/**
 * THE REATTACH STREAM (background-turn runner wave, owner ruling
 * 2026-09-25): one SSE stream per chat, same wire dialect as the POST
 * /api/chat stream. A running turn → subscribe to the live turn object:
 * FULL replay of the event log, then live chunks until settle ([DONE]).
 * No running turn → the cheap terminal ({"type":"turn-settled"} + [DONE]):
 * the record is current, the client refetches it.
 *
 * 404 mirrors the POST handler's unknown-chat. Framework route is a thin
 * wrapper over the server barrel (the import law); tests drive the seams
 * (turn-runs + ui-stream) directly.
 */
import { getChat, runningTurn, piTurnResponse, settledTurnResponse } from "@/src/server";

export async function GET(_req: Request, ctx: { params: Promise<{ id: string }> }): Promise<Response> {
	const { id } = await ctx.params;
	if (!getChat(id)) return Response.json({ error: "Unknown chat" }, { status: 404 });
	const handle = runningTurn(id);
	if (!handle) return settledTurnResponse();
	return piTurnResponse(handle);
}