import express, { Request, Response } from "express"
import { McpServer, ResourceTemplate } from "@modelcontextprotocol/sdk/server/mcp.js"
import { SSEServerTransport } from "@modelcontextprotocol/sdk/server/sse.js"
import { mcpAuthRouter } from '@modelcontextprotocol/sdk/server/auth/router.js'
import { ProxyOAuthServerProvider } from '@modelcontextprotocol/sdk/server/auth/providers/proxyProvider.js'
import { requireBearerAuth } from "@modelcontextprotocol/sdk/server/auth/middleware/bearerAuth.js"

const BASE_URL = "http://localhost:3001"
const ISSUER = "https://your-tenant.auth0.com/"

const server = new McpServer({
  name: "mcp-server",
  version: "1.0.0",
})

server.resource(
  "greeting",
  new ResourceTemplate("greeting://{name}", { list: undefined }),
  async (uri, { name }) => ({
    contents: [{
      uri: uri.href,
      text: `Hello, ${name}!`
    }]
  })
);

const app = express();

const proxyProvider = new ProxyOAuthServerProvider({
  endpoints: {
    authorizationUrl: new URL("/authorize", ISSUER).toString(),
    tokenUrl: new URL("/oauth/token", ISSUER).toString(),
    registrationUrl: new URL("/oidc/register", ISSUER).toString(),
  },
  verifyAccessToken: async (token) => {
    console.log(token)  // for test
    return {
      token,
      clientId: "dummy",
      scopes: [],
    }
  },
  getClient: async (client_id) => {
    return {
      client_id,
      redirect_uris: ["http://127.0.0.1:6274/oauth/callback"],
    }
  }
})

app.use(mcpAuthRouter({
  provider: proxyProvider,
  issuerUrl: new URL(ISSUER),
  baseUrl: new URL(BASE_URL),
}))


const transports: { [sessionId: string]: SSEServerTransport } = {};

app.get("/sse", requireBearerAuth({provider: proxyProvider}), async (_: Request, res: Response) => {
  const transport = new SSEServerTransport('/messages', res);
  transports[transport.sessionId] = transport;
  res.on("close", () => {
    delete transports[transport.sessionId];
  });
  await server.connect(transport);
});

app.post("/messages", requireBearerAuth({provider: proxyProvider}), async (req: Request, res: Response) => {
  const sessionId = req.query.sessionId as string;
  const transport = transports[sessionId];
  if (transport) {
    await transport.handlePostMessage(req, res);
  } else {
    res.status(400).send('No transport found for sessionId');
  }
});

app.listen(3001)