import { useState, useRef, useCallback } from 'react';
import { toast } from 'sonner';

interface UseFileUploadOptions {
  acceptedTypes?: string[];
  maxSizeMB?: number;
  onFileSelected?: (file: File) => void;
}

interface UseFileUploadResult {
  fileInputRef: React.RefObject<HTMLInputElement>;
  isSelecting: boolean;
  selectedFile: File | null;
  triggerFileSelect: () => void;
  handleFileChange: (event: React.ChangeEvent<HTMLInputElement>) => void;
  clearSelectedFile: () => void;
}

/**
 * A custom hook for handling file uploads with validation
 */
export function useFileUpload(options: UseFileUploadOptions = {}): UseFileUploadResult {
  const {
    acceptedTypes = ['.xlsx', '.xls', '.csv'],
    maxSizeMB = 10,
    onFileSelected
  } = options;
  
  const fileInputRef = useRef<HTMLInputElement>(null);
  const [isSelecting, setIsSelecting] = useState(false);
  const [selectedFile, setSelectedFile] = useState<File | null>(null);

  const triggerFileSelect = useCallback(() => {
    if (fileInputRef.current) {
      fileInputRef.current.click();
    }
  }, []);

  const clearSelectedFile = useCallback(() => {
    setSelectedFile(null);
    if (fileInputRef.current) {
      fileInputRef.current.value = '';
    }
  }, []);

  const handleFileChange = useCallback((event: React.ChangeEvent<HTMLInputElement>) => {
    setIsSelecting(true);
    
    try {
      const file = event.target.files?.[0];
      if (!file) {
        return;
      }

      // Validate file type
      const fileExtension = file.name.substring(file.name.lastIndexOf('.')).toLowerCase();
      if (acceptedTypes.length > 0 && !acceptedTypes.includes(fileExtension)) {
        toast.error(`Invalid file type. Accepted types: ${acceptedTypes.join(', ')}`);
        return;
      }

      // Validate file size
      const maxSizeBytes = maxSizeMB * 1024 * 1024;
      if (file.size > maxSizeBytes) {
        toast.error(`File size too large. Maximum size is ${maxSizeMB}MB`);
        return;
      }

      // Set the selected file
      setSelectedFile(file);
      
      // Call the onFileSelected callback if provided
      if (onFileSelected) {
        onFileSelected(file);
      }
      
      // Reset input value
      event.target.value = '';
    } catch (error) {
      console.error('Error selecting file:', error);
      toast.error('Error selecting file. Please try again.');
    } finally {
      setIsSelecting(false);
    }
  }, [acceptedTypes, maxSizeMB, onFileSelected]);

  return {
    fileInputRef,
    isSelecting,
    selectedFile,
    triggerFileSelect,
    handleFileChange,
    clearSelectedFile,
  };
}

export default useFileUpload;