import { Elysia } from "elysia";
import { resolveProfile } from "../lib/profile.ts";

// /@<did>(/rest)? → 301 to the canonical /@<handle> URL; renders in place if the handle won't resolve.
const DID_HANDLE_RE = /^\/@(did:[^/]+)(\/.*)?$/;

export const canonicalHandlePlugin = new Elysia({
	name: "canonical-handle",
}).onRequest(async ({ request }) => {
	const url = new URL(request.url);
	const match = url.pathname.match(DID_HANDLE_RE);
	if (!match) return;

	const did = match[1] as string;
	const rest = match[2] ?? "";

	const profile = await resolveProfile(did);
	// Skip if the handle is missing or still a DID — would 301 to the same URL.
	if (!profile.handle || profile.handle.startsWith("did:")) return;

	const canonical = `/@${profile.handle}${rest}${url.search}`;
	return new Response(null, {
		status: 301,
		headers: { Location: canonical },
	});
});