import React from 'react'
import Document, {
  Html,
  Head,
  Main,
  NextScript,
  DocumentContext,
} from 'next/document'
import { ServerStyleSheets } from '@material-ui/core/styles'
import theme from '@styles/theme'

export default class MyDocument extends Document {
  loadWindowProperty = locale => (
    <script
      dangerouslySetInnerHTML={{ __html: `window.__localeId__= "${locale}"` }}
    ></script>
  )

  render() {
    const { loadWindowProperty } = this
    const { locale } = this.props
    return (
      <Html lang={locale}>
        <Head>
          {/* PWA primary color */}
          <meta name="theme-color" content={theme.palette.primary.main} />
          <link
            rel="stylesheet"
            href="https://fonts.googleapis.com/css?family=Roboto:300,400,500,700&display=swap"
          />
        </Head>
        <body>
          {this.loadWindowProperty(locale)}
          <Main />
          <NextScript />
        </body>
      </Html>
    )
  }
}

// `getInitialProps` belongs to `_document` (instead of `_app`),
// it's compatible with server-side generation (SSG).
MyDocument.getInitialProps = async (ctx: DocumentContext) => {
  // Resolution order
  //
  // On the server:
  // 1. app.getInitialProps
  // 2. page.getInitialProps
  // 3. document.getInitialProps
  // 4. app.render
  // 5. page.render
  // 6. document.render
  //
  // On the server with error:
  // 1. document.getInitialProps
  // 2. app.render
  // 3. page.render
  // 4. document.render
  //
  // On the client
  // 1. app.getInitialProps
  // 2. page.getInitialProps
  // 3. app.render
  // 4. page.render

  // Render app and page and get the context of the page with collected side effects.
  const sheets = new ServerStyleSheets()
  const originalRenderPage = ctx.renderPage

  ctx.renderPage = () =>
    originalRenderPage({
      enhanceApp: App => props => sheets.collect(<App {...props} />),
    })

  const initialProps = await Document.getInitialProps(ctx)

  return {
    ...initialProps,
    // Styles fragment is rendered after the app and page rendering finish.
    styles: [
      ...React.Children.toArray(initialProps.styles),
      sheets.getStyleElement(),
    ],
  }
}
