import { Router } from "express";
import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
import { registerTools } from "./tools.js";

export const mcpRouter = Router();

mcpRouter.post("/mcp", async (req, res) => {
  try {
    const server = new McpServer({
      name: "awesome-index",
      version: "0.1.0",
    });
    registerTools(server);

    const transport = new StreamableHTTPServerTransport({
      sessionIdGenerator: undefined,
      enableJsonResponse: true,
    });

    res.on("close", async () => {
      await transport.close();
      await server.close();
    });

    await server.connect(transport);
    await transport.handleRequest(req, res, req.body);
  } catch (err) {
    console.error("[mcp] request failed:", err.message);
    if (!res.headersSent) {
      res.status(500).json({ jsonrpc: "2.0", error: { code: -32603, message: "Internal error" }, id: null });
    }
  }
});

mcpRouter.get("/mcp", (_req, res) => {
  res.status(405).json({ jsonrpc: "2.0", error: { code: -32000, message: "GET not supported (stateless mode)" }, id: null });
});

mcpRouter.delete("/mcp", (_req, res) => {
  res.status(405).json({ jsonrpc: "2.0", error: { code: -32000, message: "DELETE not supported (stateless mode)" }, id: null });
});