git.r.bdr.sh - rbdr/blog/blob - lib/blog.js

   1 'use strict';
   2
   3 const { access, mkdir, readdir, readFile, rm, writeFile } = require('fs/promises');
   4 const { exec } = require('child_process');
   5 const { ncp } = require('ncp');
   6 const { resolve, join } = require('path');
   7 const ParseGemini = require('gemini-to-html/parse');
   8 const RenderGemini = require('gemini-to-html/render');
   9 const { debuglog, promisify } = require('util');
  10
  11 // Generators for the Blog
  12
  13 const StaticGenerator = require('./generators/static');
  14 const HTMLGenerator = require('./generators/html');
  15 const RSSGenerator = require('./generators/rss');
  16 const TXTGenerator = require('./generators/txt');
  17
  18 // Archiving Methods
  19
  20 const GemlogArchiver = require('./archivers/gemlog');
  21
  22 const internals = {
  23
  24   // Promisified functions
  25   exec: promisify(exec),
  26   ncp: promisify(ncp),
  27
  28   debuglog: debuglog('blog'),
  29
  30   // constants
  31
  32   kFileNotFoundError: 'ENOENT',
  33   kGeminiRe: /\.gmi$/i,
  34   kMetadataFilename: 'metadata.json',
  35
  36   // Strings
  37
  38   strings: {
  39     geminiNotFound: 'Gemini file was not found in blog directory. Please update.'
  40   }
  41 };
  42
  43 /**
  44  * The Blog class is the blog generator, it's in charge of adding and
  45  * updating posts, and handling the publishing.
  46  *
  47  * @class Blog
  48  * @param {Blog.tConfiguration} config the initialization options to
  49  * extend the instance
  50  */
  51 module.exports = class Blog {
  52
  53   constructor(config) {
  54
  55     Object.assign(this, config);
  56   }
  57
  58   /**
  59    * Shifts the blog posts, adds the passed path to slot 0, and
  60    * generates files.
  61    *
  62    * @function add
  63    * @memberof Blog
  64    * @param {string} postLocation the path to the directory containing
  65    * the post structure
  66    * @return {Promise<undefined>} empty promise, returns no value
  67    * @instance
  68    */
  69   async add(postLocation) {
  70
  71     await this._ensurePostsDirectoryExists();
  72     await this._shift();
  73     await mkdir(join(this.postsDirectory, '0'));
  74     await this.update(postLocation);
  75   }
  76
  77   /**
  78    * Adds the passed path to slot 0, and generates files.
  79    *
  80    * @function update
  81    * @memberof Blog
  82    * @param {string} postLocation the path to the directory containing
  83    * the post structure
  84    * @return {Promise<undefined>} empty promise, returns no value
  85    * @instance
  86    */
  87   async update(postLocation) {
  88
  89     const metadata = await this._getMetadata();
  90     await this._ensurePostsDirectoryExists();
  91     await this._copyPost(postLocation);
  92     await this._writeMetadata(metadata);
  93
  94     await this._archive(postLocation);
  95
  96     await this.generate();
  97   }
  98
  99   /**
 100    * Publishes the files to a static host.
 101    *
 102    * @function publish
 103    * @memberof Blog
 104    * @return {Promise<undefined>} empty promise, returns no value
 105    * @instance
 106    */
 107   async publish(bucket) {
 108
 109     internals.debuglog(`Publishing to ${bucket}`);
 110     try {
 111       await internals.exec('which aws');
 112     }
 113     catch (err) {
 114       console.error('Please install and configure AWS CLI to publish.');
 115     }
 116
 117     try {
 118       await internals.exec(`aws s3 sync --acl public-read --delete ${this.staticDirectory} s3://${bucket}`);
 119       await internals.exec(`aws s3 cp --content-type 'text/plain; charset=utf-8 ' --acl public-read ${this.staticDirectory}/index.txt s3://${bucket}`);
 120     }
 121     catch (err) {
 122       console.error('Failed to publish');
 123       console.error(err.stderr);
 124     }
 125
 126     internals.debuglog('Finished publishing');
 127   }
 128
 129   /**
 130    * Publishes the archive to a host using rsync. Currently assumes
 131    * gemlog archive.
 132    *
 133    * @function publishArchive
 134    * @memberof Blog
 135    * @return {Promise<undefined>} empty promise, returns no value
 136    * @instance
 137    */
 138   async publishArchive(host) {
 139
 140     internals.debuglog(`Publishing archive to ${host}`);
 141     try {
 142       await internals.exec('which rsync');
 143     }
 144     catch (err) {
 145       console.error('Please install rsync to publish the archive.');
 146     }
 147
 148     try {
 149       const gemlogPath = resolve(join(__dirname, '../', '.gemlog'));
 150       internals.debuglog(`Reading archive from ${gemlogPath}`);
 151       await internals.exec(`rsync -r ${gemlogPath}/ ${host}`);
 152     }
 153     catch (err) {
 154       console.error('Failed to publish archive');
 155       console.error(err.stderr);
 156     }
 157
 158     internals.debuglog('Finished publishing');
 159   }
 160
 161   // Parses Gemini for each page, copies assets and generates index.
 162
 163   async generate() {
 164
 165     internals.debuglog('Generating output');
 166
 167     const posts = await this._readPosts();
 168
 169     await StaticGenerator(this.postsDirectory, this.staticDirectory, posts);
 170     await HTMLGenerator(this.templatesDirectory, this.staticDirectory, posts);
 171     await RSSGenerator(this.templatesDirectory, this.staticDirectory, posts);
 172     await TXTGenerator(this.templatesDirectory, this.staticDirectory, posts);
 173
 174     await GemlogArchiver(this.archiveDirectory);
 175   }
 176
 177   // Reads the posts into an array
 178
 179   async _readPosts() {
 180
 181     internals.debuglog('Reading posts');
 182     const posts = [];
 183
 184     for (let i = 0; i < this.maxPosts; ++i) {
 185       try {
 186         posts.push(await this._readPost(i));
 187       }
 188       catch (error) {
 189         if (error.code === internals.kFileNotFoundError) {
 190           internals.debuglog(`Skipping ${i}`);
 191           continue;
 192         }
 193
 194         throw error;
 195       }
 196     }
 197
 198     return posts;
 199   }
 200
 201   // Reads an individual post
 202
 203   async _readPost(index=0) {
 204       const postSourcePath = join(this.postsDirectory, `${index}`);
 205
 206       internals.debuglog(`Reading ${postSourcePath}`);
 207
 208       await access(postSourcePath);
 209
 210       const metadata = await this._getMetadata(index);
 211
 212       const postContentPath = await this._findBlogContent(postSourcePath);
 213       internals.debuglog(`Reading ${postContentPath}`);
 214       const postContent = await readFile(postContentPath, { encoding: 'utf8' });
 215
 216       internals.debuglog('Parsing Gemini');
 217       return {
 218         ...metadata,
 219         location: postSourcePath,
 220         index,
 221         html: RenderGemini(ParseGemini(postContent)),
 222         raw: postContent
 223       };
 224   }
 225
 226   // Shift the posts, delete any remainder.
 227
 228   async _shift() {
 229
 230
 231     for (let i = this.maxPosts - 1; i >= 0; --i) {
 232       const targetPath = join(this.postsDirectory, `${i}`);
 233       const sourcePath = join(this.postsDirectory, `${i - 1}`);
 234
 235       try {
 236         internals.debuglog(`Archiving ${targetPath}`);
 237         await rm(targetPath, { recursive: true });
 238
 239         await access(sourcePath); // check the source path
 240
 241         internals.debuglog(`Shifting blog post ${sourcePath} to ${targetPath}`);
 242         await internals.ncp(sourcePath, targetPath);
 243       }
 244       catch (error) {
 245         if (error.code === internals.kFileNotFoundError) {
 246           internals.debuglog(`Skipping ${sourcePath}: Does not exist.`);
 247           continue;
 248         }
 249
 250         throw error;
 251       }
 252     }
 253   }
 254
 255   // Moves older posts to the archive
 256
 257   async _archive() {
 258     internals.debuglog('Archiving post');
 259     const post = await this._readPost(0);
 260     await this._ensureDirectoryExists(this.archiveDirectory);
 261
 262     const targetPath = join(this.archiveDirectory, post.id);
 263
 264     try {
 265       internals.debuglog(`Removing ${targetPath}`);
 266       await rm(targetPath, { recursive: true });
 267     }
 268     finally {
 269       internals.debuglog(`Adding ${post.location} to ${targetPath}`);
 270       await internals.ncp(post.location, targetPath);
 271       internals.debuglog(`Added ${post.location} to ${targetPath}`);
 272     }
 273   }
 274
 275   // Attempts to read existing metadata. Otherwise generates new set.
 276
 277   async _getMetadata(index = 0) {
 278
 279     const metadataTarget = join(this.postsDirectory, String(index), internals.kMetadataFilename);
 280
 281     try {
 282       internals.debuglog(`Looking for metadata at ${metadataTarget}`);
 283       return JSON.parse(await readFile(metadataTarget, { encoding: 'utf8' }));
 284     }
 285     catch (e) {
 286       internals.debuglog(`Metadata not found or unreadable. Generating new set.`);
 287       const createdOn = Date.now();
 288       const metadata = {
 289         id: String(createdOn),
 290         createdOn
 291       };
 292
 293       return metadata;
 294     }
 295   }
 296
 297   // Writes metadata. Assumes post 0 since it only gets written
 298   // on create
 299
 300   async _writeMetadata(metadata) {
 301
 302     const metadataTarget = join(this.postsDirectory, '0', internals.kMetadataFilename);
 303     internals.debuglog(`Writing ${metadataTarget}`);
 304     await writeFile(metadataTarget, JSON.stringify(metadata, null, 2));
 305   }
 306
 307   // Copies a post directory to the latest slot.
 308
 309   async _copyPost(postLocation) {
 310
 311     const targetPath = join(this.postsDirectory, '0');
 312
 313     internals.debuglog(`Removing ${targetPath}`);
 314     await rm(targetPath, { recursive: true });
 315
 316     internals.debuglog(`Adding ${postLocation} to ${targetPath}`);
 317     await internals.ncp(postLocation, targetPath);
 318   }
 319
 320   // Ensures a directory exists.
 321
 322   async _ensureDirectoryExists(directory) {
 323
 324     internals.debuglog(`Checking if ${directory} exists.`);
 325     try {
 326       await access(directory);
 327     }
 328     catch (error) {
 329       if (error.code === internals.kFileNotFoundError) {
 330         internals.debuglog('Creating posts directory');
 331         await mkdir(directory);
 332         return;
 333       }
 334
 335       throw error;
 336     }
 337   }
 338
 339   // Ensures posts directory exists
 340
 341   async _ensurePostsDirectoryExists() {
 342
 343     return this._ensureDirectoryExists(this.postsDirectory);
 344     internals.debuglog(`Checking if ${this.postsDirectory} exists.`);
 345     try {
 346       await access(this.postsDirectory);
 347     }
 348     catch (error) {
 349       if (error.code === internals.kFileNotFoundError) {
 350         internals.debuglog('Creating posts directory');
 351         await mkdir(this.postsDirectory);
 352         return;
 353       }
 354
 355       throw error;
 356     }
 357   }
 358
 359   // Looks for a `.gmi` file in the blog directory, and returns the path
 360
 361   async _findBlogContent(directory) {
 362
 363     const entries = await readdir(directory);
 364
 365     const geminiEntries = entries
 366       .filter((entry) => internals.kGeminiRe.test(entry))
 367       .map((entry) => join(directory, entry));
 368
 369     if (geminiEntries.length > 0) {
 370       internals.debuglog(`Found gemini file: ${geminiEntries[0]}`);
 371       return geminiEntries[0];
 372     }
 373
 374     throw new Error(internals.strings.geminiNotFound);
 375   }
 376 };