import { HtmlBasePlugin } from "@11ty/eleventy";
import { eleventyImageTransformPlugin } from "@11ty/eleventy-img";
import pluginNavigation from "@11ty/eleventy-navigation";

import { attrs } from "@mdit/plugin-attrs";
import { markdownitLinkAttributes } from 'markdown-it-link-attributes';
import markdownitIdAttributes from "markdown-it-anchor";

import path from "node:path";
import { chunk } from "lodash-es";

import pluginFilters from "./_config/filters.js";

export default async function (eleventyConfig) {
	/* Markdown HTML attribute parsing */
	eleventyConfig.amendLibrary("md", (mdLib) => mdLib.use(attrs));

	/* Markdown apply target="_blank" to all external links */
	eleventyConfig.amendLibrary("md", (mdLib) => mdLib.use(markdownitLinkAttributes, {
    matcher(href) {
      return href.match(/^https?:\/\//);
    },
    attrs: {
      target: "_blank",
      rel: "external",
    },
  }));

	/* Markdown apply ID attributes to headers */
	eleventyConfig.amendLibrary("md", (mdLib) => mdLib.use(markdownitIdAttributes, {
		level: [2, 3, 4],
		tabIndex: false,
	}));

	/* Bundles */
	/* CSS */
	eleventyConfig.addBundle("css", {
		toFileDirectory: "dist",
		bundleHtmlContentFromSelector: "style",
	});

	/* Javascript */
	eleventyConfig.addBundle("js", {
		toFileDirectory: "dist",
		bundleHtmlContentFromSelector: "script",
	});

	/* Paginate tags */
	eleventyConfig.addCollection("doublePagination", function(collection) {
		// Get unique list of tags
		let tagSet = new Set(collection.getAllSorted().flatMap((post) => post.data.tags || []));

		// Get each item that matches the tag
		let paginationSize = 20;
		let tagMap = [];
		let tagArray = [...tagSet];
		for( let tagName of tagArray) {
			let tagItems = collection.getFilteredByTag(tagName);
			let pagedItems = chunk(tagItems.reverse(), paginationSize);			// console.log( tagName, tagItems.length, pagedItems.length );
			for( let pageNumber = 0, max = pagedItems.length; pageNumber < max; pageNumber++) {
				tagMap.push({
					tagName: tagName,
					pageNumber: pageNumber,
					pageSize: pagedItems.length,
					pageData: pagedItems[pageNumber]
				});
			}
		}

		//console.log( tagMap );
		return tagMap;
	});

	/* Passthroughs */
	eleventyConfig
		.addPassthroughCopy("favicon.ico")
		.addPassthroughCopy("robots.txt");

	/* HTML base */
	eleventyConfig.addPlugin(HtmlBasePlugin);

	/* Images */
	eleventyConfig.addPlugin(eleventyImageTransformPlugin, {
		// output image formats
		formats: ["auto"],

		// output image widths
		widths: ["auto"],

		// optional, attributes assigned on <img> nodes override these values
		htmlOptions: {
			imgAttributes: {
				loading: "lazy",
				decoding: "async",
			},
		},
		filenameFormat: function (hash, src, width, format, options) {
			// If you're building multiple widths
			// const extension = path.extname(src);
			// const name = path.basename(src, extension);
			// return `${name}-${width}.${extension}`;

			return path.basename(src);
		},
	});

	/* Navigation */
	eleventyConfig.addPlugin(pluginNavigation);

	/* All filters from _config/filters.js */
	eleventyConfig.addPlugin(pluginFilters);

	/* Draft handling */
	eleventyConfig.addPreprocessor("drafts", "*", (data, content) => {
		if (data.draft) {
			data.title = `${data.title} (draft)`;
		}

		if(data.draft && process.env.ELEVENTY_RUN_MODE === "build") {
			return false;
		}
	});

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

	/* Watch when serving */
	eleventyConfig.addWatchTarget("css");
}

export const config = {
	dir: {
		input: "src",
		includes: "../_includes",
		layouts: "../_includes/layouts",
		data: "../_data",
	},
	markdownTemplateEngine: "njk",
	htmlTemplateEngine: "njk",
	templateFormats: ["html", "md", "njk"],
};