routes.js

import { resolve, relative, extname, basename, dirname } from 'path'
import { readdir } from 'fs/promises'
import os from "os";
import { pathToFileURL } from "url";
import recordError from './api/record-error.js'

/**
* Lists all files in {dir}
* @function
* @param {string} dir - The root directory name
* @returns {Promise<string[]>}
*/
async function getFiles(dir) {
  const dirents = await readdir(dir, { withFileTypes: true })
  const files = await Promise.all(dirents.map((dirent) => {
    const res = resolve(dir, dirent.name)
    return dirent.isDirectory() ? getFiles(res) : res
  }))
  return Array.prototype.concat(...files)
}

/**
* Creates an API endpoint for files in the /api directory
* @function
* @param {Object} app - An express app instance
* @returns {Promise<void>}
*/
export default async (app) => {
  const startTS = Date.now()
  const files = await getFiles('./api/endpoints')
  const filesToLoad = files.map(async file => {
    try {
      const ext = extname(file)
      if (!['.js', '.mjs'].includes(ext)) {
        // skip loading non-js files
        return
      }

      const moduleURL = new URL(import.meta.url);
      const __dirname = decodeURIComponent(dirname(moduleURL.pathname));

      // if it's an index.js file, use the parent directory's name
      // ex. '/api/slack/index.js' is hosted at '/api/slack' (no index)
      let routePath = relative(__dirname, dirname(file))
      // if it's NOT an index.js file, include the basename
      // ex. '/api/zoom/new.js' is hosted at '/api/zoom/new'
      if (basename(file, extname(file)) != 'index') {
        routePath = `${routePath}/${basename(file, extname(file))}`
      }

      routePath = os.platform() === "win32" ? routePath.split("\\").slice(7).join("/") : routePath;
      
      const fileUri = os.platform() === "win32" ? pathToFileURL(file) : file;
      const route = (await import(fileUri)).default // just to test we can load the file

      app.all('/' + routePath, async (req, res) => {
        try {
            await route(req, res)
        } catch (err) {
          console.error(err)
          recordError(err)
        }
      })

    } catch (err) {
      console.error(err)
      console.log('Failed to load file:', file)
    }
  })
  await Promise.all(filesToLoad)
  console.log(`Finished loading in ${Date.now() - startTS}ms`)
}