require('../../lib/feature-flags')
const path = require('path')
const { loadPages, loadPageMap } = require('../../lib/pages')
const languageCodes = Object.keys(require('../../lib/languages'))
const { liquid } = require('../../lib/render-content')
const patterns = require('../../lib/patterns')
const GithubSlugger = require('github-slugger')
const slugger = new GithubSlugger()
const Entities = require('html-entities').XmlEntities
const entities = new Entities()
const { chain, difference } = require('lodash')
const checkIfNextVersionOnly = require('../../lib/check-if-next-version-only')

const testOldSiteTree = process.env.FEATURE_NEW_SITETREE ? test.skip : test

describe('pages module', () => {
  jest.setTimeout(60 * 1000)

  let pages

  beforeAll(async (done) => {
    pages = await loadPages()
    done()
  })

  describe('loadPages', () => {
    test('yields a non-empty array of Page objects', async () => {
      expect(Array.isArray(pages)).toBe(true)
      expect(pages.length).toBeGreaterThan(100)
    })

    test('every page has a `languageCode`', async () => {
      expect(pages.every(page => languageCodes.includes(page.languageCode))).toBe(true)
    })

    test('every page has a non-empty `permalinks` array', async () => {
      const brokenPages = pages
        .filter(page => !Array.isArray(page.permalinks) || page.permalinks.length === 0)
        // Ignore pages that only have "next" versions specified and therefore no permalinks;
        // These pages are not broken, they just won't render in the currently supported versions.
        .filter(page => !Object.values(page.versions).every(pageVersion => checkIfNextVersionOnly(pageVersion)))

      const expectation = JSON.stringify(brokenPages.map(page => page.fullPath), null, 2)
      expect(brokenPages.length, expectation).toBe(0)
    })

    // **TODO** fix duplicate redirects after new site tree feature flag is enabled
    // we can't put this in tests/redirects because duplicate routes have already been
    // overwritten during context.pages.redirects object assignment and can't be searched for
    testOldSiteTree('redirect_from routes are unique across English pages', () => {
      const sourceRedirectFrom = chain(pages)
        .filter(['languageCode', 'en'])
        .filter('redirect_from')
        .map('redirect_from')
        .flatten()
        .value()
      const duplicates = sourceRedirectFrom.reduce((acc, el, i, arr) => {
        if (arr.indexOf(el) !== i && acc.indexOf(el) < 0) acc.push(el)
        return acc
      }, [])

      const message = `Found ${duplicates.length} duplicate redirect_from ${duplicates.length === 1 ? 'path' : 'paths'}.\n
  ${duplicates.join('\n')}`
      expect(duplicates.length, message).toBe(0)
    })

    test('every English page has a filename that matches its slugified title', async () => {
      const nonMatches = pages
        .filter(page => {
          slugger.reset()
          return page.languageCode === 'en' && // only check English
          !page.relativePath.includes('index.md') && // ignore TOCs
          !page.allowTitleToDifferFromFilename && // ignore docs with override
          slugger.slug(entities.decode(page.title)) !== path.basename(page.relativePath, '.md')
        })
        // make the output easier to read
        .map(page => {
          return JSON.stringify({
            file: path.basename(page.relativePath),
            title: page.title,
            path: page.fullPath
          }, null, 2)
        })

      const message = `
  Found ${nonMatches.length} ${nonMatches.length === 1 ? 'file' : 'files'} that do not match their slugified titles.\n
  ${nonMatches.join('\n')}\n
  To fix, run script/reconcile-filenames-with-ids.js\n\n`

      expect(nonMatches.length, message).toBe(0)
    })

    test('every page has valid frontmatter', async () => {
      const frontmatterErrors = chain(pages)
        // .filter(page => page.languageCode === 'en')
        .map(page => page.frontmatterErrors)
        .flatten()
        .value()

      const failureMessage = JSON.stringify(frontmatterErrors, null, 2) +
        '\n\n' +
        chain(frontmatterErrors).map('filepath').join('\n').value()

      expect(frontmatterErrors.length, failureMessage).toBe(0)
    })

    test('every page has valid Liquid templating', async () => {
      const liquidErrors = []

      for (const page of pages) {
        const markdown = page.raw
        if (!patterns.hasLiquid.test(markdown)) continue
        try {
          await liquid.parse(markdown)
        } catch (error) {
          liquidErrors.push({
            filename: page.fullPath,
            error: error.message
          })
        }
      }

      const failureMessage = JSON.stringify(liquidErrors, null, 2)
      expect(liquidErrors.length, failureMessage).toBe(0)
    })

    test('every non-English page has a matching English page', async () => {
      const englishPaths = chain(pages)
        .filter(page => page.languageCode === 'en')
        .map(page => page.relativePath)
        .value()
      const nonEnglishPaths = chain(pages)
        .filter(page => page.languageCode !== 'en')
        .map(page => page.relativePath)
        .uniq()
        .value()

      const diff = difference(nonEnglishPaths, englishPaths)
      const failureMessage = `Unmatched non-English pages:\n - ${diff.join('\n - ')}`
      expect(diff.length, failureMessage).toBe(0)
    })
  })

  describe('loadPageMap', () => {
    let pageMap
    beforeAll(async () => {
      pageMap = await loadPageMap(pages)
    })

    test('yields a non-empty object with more unique entries than pages', async () => {
      // Why does it contain MORE unique entries, you ask?
      // TL;DR: The pages array contains one item per Page + language, with a `permalinks` array
      // property for each product version supported (free-pro-team, enterprise-server@2.22, etc.)
      // The pageMap, on the other hand, is keyed by unique URLs, so it has 1-N (where N is the
      // number of product versions supported) keys pointing to the same Page + language object

      expect(Array.isArray(pageMap)).toBe(false)
      expect(Object.keys(pageMap).length).toBeGreaterThan(pages.length)
    })

    test('has an identical key list to the deep permalinks of the array', async () => {
      const allPermalinks = pages.flatMap(page => page.permalinks.map(pl => pl.href)).sort()
      const allPageUrls = Object.keys(pageMap).sort()

      expect(allPageUrls).toEqual(allPermalinks)
    })
  })
})