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

interface ItemFormData {
  name: string;
  category: string;
  item_type: string;
  quantity: number;
  barcode?: string;
  part_number?: string;
  box_label?: string;
}

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

interface UseItemCreateReturn {
  step: 'details' | 'photo' | 'preview' | 'confirm';
  formData: ItemFormData;
  setFormData: (data: Partial<ItemFormData>) => void;
  uploadedPhoto: UploadedPhoto | null;
  cropBounds: CropBounds | null;
  setCropBounds: (bounds: CropBounds | null) => void;
  isLoading: boolean;
  error: string | null;
  photoError: string | null;
  goToStep: (step: 'details' | 'photo' | 'preview' | 'confirm') => void;
  nextStep: () => void;
  prevStep: () => void;
  uploadPhoto: (file: File, photoItemId?: number) => Promise<void>;
  submitItem: (userId: number) => Promise<any>;
  reset: () => void;
}

const initialFormData: ItemFormData = {
  name: '',
  category: '',
  item_type: '',
  quantity: 1,
  barcode: '',
  part_number: '',
  box_label: '',
};

export function useItemCreate(): UseItemCreateReturn {
  const [step, setStep] = useState<'details' | 'photo' | 'preview' | 'confirm'>('details');
  const [formData, setFormDataState] = useState<ItemFormData>(initialFormData);
  const [uploadedPhoto, setUploadedPhoto] = useState<UploadedPhoto | null>(null);
  const [cropBounds, setCropBounds] = useState<CropBounds | null>(null);
  const [isLoading, setIsLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [photoError, setPhotoError] = useState<string | null>(null);
  const [itemId, setItemId] = useState<number | null>(null);

  const setFormData = useCallback((data: Partial<ItemFormData>) => {
    setFormDataState((prev) => ({ ...prev, ...data }));
  }, []);

  const goToStep = useCallback((newStep: 'details' | 'photo' | 'preview' | 'confirm') => {
    setError(null);
    setPhotoError(null);
    setStep(newStep);
  }, []);

  const nextStep = useCallback(() => {
    const steps: Array<'details' | 'photo' | 'preview' | 'confirm'> = ['details', 'photo', 'preview', 'confirm'];
    const currentIndex = steps.indexOf(step);
    if (currentIndex < steps.length - 1) {
      goToStep(steps[currentIndex + 1]);
    }
  }, [step, goToStep]);

  const prevStep = useCallback(() => {
    const steps: Array<'details' | 'photo' | 'preview' | 'confirm'> = ['details', 'photo', 'preview', 'confirm'];
    const currentIndex = steps.indexOf(step);
    if (currentIndex > 0) {
      goToStep(steps[currentIndex - 1]);
    }
  }, [step, goToStep]);

  const uploadPhoto = useCallback(
    async (file: File, photoItemId?: number) => {
      const idToUse = photoItemId || itemId;

      if (!idToUse) {
        setPhotoError('Item must be created before uploading photo');
        return;
      }

      setPhotoError(null);
      setIsLoading(true);

      try {
        const formDataUpload = new FormData();
        formDataUpload.append('file', file);

        // If crop bounds are set, add them to the request
        if (cropBounds) {
          formDataUpload.append('crop_bounds', JSON.stringify(cropBounds));
        }

        const response = await inventoryApi.uploadItemPhoto(idToUse, formDataUpload);

        if (response.status === 'ok' && response.photo) {
          setUploadedPhoto({
            thumbnail_url: response.photo.thumbnail_url,
            full_url: response.photo.full_url,
            uploaded_at: response.photo.uploaded_at,
          });
          setIsLoading(false);
        } else {
          throw new Error('Invalid response from server');
        }
      } catch (err: any) {
        const errorMsg = err.message || 'Photo upload failed';
        setPhotoError(errorMsg);
        setIsLoading(false);
        throw new Error(errorMsg);
      }
    },
    [itemId, cropBounds]
  );

  const submitItem = useCallback(
    async (userId: number) => {
      setError(null);
      setIsLoading(true);

      try {
        // Validate form data
        if (!formData.name.trim()) {
          const errorMsg = 'Item name is required';
          setError(errorMsg);
          setIsLoading(false);
          return undefined;
        }
        if (!formData.category) {
          const errorMsg = 'Category is required';
          setError(errorMsg);
          setIsLoading(false);
          return undefined;
        }
        if (!formData.item_type) {
          const errorMsg = 'Item type is required';
          setError(errorMsg);
          setIsLoading(false);
          return undefined;
        }

        // Create item first (without photo)
        const createdItem = await inventoryApi.createItem(userId, formData);

        if (!createdItem.id) {
          const errorMsg = 'Failed to create item';
          setError(errorMsg);
          setIsLoading(false);
          return undefined;
        }

        setItemId(createdItem.id);
        setIsLoading(false);

        return createdItem;
      } catch (err: any) {
        const errorMsg = err.message || 'Failed to create item';
        setError(errorMsg);
        setIsLoading(false);
        return undefined;
      }
    },
    [formData]
  );

  const reset = useCallback(() => {
    setStep('details');
    setFormDataState(initialFormData);
    setUploadedPhoto(null);
    setCropBounds(null);
    setItemId(null);
    setError(null);
    setPhotoError(null);
  }, []);

  return {
    step,
    formData,
    setFormData,
    uploadedPhoto,
    cropBounds,
    setCropBounds,
    isLoading,
    error,
    photoError,
    goToStep,
    nextStep,
    prevStep,
    uploadPhoto,
    submitItem,
    reset,
  };
}