const express = require('express')
const { SitemapStream, streamToPromise } = require('sitemap')
const { createGzip } = require('zlib')

const app = express()
let sitemap

app.get('/sitemap.xml', function(req, res) {
  res.header('Content-Type', 'application/xml');
  res.header('Content-Encoding', 'gzip');
  // if we have a cached entry send it
  if (sitemap) {
    res.send(sitemap)
    return
  }

  try {
    const smStream = new SitemapStream({ hostname: 'https://example.com/' })
    const pipeline = smStream.pipe(createGzip())

    // pipe your entries or directly write them.
    smStream.write({ url: '/page-1/',  changefreq: 'daily', priority: 0.3 })
    smStream.write({ url: '/page-2/',  changefreq: 'monthly',  priority: 0.7 })
    smStream.write({ url: '/page-3/'})    // changefreq: 'weekly',  priority: 0.5
    smStream.write({ url: '/page-4/',   img: "http://urlTest.com" })
    smStream.end()

    // cache the response
    streamToPromise(pipeline).then(sm => sitemap = sm)
    // stream write the response
    pipeline.pipe(res).on('error', (e) => {throw e})
  } catch (e) {
    console.error(e)
    res.status(500).end()
  }
})

app.listen(3000, () => {
  console.log('listening')
});

const { createReadStream, createWriteStream } = require('fs');
const { resolve } = require('path');
const { createGzip } = require('zlib')
const {
  SitemapAndIndexStream,
  SitemapStream,
  lineSeparatedURLsToSitemapOptions
} = require('sitemap')

const sms = new SitemapAndIndexStream({
  limit: 10000, // defaults to 45k
  // SitemapAndIndexStream will call this user provided function every time
  // it needs to create a new sitemap file. You merely need to return a stream
  // for it to write the sitemap urls to and the expected url where that sitemap will be hosted
  getSitemapStream: (i) => {
    const sitemapStream = new SitemapStream();
    const path = `./sitemap-${i}.xml`;

    sitemapStream
      .pipe(createGzip()) // compress the output of the sitemap
      .pipe(createWriteStream(resolve(path + '.gz'))); // write it to sitemap-NUMBER.xml

    return [new URL(path, 'https://example.com/subdir/').toString(), sitemapStream];
  },
});

lineSeparatedURLsToSitemapOptions(
  createReadStream('./your-data.json.txt')
)
.pipe(sms)
.pipe(createGzip())
.pipe(createWriteStream(resolve('./sitemap-index.xml.gz')));

const { SitemapStream, streamToPromise } = require('sitemap');
const smStream = new SitemapStream({
  hostname: 'http://www.mywebsite.com',
  xslUrl: "https://example.com/style.xsl",
  lastmodDateOnly: false, // print date not time
  xmlns: { // trim the xml namespace
    news: true, // flip to false to omit the xml namespace for news
    xhtml: true,
    image: true,
    video: true,
  }
 })
// coalesce stream to value
// alternatively you can pipe to another stream
streamToPromise(smStream).then(console.log)

smStream.write({
  url: '/page1',
  changefreq: 'weekly',
  priority: 0.8, // A hint to the crawler that it should prioritize this over items less than 0.8
})

// each sitemap entry supports many options
// See [Sitemap Item Options](./api.md#sitemap-item-options) below for details
smStream.write({
  url: 'http://test.com/page-1/',
  img: [
    {
      url: 'http://test.com/img1.jpg',
      caption: 'An image',
      title: 'The Title of Image One',
      geoLocation: 'London, United Kingdom',
      license: 'https://creativecommons.org/licenses/by/4.0/'
    },
    {
      url: 'http://test.com/img2.jpg',
      caption: 'Another image',
      title: 'The Title of Image Two',
      geoLocation: 'London, United Kingdom',
      license: 'https://creativecommons.org/licenses/by/4.0/'
    }
  ],
  video: [
    {
      thumbnail_loc: 'http://test.com/tmbn1.jpg',
      title: 'A video title',
      description: 'This is a video'
    },
    {
      thumbnail_loc: 'http://test.com/tmbn2.jpg',
      title: 'A video with an attribute',
      description: 'This is another video',
      'player_loc': 'http://www.example.com/videoplayer.mp4?video=123',
      'player_loc:autoplay': 'ap=1'
    }
  ],
  links: [
    { lang: 'en', url: 'http://test.com/page-1/' },
    { lang: 'ja', url: 'http://test.com/page-1/ja/' }
  ],
  androidLink: 'android-app://com.company.test/page-1/',
  news: {
    publication: {
      name: 'The Example Times',
      language: 'en'
    },
    genres: 'PressRelease, Blog',
    publication_date: '2008-12-23',
    title: 'Companies A, B in Merger Talks',
    keywords: 'business, merger, acquisition, A, B',
    stock_tickers: 'NASDAQ:A, NASDAQ:B'
  }
})
// indicate there is nothing left to write
smStream.end()