import { useState, useEffect } from 'react';
import { useRouter } from 'next/router';
import { VOCAB, collectionDisplayName } from './collection-vocabulary.js';
import { downloadCollectionCardsCsv } from './collection-cards-csv.js';

/**
 * Card/collection page state and handlers (god-component split).
 */
export function useCollectionView({ user = null, authLoading = true } = {}) {
  const router = useRouter();
  const { identifier } = router.query;
  
  const [collection, setCollection] = useState(null);
  const [cards, setCards] = useState([]);
  const [loading, setLoading] = useState(true);
  const [isFavorited, setIsFavorited] = useState(false);
  const [showShareModal, setShowShareModal] = useState(false);
  const [showEditModal, setShowEditModal] = useState(false);
  const [showDeleteModal, setShowDeleteModal] = useState(false);
  const [copySuccess, setCopySuccess] = useState(false);
  const [selectedTCG, setSelectedTCG] = useState('MTG');
  
  // Edit form state
  const [editForm, setEditForm] = useState({
    name: '',
    description: '',
    isPublic: false,
    image: '',
    tags: []
  });
  
  // Filter states
  const [searchQuery, setSearchQuery] = useState('');
  const [selectedRarity, setSelectedRarity] = useState('All Rarities');
  const [selectedType, setSelectedType] = useState('All Types');
  const [groupBy, setGroupBy] = useState('Group by Game');
  const [sortBy, setSortBy] = useState('Sort by Name');
  const [viewMode, setViewMode] = useState('grid');
  const [searchCards, setSearchCards] = useState('');
  const [searchResults, setSearchResults] = useState([]);
  const [showSearchResults, setShowSearchResults] = useState(false);
  const [showUploadModal, setShowUploadModal] = useState(false);
  
  // Card interaction states
  const [selectedCards, setSelectedCards] = useState([]);
  const [favoritedCards, setFavoritedCards] = useState(new Set());
  
  const loadFavoritedCards = async () => {
    try {
      const token = localStorage.getItem('auth_token');
      if (!token) return;
  
      const response = await fetch('/api/favorites?type=card', {
        headers: {
          'Authorization': `Bearer ${token}`
        }
      });
  
      if (response.ok) {
        const data = await response.json();
        const favoriteIds = new Set(data.favorites.map(fav => parseInt(fav.item_id)));
        setFavoritedCards(favoriteIds);
      }
    } catch (error) {
      console.error('Error loading favorited cards:', error);
    }
  };
  
  const checkIfFavorited = async () => {
    try {
      const response = await fetch(`/api/favorites?type=collection`, {
        headers: {
          'Authorization': `Bearer ${localStorage.getItem('auth_token')}`
        }
      });
      if (response.ok) {
        const data = await response.json();
        const isFav = data.favorites.some(fav => fav.item_id === collection?.id);
        setIsFavorited(isFav);
      } else {
        console.error('Failed to check favorites:', response.status);
      }
    } catch (error) {
      console.error('Error checking favorites:', error);
    }
  };
  
  const fetchCollectionData = async () => {
    try {
      // First try to fetch without authentication (for public collections)
      let response = await fetch(`/api/collections/${identifier}`);
      
      // If that fails and we have a user, try with authentication
      if (!response.ok && user) {
        response = await fetch(`/api/collections/${identifier}`, {
          headers: {
            'Authorization': `Bearer ${localStorage.getItem('auth_token')}`
          }
        });
      }
      
      if (response.ok) {
        const data = await response.json();
        
        // Check if we accessed via numeric ID and need to redirect to slug
        if (data.slug && identifier !== data.slug && !isNaN(parseInt(identifier))) {
          // Redirect to slug URL
          router.replace(`/collection/${data.slug}`, undefined, { shallow: false });
          return;
        }
        
        setCollection(data);
        setEditForm({
          name: data.name || '',
          description: data.description || '',
          isPublic: data.isPublic || false,
          image: data.image || '',
          tags: Array.isArray(data.tags) ? data.tags : (data.tags ? data.tags.split(',') : [])
        });
        
        // Fetch collection cards (try public first, then authenticated)
        let cardsResponse = await fetch(`/api/collections/${identifier}/cards`);
        
        if (!cardsResponse.ok && user) {
          cardsResponse = await fetch(`/api/collections/${identifier}/cards`, {
            headers: {
              'Authorization': `Bearer ${localStorage.getItem('auth_token')}`
            }
          });
        }
        
        if (cardsResponse.ok) {
          const cardsData = await cardsResponse.json();
          setCards(cardsData.cards || []);
        }
        
        // Check if collection is favorited
        checkIfFavorited();
      } else if (response.status === 401 || response.status === 403) {
        // Collection is private and user is not authenticated/authorized
        if (!user) {
          router.push('/login');
        } else {
          // User is authenticated but doesn't have access
          router.push('/collections');
        }
      }
    } catch (error) {
      console.error('Error fetching collection:', error);
    } finally {
      setLoading(false);
    }
  };
  
  useEffect(() => {
    if (identifier) {
      // eslint-disable-next-line react-hooks/set-state-in-effect -- load list when slug or auth changes
      fetchCollectionData();
      if (user) {
        loadFavoritedCards();
      }
    }
    // eslint-disable-next-line react-hooks/exhaustive-deps -- reload when list slug or auth changes
  }, [identifier, user]);
  
  const handleEditCollection = async () => {
    try {
      const response = await fetch(`/api/collections/${identifier}`, {
        method: 'PUT',
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${localStorage.getItem('auth_token')}`
        },
        body: JSON.stringify({
          name: editForm.name,
          description: editForm.description,
          isPublic: editForm.isPublic,
          image: editForm.image,
          tags: editForm.tags
        })
      });
  
      if (response.ok) {
        const updatedCollection = await response.json();
        
        // If the name changed and we got a new slug, redirect
        if (updatedCollection.slug && updatedCollection.slug !== identifier) {
          router.push(`/collection/${updatedCollection.slug}`);
        } else {
          // Just refresh the data
          fetchCollectionData();
        }
        
        setShowEditModal(false);
      } else {
        const error = await response.json();
        alert(error.error || 'Failed to update list');
      }
    } catch (error) {
      console.error('Error updating collection:', error);
      alert('Network error. Please try again.');
    }
  };
  
  const handleDeleteCollection = async () => {
    try {
      const response = await fetch(`/api/collections/${identifier}`, {
        method: 'DELETE',
        headers: {
          'Authorization': `Bearer ${localStorage.getItem('auth_token')}`
        }
      });
  
      if (response.ok) {
        router.push('/collections');
      } else {
        const error = await response.json();
        alert(error.error || 'Failed to delete list');
      }
    } catch (error) {
      console.error('Error deleting collection:', error);
      alert('Network error. Please try again.');
    }
  };
  
  const handleSearchCards = async (query) => {
    if (query.length < 2) {
      setSearchResults([]);
      setShowSearchResults(false);
      return;
    }
  
    try {
      const response = await fetch(`/api/cards/search?q=${encodeURIComponent(query)}&limit=10`);
      if (response.ok) {
        const data = await response.json();
        setSearchResults(data.cards || []);
        setShowSearchResults(true);
      }
    } catch (error) {
      console.error('Error searching cards:', error);
    }
  };
  
  const handleAddCard = async (card) => {
    try {
      const response = await fetch(`/api/collections/${identifier}/cards`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${localStorage.getItem('auth_token')}`
        },
        body: JSON.stringify({
          cardId: card.id,
          quantity: 1
        })
      });
  
      if (response.ok) {
        setSearchCards('');
        setShowSearchResults(false);
        fetchCollectionData(); // Refresh the collection data
      }
    } catch (error) {
      console.error('Error adding card:', error);
    }
  };
  
  const toggleFavorite = async () => {
    try {
      if (isFavorited) {
        // Remove from favorites
        const response = await fetch('/api/favorites', {
          method: 'DELETE',
          headers: {
            'Content-Type': 'application/json',
            'Authorization': `Bearer ${localStorage.getItem('auth_token')}`
          },
          body: JSON.stringify({
            itemType: 'collection',
            itemId: collection.id
          })
        });
  
        if (response.ok) {
          setIsFavorited(false);
        } else {
          console.error('Failed to remove favorite:', response.status);
        }
      } else {
        // Add to favorites
        const response = await fetch('/api/favorites', {
          method: 'POST',
          headers: {
            'Content-Type': 'application/json',
            'Authorization': `Bearer ${localStorage.getItem('auth_token')}`
          },
          body: JSON.stringify({
            itemType: 'collection',
            itemId: collection.id
          })
        });
  
        if (response.ok) {
          setIsFavorited(true);
        } else {
          console.error('Failed to add favorite:', response.status);
        }
      }
    } catch (error) {
      console.error('Error toggling favorite:', error);
    }
  };
  
  const togglePublic = async () => {
    try {
      const response = await fetch(`/api/collections/${identifier}`, {
        method: 'PUT',
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${localStorage.getItem('auth_token')}`
        },
        body: JSON.stringify({
          isPublic: !collection.isPublic
        })
      });
  
      if (response.ok) {
        setCollection(prev => ({
          ...prev,
          isPublic: !prev.isPublic
        }));
      }
    } catch (error) {
      console.error('Error updating collection:', error);
    }
  };
  
  const handleImageUpload = async (imageUrl) => {
    try {
      const response = await fetch(`/api/collections/${identifier}`, {
        method: 'PUT',
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${localStorage.getItem('auth_token')}`
        },
        body: JSON.stringify({
          image: imageUrl
        })
      });
  
      if (response.ok) {
        setCollection(prev => ({
          ...prev,
          image: imageUrl
        }));
      }
    } catch (error) {
      console.error('Error updating collection image:', error);
    }
  };
  
  // Card interaction handlers
  const handleToggleSelect = (card) => {
    setSelectedCards(prev => {
      const isSelected = prev.some(c => c.id === card.id);
      if (isSelected) {
        return prev.filter(c => c.id !== card.id);
      } else {
        return [...prev, card];
      }
    });
  };
  
  const handleToggleFavorite = async (card) => {
    try {
      const isFavorited = favoritedCards.has(card.id);
      const method = isFavorited ? 'DELETE' : 'POST';
      
      const response = await fetch('/api/favorites', {
        method,
        headers: {
          'Content-Type': 'application/json',
          'Authorization': `Bearer ${localStorage.getItem('auth_token')}`
        },
        body: JSON.stringify({
          itemType: 'card',
          itemId: card.id
        })
      });
  
      if (response.ok) {
        setFavoritedCards(prev => {
          const newSet = new Set(prev);
          if (isFavorited) {
            newSet.delete(card.id);
          } else {
            newSet.add(card.id);
          }
          return newSet;
        });
      }
    } catch (error) {
      console.error('Error toggling favorite:', error);
    }
  };
  
  const handleAddToCollection = (card) => {
    // This would open a collection selection modal
    console.log('Add to collection:', card);
  };
  
  const handleAddToDeck = (card) => {
    // This would open a deck selection modal
    console.log('Add to deck:', card);
  };
  
  const handleDownloadCSV = () => {
    downloadCollectionCardsCsv(cards, collection?.name);
  };
  
  // Group cards by game
  const groupedCards = cards.reduce((acc, card) => {
    const game = card.game || 'Other';
    if (!acc[game]) acc[game] = [];
    acc[game].push(card);
    return acc;
  }, {});
  
  // Get game display names and counts
  const gameStats = {};
  Object.keys(groupedCards).forEach(game => {
    if (game && game !== 'Other') {
      gameStats[game] = groupedCards[game].length;
    }
  });

  const showInitialLoading = authLoading || loading;

  return {
    cards,
    collection,
    copySuccess,
    editForm,
    favoritedCards,
    gameStats,
    groupBy,
    groupedCards,
    handleAddCard,
    handleAddToCollection,
    handleAddToDeck,
    handleDeleteCollection,
    handleDownloadCSV,
    handleEditCollection,
    handleImageUpload,
    handleSearchCards,
    handleToggleFavorite,
    handleToggleSelect,
    identifier,
    isFavorited,
    loading,
    router,
    searchCards,
    searchQuery,
    searchResults,
    selectedCards,
    selectedRarity,
    selectedTCG,
    selectedType,
    setCards,
    setCollection,
    setCopySuccess,
    setEditForm,
    setFavoritedCards,
    setGroupBy,
    setIsFavorited,
    setLoading,
    setSearchCards,
    setSearchQuery,
    setSearchResults,
    setSelectedCards,
    setSelectedRarity,
    setSelectedTCG,
    setSelectedType,
    setShowDeleteModal,
    setShowEditModal,
    setShowSearchResults,
    setShowShareModal,
    setShowUploadModal,
    setSortBy,
    setViewMode,
    showDeleteModal,
    showEditModal,
    showInitialLoading,
    showSearchResults,
    showShareModal,
    showUploadModal,
    sortBy,
    toggleFavorite,
    togglePublic,
    viewMode
  };
}