feat: impl file rename

packages/convex/model/files.ts

@@ -0,0 +1,36 @@
+import type { Id } from "../_generated/dataModel"
+import type { AuthenticatedMutationCtx } from "../functions"
+import * as Err from "./error"
+
+export async function renameFile(
+	ctx: AuthenticatedMutationCtx,
+	{
+		directoryId,
+		itemId,
+		newName,
+	}: {
+		directoryId?: Id<"directories">
+		itemId: Id<"files">
+		newName: string
+	},
+) {
+	const existing = await ctx.db
+		.query("files")
+		.withIndex("uniqueFileInDirectory", (q) =>
+			q
+				.eq("userId", ctx.user._id)
+				.eq("directoryId", directoryId)
+				.eq("name", newName)
+				.eq("deletedAt", undefined),
+		)
+		.first()
+
+	if (existing) {
+		throw Err.create(
+			Err.Code.FileExists,
+			`File with name ${newName} already exists in ${directoryId ? `directory ${directoryId}` : "root"}`,
+		)
+	}
+
+	await ctx.db.patch(itemId, { name: newName })
+}