Response(null, { status: 304 });
+
+		const [start = 0, end = Number.POSITIVE_INFINITY] =
+			reqHeaders.range?.split("-").map(Number) ?? [];
+		return new Response(file.slice(start, end), {
+			headers: {
+				Etag: etag,
+				"Cache-Control": `public, max-age=${3 * 60 * 60}`,
+			},
+		}) as any;
+	},
+	{
+		detail: { description: "Access an image by id." },
+		params: t.Object({
+			id: t.String({
+				desription: "Id of the image to retrive.",
+				format: "regex",
+				pattern: "^[0-9a-fA-F]*$",
+			}),
+		}),
+		query: t.Object({
+			quality: t.Optional(
+				t.UnionEnum(["high", "medium", "low"], {
+					default: "high",
+					description: "The quality you want your image to be in.",
+				}),
+			),
+		}),
+		response: {
+			200: t.File({ description: "The whole image" }),
+			206: t.File({ description: "Only the range of the image requested" }),
+			304: t.Void({ description: "Cached image already up-to-date" }),
+			404: { ...KError, description: "No image found with this id." },
+		},
+	},
+);
+
+// stolen from https://github.com/elysiajs/elysia-static/blob/main/src/cache.ts
+
+export async function isCached(
+	headers: Record<string, string | undefined>,
+	etag: string,
+	filePath: string,
+) {
+	// Always return stale when Cache-Control: no-cache
+	// to support end-to-end reload requests
+	// https://tools.ietf.org/html/rfc2616#section-14.9.4
+	if (
+		headers["cache-control"] &&
+		headers["cache-control"].indexOf("no-cache") !== -1
+	)
+		return false;
+
+	// if-none-match
+	if ("if-none-match" in headers) {
+		const ifNoneMatch = headers["if-none-match"];
+
+		if (ifNoneMatch === "*") return true;
+
+		if (ifNoneMatch === null) return false;
+
+		if (typeof etag !== "string") return false;
+
+		const isMatching = ifNoneMatch === etag;
+
+		if (isMatching) return true;
+
+		/**
+		 * A recipient MUST ignore If-Modified-Since if the request contains an
+		 * If-None-Match header field; the condition in If-None-Match is considered
+		 * to be a more accurate replacement for the condition in If-Modified-Since,
+		 * and the two are only combined for the sake of interoperating with older
+		 * intermediaries that might not implement If-None-Match.
+		 *
+		 * @see RFC 9110 section 13.1.3
+		 */
+		return false;
+	}
+
+	// if-modified-since
+	if (headers["if-modified-since"]) {
+		const ifModifiedSince = headers["if-modified-since"];
+		let lastModified: Date | undefined;
+		try {
+			lastModified = (await stat(filePath)).mtime;
+		} catch {
+			/* empty */
+		}
+
+		if (
+			lastModified !== undefined &&
+			lastModified.getTime() <= Date.parse(ifModifiedSince)
+		)
+			return true;
+	}
+
+	return false;
+}
+
+export async function generateETag(file: BunFile) {
+	const hash = new Bun.CryptoHasher("md5");
+	hash.update(await file.arrayBuffer());
+
+	return hash.digest("base64");
+}

api/src/elysia.ts

@@ -1,5 +1,6 @@
 import { Elysia } from "elysia";
 import { entriesH } from "./controllers/entries";
+import { imagesH } from "./controllers/images";
 import { seasonsH } from "./controllers/seasons";
 import { seed } from "./controllers/seed";
 import { collections } from "./controllers/shows/collections";
@@ -53,7 +54,8 @@ export const app = new Elysia()
 	.use(collections)
 	.use(entriesH)
 	.use(seasonsH)
-	.use(videosH)
 	.use(studiosH)
 	.use(staffH)
+	.use(videosH)
+	.use(imagesH)
 	.use(seed);

api/src/index.ts

@@ -60,6 +60,8 @@ app
 					{ name: "movies", description: "Routes about movies" },
 					{ name: "series", description: "Routes about series" },
 					{ name: "collections", description: "Routes about collections" },
+					{ name: "studios", description: "Routes about studios" },
+					{ name: "staff", description: "Routes about staff & roles" },
 					{
 						name: "videos",
 						description: comment`
@@ -67,8 +69,10 @@ app
 							Can be used for administration or third party apps.
 						`,
 					},
-					{ name: "studios", description: "Routes about studios" },
-					{ name: "staff", description: "Routes about staff & roles" },
+					{
+						name: "images",
+						description: "Routes about images: posters, thumbnails...",
+					},
 				],
 			},
 		}),