cloudflare r2 for images

src/lib/server/storage/r2.ts

@@ -0,0 +1,70 @@
+import { env } from '$env/dynamic/private';
+import { S3Client } from 'bun';
+
+function isConfigured(): boolean {
+	return !!(env.R2_ACCESS_KEY_ID && env.R2_SECRET_ACCESS_KEY && env.R2_ACCOUNT_ID && env.R2_BUCKET && env.R2_PUBLIC_URL);
+}
+
+let client: S3Client | null = null;
+
+function getClient(): S3Client {
+	if (!client) {
+		client = new S3Client({
+			accessKeyId: env.R2_ACCESS_KEY_ID,
+			secretAccessKey: env.R2_SECRET_ACCESS_KEY,
+			bucket: env.R2_BUCKET,
+			endpoint: `https://${env.R2_ACCOUNT_ID}.r2.cloudflarestorage.com`
+		});
+	}
+	return client;
+}
+
+function urlToKey(url: string): string {
+	const u = new URL(url);
+	if (u.hostname === 'assets.ppy.sh') {
+		// e.g. /beatmaps/3591031/covers/card@2x.jpg → beatmaps/3591031/covers/card@2x.jpg
+		return u.pathname.replace(/^\//, '');
+	}
+	if (u.hostname === 'a.ppy.sh') {
+		// e.g. /12345 → avatars/12345
+		return `avatars${u.pathname}`;
+	}
+	// Generic fallback: stable key from URL path
+	return `misc${u.pathname}`;
+}
+
+// In-memory set of keys confirmed to exist in R2 (reset on server restart — that's fine)
+const knownKeys = new Set<string>();
+
+/**
+ * Returns a CDN URL for the given osu! image URL, uploading to R2 on first access.
+ * Falls back to the original URL if R2 is not configured or the upload fails.
+ */
+export async function proxyImage(osuUrl: string): Promise<string> {
+	if (!isConfigured()) return osuUrl;
+
+	const key = urlToKey(osuUrl);
+	const cdnUrl = `${env.R2_PUBLIC_URL}/${key}`;
+
+	if (knownKeys.has(key)) return cdnUrl;
+
+	try {
+		const r2 = getClient();
+		const file = r2.file(key);
+
+		const exists = await file.exists();
+		if (!exists) {
+			const res = await fetch(osuUrl);
+			if (!res.ok) throw new Error(`fetch ${osuUrl} → ${res.status}`);
+			const contentType = res.headers.get('content-type') ?? 'image/jpeg';
+			await file.write(res, { type: contentType });
+			console.log(`[R2] uploaded ${key}`);
+		}
+
+		knownKeys.add(key);
+		return cdnUrl;
+	} catch (err: unknown) {
+		console.error('[R2] proxyImage failed for', key, '—', err instanceof Error ? err.message : err);
+		return osuUrl;
+	}
+}