packages/@sanity/server/src/baseServer.js

import path from 'path'
import express from 'express'
import React from 'react'
import ReactDOM from 'react-dom/server'
import requireUncached from 'require-uncached'
import {resolveParts} from '@sanity/resolver'
import getStaticBasePath from './util/getStaticBasePath'

const docPart = 'part:@sanity/base/document'
const initPart = 'part:@sanity/server/initializer'

const getDefaultModule = mod => {
  return mod && mod.__esModule ? mod.default : mod
}

const getTitle = (project = {}) => {
  const projectName = (project && project.name) || ''
  return projectName ? `${projectName} – Sanity` : 'Sanity'
}

const assetify = (assetPath, hashes) => ({
  path: assetPath,
  hash: hashes[assetPath]
})

const getDocumentComponent = basePath =>
  resolveParts({basePath}).then(res => {
    const part = res.implementations[docPart]
    if (!part) {
      throw new Error(
        `Part '${docPart}' is not implemented by any plugins, are you missing @sanity/base?`
      )
    }

    return getDefaultModule(requireUncached(part[0].path))
  })

export function getBaseServer() {
  return express()
}

export function getDocumentElement({project, basePath, hashes}, props = {}) {
  const assetHashes = hashes || {}

  // Project filesystem base path
  return getDocumentComponent(basePath).then(Document =>
    React.createElement(
      Document,
      Object.assign(
        {
          // URL base path
          basePath: process.env.STUDIO_BASEPATH || (project && project.basePath) || '',
          title: getTitle(project),
          stylesheets: ['css/main.css'].map(item => assetify(item, assetHashes)),
          scripts: ['js/vendor.bundle.js', 'js/app.bundle.js'].map(item =>
            assetify(item, assetHashes)
          )
        },
        props
      )
    )
  )
}

export function applyStaticRoutes(app, config = {}) {
  const staticPath = config.staticPath || path.join(__dirname, '..', 'public')
  const staticBasePath = getStaticBasePath(config)

  app.use(staticBasePath, express.static(staticPath))

  app.get('*', (req, res) => {
    if (req.url.startsWith(staticBasePath)) {
      return res.status(404).send('File not found')
    }

    return getDocumentElement(config)
      .then(doc => res.send(`<!doctype html>${ReactDOM.renderToStaticMarkup(doc)}`))
      .catch(err => {
        console.error(err.stack) // eslint-disable-line no-console

        res
          .set('Content-Type', 'text/plain')
          .status(500)
          .send(err.stack)
      })
  })

  return app
}

export function callInitializers(config) {
  resolveParts({config}).then(res => {
    const parts = res.implementations[initPart]
    if (!parts) {
      return
    }

    res.implementations[initPart]
      .map(part => getDefaultModule(require(part.path)))
      .forEach(initializer => initializer(config))
  })
}