/**
 * Hook for tracking LinkML schema loading progress
 */

import { useState, useEffect } from 'react';
import { linkmlSchemaService, type SchemaLoadingProgress } from '../lib/linkml/linkml-schema-service';

export interface UseSchemaLoadingProgressResult {
  progress: SchemaLoadingProgress | null;
  isLoading: boolean;
  isComplete: boolean;
}

/**
 * Hook that subscribes to LinkML schema loading progress
 * 
 * @returns Object containing progress state, loading status, and completion status
 * 
 * @example
 * ```tsx
 * const { progress, isLoading, isComplete } = useSchemaLoadingProgress();
 * 
 * if (isLoading && progress) {
 *   return (
 *     <div>
 *       <p>{progress.message}</p>
 *       <progress value={progress.percent} max={100} />
 *     </div>
 *   );
 * }
 * ```
 */
export function useSchemaLoadingProgress(): UseSchemaLoadingProgressResult {
  const [progress, setProgress] = useState<SchemaLoadingProgress | null>(null);
  
  useEffect(() => {
    // Subscribe to progress updates
    const unsubscribe = linkmlSchemaService.onProgress((newProgress) => {
      setProgress(newProgress);
    });
    
    // Trigger initialization if not already loading
    linkmlSchemaService.initialize().catch(console.error);
    
    return unsubscribe;
  }, []);
  
  return {
    progress,
    isLoading: progress !== null && progress.phase !== 'complete',
    isComplete: progress?.phase === 'complete',
  };
}

export default useSchemaLoadingProgress;