import type { RepoCollection, RepoEvent } from './type'

export const selectRepoFromCollection = (
  collection: RepoCollection
): RepoEvent | undefined => {
  if (collection.selected_event_id && collection.selected_event_id.length > 0)
    return collection.events.find(
      (e) => e.event_id === collection.selected_event_id
    )

  return [...collection.events].sort((a, b) => {
    const a_ref = a.referenced_by ? a.referenced_by.length : 0
    const b_ref = b.referenced_by ? b.referenced_by.length : 0
    if (a_ref === b_ref) return b.created_at - a.created_at
    return b_ref - a_ref
  })[0]
}

/** most servers will produce a CORS error so a proxy should be used */
export const cloneArrayToReadMeUrls = (clone: string[]): string[] => {
  const addresses = clone.map(extractRepoAddress)
  /**
   * at the time of this commit these urls work for:
   * self-hosted gitea (or forgejo), gitlab
   * github.com
   * bitbucket.org
   * gitlab.org
   * gitea.com
   * codeberg.org (forgejo instance)
   * sourcehut (git.sr.ht)
   * launchpad.net
   * It doesnt work for:
   * self-hosted gogs (requires branch name repo/raw/master/README.md)
   * sourceforge.net (https://sourceforge.net/p/mingw/catgets/ci/master/tree/README?format=raw)
   * notabug.org (requires branch name notabug.org/org/repo/raw/master/README.md)
   */
  return [
    ...addresses.flatMap((address) => {
      let prefix = 'raw/HEAD'
      if (address.includes('sr.ht')) prefix = 'blob/HEAD'
      if (
        address.includes('git.launchpad.net') ||
        address.includes('git.savannah.gnu.org')
      )
        prefix = 'plain'
      if (address.includes('github.com')) {
        // raw.githubusercontent.com can be used without CORS error
        address = address.replace('github.com', 'raw.githubusercontent.com')
        prefix = 'HEAD'
      }
      return ['README.md', 'readme.md'].map(
        (filename) => `https://${address}/${prefix}/${filename}`
      )
    }),
  ]
}

const extractRepoAddress = (clone_string: string): string => {
  let s = clone_string
  // remove trailing slash
  if (s.endsWith('/')) s = s.substring(0, s.length - 1)
  // remove trailing .git
  if (s.endsWith('.git')) s = s.substring(0, s.length - 4)
  // remove :// and anything before
  if (s.includes('://')) s = s.split('://')[1]
  // remove @ and anything before
  if (s.includes('@')) s = s.split('@')[1]
  // replace : with /
  s = s.replace(/\s|:[0-9]+/g, '')
  s = s.replace(':', '/')
  return s
}