const debug = require('debug')('nuxt:render')
const co = require('co')
const { urlJoin } = require('./utils')
const { getContext } = require('./utils')

exports.render = function (req, res) {
  if (!this.renderer) {
    setTimeout(() => {
      this.render(req, res)
    }, 1000)
    return
  }
  const self = this
  const context = getContext(req, res)
  co(function * () {
    if (self.dev) {
      // Call webpack middlewares only in development
      yield self.webpackDevMiddleware(req, res)
      yield self.webpackHotMiddleware(req, res)
    }
    // If base in req.url, remove it for the middlewares and vue-router
    if (self.options.router.base !== '/' && req.url.indexOf(self.options.router.base) === 0) {
      // Compatibility with base url for dev server
      req.url = req.url.replace(self.options.router.base, '/')
    }
    // Serve static/ files
    yield self.serveStatic(req, res)
    // Serve .nuxt/dist/ files (only for production)
    if (!self.dev && self._nuxtRegexp.test(req.url)) {
      const url = req.url
      req.url = req.url.replace(self._nuxtRegexp, '/')
      yield self.serveStaticNuxt(req, res)
      req.url = url
    }
  })
  .then(() => {
    if (this.dev && this._nuxtRegexp.test(req.url) && req.url.includes('.hot-update.json')) {
      res.statusCode = 404
      return res.end()
    }
    return this.renderRoute(req.url, context)
  })
  .then(({ html, error }) => {
    if (error) {
      res.statusCode = context.nuxt.error.statusCode || 500
    }
    res.setHeader('Content-Type', 'text/html; charset=utf-8')
    res.setHeader('Content-Length', Buffer.byteLength(html))
    res.end(html, 'utf8')
  })
  .catch((err) => {
    res.statusCode = 500
    res.end(this.errorTemplate({ err }), 'utf8')
  })
}

exports.renderRoute = function (url, context = {}) {
  debug(`Rendering url ${url}`)
  // Add url and isSever to the context
  context.url = url
  context.isServer = true
  // Call rendertoSting from the bundleRenderer and generate the HTML (will update the context as well)
  const self = this
  return co(function * () {
    let app = yield self.renderToString(context)
    if (context.nuxt && context.nuxt.error instanceof Error) {
      context.nuxt.error = { statusCode: 500, message: context.nuxt.error.message }
    }
    if (context.redirected) {
      app = '<div id="__nuxt"></div>'
    }
    const html = self.appTemplate({
      dev: self.dev, // Use to add the extracted CSS <link> in production
      baseUrl: self.options.router.base,
      APP: app,
      context: context,
      files: {
        css: urlJoin(self.options.router.base, '/_nuxt/', self.options.build.filenames.css),
        vendor: urlJoin(self.options.router.base, '/_nuxt/', self.options.build.filenames.vendor),
        app: urlJoin(self.options.router.base, '/_nuxt/', self.options.build.filenames.app)
      }
    })
    return {
      html,
      error: context.nuxt.error,
      redirected: context.redirected
    }
  })
}