text: import * as React from "react"
  import PropTypes from "prop-types"
  import { Helmet } from "react-helmet"
  import { useStaticQuery, graphql } from "gatsby"
  import { isProduction } from "../constants";
  
  const SEO = ({ description, lang, meta, title }) => {
    const { site } = useStaticQuery(
      graphql`
        query {
          site {
            siteMetadata {
              title
              description
              social {
                twitter
              }
            }
          }
        }
      `
    )
  
    const metaDescription = description || site.siteMetadata.description
    const defaultTitle = site.siteMetadata?.title
  
    return (
      <Helmet
        htmlAttributes={{
          lang,
        }}
        title={title}
        titleTemplate={defaultTitle ? `%s | ${defaultTitle}` : null}
        meta={[
          {
            name: `description`,
            content: metaDescription,
          },
          {
            property: `og:title`,
            content: title,
          },
          {
            property: `og:description`,
            content: metaDescription,
          },
          {
            property: `og:type`,
            content: `website`,
          },
          {
            name: `twitter:card`,
            content: `summary`,
          },
          {
            name: `twitter:creator`,
            content: site.siteMetadata?.social?.twitter || ``,
          },
          {
            name: `twitter:title`,
            content: title,
          },
          {
            name: `twitter:description`,
            content: metaDescription,
          },
        ].concat(meta)}
      >
        {isProduction && (
          <script
            data-ad-client="ca-pub-5695240543467288"
            async
            src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"
          ></script>
        )}
      </Helmet>
    )
  }
  
  SEO.defaultProps = {
    lang: `en`,
    meta: [],
    description: ``,
  }
  
  SEO.propTypes = {
    description: PropTypes.string,
    lang: PropTypes.string,
    meta: PropTypes.arrayOf(PropTypes.object),
    title: PropTypes.string.isRequired,
  }
  
  export default SEO
  