@lobehub/ui/es/hooks/useMarkdown/utils.js

Lobe UI is an open-source UI component library for building AIGC web apps

import { preprocessLaTeX } from "./latex";

// Cache configuration
var CACHE_SIZE = 50;

/**
 * Cache for storing processed content to avoid redundant processing
 */
export var contentCache = new Map();

/**
 * Adds content to the cache with size limitation
 * Removes oldest entry if cache size limit is reached
 *
 * @param key The cache key
 * @param value The processed content to store
 */
export var addToCache = function addToCache(key, value) {
  if (contentCache.size >= CACHE_SIZE) {
    // Remove the oldest cache entry
    var firstKey = contentCache.keys().next().value;
    if (firstKey) contentCache.delete(firstKey);
  }
  contentCache.set(key, value);
};

/**
 * Transforms citation references in the format [n] to markdown links
 *
 * @param rawContent The markdown content with citation references
 * @param length The number of citations
 * @returns The content with citations transformed to markdown links
 */
export var transformCitations = function transformCitations(rawContent) {
  var length = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 0;
  if (length === 0) return rawContent;

  // 生成引用索引
  var citationIndices = Array.from({
    length: length
  }).fill('').map(function (_, index) {
    return index + 1;
  });

  // 匹配所有潜在的引用
  var pattern = new RegExp("\\[(".concat(citationIndices.join('|'), ")\\]"), 'g');
  var matches = [];
  var match;
  while ((match = pattern.exec(rawContent)) !== null) {
    matches.push({
      id: match[1],
      index: match.index,
      length: match[0].length
    });
  }

  // 识别所有需要排除的区域
  var excludedRanges = [];

  // 查找LaTeX块 $$...$$
  var latexBlockRegex = /\$\$([\S\s]*?)\$\$/g;
  while ((match = latexBlockRegex.exec(rawContent)) !== null) {
    excludedRanges.push({
      end: match.index + match[0].length - 1,
      start: match.index
    });
  }

  // 查找行内LaTeX $...$
  var inlineLatexRegex = /\$([^$]*?)\$/g;
  while ((match = inlineLatexRegex.exec(rawContent)) !== null) {
    excludedRanges.push({
      end: match.index + match[0].length - 1,
      start: match.index
    });
  }

  // 查找代码块 ```...```
  var codeBlockRegex = /```([\S\s]*?)```/g;
  while ((match = codeBlockRegex.exec(rawContent)) !== null) {
    excludedRanges.push({
      end: match.index + match[0].length - 1,
      start: match.index
    });
  }

  // 查找行内代码 `...`
  var inlineCodeRegex = /`([^`]*?)`/g;
  while ((match = inlineCodeRegex.exec(rawContent)) !== null) {
    excludedRanges.push({
      end: match.index + match[0].length - 1,
      start: match.index
    });
  }

  // 过滤掉在排除区域内的引用
  var validMatches = matches.filter(function (citation) {
    return !excludedRanges.some(function (range) {
      return citation.index >= range.start && citation.index <= range.end;
    });
  });

  // 从后向前替换，避免索引变化问题
  var result = rawContent;
  for (var i = validMatches.length - 1; i >= 0; i--) {
    var citation = validMatches[i];
    var before = result.slice(0, Math.max(0, citation.index));
    var after = result.slice(Math.max(0, citation.index + citation.length));
    result = before + "[#citation-".concat(citation.id, "](citation-").concat(citation.id, ")") + after;
  }

  // 处理连续引用
  return result.replaceAll('][', '] [');
};

/**
 * Preprocessing options for markdown content
 */

export var preprocessMarkdownContent = function preprocessMarkdownContent(str) {
  var _ref = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {},
    enableCustomFootnotes = _ref.enableCustomFootnotes,
    enableLatex = _ref.enableLatex,
    citationsLength = _ref.citationsLength;
  var content = str;

  // Process LaTeX expressions
  if (enableLatex) {
    content = preprocessLaTeX(content);
  }

  // Process custom footnotes/citations
  if (enableCustomFootnotes) {
    content = transformCitations(content, citationsLength);
  }
  return content;
};