import * as cheerio from 'cheerio'

import { USER_AGENTS } from './consts'
import type { AlbumRow } from './types'

function getRandom(list: any[]) {
  return list[Math.floor(Math.random() * list.length)]
}

export function politeFetch(url: string, lastReqRef: React.RefObject<number>) {
  const elapsed = Date.now() - lastReqRef.current
  const corsUrl = `https://cors.chitowarlock.com/${url}`

  const headers = {
    'User-Agent': getRandom(USER_AGENTS),
    Referer: 'https://downloads.khinsider.com/',
    'Accept-Language': 'en-US,en;q=0.5',
    Accept: 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*//**;q=0.8',
    'Accept-Encoding': 'gzip, deflate, br'
  }

  return fetch(corsUrl, { headers, signal: AbortSignal.timeout(10 * 1000) }).finally(() => {
    lastReqRef.current = Date.now()
  })
}

export async function searchAlbums(query: string, lastReqRef: React.RefObject<number>) {
  const searchUrl = `https://downloads.khinsider.com/search?search=${query}`
  const searchHtml = await (await politeFetch(searchUrl, lastReqRef)).text()

  const $ = cheerio.load(searchHtml)
  const albumRows = $('table.albumList tr:not(:first-child)')

  const albums: AlbumRow[] = []

  albumRows.each((index, row) => {
    const albumLink = $(row).find('td:nth-of-type(2) a')
    if (albumLink.length === 0) return

    const albumName = albumLink.text().trim()
    const albumUrl = `https://downloads.khinsider.com${albumLink.attr('href')}`

    albums.push({ name: albumName, url: albumUrl })
  })

  const seen = new Set()
  const uniqueAlbums = albums.filter((album) => {
    if (seen.has(album.url)) return false
    seen.add(album.url)
    return true
  })

  return uniqueAlbums
}

export async function getTracks(url: string, lastReqRef: React.RefObject<number>) {
  const albumHtml = await (await politeFetch(url, lastReqRef)).text()
  const $ = cheerio.load(albumHtml)
  const tracks: { name: string; url: string; format: string }[] = []

  $('table#songlist tr:has(a[href$=".mp3"]), table#songlist tr:has(a[href$=".flac"])').each((index, row) => {
    const link = $(row).find('a[href$=".mp3"], a[href$=".flac"]')
    if (link.length === 0) return

    const trackUrl = link.attr('href')!.startsWith('http')
      ? link.attr('href')!
      : `https://downloads.khinsider.com${link.attr('href')}`

    tracks.push({
      name: link.text().trim(),
      url: trackUrl,
      format: link.attr('href')!.toLowerCase().endsWith('.flac') ? 'flac' : 'mp3'
    })
  })

  return tracks
}