add receipts support

src/lib/object-storage.ts

@@ -0,0 +1,117 @@
+import "server-only";
+import { mkdir, readFile, unlink, writeFile } from "fs/promises";
+import path from "path";
+
+// Local dev fallback when S3_* env vars are unset. Files land in .data/receipts/.
+const LOCAL_RECEIPTS_DIR = path.join(process.cwd(), ".data", "receipts");
+
+function isS3Configured(): boolean {
+  return Boolean(
+    process.env.S3_BUCKET &&
+      process.env.S3_ACCESS_KEY &&
+      process.env.S3_SECRET_KEY,
+  );
+}
+
+export function getStorageBackend(): "s3" | "local" {
+  return isS3Configured() ? "s3" : "local";
+}
+
+type S3Module = typeof import("@aws-sdk/client-s3");
+
+let s3ModulePromise: Promise<S3Module> | null = null;
+let s3Client: InstanceType<S3Module["S3Client"]> | null = null;
+
+async function getS3() {
+  if (!s3ModulePromise) {
+    s3ModulePromise = import("@aws-sdk/client-s3");
+  }
+  const mod = await s3ModulePromise;
+  if (!s3Client) {
+    s3Client = new mod.S3Client({
+      region: process.env.S3_REGION ?? "us-east-1",
+      endpoint: process.env.S3_ENDPOINT,
+      credentials: {
+        accessKeyId: process.env.S3_ACCESS_KEY!,
+        secretAccessKey: process.env.S3_SECRET_KEY!,
+      },
+      // Required for MinIO and most S3-compatible endpoints.
+      forcePathStyle: Boolean(process.env.S3_ENDPOINT),
+    });
+  }
+  return { client: s3Client, ...mod };
+}
+
+function localPathForKey(key: string) {
+  return path.join(LOCAL_RECEIPTS_DIR, key);
+}
+
+export async function putObject(
+  key: string,
+  body: Buffer,
+  contentType: string,
+): Promise<void> {
+  if (isS3Configured()) {
+    const { client, PutObjectCommand } = await getS3();
+    await client.send(
+      new PutObjectCommand({
+        Bucket: process.env.S3_BUCKET!,
+        Key: key,
+        Body: body,
+        ContentType: contentType,
+      }),
+    );
+    return;
+  }
+
+  const filePath = localPathForKey(key);
+  await mkdir(path.dirname(filePath), { recursive: true });
+  await writeFile(filePath, body);
+}
+
+export async function getObject(key: string): Promise<Buffer> {
+  if (isS3Configured()) {
+    const { client, GetObjectCommand } = await getS3();
+    const response = await client.send(
+      new GetObjectCommand({
+        Bucket: process.env.S3_BUCKET!,
+        Key: key,
+      }),
+    );
+    const bytes = await response.Body?.transformToByteArray();
+    if (!bytes) {
+      throw new Error("Empty object body");
+    }
+    return Buffer.from(bytes);
+  }
+
+  return readFile(localPathForKey(key));
+}
+
+export async function deleteObject(key: string): Promise<void> {
+  if (isS3Configured()) {
+    const { client, DeleteObjectCommand } = await getS3();
+    await client.send(
+      new DeleteObjectCommand({
+        Bucket: process.env.S3_BUCKET!,
+        Key: key,
+      }),
+    );
+    return;
+  }
+
+  try {
+    await unlink(localPathForKey(key));
+  } catch (error) {
+    if ((error as NodeJS.ErrnoException).code !== "ENOENT") {
+      throw error;
+    }
+  }
+}
+
+export const RECEIPT_MAX_BYTES = 10 * 1024 * 1024;
+
+export function isAllowedReceiptMime(mimeType: string): boolean {
+  const normalized = mimeType.toLowerCase().split(";")[0]?.trim() ?? "";
+  return normalized === "application/pdf" || normalized.startsWith("image/");
+}