import path from "path";
import express from "express";
import compression from "compression";
import morgan from "morgan";
import { createRequestHandler } from "@remix-run/express";
import { WebSocketServer } from "ws";
import { broadcastDevReady, logDevReady } from "@remix-run/server-runtime";
import type { Server as IoServer } from "socket.io";
import type { Server as EngineServer } from "engine.io";
import { RegistryProxy } from "~/v3/registryProxy.server";
import { RateLimitMiddleware, apiRateLimiter } from "~/services/apiRateLimit.server";
import { type RunWithHttpContextFunction } from "~/services/httpAsyncStorage.server";
import { nanoid } from "nanoid";

const app = express();

if (process.env.DISABLE_COMPRESSION !== "1") {
  app.use(compression());
}

// http://expressjs.com/en/advanced/best-practice-security.html#at-a-minimum-disable-x-powered-by-header
app.disable("x-powered-by");

// Remix fingerprints its assets so we can cache forever.
app.use("/build", express.static("public/build", { immutable: true, maxAge: "1y" }));

// Everything else (like favicon.ico) is cached for an hour. You may want to be
// more aggressive with this caching.
app.use(express.static("public", { maxAge: "1h" }));

app.use(morgan("tiny"));

process.title = "node webapp-server";

const MODE = process.env.NODE_ENV;
const BUILD_DIR = path.join(process.cwd(), "build");
const build = require(BUILD_DIR);

const port = process.env.REMIX_APP_PORT || process.env.PORT || 3000;

if (process.env.HTTP_SERVER_DISABLED !== "true") {
  const socketIo: { io: IoServer } | undefined = build.entry.module.socketIo;
  const wss: WebSocketServer | undefined = build.entry.module.wss;
  const registryProxy: RegistryProxy | undefined = build.entry.module.registryProxy;
  const apiRateLimiter: RateLimitMiddleware = build.entry.module.apiRateLimiter;
  const runWithHttpContext: RunWithHttpContextFunction = build.entry.module.runWithHttpContext;

  if (registryProxy && process.env.ENABLE_REGISTRY_PROXY === "true") {
    console.log(`🐳 Enabling container registry proxy to ${registryProxy.origin}`);

    // Adjusted to match /v2 and any subpath under /v2
    app.all("/v2/*", async (req, res) => {
      await registryProxy.call(req, res);
    });

    // This might also be necessary if you need to explicitly match /v2 as well
    app.all("/v2", async (req, res) => {
      await registryProxy.call(req, res);
    });
  }

  app.use((req, res, next) => {
    // helpful headers:
    res.set("Strict-Transport-Security", `max-age=${60 * 60 * 24 * 365 * 100}`);

    // /clean-urls/ -> /clean-urls
    if (req.path.endsWith("/") && req.path.length > 1) {
      const query = req.url.slice(req.path.length);
      const safepath = req.path.slice(0, -1).replace(/\/+/g, "/");
      res.redirect(301, safepath + query);
      return;
    }
    next();
  });

  app.use((req, res, next) => {
    // Generate a unique request ID for each request
    const requestId = nanoid();

    runWithHttpContext({ requestId, path: req.url, host: req.hostname }, next);
  });

  if (process.env.DASHBOARD_AND_API_DISABLED !== "true") {
    app.use(apiRateLimiter);

    app.all(
      "*",
      // @ts-ignore
      createRequestHandler({
        build,
        mode: MODE,
      })
    );
  } else {
    // we need to do the health check here at /healthcheck
    app.get("/healthcheck", (req, res) => {
      res.status(200).send("OK");
    });
  }

  const server = app.listen(port, () => {
    console.log(`✅ server ready: http://localhost:${port} [NODE_ENV: ${MODE}]`);

    if (MODE === "development") {
      broadcastDevReady(build)
        .then(() => logDevReady(build))
        .catch(console.error);
    }
  });

  server.keepAliveTimeout = 65 * 1000;

  process.on("SIGTERM", () => {
    server.close((err) => {
      if (err) {
        console.error("Error closing express server:", err);
      } else {
        console.log("Express server closed gracefully.");
      }
    });
  });

  socketIo?.io.attach(server);
  server.removeAllListeners("upgrade"); // prevent duplicate upgrades from listeners created by io.attach()

  server.on("upgrade", async (req, socket, head) => {
    console.log(
      `Attemping to upgrade connection at url ${req.url} with headers: ${JSON.stringify(
        req.headers
      )}`
    );

    socket.on("error", (err) => {
      console.error("Connection upgrade error:", err);
    });

    const url = new URL(req.url ?? "", "http://localhost");

    // Upgrade socket.io connection
    if (url.pathname.startsWith("/socket.io/")) {
      console.log(`Socket.io client connected, upgrading their connection...`);

      // https://github.com/socketio/socket.io/issues/4693
      (socketIo?.io.engine as EngineServer).handleUpgrade(req, socket, head);
      return;
    }

    // Only upgrade the connecting if the path is `/ws`
    if (url.pathname !== "/ws") {
      // Setting the socket.destroy() error param causes an error event to be emitted which needs to be handled with socket.on("error") to prevent uncaught exceptions.
      socket.destroy(
        new Error(
          "Cannot connect because of invalid path: Please include `/ws` in the path of your upgrade request."
        )
      );
      return;
    }

    console.log(`Client connected, upgrading their connection...`);

    // Handle the WebSocket connection
    wss?.handleUpgrade(req, socket, head, (ws) => {
      wss?.emit("connection", ws, req);
    });
  });
} else {
  require(BUILD_DIR);
  console.log(`✅ app ready (skipping http server)`);
}
