/**
 * Metadata Utilities
 * Centralized metadata handling and sanitization functions
 */

/**
 * Sanitize metadata value for safe storage
 */
export function sanitizeMetadataValue(value: string | undefined | null): string {
  if (!value) return "";

  // Remove potentially problematic characters
  return value
    .replace(/[\r\n\t]/g, " ")  // Replace newlines and tabs with spaces
    .replace(/[^\x20-\x7E]/g, "") // Remove non-printable characters
    .trim()
    .substring(0, 1000); // Limit length to prevent storage issues
}

/**
 * Create standardized metadata object
 */
export function createMetadata(data: Record<string, any>): Record<string, string> {
  const metadata: Record<string, string> = {};

  for (const [key, value] of Object.entries(data)) {
    if (value !== undefined && value !== null) {
      metadata[key] = sanitizeMetadataValue(String(value));
    }
  }

  return metadata;
}

/**
 * Merge metadata objects safely
 */
export function mergeMetadata(
  ...metadataObjects: (Record<string, string> | undefined)[]
): Record<string, string> {
  const result: Record<string, string> = {};

  for (const metadata of metadataObjects) {
    if (metadata) {
      Object.assign(result, metadata);
    }
  }

  return result;
}

/**
 * Extract common metadata fields
 */
export function extractCommonMetadata(source: any): Record<string, string> {
  return createMetadata({
    id: source.id,
    title: source.title,
    description: source.description,
    createdAt: source.createdAt || new Date().toISOString(),
    updatedAt: source.updatedAt || new Date().toISOString(),
    duration: source.duration,
    fileSize: source.fileSize,
  });
}

/**
 * Create request metadata
 */
export function createRequestMetadata(requestId: string, additionalData?: Record<string, any>): Record<string, string> {
  return createMetadata({
    requestId,
    timestamp: new Date().toISOString(),
    ...additionalData,
  });
}