const { DateTime } = require('luxon')
const markdownItAnchor = require('markdown-it-anchor')
const postcss = require('postcss')
const tailwindcss = require('tailwindcss')
const autoprefixer = require('autoprefixer')
const util = require('util')

const pluginRss = require('@11ty/eleventy-plugin-rss')
const pluginSyntaxHighlight = require('@11ty/eleventy-plugin-syntaxhighlight')
const pluginBundle = require('@11ty/eleventy-plugin-bundle')
const pluginNavigation = require('@11ty/eleventy-navigation')
const { EleventyHtmlBasePlugin } = require('@11ty/eleventy')

const pluginDrafts = require('./eleventy.config.drafts.js')
const pluginImages = require('./eleventy.config.images.js')

module.exports = function (eleventyConfig) {
  // Copy the contents of the `public` folder to the output folder
  // For example, `./public/css/` ends up in `_site/css/`
  eleventyConfig.addPassthroughCopy({
    './public/': '/',
  })

  eleventyConfig.addNunjucksAsyncFilter('postcss', (cssCode, done) => {
    postcss([tailwindcss(require('./tailwind.config.js')), autoprefixer()])
      .process(cssCode)
      .then(
        (r) => done(null, r.css),
        (e) => done(e, null),
      )
  })

  eleventyConfig.addWatchTarget('styles/**/*.css')

  // Run Eleventy when these files change:
  // https://www.11ty.dev/docs/watch-serve/#add-your-own-watch-targets

  // Watch content images for the image pipeline.
  eleventyConfig.addWatchTarget('content/**/*.{svg,webp,png,jpeg}')

  // App plugins
  eleventyConfig.addPlugin(pluginDrafts)
  eleventyConfig.addPlugin(pluginImages)

  // Official plugins
  eleventyConfig.addPlugin(pluginRss)
  eleventyConfig.addPlugin(pluginSyntaxHighlight, {
    preAttributes: { tabindex: 0 },
  })
  eleventyConfig.addPlugin(pluginNavigation)
  eleventyConfig.addPlugin(EleventyHtmlBasePlugin)
  eleventyConfig.addPlugin(pluginBundle)

  // Filters
  eleventyConfig.addFilter('readableDate', (dateObj, format, zone) => {
    // Formatting tokens for Luxon: https://moment.github.io/luxon/#/formatting?id=table-of-tokens
    return DateTime.fromJSDate(dateObj, { zone: zone || 'utc' }).toFormat(
      format || 'dd LLLL yyyy',
    )
  })

  eleventyConfig.addFilter('htmlDateString', (dateObj) => {
    // dateObj input: https://html.spec.whatwg.org/multipage/common-microsyntaxes.html#valid-date-string
    return DateTime.fromJSDate(dateObj, { zone: 'utc' }).toFormat('yyyy-LL-dd')
  })

  // Get the first `n` elements of a collection.
  eleventyConfig.addFilter('head', (array, n) => {
    if (!Array.isArray(array) || array.length === 0) {
      return []
    }
    if (n < 0) {
      return array.slice(n)
    }

    return array.slice(0, n)
  })

  // Return the smallest number argument
  eleventyConfig.addFilter('min', (...numbers) => {
    return Math.min.apply(null, numbers)
  })

  // Return all the tags used in a collection
  eleventyConfig.addFilter('getAllTags', (collection) => {
    let tagSet = new Set()
    for (let item of collection) {
      ;(item.data.tags || []).forEach((tag) => tagSet.add(tag))
    }
    return Array.from(tagSet)
  })

  eleventyConfig.addFilter('filterTagList', function filterTagList(tags) {
    return (tags || []).filter(
      (tag) => ['all', 'nav', 'post', 'posts'].indexOf(tag) === -1,
    )
  })

  eleventyConfig.addFilter('console', function (value) {
    const str = util.inspect(value)
    return `<div style="white-space: pre-wrap;">${unescape(str)}</div>;`
  })

  // Customize Markdown library settings:
  eleventyConfig.amendLibrary('md', (mdLib) => {
    mdLib.use(markdownItAnchor, {
      permalink: markdownItAnchor.permalink.ariaHidden({
        placement: 'after',
        class: 'header-anchor no-underline text-xs',
        symbol: '🔗',
        ariaHidden: false,
      }),
      level: [1, 2, 3, 4],
      slugify: eleventyConfig.getFilter('slugify'),
    })
  })

  // Features to make your build faster (when you need them)

  // If your passthrough copy gets heavy and cumbersome, add this line
  // to emulate the file copy on the dev server. Learn more:
  // https://www.11ty.dev/docs/copy/#emulate-passthrough-copy-during-serve

  // eleventyConfig.setServerPassthroughCopyBehavior("passthrough");

  return {
    // Control which files Eleventy will process
    // e.g.: *.md, *.njk, *.html, *.liquid
    templateFormats: ['md', 'njk', 'html', 'liquid'],

    // Pre-process *.md files with: (default: `liquid`)
    markdownTemplateEngine: 'njk',

    // Pre-process *.html files with: (default: `liquid`)
    htmlTemplateEngine: 'njk',

    // These are all optional:
    dir: {
      input: 'content', // default: "."
      includes: '../_includes', // default: "_includes"
      data: '../_data', // default: "_data"
      output: '../../dist/lander',
    },

    // -----------------------------------------------------------------
    // Optional items:
    // -----------------------------------------------------------------

    // If your site deploys to a subdirectory, change `pathPrefix`.
    // Read more: https://www.11ty.dev/docs/config/#deploy-to-a-subdirectory-with-a-path-prefix

    // When paired with the HTML <base> plugin https://www.11ty.dev/docs/plugins/html-base/
    // it will transform any absolute URLs in your HTML to include this
    // folder name and does **not** affect where things go in the output folder.
    pathPrefix: '/',
  }
}