import { Elysia, t } from "elysia";

export const MCPRoute = new Elysia({
  prefix: "/mcp-server", // ✅ Sesuaikan dengan endpoint n8n
  tags: ["mcp-server"],
})
  .post("/mcp", ({ body, set }) => {
    const { id, method, params } = body as any;

    set.headers["Content-Type"] = "application/json";
    set.headers["Transfer-Encoding"] = "chunked";
    set.headers["Connection"] = "keep-alive";

    const stream = new ReadableStream({
      async start(controller) {
        // tools.list → kirim daftar tools
        if (method === "tools/list") {
          controller.enqueue(
            JSON.stringify({
              jsonrpc: "2.0",
              id,
              result: [
                {
                  name: "sayHello",
                  description: "Greets user",
                  inputSchema: {
                    type: "object",
                    properties: { name: { type: "string" } },
                  },
                },
              ],
            }) + "\n"
          );
          controller.close();
        }

        // tools.sayHello → streaming bertahap
        else if (method === "tools/sayHello") {
          controller.enqueue(
            JSON.stringify({
              jsonrpc: "2.0",
              id,
              result: { message: "Processing..." },
            }) + "\n"
          );
          await Bun.sleep(500);
          controller.enqueue(
            JSON.stringify({
              jsonrpc: "2.0",
              id,
              result: { message: `Hello ${params?.name || ""}` },
            }) + "\n"
          );
          controller.close();
        }

        // Method tidak ditemukan
        else {
          controller.enqueue(
            JSON.stringify({
              jsonrpc: "2.0",
              id,
              error: { code: -32601, message: `Method ${method} not found` },
            }) + "\n"
          );
          controller.close();
        }
      },
    });

    return new Response(stream);
  }, {
    body: t.Object({
      jsonrpc: t.Optional(t.String()),
      method: t.String(),
      params: t.Optional(t.Record(t.String(), t.Any())),
      id: t.Optional(t.Union([t.String(), t.Number()])),
    }),
  });

export default MCPRoute;