import { DateTime } from "luxon";
import markdownItAnchor from "markdown-it-anchor";
import markdownItAbbr from "markdown-it-abbr/dist/markdown-it-abbr.js";
import markdownItKatex from "@vscode/markdown-it-katex";

import { feedPlugin } from "@11ty/eleventy-plugin-rss";
import pluginSyntaxHighlight from "@11ty/eleventy-plugin-syntaxhighlight";
import pluginBundle from "@11ty/eleventy-plugin-bundle";
import pluginNavigation from "@11ty/eleventy-navigation";

import { EleventyHtmlBasePlugin } from "@11ty/eleventy";
import { eleventyImageTransformPlugin } from "@11ty/eleventy-img";

import fs from "fs/promises";

/** @param {import('@11ty/eleventy').UserConfig} eleventyConfig */
export default async 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/": "/",
    "./node_modules/katex/dist/fonts/": "/bundle/fonts/", // needs to be here for css reasons.
  });

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

  // App plugins
  eleventyConfig.addPreprocessor("drafts", "*", (data, _content) => {
		if(data.draft && process.env.ELEVENTY_RUN_MODE === "build") {
			return false;
		}
	});
  // eleventyConfig.addPlugin(pluginFonts);
  // Official plugins
  let mkFeed = function (type, path) {
    eleventyConfig.addPlugin(feedPlugin, {
      type: type,
      outputPath: path,
      collection: {
        name: "posts",
        limit: 0,
      },
      metadata: {
        title: "Musings",
        base: "https://saji.dev",
        language: "en",
      },
    });
  };
  mkFeed("rss", "/rss.feed.xml");
  mkFeed("atom", "/atom.feed.xml");
  mkFeed("json", "/feed.json");

  eleventyConfig.addPlugin(pluginSyntaxHighlight, {
    preAttributes: { tabindex: 0 },
  });
  eleventyConfig.addPlugin(pluginNavigation);
  eleventyConfig.addPlugin(EleventyHtmlBasePlugin);
  eleventyConfig.addPlugin(pluginBundle);
  eleventyConfig.addPlugin(eleventyImageTransformPlugin, {
    extensions: "html",
    formats: ["webp", "jpeg", null],
    widths: [400, 800, 1280, null],
    defaultAttributes: {
      loading: "lazy",
      decoding: "async",
      sizes: "auto",
    },
  });

  // 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,
    );
  });

  let mdIt;
  // Customize Markdown library settings:
  eleventyConfig.amendLibrary("md", (mdLib) => {
    // hack to let us use the markdown renderer for later.
    mdIt = mdLib;
    mdLib.use(markdownItAnchor, {
      permalink: markdownItAnchor.permalink.ariaHidden({
        placement: "after",
        class: "header-anchor",
        symbol: "@",
        ariaHidden: false,
      }),
      level: [1, 2, 3, 4],
      slugify: eleventyConfig.getFilter("slugify"),
    });
    mdLib.use(markdownItAbbr);
    mdLib.use(markdownItKatex.default);
  });

  eleventyConfig.addShortcode("currentBuildDate", () => {
    return new Date().toISOString();
  });

  eleventyConfig.addShortcode("includeRaw", async (file) =>
    fs.readFile(file, "utf8"),
  );

  //eleventyConfig.addPairedShortcode("section", async (content, transition = "none") => {
  //	return `<section data-transition=${transition}> ${mdIt.renderInline(content)} </section>`;
  //})
  //
  eleventyConfig.addPairedShortcode("callout", function (content) {
    // The 'content' variable holds the text/HTML placed between
    // {% callout %} and {% endcallout %}
    // We wrap it with our div structure.
    return `<div class="callout">${content}</div>`;
  });

  eleventyConfig.addBundle("css");
  eleventyConfig.addBundle("js");
  eleventyConfig.addBundle("html");

  // 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: "_site",
    },

    // -----------------------------------------------------------------
    // 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: "/",
  };
}