user-docs

/**
 * Document Loader
 * Orchestrates loading and parsing of documents from various formats
 */

import { readFile } from 'fs/promises';
import { createHash } from 'crypto';
import path from 'path';
import type { DocumentFormat, ParsedDocument, ParserOptions } from '../types';
import { TextParser, MarkdownParser } from './parsers/textParser';
import { PdfParser } from './parsers/pdfParser';

export class DocumentLoader {
  /**
   * Load and parse a document based on its format
   */
  static async load(
    filePath: string,
    options?: ParserOptions
  ): Promise<ParsedDocument & { hash: string }> {
    const format = this.detectFormat(filePath);
    const hash = await this.hashFile(filePath);

    let parsed: ParsedDocument;

    switch (format) {
      case 'txt':
        parsed = await TextParser.parse(filePath, options);
        break;
      
      case 'md':
        parsed = await MarkdownParser.parse(filePath, options);
        break;
      
      case 'pdf':
        parsed = await PdfParser.parse(filePath, options);
        break;
      
      default:
        throw new Error(`Unsupported file format: ${format}`);
    }

    // Add filename as title if not present
    if (!parsed.metadata.title) {
      parsed.metadata.title = path.basename(filePath, path.extname(filePath));
    }

    return {
      ...parsed,
      hash,
    };
  }

  /**
   * Detect document format from file extension
   */
  static detectFormat(filePath: string): DocumentFormat {
    const ext = path.extname(filePath).toLowerCase();
    
    switch (ext) {
      case '.txt':
        return 'txt';
      case '.md':
      case '.markdown':
        return 'md';
      case '.pdf':
        return 'pdf';
      default:
        return 'unknown';
    }
  }

  /**
   * Calculate SHA-256 hash of file content
   */
  private static async hashFile(filePath: string): Promise<string> {
    const buffer = await readFile(filePath);
    return createHash('sha256').update(buffer).digest('hex');
  }

  /**
   * Check if file format is supported
   */
  static isSupported(filePath: string): boolean {
    const format = this.detectFormat(filePath);
    return ['txt', 'md', 'pdf'].includes(format);
  }
}