Lady’s Gitweb - GitWikiWeb/blob - build.js

   1 // 🐙🕸️ GitWikiWeb ∷ build.js
   2 // ====================================================================
   3 //
   4 // Copyright © 2023 Lady [@ Lady’s Computer].
   5 //
   6 // This Source Code Form is subject to the terms of the Mozilla Public
   7 // License, v. 2.0. If a copy of the MPL was not distributed with this
   8 // file, You can obtain one at <https://mozilla.org/MPL/2.0/>.
   9 //
  10 // --------------------------------------------------------------------
  11 //
  12 // A script for generating static wiki pages from a git repository.
  13 //
  14 // First, clone this repository to your machine in an accessible
  15 // location (for example, `/srv/git/GitWikiWeb`). A bare repository is
  16 // fine; customize the templates and stylesheets as you like. Then, use
  17 // this file as the post‐receive hook for your wiki as follows :—
  18 //
  19 //     #!/usr/bin/env -S sh
  20 //     export GITWIKIWEB=/srv/git/GitWikiWeb
  21 //     git archive --remote=$GITWIKIWEB HEAD build.js \
  22 //       | tar -xO \
  23 //       | deno run -A - ~/public/wiki $GITWIKIWEB current
  24 //
  25 // The directory `~/public/wiki` (or whatever you specify as the first
  26 // argument to `deno run -A -`) **will be deleted** and a new static
  27 // wiki will be generated in its place. This script is not very smart
  28 // (yet) and cannot selectively determine which pages will need
  29 // updating. It just wipes and regenerates the whole thing.
  30 //
  31 // This script will make a number of requests to `$GITWIKIWEB` to
  32 // download the latest templates, stylesheets, ⁊·c from this
  33 // repository. Consequently, it is best that you set it to a repository
  34 // you control and can ensure uptime for—ideally one local to the
  35 // computer hosting the wiki.
  36
  37 import {
  38   emptyDir,
  39   ensureDir,
  40 } from "https://deno.land/std@0.196.0/fs/mod.ts";
  41 import {
  42   JSON_SCHEMA,
  43   parse as parseYaml,
  44 } from "https://deno.land/std@0.196.0/yaml/mod.ts";
  45 import djot from "npm:@djot/djot@0.3.1";
  46 import { Parser } from "npm:htmlparser2@9.0.0";
  47 import { DomHandler, Element, Text } from "npm:domhandler@5.0.3";
  48 import * as domutils from "npm:domutils@3.1.0";
  49 import domSerializer from "npm:dom-serializer@2.0.0";
  50
  51 const DESTINATION = Deno.args[0] ?? "~/public/wiki";
  52 const REMOTE = Deno.args[1] ?? "/srv/git/GitWikiWeb";
  53 const REV = Deno.args[2] ?? "HEAD";
  54
  55 const READ_ONLY = {
  56   configurable: false,
  57   enumerable: true,
  58   writable: false,
  59 };
  60
  61 const NIL = Object.preventExtensions(Object.create(null));
  62
  63 const rawBlock = (strings, ...substitutions) => ({
  64   tag: "raw_block",
  65   format: "html",
  66   text: String.raw(strings, substitutions),
  67 });
  68 const rawInline = (strings, ...substitutions) => ({
  69   tag: "raw_inline",
  70   format: "html",
  71   text: String.raw(strings, substitutions),
  72 });
  73 const str = (strings, ...substitutions) => ({
  74   tag: "str",
  75   text: String.raw(strings, substitutions),
  76 });
  77
  78 const getDOM = (source) => {
  79   let result;
  80   const handler = new DomHandler((error, dom) => {
  81     if (error) {
  82       throw new Error("GitWikiWeb: Failed to process DOM.", {
  83         cause: error,
  84       });
  85     } else {
  86       result = dom;
  87     }
  88   });
  89   const parser = new Parser(handler);
  90   parser.write(source);
  91   parser.end();
  92   return result;
  93 };
  94
  95 const getRemoteContent = async (pathName) => {
  96   const getArchive = new Deno.Command("git", {
  97     args: ["archive", `--remote=${REMOTE}`, REV, pathName],
  98     stdout: "piped",
  99     stderr: "piped",
 100   }).spawn();
 101   const untar = new Deno.Command("tar", {
 102     args: ["-xO"],
 103     stdin: "piped",
 104     stdout: "piped",
 105     stderr: "piped",
 106   }).spawn();
 107   getArchive.stdout.pipeTo(untar.stdin);
 108   const [
 109     err1,
 110     getArchiveStatus,
 111     result,
 112     err2,
 113     untarStatus,
 114   ] = await Promise.allSettled([
 115     new Response(getArchive.stderr).text(),
 116     getArchive.status,
 117     new Response(untar.stdout).text(),
 118     new Response(untar.stderr).text(),
 119     untar.status,
 120   ]).then(logErrorsAndCollectResults);
 121   if (err1 || err2) {
 122     console.error(err1 + err2);
 123   } else {
 124     /* do nothing */
 125   }
 126   if (!getArchiveStatus.success) {
 127     throw new Error(
 128       `GitWikiWeb: git archive returned nonzero exit code: ${getArchiveStatus.code}.`,
 129     );
 130   } else if (!untarStatus.success) {
 131     throw new Error(
 132       `GitWikiWeb: tar returned nonzero exit code: ${untarStatus.code}.`,
 133     );
 134   } else {
 135     return result || "";
 136   }
 137 };
 138
 139 const logErrorsAndCollectResults = (results) =>
 140   results.map(({ value, reason }) => {
 141     if (reason) {
 142       console.error(reason);
 143       return undefined;
 144     } else {
 145       return value;
 146     }
 147   });
 148
 149 const getReferenceFromPath = (path) =>
 150   /Sources\/([A-Z][0-9A-Za-z]*(?:\/[A-Z][0-9A-Za-z]*)+)\.djot$/u
 151     .exec(path)?.[1]?.replace?.("/", ":"); // only replaces first slash
 152
 153 const listOfInternalLinks = (references, wrapper = ($) => $) => ({
 154   tag: "bullet_list",
 155   tight: true,
 156   style: "*",
 157   children: Array.from(
 158     references,
 159     (reference) => {
 160       const [namespace, pageName] = splitReference(reference);
 161       return {
 162         tag: "list_item",
 163         children: [{
 164           tag: "para",
 165           children: [wrapper({
 166             tag: "link",
 167             attributes: {
 168               "data-realm": "internal",
 169               "data-pagename": pageName,
 170               "data-namespace": namespace,
 171             },
 172             reference,
 173             children: [],
 174           })],
 175         }],
 176       };
 177     },
 178   ),
 179 });
 180
 181 const diffReferences = async (hash, againstHead = false) => {
 182   const diff = new Deno.Command("git", {
 183     args: [
 184       "diff-tree",
 185       "-r",
 186       "-z",
 187       "--name-only",
 188       "--no-renames",
 189       "--diff-filter=AM",
 190       ...(againstHead ? [hash, "HEAD"] : [hash]),
 191     ],
 192     stdout: "piped",
 193     stderr: "piped",
 194   }).spawn();
 195   const [diffNames] = await Promise.allSettled([
 196     new Response(diff.stdout).text(),
 197     new Response(diff.stderr).text(),
 198   ]).then(logErrorsAndCollectResults);
 199   return references(diffNames.split("\0")); // returns an iterable
 200 };
 201
 202 function* references(paths) {
 203   for (const path of paths) {
 204     const reference = getReferenceFromPath(path);
 205     if (reference) {
 206       yield reference;
 207     } else {
 208       /* do nothing */
 209     }
 210   }
 211 }
 212
 213 const splitReference = (reference) => {
 214   const colonIndex = reference.indexOf(":");
 215   return [
 216     reference.substring(0, colonIndex),
 217     reference.substring(colonIndex + 1),
 218   ];
 219 };
 220
 221 class GitWikiWebPage {
 222   #internalLinks = new Set();
 223   #externalLinks = new Map();
 224
 225   constructor(namespace, name, ast, source, config) {
 226     const internalLinks = this.#internalLinks;
 227     const externalLinks = this.#externalLinks;
 228     const sections = Object.create(null);
 229     djot.applyFilter(ast, () => {
 230       let titleSoFar = null; // used to collect strs from headings
 231       return {
 232         definition_list: {
 233           enter: (e) => {
 234             const attributes = e.attributes ?? {};
 235             if (
 236               (attributes.class ?? "").split(/\s/gu).includes(
 237                 "timeline",
 238               )
 239             ) {
 240               const years = new Map();
 241               for (
 242                 const { children: [{ children: termChildren }, defn] }
 243                   of e.children
 244               ) {
 245                 const { label, year } = (() => {
 246                   if (termChildren.length != 1) {
 247                     return { label: termChildren, year: termChildren };
 248                   } else {
 249                     const str = termChildren[0];
 250                     if (str.tag != "str") {
 251                       return {
 252                         label: termChildren,
 253                         year: termChildren,
 254                       };
 255                     } else {
 256                       const { text } = str;
 257                       return {
 258                         label: text,
 259                         year:
 260                           /^(-?[0-9X]{4})(?:-[0-9X]{2}(?:-[0-9X]{2})?)?$/u
 261                             .exec(text)?.[1] ?? text,
 262                       };
 263                     }
 264                   }
 265                 })();
 266                 const yearList = (() => {
 267                   const result = {
 268                     tag: "bullet_list",
 269                     tight: false,
 270                     style: "-",
 271                     children: [],
 272                   };
 273                   if (years.has(year)) {
 274                     const yearMap = years.get(year);
 275                     if (yearMap.has(label)) {
 276                       return yearMap.get(label);
 277                     } else {
 278                       yearMap.set(label, result);
 279                       return result;
 280                     }
 281                   } else {
 282                     years.set(year, new Map([[label, result]]));
 283                     return result;
 284                   }
 285                 })();
 286                 const misc = { tag: "list_item", children: [] };
 287                 for (const child of defn.children) {
 288                   if (child.tag == "bullet_list") {
 289                     yearList.children.push(...child.children);
 290                   } else {
 291                     misc.children.push(child);
 292                   }
 293                 }
 294                 if (misc.children.length > 0) {
 295                   yearList.children.unshift(misc);
 296                 } else {
 297                   /* do nothing */
 298                 }
 299               }
 300               const sorted = [...years].sort(([a], [b]) =>
 301                 typeof a != "string" || isNaN(a) ||
 302                   typeof b != "string" || isNaN(b) || +a == +b
 303                   ? 0
 304                   : 1 - 2 * (+a < b)
 305               );
 306               sorted.forEach((pair) =>
 307                 pair[1] = [...pair[1]].sort(([a], [b]) =>
 308                   1 - 2 * (a < b)
 309                 )
 310               );
 311               return {
 312                 tag: "div",
 313                 attributes,
 314                 children: sorted.flatMap(([year, yearDef]) => [
 315                   rawBlock`<details open="">`,
 316                   rawBlock`<summary>`,
 317                   ...(Array.isArray(year) ? year : [str`${year}`]),
 318                   rawBlock`</summary>`,
 319                   rawBlock`<dl>`,
 320                   ...yearDef.map(([label, list]) => ({
 321                       tag: "div",
 322                       children: [
 323                         rawBlock`<dt>`,
 324                         ...(Array.isArray(label) ? label : [str`${label}`]),
 325                         rawBlock`</dt>`,
 326                         rawBlock`<dd>`,
 327                         list,
 328                         rawBlock`</dd>`,
 329                       ],
 330                     })),
 331                   rawBlock`</dl>`,
 332                   rawBlock`</details>`,
 333                 ]),
 334               };
 335             } else {
 336               /* do nothing */
 337             }
 338           },
 339           exit: (_) => {},
 340         },
 341         hard_break: {
 342           enter: (_) => {
 343             if (titleSoFar != null) {
 344               titleSoFar += " ";
 345             } else {
 346               /* do nothing */
 347             }
 348           },
 349           exit: (_) => {},
 350         },
 351         heading: {
 352           enter: (_) => {
 353             titleSoFar = "";
 354           },
 355           exit: (e) => {
 356             e.attributes ??= {};
 357             const { attributes } = e;
 358             attributes.title ??= titleSoFar;
 359             titleSoFar = null;
 360           },
 361         },
 362         link: {
 363           enter: (e) => {
 364             e.attributes ??= {};
 365             const { attributes, reference, destination } = e;
 366             if (
 367               /^(?:[A-Z][0-9A-Za-z]*|[@#])?:(?:[A-Z][0-9A-Za-z]*(?:\/[A-Z][0-9A-Za-z]*)*)?$/u
 368                 .test(reference ?? "")
 369             ) {
 370               const [namespacePrefix, pageName] = splitReference(
 371                 reference,
 372               );
 373               const expandedNamespace = {
 374                 "": "Page",
 375                 "@": "Editor",
 376                 "#": "Category",
 377               }[namespacePrefix] ?? namespacePrefix;
 378               const resolvedReference = pageName == ""
 379                 ? `Namespace:${expandedNamespace}`
 380                 : `${expandedNamespace}:${pageName}`;
 381               e.reference = resolvedReference;
 382               attributes["data-realm"] = "internal";
 383               attributes["data-pagename"] = pageName;
 384               attributes["data-namespace"] = expandedNamespace;
 385               if (
 386                 resolvedReference.startsWith("Editor:") &&
 387                 (attributes.class ?? "").split(/\s/gu).includes("sig")
 388               ) {
 389                 // This is a special internal link; do not record it.
 390                 /* do nothing */
 391               } else {
 392                 // This is a non‐special internal link; record it.
 393                 internalLinks.add(resolvedReference);
 394               }
 395             } else {
 396               attributes["data-realm"] = "external";
 397               const remote = destination ??
 398                 ast.references[reference]?.destination;
 399               if (remote) {
 400                 externalLinks.set(remote, attributes?.title);
 401               } else {
 402                 /* do nothing */
 403               }
 404             }
 405           },
 406         },
 407         non_breaking_space: {
 408           enter: (_) => {
 409             if (titleSoFar != null) {
 410               titleSoFar += "\xA0";
 411             } else {
 412               /* do nothing */
 413             }
 414           },
 415           exit: (_) => {},
 416         },
 417         section: {
 418           enter: (_) => {},
 419           exit: (e) => {
 420             e.attributes ??= {};
 421             const { attributes, children } = e;
 422             const heading = children.find(({ tag }) =>
 423               tag == "heading"
 424             );
 425             const title = (() => {
 426               if (heading?.attributes?.title) {
 427                 const result = heading.attributes.title;
 428                 delete heading.attributes.title;
 429                 return result;
 430               } else {
 431                 return heading.level == 1
 432                   ? `${namespace}:${name}`
 433                   : "untitled section";
 434               }
 435             })();
 436             const variantTitles = Object.create(null);
 437             for (const attr in attributes) {
 438               if (attr.startsWith("v-")) {
 439                 Object.defineProperty(
 440                   variantTitles,
 441                   attr.substring(2),
 442                   { ...READ_ONLY, value: attributes[attr] },
 443                 );
 444                 delete attributes[attr];
 445               } else {
 446                 continue;
 447               }
 448             }
 449             const definition = Object.create(null, {
 450               title: { ...READ_ONLY, value: title },
 451               variantTitles: {
 452                 ...READ_ONLY,
 453                 value: Object.preventExtensions(variantTitles),
 454               },
 455             });
 456             if (heading.level == 1 && !("main" in sections)) {
 457               attributes.id = "main";
 458               heading.attributes ??= {};
 459               heading.attributes.class = "main";
 460             } else {
 461               /* do nothing */
 462             }
 463             try {
 464               Object.defineProperty(
 465                 sections,
 466                 attributes.id,
 467                 {
 468                   ...READ_ONLY,
 469                   writable: true,
 470                   value: Object.preventExtensions(definition),
 471                 },
 472               );
 473             } catch (cause) {
 474               throw new Error(
 475                 `GitWikiWeb: A section with the provided @id already exists: ${attributes.id}`,
 476                 { cause },
 477               );
 478             }
 479           },
 480         },
 481         soft_break: {
 482           enter: (_) => {
 483             if (titleSoFar != null) {
 484               titleSoFar += " ";
 485             } else {
 486               /* do nothing */
 487             }
 488           },
 489           exit: (_) => {},
 490         },
 491         str: {
 492           enter: ({ text }) => {
 493             if (titleSoFar != null) {
 494               titleSoFar += text;
 495             } else {
 496               /* do nothing */
 497             }
 498           },
 499           exit: (_) => {},
 500         },
 501         symb: {
 502           enter: (e) => {
 503             const { alias } = e;
 504             const codepoint = /^U\+([0-9A-Fa-f]+)$/u.exec(alias)?.[1];
 505             if (codepoint) {
 506               return str`${
 507                 String.fromCodePoint(parseInt(codepoint, 16))
 508               }`;
 509             } else {
 510               const resolved = config.symbols?.[alias];
 511               return resolved != null ? str`${resolved}` : e;
 512             }
 513           },
 514         },
 515       };
 516     });
 517     Object.defineProperties(this, {
 518       ast: { ...READ_ONLY, value: ast },
 519       namespace: { ...READ_ONLY, value: namespace },
 520       name: { ...READ_ONLY, value: name },
 521       sections: {
 522         ...READ_ONLY,
 523         value: Object.preventExtensions(sections),
 524       },
 525       source: { ...READ_ONLY, value: source },
 526     });
 527   }
 528
 529   *externalLinks() {
 530     yield* this.#externalLinks;
 531   }
 532
 533   *internalLinks() {
 534     yield* this.#internalLinks;
 535   }
 536 }
 537
 538 {
 539   // Patches for Djot HTML renderer.
 540   const { HTMLRenderer: { prototype: htmlRendererPrototype } } = djot;
 541   const { inTags: upstreamInTags } = htmlRendererPrototype;
 542   htmlRendererPrototype.inTags = function (
 543     tag,
 544     node,
 545     newlines,
 546     extraAttrs = undefined,
 547   ) {
 548     const attributes = node.attributes ?? NIL;
 549     if ("as" in attributes) {
 550       const newTag = attributes.as;
 551       delete attributes.as;
 552       return upstreamInTags.call(
 553         this,
 554         newTag,
 555         node,
 556         newlines,
 557         extraAttrs,
 558       );
 559     } else {
 560       return upstreamInTags.call(
 561         this,
 562         tag,
 563         node,
 564         newlines,
 565         extraAttrs,
 566       );
 567     }
 568   };
 569 }
 570 {
 571   const config = await getRemoteContent("config.yaml").then((yaml) =>
 572     parseYaml(yaml, { schema: JSON_SCHEMA })
 573   );
 574   const ls = new Deno.Command("git", {
 575     args: ["ls-tree", "-rz", "HEAD"],
 576     stdout: "piped",
 577     stderr: "piped",
 578   }).spawn();
 579   const [
 580     objects,
 581     lserr,
 582     lsstatus,
 583   ] = await Promise.allSettled([
 584     new Response(ls.stdout).text().then((lsout) =>
 585       lsout
 586         .split("\0")
 587         .slice(0, -1) // drop the last entry; it is empty
 588         .map(($) => $.split(/\s+/g))
 589     ),
 590     new Response(ls.stderr).text(),
 591     ls.status,
 592   ]).then(logErrorsAndCollectResults);
 593   if (lserr) {
 594     console.error(lserr);
 595   } else {
 596     /* do nothing */
 597   }
 598   if (!lsstatus.success) {
 599     throw new Error(
 600       `GitWikiWeb: git ls-tree returned nonzero exit code: ${lsstatus.code}.`,
 601     );
 602   } else {
 603     const requiredButMissingPages = new Map([
 604       ["Special:FrontPage", "front page"],
 605       ["Special:NotFound", "not found"],
 606       ["Special:RecentlyChanged", "recently changed"],
 607     ]);
 608     const pages = new Map();
 609     const promises = [emptyDir(DESTINATION)];
 610     for (const object of objects) {
 611       const hash = object[2];
 612       const path = object[3];
 613       const reference = getReferenceFromPath(path);
 614       if (reference == null) {
 615         continue;
 616       } else {
 617         const [namespace, pageName] = splitReference(reference);
 618         const cat = new Deno.Command("git", {
 619           args: ["cat-file", "blob", hash],
 620           stdout: "piped",
 621           stderr: "piped",
 622         }).spawn();
 623         const promise = Promise.allSettled([
 624           new Response(cat.stdout).text(),
 625           new Response(cat.stderr).text(),
 626           cat.status,
 627         ]).then(logErrorsAndCollectResults).then(
 628           ([source, caterr, catstatus]) => {
 629             if (caterr) {
 630               console.error(caterr);
 631             } else {
 632               /* do nothing */
 633             }
 634             if (!catstatus.success) {
 635               throw new Error(
 636                 `GitWikiWeb: git cat-file returned nonzero exit code: ${catstatus.code}.`,
 637               );
 638             } else {
 639               const reference = `${namespace}:${pageName}`;
 640               const page = new GitWikiWebPage(
 641                 namespace,
 642                 pageName,
 643                 djot.parse(source, {
 644                   warn: ($) =>
 645                     console.warn(`Djot(${reference}): ${$.render()}`),
 646                 }),
 647                 source,
 648                 config,
 649               );
 650               pages.set(reference, page);
 651               requiredButMissingPages.delete(reference);
 652             }
 653           },
 654         );
 655         promises.push(promise);
 656       }
 657     }
 658     for (const [reference, defaultTitle] of requiredButMissingPages) {
 659       const [namespace, pageName] = splitReference(reference);
 660       const source = `# ${defaultTitle}\n`;
 661       const page = new GitWikiWebPage(
 662         namespace,
 663         pageName,
 664         djot.parse(source, {
 665           warn: ($) =>
 666             console.warn(`Djot(${reference}): ${$.render()}`),
 667         }),
 668         source,
 669         config,
 670       );
 671       pages.set(reference, page);
 672     }
 673     await Promise.allSettled(promises).then(
 674       logErrorsAndCollectResults,
 675     );
 676     const [template, recentlyChanged] = await Promise.allSettled([
 677       getRemoteContent("template.html"),
 678       (async () => {
 679         const dateParse = new Deno.Command("git", {
 680           args: ["rev-parse", "--after=1 week ago"],
 681           stdout: "piped",
 682           stderr: "piped",
 683         }).spawn();
 684         const [maxAge] = await Promise.allSettled([
 685           new Response(dateParse.stdout).text(),
 686           new Response(dateParse.stderr).text(),
 687         ]).then(logErrorsAndCollectResults);
 688         let commit;
 689         if (!maxAge) {
 690           /* do nothing */
 691         } else {
 692           const revList = new Deno.Command("git", {
 693             args: ["rev-list", maxAge, "--reverse", "HEAD"],
 694             stdout: "piped",
 695             stderr: "piped",
 696           }).spawn();
 697           [commit] = await Promise.allSettled([
 698             new Response(revList.stdout).text().then((list) =>
 699               list.split("\n")[0]
 700             ),
 701             new Response(revList.stderr).text(),
 702           ]).then(logErrorsAndCollectResults);
 703         }
 704         if (!commit) {
 705           const revList2 = new Deno.Command("git", {
 706             args: ["rev-list", "--max-count=1", "HEAD^"],
 707             stdout: "piped",
 708             stderr: "piped",
 709           }).spawn();
 710           [commit] = await Promise.allSettled([
 711             new Response(revList2.stdout).text().then((list) =>
 712               list.trim()
 713             ),
 714             new Response(revList2.stderr).text(),
 715           ]).then(logErrorsAndCollectResults);
 716         } else {
 717           /* do nothing */
 718         }
 719         const results = new Array(6);
 720         const seen = new Set();
 721         const maxRecency = Math.max(config.max_recency | 0, 0);
 722         let recency = maxRecency;
 723         let current;
 724         do {
 725           const show = new Deno.Command("git", {
 726             args: [
 727               "show",
 728               "-s",
 729               "--format=%H%x00%cI%x00%cD",
 730               recency ? `HEAD~${maxRecency - recency}` : commit,
 731             ],
 732             stdout: "piped",
 733             stderr: "piped",
 734           }).spawn();
 735           const [
 736             [hash, dateTime, humanReadable],
 737           ] = await Promise.allSettled([
 738             new Response(show.stdout).text().then((rev) =>
 739               rev.trim().split("\0")
 740             ),
 741             new Response(show.stderr).text(),
 742           ]).then(logErrorsAndCollectResults);
 743           const refs = [];
 744           current = hash;
 745           for (
 746             const ref of (await diffReferences(current, !recency))
 747           ) {
 748             if (seen.has(ref)) {
 749               /* do nothing */
 750             } else {
 751               refs.push(ref);
 752               seen.add(ref);
 753             }
 754           }
 755           results[recency] = { dateTime, hash, humanReadable, refs };
 756         } while (recency-- > 0 && current && current != commit);
 757         return results;
 758       })(),
 759       ...Array.from(
 760         pages.keys(),
 761         (name) => ensureDir(`${DESTINATION}/${name}`),
 762       ),
 763       ["style.css"].map((dependency) =>
 764         getRemoteContent(dependency).then((source) =>
 765           Deno.writeTextFile(
 766             `${DESTINATION}/${dependency}`,
 767             source,
 768             { createNew: true },
 769           )
 770         )
 771       ),
 772     ]).then(logErrorsAndCollectResults);
 773     promises.length = 0;
 774     const { redLinks, subpages } = (() => {
 775       const redLinks = new Set();
 776       const subpages = new Map();
 777       for (const [pageRef, page] of pages) {
 778         let superRef = pageRef;
 779         while (
 780           (superRef = superRef.substring(0, superRef.indexOf("/")))
 781         ) {
 782           // Iterate over potential superpages and record them if they
 783           // actually exist.
 784           if (pages.has(superRef)) {
 785             // There is a superpage for the current page; record it.
 786             if (subpages.has(superRef)) {
 787               // The identified superpage already has other subpages.
 788               subpages.get(superRef).add(pageRef);
 789             } else {
 790               // The identified superpage does not already have other
 791               // subpages.
 792               subpages.set(superRef, new Set([pageRef]));
 793             }
 794             break;
 795           } else {
 796             // The superpage for the current page has not been found
 797             // yet.
 798             /* do nothing */
 799           }
 800         }
 801         for (const link of page.internalLinks()) {
 802           // Iterate over the internal links of the current page and
 803           // ensure they are all defined.
 804           if (pages.has(link)) {
 805             // The link was defined.
 806             continue;
 807           } else {
 808             // The link was not defined; it is a redlink.
 809             redLinks.add(link);
 810           }
 811         }
 812       }
 813       return { redLinks, subpages };
 814     })();
 815     for (const [pageRef, page] of pages) {
 816       const { ast, sections, source } = page;
 817       const title = sections.main?.title ?? pageRef;
 818       const internalLinks = new Set(page.internalLinks());
 819       const externalLinks = new Map(page.externalLinks());
 820       const subpageRefs = subpages.get(pageRef) ?? new Set();
 821       djot.applyFilter(ast, () => {
 822         let isNavigationPage = true;
 823         return {
 824           doc: {
 825             enter: (e) => {
 826               const seeAlsoSection = [];
 827               const linksSection = [];
 828               if (subpageRefs.size) {
 829                 seeAlsoSection.push(
 830                   rawBlock`<nav id="seealso">`,
 831                   {
 832                     tag: "heading",
 833                     level: 2,
 834                     children: [
 835                       str`see also`,
 836                     ],
 837                   },
 838                   rawBlock`<section id="subpages">`,
 839                   {
 840                     tag: "heading",
 841                     level: 3,
 842                     children: [
 843                       str`subpages`,
 844                     ],
 845                   },
 846                   listOfInternalLinks(subpageRefs),
 847                   rawBlock`</section>`,
 848                   rawBlock`</nav>`,
 849                 );
 850               } else {
 851                 /* do nothing */
 852               }
 853               if (internalLinks.size || externalLinks.size) {
 854                 linksSection.push(
 855                   rawBlock`<nav id="links">`,
 856                   {
 857                     tag: "heading",
 858                     level: 2,
 859                     children: [str`this page contains links`],
 860                   },
 861                 );
 862                 if (internalLinks.size) {
 863                   linksSection.push(
 864                     rawBlock`<details open="">`,
 865                     rawBlock`<summary>on this wiki</summary>`,
 866                     listOfInternalLinks(internalLinks),
 867                     rawBlock`</details>`,
 868                   );
 869                 } else {
 870                   /* do nothing */
 871                 }
 872                 if (externalLinks.size) {
 873                   linksSection.push(
 874                     rawBlock`<details open="">`,
 875                     rawBlock`<summary>elsewhere on the Web</summary>`,
 876                     {
 877                       tag: "bullet_list",
 878                       tight: true,
 879                       style: "*",
 880                       children: Array.from(
 881                         externalLinks,
 882                         ([destination, text]) => ({
 883                           tag: "list_item",
 884                           children: [{
 885                             tag: "para",
 886                             children: [{
 887                               tag: "link",
 888                               attributes: { "data-realm": "external" },
 889                               destination,
 890                               children: text
 891                                 ? [
 892                                   rawInline`<cite>`,
 893                                   str`${text}`,
 894                                   rawInline`</cite>`,
 895                                 ]
 896                                 : [
 897                                   rawInline`<code>`,
 898                                   str`${destination}`,
 899                                   rawInline`</code>`,
 900                                 ],
 901                             }],
 902                           }],
 903                         }),
 904                       ),
 905                     },
 906                     rawBlock`</details>`,
 907                   );
 908                 } else {
 909                   /* do nothing */
 910                 }
 911                 linksSection.push(
 912                   rawBlock`</nav>`,
 913                 );
 914               } else {
 915                 /* do nothing */
 916               }
 917               const childrenAndLinks = [
 918                 ...e.children,
 919                 ...seeAlsoSection,
 920                 rawBlock`<footer>`,
 921                 rawBlock`${"\uFFFF"}`, // footnote placeholder
 922                 ...linksSection,
 923                 rawBlock`</footer>`,
 924               ];
 925               const { content, navigation } = (() => {
 926                 const navigation = [];
 927                 if (pageRef == "Special:RecentlyChanged") {
 928                   navigation.push({
 929                     tag: "bullet_list",
 930                     attributes: { class: "recent-changes" },
 931                     tight: true,
 932                     style: "*",
 933                     children: Array.from(function* () {
 934                       for (
 935                         const [index, result] of recentlyChanged
 936                           .entries()
 937                       ) {
 938                         if (result != null) {
 939                           const {
 940                             dateTime,
 941                             humanReadable,
 942                             refs,
 943                           } = result;
 944                           yield* listOfInternalLinks(refs, (link) => ({
 945                             tag: index == 0 ? "span" : "strong",
 946                             attributes: { "data-recency": `${index}` },
 947                             children: [
 948                               link,
 949                               ...(index == 0 ? [] : [
 950                                 str` `,
 951                                 rawInline`<small>(<time dateTime="${dateTime}">`,
 952                                 str`${humanReadable}`,
 953                                 rawInline`</time>)</small>`,
 954                               ]),
 955                             ],
 956                           })).children;
 957                         } else {
 958                           /* do nothing */
 959                         }
 960                       }
 961                     }()).reverse(),
 962                   });
 963                 } else {
 964                   isNavigationPage = false;
 965                   return { content: childrenAndLinks, navigation };
 966                 }
 967                 return {
 968                   content: [
 969                     {
 970                       tag: "heading",
 971                       attributes: {
 972                         class: "main",
 973                         generated: "", // will be removed later
 974                       },
 975                       level: 1,
 976                       children: [str`${title}`],
 977                     },
 978                     rawBlock`<details id="navigation-about" open="">`,
 979                     rawBlock`<summary>about this listing</summary>`,
 980                     rawBlock`<article>`,
 981                     ...childrenAndLinks,
 982                     rawBlock`</article>`,
 983                     rawBlock`</details>`,
 984                   ],
 985                   navigation: [
 986                     rawBlock`<nav id="navigation">`,
 987                     ...navigation,
 988                     rawBlock`</nav>`,
 989                   ],
 990                 };
 991               })();
 992               e.children = [
 993                 rawBlock`<article>`,
 994                 ...content,
 995                 ...navigation,
 996                 rawBlock`</article>`,
 997               ];
 998             },
 999             exit: (_) => {},
1000           },
1001           heading: {
1002             enter: (e) => {
1003               const attributes = e.attributes ?? NIL;
1004               if (
1005                 isNavigationPage && e.level == 1 &&
1006                 attributes?.class == "main"
1007               ) {
1008                 if ("generated" in attributes) {
1009                   delete attributes.generated;
1010                 } else {
1011                   return { stop: [] };
1012                 }
1013               } else {
1014                 /* do nothing */
1015               }
1016             },
1017             exit: (e) => {
1018               if (e.level == 1 && e.attributes?.class == "main") {
1019                 return [
1020                   rawBlock`<header class="main">`,
1021                   e,
1022                   { tag: "verbatim", text: pageRef },
1023                   rawBlock`</header>`,
1024                 ];
1025               } else {
1026                 /* do nothing */
1027               }
1028             },
1029           },
1030           link: {
1031             enter: (_) => {},
1032             exit: (e) => {
1033               e.attributes ??= {};
1034               const { attributes, children, reference } = e;
1035               if (attributes["data-realm"] == "internal") {
1036                 delete e.reference;
1037                 if (redLinks.has(reference)) {
1038                   e.destination =
1039                     `/Special:NotFound?path=/${reference}`;
1040                   attributes["data-notfound"] = "";
1041                 } else {
1042                   e.destination = `/${reference}`;
1043                 }
1044                 if (children.length == 0) {
1045                   const section =
1046                     pages.get(reference)?.sections?.main ?? NIL;
1047                   const { v } = attributes;
1048                   if (v == null) {
1049                     children.push(
1050                       str`${section.title ?? reference}`,
1051                     );
1052                   } else {
1053                     delete attributes.v;
1054                     children.push(
1055                       str`${
1056                         section.variantTitles?.[v] ?? section.title ??
1057                           reference
1058                       }`,
1059                     );
1060                   }
1061                 }
1062               } else {
1063                 if (children.length == 0 && "title" in attributes) {
1064                   children.push(
1065                     rawInline`<cite>`,
1066                     str`${attributes.title}`,
1067                     rawInline`</cite>`,
1068                   );
1069                 }
1070               }
1071               if (
1072                 (attributes.class ?? "").split(/\s/gu).includes("sig")
1073               ) {
1074                 return {
1075                   tag: "span",
1076                   attributes: { class: "sig" },
1077                   children: [str`—${"\xA0"}`, e],
1078                 };
1079               } else {
1080                 /* do nothing */
1081               }
1082             },
1083           },
1084           section: {
1085             enter: (_) => {},
1086             exit: (e) => {
1087               if (e.children.length < 1) {
1088                 // The heading for this section was removed and it had
1089                 // no other children.
1090                 return [];
1091               } else {
1092                 /* do nothing */
1093               }
1094             },
1095           },
1096         };
1097       });
1098       const renderedAST = djot.renderAST(ast);
1099       const doc = getDOM(template);
1100       const result = getDOM(djot.renderHTML(ast, {
1101         overrides: {
1102           raw_block: (node, context) => {
1103             if (node.format == "html" && node.text == "\uFFFF") {
1104               if (context.nextFootnoteIndex > 1) {
1105                 const result = context.renderNotes(ast.footnotes);
1106                 context.nextFootnoteIndex = 1;
1107                 return result;
1108               } else {
1109                 return "";
1110               }
1111             } else {
1112               return context.renderAstNodeDefault(node);
1113             }
1114           },
1115         },
1116       }));
1117       const headElement = domutils.findOne(
1118         (node) => node.name == "head",
1119         doc,
1120       );
1121       const titleElement = domutils.findOne(
1122         (node) => node.name == "title",
1123         headElement,
1124       );
1125       const contentElement = domutils.findOne(
1126         (node) => node.name == "gitwikiweb-content",
1127         doc,
1128       );
1129       if (headElement == null) {
1130         throw new Error(
1131           "GitWikiWeb: Template must explicitly include a <head> element.",
1132         );
1133       } else {
1134         domutils.appendChild(
1135           headElement,
1136           new Element("link", {
1137             rel: "source",
1138             type: "text/x.djot",
1139             href: `/${pageRef}/source.djot`,
1140           }),
1141         );
1142         if (titleElement == null) {
1143           domutils.prependChild(
1144             headElement,
1145             new Element("title", {}, [new Text(title)]),
1146           );
1147         } else {
1148           domutils.prependChild(titleElement, new Text(`${title} | `));
1149         }
1150       }
1151       if (contentElement == null) {
1152         throw new Error(
1153           "GitWikiWeb: Template did not include a <gitwikiweb-content> element.",
1154         );
1155       } else {
1156         for (const node of [...result]) {
1157           domutils.prepend(contentElement, node);
1158         }
1159         domutils.removeElement(contentElement);
1160       }
1161       promises.push(
1162         Deno.writeTextFile(
1163           `${DESTINATION}/${pageRef}/index.html`,
1164           domSerializer(doc, {
1165             emptyAttrs: true,
1166             encodeEntities: "utf8",
1167             selfClosingTags: true,
1168             xmlMode: false,
1169           }),
1170           { createNew: true },
1171         ),
1172       );
1173       promises.push(
1174         Deno.writeTextFile(
1175           `${DESTINATION}/${pageRef}/index.ast`,
1176           renderedAST,
1177           { createNew: true },
1178         ),
1179       );
1180       promises.push(
1181         Deno.writeTextFile(
1182           `${DESTINATION}/${pageRef}/source.djot`,
1183           source,
1184           { createNew: true },
1185         ),
1186       );
1187     }
1188     await Promise.allSettled(promises).then(
1189       logErrorsAndCollectResults,
1190     );
1191     console.log(`GitWikiWeb: Wrote ${pages.size} page(s).`);
1192   }
1193 }