generateCoursePreview.mjs

import axios from "axios";
import fs from "fs";
import { JSDOM } from "jsdom";



let now = new Date()
let sitemapUrls = []

let dom = await JSDOM.fromFile('./dist/200.html')
let document = dom.window.document

function setMeta(name, content) {
  let meta
  meta = document.querySelector(`meta[name="${name}"]`)
  if (!meta) {
    meta = document.createElement('meta')
    meta.setAttribute('name', name)
    document.head.appendChild(meta)
  }
  meta.setAttribute('content', content)
}
function updateTags({ title, description, image, url }) {
  setMeta('og:title', title)
  setMeta('og:description', description)
  setMeta('og:url', url)
  setMeta('og:image', image)
  setMeta('description', description)
  setMeta('twitter:title', title)
  setMeta('twitter:description', description)
  setMeta('twitter:image', image)
  setMeta('twitter:card', 'summary_large_image')
  document.querySelector('title').textContent = title
}
console.log('Generate course preview')
let yearSems = await axios.get('https://gnehs.github.io/ntut-course-crawler-node/main.json').then((res) => res.data);
let withdrawal = await axios.get(`https://gnehs.github.io/ntut-course-crawler-node/analytics/withdrawal.json`).then((res) => res.data);
console.log(`Data fetched`)

let tasks = []
tasks.push(...Object.entries(yearSems)
  .map((([year, sems]) => sems.map(sem => ({ year, sem }))))
  .flat()
  .map(async ({ year, sem }) => {
    let courses = await axios.get(`https://gnehs.github.io/ntut-course-crawler-node/${year}/${sem}/main.json`).then(x => x.data)
    let departments = await axios.get(`https://gnehs.github.io/ntut-course-crawler-node/${year}/${sem}/department.json`).then(x => x.data)
    fs.mkdirSync(`./dist/course/${year}/${sem}/`, { recursive: true })
    fs.mkdirSync(`./dist/class/${year}/${sem}/`, { recursive: true })

    courses.map(course => {
      let courseNumber = [`𝟬`, `𝟭`, `𝟮`, `𝟯`, `𝟰`, `𝟱`, `𝟲`, `𝟳`, `𝟴`, `𝟵`]
      let parsedCourseId = course.id.split('').map((c) => courseNumber[c]).join('')

      let title = `${parsedCourseId} ${course.name.zh}`
      let description = `${course.description.zh}`
      let image = `https://ntut-course-og.gnehs.net/api?year=${year}&sem=${sem}&id=${course.id}`
      let url = `https://ntut-course.gnehs.net/course/${year}/${sem}/${course.id}`
      updateTags({ title, description, image, url })

      fs.writeFileSync(`./dist/course/${year}/${sem}/${course.id}.html`, dom.serialize().replace(/&/g, '&'))
      sitemapUrls.push(url)
    })
    console.log(`Generate routes: ${year}/${sem} for ${courses.length} courses`)
    departments.map(department => {
      department.class.map(x => {
        let courseData = courses.filter(y => y.class.some(z => z.name == x.name))

        let title = x.name
        let description = `在北科好朋友上查看課程「${x.name}」的資訊`
        if (courseData.length) {
          description += `，包含${[...new Set(courseData.map(x => x.name.zh))].slice(0, 3).join('、')}課程與博雅、必選修等相關資訊`
        } else {
          description += `，如必選修課程、博雅等相關課程資訊`
        }
        let image = `https://ntut-course-og.gnehs.net/api/class?year=${year}&sem=${sem}&id=${x.id}`
        let url = `https://ntut-course.gnehs.net/class/${year}/${sem}/${encodeURIComponent(x.name)}`

        updateTags({ title, description, image, url })
        fs.writeFileSync(`./dist/class/${year}/${sem}/${x.name}.html`, dom.serialize().replace(/&/g, '&'))
        sitemapUrls.push(url)
      })
    })

    console.log(`Generate routes: ${year}/${sem} for ${departments.map(x => x.class).flat().length} classes`)

  })
)
fs.mkdirSync(`./dist/teacher/`, { recursive: true })
tasks.push(...withdrawal.data.map(x => {
  let title = x.name
  let description = `在北科好朋友上查看教師「${x.name}」的資訊，包含${[...new Set(x.course.map(x => x.name.zh))].slice(0, 3).join('、')}等課程與選課人數等相關資訊`
  let image = `https://ntut-course-og.gnehs.net/api/teacher?name=${encodeURIComponent(x.name)}`
  let url = `https://ntut-course.gnehs.net/teacher/${encodeURIComponent(x.name)}`
  updateTags({ title, description, image, url })

  fs.writeFileSync(`./dist/teacher/${x.name}.html`, dom.serialize().replace(/&/g, '&'))
  sitemapUrls.push(url)
}))
await Promise.all(tasks)
console.log(`Generate time: ${((new Date() - now) / 1000).toFixed(2)}s`)

//https://stackoverflow.com/questions/8495687/split-array-into-chunks
Object.defineProperty(Array.prototype, 'chunk', {
  value: function (n) {
    let ceil = Math.ceil;
    return Array.from(Array(ceil(this.length / n)), (_, i) => this.slice(i * n, i * n + n));
  }
});
sitemapUrls.chunk(50000).forEach((chunk, index) => {
  fs.writeFileSync(`./dist/sitemap-${index + 1}.txt`, chunk.join('\n'), { encoding: 'utf8' })
})
console.log(`${sitemapUrls.length} urls in sitemap`)