@coworker-agency/rag/src/indexer/metadata.js

Retrieval Augmented Generation (RAG) library for document indexing, vector storage, and AI-powered question answering

/**
 * Document Metadata Generator
 * 
 * Tools for extracting and generating metadata from documents
 */

/**
 * Generate metadata for a document from Supabase Storage
 * @param {Object} file - File object from Supabase storage
 * @returns {Object} Document metadata
 */
export function generateDocumentMetadata(file) {
  if (!file) {
    throw new Error('File object is required');
  }
  
  // Extract file extension
  const fileExtension = getFileExtension(file.name);
  
  // Format file size in a human-readable format
  const fileSizeFormatted = formatFileSize(file.size || 0);
  
  // Create timestamp
  const timestamp = new Date().toISOString();
  
  return {
    fileName: file.name,
    fileType: fileExtension,
    mimeType: getMimeType(fileExtension),
    fileSize: file.size || 0,
    fileSizeFormatted,
    created: file.created_at || timestamp,
    lastModified: file.last_modified || timestamp,
    indexed: timestamp,
    source: 'supabase_storage',
  };
}

/**
 * Get file extension from filename
 * @param {string} filename - Name of the file
 * @returns {string} File extension
 */
export function getFileExtension(filename) {
  return filename.split('.').pop().toLowerCase();
}

/**
 * Get MIME type based on file extension
 * @param {string} extension - File extension
 * @returns {string} MIME type
 */
function getMimeType(extension) {
  const mimeTypes = {
    'pdf': 'application/pdf',
    'txt': 'text/plain',
    'md': 'text/markdown',
    'json': 'application/json',
    'csv': 'text/csv',
    'doc': 'application/msword',
    'docx': 'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
    'xls': 'application/vnd.ms-excel',
    'xlsx': 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
    'ppt': 'application/vnd.ms-powerpoint',
    'pptx': 'application/vnd.openxmlformats-officedocument.presentationml.presentation',
    'html': 'text/html',
    'htm': 'text/html'
  };
  
  return mimeTypes[extension] || 'application/octet-stream';
}

/**
 * Format file size in human-readable format
 * @param {number} bytes - File size in bytes
 * @returns {string} Formatted file size
 */
function formatFileSize(bytes) {
  if (bytes === 0) return '0 Bytes';
  
  const k = 1024;
  const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB'];
  const i = Math.floor(Math.log(bytes) / Math.log(k));
  
  return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i];
}