import express from 'express'
import truncate from 'lodash-es/truncate.js'
import { ErrorLevel, SitemapStream, streamToPromise } from 'sitemap'
import { logger } from '@server/helpers/logger.js'
import { getServerActor } from '@server/models/application/application.js'
import { buildNSFWFilter } from '../helpers/express-utils.js'
import { ROUTE_CACHE_LIFETIME, WEBSERVER } from '../initializers/constants.js'
import { apiRateLimiter, asyncMiddleware, cacheRoute } from '../middlewares/index.js'
import { AccountModel } from '../models/account/account.js'
import { VideoModel } from '../models/video/video.js'
import { VideoChannelModel } from '../models/video/video-channel.js'
import { VideoFileStream, VideoInclude } from '@peertube/peertube-models'

const sitemapRouter = express.Router()

sitemapRouter.use('/sitemap.xml',
  apiRateLimiter,
  cacheRoute(ROUTE_CACHE_LIFETIME.SITEMAP),
  asyncMiddleware(getSitemap)
)

// ---------------------------------------------------------------------------

export {
  sitemapRouter
}

// ---------------------------------------------------------------------------

async function getSitemap (req: express.Request, res: express.Response) {
  let urls = getSitemapBasicUrls()

  urls = urls.concat(await getSitemapLocalVideoUrls())
  urls = urls.concat(await getSitemapVideoChannelUrls())
  urls = urls.concat(await getSitemapAccountUrls())

  const sitemapStream = new SitemapStream({
    hostname: WEBSERVER.URL,
    errorHandler: (err: Error, level: ErrorLevel) => {
      if (level === 'warn') {
        logger.warn('Warning in sitemap generation.', { err })
      } else if (level === 'throw') {
        logger.error('Error in sitemap generation.', { err })

        throw err
      }
    }
  })

  for (const urlObj of urls) {
    sitemapStream.write(urlObj)
  }
  sitemapStream.end()

  const xml = await streamToPromise(sitemapStream)

  res.header('Content-Type', 'application/xml')
  res.send(xml)
}

async function getSitemapVideoChannelUrls () {
  const rows = await VideoChannelModel.listLocalsForSitemap('createdAt')

  return rows.map(channel => ({ url: channel.getClientUrl() }))
}

async function getSitemapAccountUrls () {
  const rows = await AccountModel.listLocalsForSitemap('createdAt')

  return rows.map(account => ({ url: account.getClientUrl() }))
}

async function getSitemapLocalVideoUrls () {
  const serverActor = await getServerActor()

  let acc: { url: string, video: any[] }[] = []

  const chunkSize = 200
  let hasData = true
  let i = 0

  while (hasData && i < 1000) {
    const { data } = await VideoModel.listForApi({
      start: chunkSize * i,
      count: chunkSize,
      sort: 'createdAt',
      displayOnlyForFollower: {
        actorId: serverActor.id,
        orLocalVideos: true
      },
      isLocal: true,
      nsfw: buildNSFWFilter(),
      countVideos: false,
      include: VideoInclude.FILES | VideoInclude.TAGS
    })

    hasData = data.length !== 0
    i++

    acc = acc.concat(
      data.map(v => {
        const contentLoc = v.getHLSPlaylist()?.getMasterPlaylistUrl(v) ||
          v.getMaxQualityFile(VideoFileStream.VIDEO)?.getFileUrl(v) ||
          v.getMaxQualityFile(VideoFileStream.AUDIO)?.getFileUrl(v)

        return {
          url: WEBSERVER.URL + v.getWatchStaticPath(),
          video: [
            {
              // Sitemap title should be < 100 characters
              'title': truncate(v.name, { length: 100, omission: '...' }),
              // Sitemap description should be < 2000 characters
              'description': truncate(v.description || v.name, { length: 2000, omission: '...' }),
              'player_loc': WEBSERVER.URL + v.getEmbedStaticPath(),
              'thumbnail_loc': WEBSERVER.URL + v.getMiniatureStaticPath(),
              'content_loc': contentLoc,
              'duration': v.duration,
              'view_count': v.views,
              'publication_date': v.publishedAt.toISOString(),
              'uploader': v.VideoChannel.getDisplayName(),
              'uploader:info': v.VideoChannel.getClientUrl(),
              'live': v.isLive ? 'YES' : 'NO',
              'family_friendly': v.nsfw ? 'NO' : 'YES',
              'rating': (v.likes * 5) / (v.likes + v.dislikes) || 0, // Rating is between 0.0 and 5.0
              'tag': v.Tags.map(t => t.name)
            }
          ]
        }
      })
    )
  }

  return acc
}

function getSitemapBasicUrls () {
  const paths = [
    '/about/instance',
    '/videos/local'
  ]

  return paths.map(p => ({ url: WEBSERVER.URL + p }))
}