/*
 * File: usePredictions.ts
 * Description: Custom hook for managing AI predictions state and actions
 * Design & Developed by Tech4Biz Solutions
 * Copyright (c) Spurrin Innovations. All rights reserved.
 */

import { useEffect, useCallback } from 'react';
import { useAppDispatch, useAppSelector } from '../../../store/hooks';
import {
  fetchAllPredictions,
  setActiveTab,
  setSearchQuery,
  clearErrors,
  clearSearch,
  selectActiveTab,
  selectSearchQuery,
  selectPredictionsWithFeedback,
  selectPredictionsWithoutFeedback,
  selectIsLoading,
  selectError,
  selectCurrentPredictions,
  selectCurrentLoadingState,
  selectCurrentError,
} from '../redux/predictionsSlice';
import { selectUser } from '../../Auth/redux';
import type { PredictionTabType } from '../types/predictions';

// ============================================================================
// USE PREDICTIONS HOOK
// ============================================================================

/**
 * usePredictions Hook
 * 
 * Purpose: Manage AI predictions state and provide actions
 * 
 * Features:
 * - Fetch all predictions from single API call
 * - Frontend filtering for feedback status
 * - Manage active tab state
 * - Handle search functionality
 * - Provide loading and error states
 * - Auto-fetch data when needed
 */
export const usePredictions = () => {
  const dispatch = useAppDispatch();

  // ============================================================================
  // SELECTORS
  // ============================================================================

  const activeTab = useAppSelector(selectActiveTab);
  const searchQuery = useAppSelector(selectSearchQuery);
  
  // Performance optimization: Load both datasets upfront
  const predictionsWithFeedback = useAppSelector(selectPredictionsWithFeedback);
  const predictionsWithoutFeedback = useAppSelector(selectPredictionsWithoutFeedback);
  
  const isLoading = useAppSelector(selectIsLoading);
  const error = useAppSelector(selectError);
  
  // Performance optimization: Direct dataset selection - no filtering needed
  const currentPredictions = useAppSelector(selectCurrentPredictions);
  const currentLoadingState = useAppSelector(selectCurrentLoadingState);
  const currentError = useAppSelector(selectCurrentError);

  // Get authentication token from auth store
  const authToken = useAppSelector(selectUser)?.access_token;

  // ============================================================================
  // ACTIONS
  // ============================================================================

  /**
   * Switch Active Tab
   * 
   * Purpose: Change between feedback tabs
   * Performance: Instant switching - no filtering needed as both datasets are pre-loaded
   */
  const switchTab = useCallback((tab: PredictionTabType) => {
    dispatch(setActiveTab(tab));
  }, [dispatch]);

  /**
   * Update Search Query
   * 
   * Purpose: Update search query for filtering predictions
   */
  const updateSearchQuery = useCallback((query: string) => {
    dispatch(setSearchQuery(query));
  }, [dispatch]);

  /**
   * Clear Search
   * 
   * Purpose: Clear search query
   */
  const clearSearchQuery = useCallback(() => {
    dispatch(clearSearch());
  }, [dispatch]);

  /**
   * Clear Errors
   * 
   * Purpose: Clear error states
   */
  const clearErrorStates = useCallback(() => {
    dispatch(clearErrors());
  }, [dispatch]);

  /**
   * Refresh Predictions
   * 
   * Purpose: Refresh all predictions data
   */
  const refreshPredictions = useCallback(() => {
    if (!authToken) return;
    dispatch(fetchAllPredictions(authToken));
  }, [dispatch, authToken]);

  /**
   * Fetch All Predictions
   * 
   * Purpose: Fetch all predictions from API
   */
  const fetchPredictions = useCallback(() => {
    if (!authToken) return;
    dispatch(fetchAllPredictions(authToken));
  }, [dispatch, authToken]);

  // ============================================================================
  // EFFECTS
  // ============================================================================

  /**
   * Auto-fetch data when component mounts or token changes
   * Performance optimization: Load both datasets upfront to eliminate tab switching delays
   */
  useEffect(() => {
    if (!authToken) return;
    
    // Performance optimization: Always fetch if either dataset is empty
    // This ensures both datasets are loaded upfront for instant tab switching
    if (predictionsWithFeedback.length === 0 || predictionsWithoutFeedback.length === 0) {
      dispatch(fetchAllPredictions(authToken));
    }
  }, [authToken, predictionsWithFeedback.length, predictionsWithoutFeedback.length, dispatch]);

  // ============================================================================
  // RETURN VALUES
  // ============================================================================

  return {
    // State
    activeTab,
    searchQuery,
    predictionsWithFeedback,
    predictionsWithoutFeedback,
    currentPredictions,
    
    // Loading states
    isLoading,
    currentLoadingState,
    
    // Error states
    error,
    currentError,
    
    // Actions
    switchTab,
    updateSearchQuery,
    clearSearchQuery,
    clearErrorStates,
    refreshPredictions,
    fetchPredictions,
    
    // Constants
    authToken
  };
};

/*
 * End of File: usePredictions.ts
 * Design & Developed by Tech4Biz Solutions
 * Copyright (c) Spurrin Innovations. All rights reserved.
 */