Function useDataPreview

frontend/src/hooks/useDataPreview.ts:36–537

(targetFileId?: string)

 * Follows the same pattern as useQueryExecution for consistency
 */
export const useDataPreview = (targetFileId?: string): DataPreviewResult => {
  const activeFile = useAppStore(selectActiveFile);
  const { executePaginatedQuery, getObjectType } = useDuckDBStore();
  
  const { 
    getFileState, 
    updateFileState, 
    initializeFileState 
  } = useDataPreviewStore();
  
  // Local loading state for page changes
  const [isChangingPage, setIsChangingPage] = useState(false);
  
  // Use provided fileId or fall back to active file
  const fileId = targetFileId || activeFile?.id || '';
  const fileState = getFileState(fileId) || {
    currentPage: 1,
    rowsPerPage: 1000,
    totalRows: 0,
    totalPages: 0,
    data: null,
    columns: null,
    isLoading: false,
    isCountLoading: false,
    error: null,
    lastFetchTime: 0,
  };
  
  // Get current file based on fileId parameter
  const currentFile = targetFileId 
    ? useAppStore.getState().files.find(f => f.id === targetFileId)
    : activeFile;

  // Initialize file state when file changes
  useEffect(() => {
    if (fileId) {
      initializeFileState(fileId);
    }
  }, [fileId, initializeFileState]);
  
  /**
   * Load initial data for the target file
   */
  const loadInitialData = useCallback(async () => {
    if (!currentFile?.tableName || !fileId) return;
    
    const existingState = getFileState(fileId);
    
    // If we already have data cached and it's recent (< 5 minutes), use it
    if (existingState?.data && existingState.lastFetchTime > Date.now() - 5 * 60 * 1000) {
      console.log('[useDataPreview] Using cached data for file:', currentFile.fileName);
      return;
    }
    
    try {
      updateFileState(fileId, { 
        isLoading: true, 
        error: null