feat: initial impl of file proxy

packages/convex/model/filepreview.ts

@@ -0,0 +1,36 @@
+import type { Doc, Id } from "../_generated/dataModel"
+import type {
+	AuthenticatedMutationCtx,
+	AuthenticatedQueryCtx,
+} from "../functions"
+import * as FileShare from "./fileshare"
+
+const PREVIEW_FILE_SHARE_VALID_FOR_MS = 1000 * 60 * 10 // 10 minutes
+
+export async function find(
+	ctx: AuthenticatedMutationCtx | AuthenticatedQueryCtx,
+	{ storageId }: { storageId: Id<"_storage"> },
+) {
+	return await FileShare.findByStorageId(ctx, { storageId })
+}
+
+export async function create(
+	ctx: AuthenticatedMutationCtx,
+	{ storageId }: { storageId: Id<"_storage"> },
+) {
+	return await FileShare.create(ctx, {
+		shareToken: crypto.randomUUID(),
+		storageId,
+		expiresAt: new Date(Date.now() + PREVIEW_FILE_SHARE_VALID_FOR_MS),
+	})
+}
+
+export async function extend(
+	ctx: AuthenticatedMutationCtx,
+	{ doc }: { doc: Doc<"fileShares"> },
+) {
+	return await FileShare.updateExpiry(ctx, {
+		doc,
+		expiresAt: new Date(Date.now() + PREVIEW_FILE_SHARE_VALID_FOR_MS),
+	})
+}