import { useState, useCallback } from 'react';
import { inventoryApi } from '@/lib/api';

interface Photo {
  thumbnail_url: string;
  full_url: string;
  uploaded_at: string;
}

interface UsePhotoUploadReturn {
  upload: (file: File, itemId: number) => Promise<Photo>;
  isLoading: boolean;
  error: string | null;
}

const ACCEPTED_MIME_TYPES = ['image/jpeg', 'image/png', 'image/webp', 'image/gif'];
const MAX_FILE_SIZE = 10 * 1024 * 1024; // 10MB

export function usePhotoUpload(): UsePhotoUploadReturn {
  const [isLoading, setIsLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);

  const validateFile = useCallback((file: File): { valid: boolean; error?: string } => {
    // Validate file size
    if (file.size > MAX_FILE_SIZE) {
      return {
        valid: false,
        error: 'File too large, max 10MB',
      };
    }

    // Validate MIME type
    if (!ACCEPTED_MIME_TYPES.includes(file.type)) {
      return {
        valid: false,
        error: 'Invalid image format',
      };
    }

    return { valid: true };
  }, []);

  const upload = useCallback(
    async (file: File, itemId: number): Promise<Photo> => {
      setError(null);
      setIsLoading(true);

      try {
        // Validate file (synchronously)
        const validation = validateFile(file);
        if (!validation.valid) {
          const errorMsg = validation.error || 'File validation failed';
          setError(errorMsg);
          setIsLoading(false);
          throw new Error(errorMsg);
        }

        // Create FormData for multipart upload
        const formData = new FormData();
        formData.append('file', file);

        // Upload to backend
        const response = await inventoryApi.uploadItemPhoto(itemId, formData);

        // Handle response
        if (response.status === 'ok' && response.photo) {
          const photo: Photo = {
            thumbnail_url: response.photo.thumbnail_url,
            full_url: response.photo.full_url,
            uploaded_at: response.photo.uploaded_at,
          };
          setIsLoading(false);
          return photo;
        }

        throw new Error('Invalid response from server');
      } catch (err: any) {
        const errorMsg = err.message || 'Upload failed';
        setError(errorMsg);
        setIsLoading(false);
        throw new Error(errorMsg);
      }
    },
    [validateFile]
  );

  return {
    upload,
    isLoading,
    error,
  };
}