// src/hooks/useWatchedItems.tsx
import { useMemo, useCallback } from 'react';
import { useAuth } from '../hooks/useAuth';
import { useUserData } from '../hooks/useUserData';
import { useAddWatchedItemMutation, useRemoveWatchedItemMutation } from './mutations';
import { logger } from '../services/logger.client';

/**
 * A custom hook to manage all state and logic related to a user's watched items.
 *
 * This hook has been refactored to use TanStack Query mutations (ADR-0005 Phase 4).
 * It provides a simplified interface for adding and removing watched items with:
 * - Automatic cache invalidation
 * - Success/error notifications
 * - No manual state management
 *
 * The interface remains backward compatible with the previous implementation.
 */
const useWatchedItemsHook = () => {
  const { userProfile } = useAuth();
  const { watchedItems } = useUserData();

  // TanStack Query mutation hooks
  const addWatchedItemMutation = useAddWatchedItemMutation();
  const removeWatchedItemMutation = useRemoveWatchedItemMutation();

  // Consolidate errors from both mutations
  const error = useMemo(() => {
    const addErr = addWatchedItemMutation.error;
    const removeErr = removeWatchedItemMutation.error;
    return addErr?.message || removeErr?.message || null;
  }, [addWatchedItemMutation.error, removeWatchedItemMutation.error]);

  /**
   * Add an item to the watched items list.
   * Uses TanStack Query mutation which automatically invalidates the cache.
   */
  const addWatchedItem = useCallback(
    async (itemName: string, category_id: number) => {
      if (!userProfile) return;

      try {
        await addWatchedItemMutation.mutateAsync({ itemName, category_id });
      } catch (error) {
        // Error is already handled by the mutation hook (notification shown)
        // Just log for debugging
        logger.error({ err: error }, '[useWatchedItems] Failed to add item');
      }
    },
    [userProfile, addWatchedItemMutation],
  );

  /**
   * Remove an item from the watched items list.
   * Uses TanStack Query mutation which automatically invalidates the cache.
   */
  const removeWatchedItem = useCallback(
    async (masterItemId: number) => {
      if (!userProfile) return;

      try {
        await removeWatchedItemMutation.mutateAsync({ masterItemId });
      } catch (error) {
        // Error is already handled by the mutation hook (notification shown)
        // Just log for debugging
        logger.error({ err: error }, '[useWatchedItems] Failed to remove item');
      }
    },
    [userProfile, removeWatchedItemMutation],
  );

  return {
    watchedItems,
    addWatchedItem,
    removeWatchedItem,
    error,
  };
};

export { useWatchedItemsHook as useWatchedItems };