dtp-newsroom/src/app/services/text.ts

// app/services/text.ts
// Copyright (C) 2025 DTP Technologies, LLC
// All Rights Reserved

import assert from "node:assert";

import { createRequire } from "module";
const require = createRequire(import.meta.url); // jshint ignore:line

import striptags from "striptags";
import diacritics from "diacritics";
const shoetest = require("shoetest");

import {
  Marked,
  Tokens as MarkedTokens,
  Renderer as MarkedRenderer,
} from "marked";

import WebTextFilter from "./lib/edit-with-vi.js";

import { DtpPlatform, DtpService, DtpUnzalgo } from "../../lib/dtplib.js";

export type ReplacerFunction = (mention: string) => string;

export class TextService extends DtpService {

  static get name ( ) { return "TextService"; }
  static get slug ( ) { return "text"; }

  markedRenderer?: MarkedRenderer;
  marked?: Marked;

  constructor(platform: DtpPlatform) {
    super(platform, TextService);
  }

  async start ( ) : Promise<void> {
    await super.start();

    this.markedRenderer = new MarkedRenderer();
    this.markedRenderer.link = (link: MarkedTokens.Link) : string => {
      if (link.title) {
        return `<a href="${link.href}" title="${link.title}">${link.text}</a>`;
      }
      return `<a href="${link.href}">${link.text}</a>`;
    };
    this.markedRenderer.image = (image: MarkedTokens.Image) => {
      if (image.title) {
        return `<p><img src="${image.href}" class="responsive" title="${image.title}"></img><div class="image-caption">${image.text}</div>`;
      }
      return `<p><img src="${image.href}" class="image centered"></img><div class="image-caption">${image.text}</div>`;
    };

    this.marked = new Marked({
      breaks: true,
      gfm: true,
      renderer: this.markedRenderer,
    });
  }

  /**
   * Basic text cleaning function to remove Zalgo and tags.
   * @param {String} text The text to be cleaned
   * @returns The cleaned text
   */
  clean(text: string): string {
    text = DtpUnzalgo.clean(text);
    text = striptags(text.trim());
    return text;
  }

  /**
   * The heavy hammer of text filtering that removes all malicious and annoying
   * things I know about as of this writing. Zalgo, tags, shoetest, diacritics,
   * and our own custom nonsense UTF-8 and Unicode filters.
   *
   * This filter is very heavy-handed and merciless.
   *
   * @param text string The text to be filtered
   * @returns The filtered text
   */
  filter(text: string): string {
    if (!text || typeof text !== "string" || text.length < 1) {
      return text;
    }

    text = WebTextFilter.filterNonsense(text);
    text = WebTextFilter.filterGuff(text);
    text = WebTextFilter.filterHtml(text);

    text = shoetest.simplify(text);
    text = diacritics.remove(text);

    /*
     * Once all the stupidity has been stripped, strip the HTML
     * tags that might remain.
     */
    return this.clean(text);
  }

  async renderMarkdown (markdown: string) : Promise<string> {
    assert(this.marked, "Marked instance is required");
    return this.marked.parse(markdown);
  }
}

export default TextService;