import { ContentHandler } from '../content-handler'

export class GitHubHandler extends ContentHandler {
  constructor() {
    super()
    this.name = 'github'
  }

  shouldPreParse(url: string, dom: Document): boolean {
    return new URL(url).hostname.endsWith('github.com')
  }

  async preParse(url: string, dom: Document): Promise<Document> {
    const body = dom.querySelector('body')
    const article = dom.querySelector('article')
    const twitterTitle = dom.querySelector(`meta[name='twitter:title']`)
    const linkAuthor = dom.querySelector(`span[itemprop='author']`)

    if (body && article) {
      body.replaceChildren(article)

      // Attempt to set the author also. This is available on repo homepages
      // but not on things like PRs. Ideally we want PRs and issues to have
      // author set to the author of the PR/issue.
      if (linkAuthor && linkAuthor.textContent) {
        const author = dom.createElement('span')
        author.setAttribute('rel', 'author')
        author.innerHTML = linkAuthor.textContent
        article.appendChild(author)
      }
    }

    // Remove the GitHub - and repo org from the title
    const twitterTitleContent = twitterTitle?.getAttribute('content')
    if (twitterTitle && twitterTitleContent) {
      twitterTitle.setAttribute(
        'content',
        twitterTitleContent.replace(/GitHub - (.*?)\//, ''),
      )
    }

    return Promise.resolve(dom)
  }
}