import express from 'express';
import type { Express } from 'express';
import fs from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

export function serveStatic(app: Express) {
  // In production CJS bundle, __dirname points to the compiled file
  // so we check both the bundle-relative path and cwd
  const bundleDistPath = path.resolve(__dirname, "..", "public");
  const cwdDistPath = path.resolve(process.cwd(), "dist", "public");
  const distPath = fs.existsSync(cwdDistPath) ? cwdDistPath : bundleDistPath;

  if (!fs.existsSync(distPath)) {
    throw new Error(
      `Could not find the build directory: ${distPath}, make sure to build the client first`,
    );
  }

  app.use(express.static(distPath));

  // fall through to index.html if the file doesn't exist
  app.use("/{*path}", (_req, res) => {
    res.sendFile(path.resolve(distPath, "index.html"));
  });
}