'use strict';

// This is a server to host data-local resources like databases and RSC

const path = require('path');

const url = require('url');

if (typeof fetch === 'undefined') {

  // Patch fetch for earlier Node versions.

  global.fetch = require('undici').fetch;

}

const express = require('express');

const bodyParser = require('body-parser');

const busboy = require('busboy');

const app = express();

const compress = require('compression');

const {Readable} = require('node:stream');

app.use(compress());

// Application

const {readFile} = require('fs').promises;

const React = require('react');

const moduleBasePath = new URL('../src', url.pathToFileURL(__filename)).href;

async function renderApp(res, returnValue) {

  const {renderToPipeableStream} = await import('react-server-dom-esm/server');

  const m = await import('../src/App.js');

  const App = m.default;

  const root = React.createElement(App);

  // For client-invoked server actions we refresh the tree and return a return value.

  const payload = returnValue ? {returnValue, root} : root;

  const {pipe} = renderToPipeableStream(payload, moduleBasePath);

  pipe(res);

}

app.get('/', async function (req, res) {

  await renderApp(res, null);

});

app.post('/', bodyParser.text(), async function (req, res) {

  const {

    renderToPipeableStream,

    decodeReply,

    decodeReplyFromBusboy,

    decodeAction,

  } = await import('react-server-dom-esm/server');

  const serverReference = req.get('rsc-action');

  if (serverReference) {

    // This is the client-side case

    const [filepath, name] = serverReference.split('#');

    const action = (await import(filepath))[name];

    // Validate that this is actually a function we intended to expose and

    // not the client trying to invoke arbitrary functions. In a real app,

    // you'd have a manifest verifying this before even importing it.

    if (action.$$typeof !== Symbol.for('react.server.reference')) {

      throw new Error('Invalid action');

    }

    let args;

    if (req.is('multipart/form-data')) {

      // Use busboy to streamingly parse the reply from form-data.

      const bb = busboy({headers: req.headers});

      const reply = decodeReplyFromBusboy(bb, moduleBasePath);

      req.pipe(bb);

      args = await reply;

    } else {

      args = await decodeReply(req.body, moduleBasePath);

    }

    const result = action.apply(null, args);

    try {

      // Wait for any mutations

      await result;

    } catch (x) {

      // We handle the error on the client

    }

    // Refresh the client and return the value

    renderApp(res, result);

  } else {

    // This is the progressive enhancement case

    const UndiciRequest = require('undici').Request;

    const fakeRequest = new UndiciRequest('http://localhost', {

      method: 'POST',

      headers: {'Content-Type': req.headers['content-type']},

      body: Readable.toWeb(req),

      duplex: 'half',

    });

    const formData = await fakeRequest.formData();

    const action = await decodeAction(formData, moduleBasePath);

    try {

      // Wait for any mutations

      await action();

    } catch (x) {

      const {setServerState} = await import('../src/ServerState.js');

      setServerState('Error: ' + x.message);

    }

    renderApp(res, null);

  }

});

app.get('/todos', function (req, res) {

  res.json([

    {

      id: 1,

      text: 'Shave yaks',

    },

    {

      id: 2,

      text: 'Eat kale',

    },

  ]);

});

app.listen(3001, () => {

  console.log('Regional Flight Server listening on port 3001...');

});

app.on('error', function (error) {

  if (error.syscall !== 'listen') {

    throw error;

  }

  switch (error.code) {

    case 'EACCES':

      console.error('port 3001 requires elevated privileges');

      process.exit(1);

      break;

    case 'EADDRINUSE':

      console.error('Port 3001 is already in use');

      process.exit(1);

      break;

    default:

      throw error;

  }

});