tweb-i2p/src/lib/richTextProcessor/parseEntities.ts

/*
 * https://github.com/morethanwords/tweb
 * Copyright (C) 2019-2021 Eduard Kuzmenko
 * https://github.com/morethanwords/tweb/blob/master/LICENSE
 * 
 * Originally from:
 * https://github.com/zhukov/webogram
 * Copyright (C) 2014 Igor Zhukov <igor.beatle@gmail.com>
 * https://github.com/zhukov/webogram/blob/master/LICENSE
 */

import { EMAIL_REG_EXP, FULL_REG_EXP } from ".";
import TLD from "../../config/tld";
import { MessageEntity } from "../../layer";
import checkBrackets from "./checkBrackets";
import getEmojiUnified from "./getEmojiUnified";

export default function parseEntities(text: string) {
  let match: any;
  let raw = text;
  const entities: MessageEntity[] = [];
  let matchIndex;
  let rawOffset = 0;
  // var start = tsNow()
  FULL_REG_EXP.lastIndex = 0;
  while((match = raw.match(FULL_REG_EXP))) {
    matchIndex = rawOffset + match.index;

    //console.log('parseEntities match:', match);

    if(match[3]) { // mentions
      entities.push({
        _: 'messageEntityMention',
        offset: matchIndex + match[1].length,
        length: match[2].length + match[3].length
      });
    } else if(match[4]) {
      if(EMAIL_REG_EXP.test(match[4])) { // email
        entities.push({
          _: 'messageEntityEmail',
          offset: matchIndex,
          length: match[4].length
        });
      } else {
        let url: string;
        let protocol = match[5];
        const tld = match[6];
        // let excluded = '';
        if(tld) { // URL
          if(!protocol && (tld.substr(0, 4) === 'xn--' || TLD.indexOf(tld.toLowerCase()) !== -1)) {
            protocol = 'http://';
          }

          if(protocol) {
            const balanced = checkBrackets(match[4]);
            if(balanced.length !== match[4].length) {
              // excluded = match[4].substring(balanced.length);
              match[4] = balanced;
            }

            url = (match[5] ? '' : protocol) + match[4];
          }
        } else { // IP address
          url = (match[5] ? '' : 'http://') + match[4];
        }

        if(url) {
          entities.push({
            _: 'messageEntityUrl',
            offset: matchIndex,
            length: match[4].length
          });
        }
      }
    } else if(match[7]) { // New line
      entities.push({
        _: 'messageEntityLinebreak',
        offset: matchIndex,
        length: 1
      });
    } else if(match[8]) { // Emoji
      //console.log('hit', match[8]);
      const unified = getEmojiUnified(match[8]);
      if(unified) {
        entities.push({
          _: 'messageEntityEmoji',
          offset: matchIndex,
          length: match[8].length,
          unicode: unified
        });
      }
    } else if(match[11]) { // Hashtag
      entities.push({
        _: 'messageEntityHashtag',
        offset: matchIndex + (match[10] ? match[10].length : 0),
        length: match[11].length
      });
    } else if(match[13]) { // Bot command
      entities.push({
        _: 'messageEntityBotCommand',
        offset: matchIndex + (match[11] ? match[11].length : 0) + (match[12] ? match[12].length : 0),
        length: 1 + match[13].length + (match[14] ? 1 + match[14].length : 0),
        unsafe: true
      });
    }

    raw = raw.substr(match.index + match[0].length);
    rawOffset += match.index + match[0].length;
  }

  // if (entities.length) {
  //   console.log('parse entities', text, entities.slice())
  // }
  return entities;
}