import { useState, useEffect } from 'react';
import { useRouter } from 'next/router';
import Layout from '../components/Layout';
import PermissionIndicator from '../components/PermissionIndicator';
import { useAuth } from '../lib/use-auth';

export default function Collections() {
  const router = useRouter();
  const { user, loading: authLoading } = useAuth();
  
  const [collections, setCollections] = useState([]);
  const [loading, setLoading] = useState(true);
  const [showCreateModal, setShowCreateModal] = useState(false);
  const [editingCollection, setEditingCollection] = useState(null);
  const [searchQuery, setSearchQuery] = useState('');
  const [sortBy, setSortBy] = useState('name'); // name, value, cardCount, createdAt

  const [newCollection, setNewCollection] = useState({
    name: '',
    description: '',
    isPublic: false,
    image: '',
    tags: []
  });
  const [showSuccessModal, setShowSuccessModal] = useState(false);
  const [createdCollection, setCreatedCollection] = useState(null);

  // Redirect to login if not authenticated
  useEffect(() => {
    if (!authLoading && !user) {
      router.push('/login');
    }
  }, [authLoading, user, router]);

  useEffect(() => {
    if (user) {
      fetchCollections();
    }
  }, [user]);

  const fetchCollections = async () => {
    try {
      const response = await fetch('/api/collections');
      if (response.ok) {
        const data = await response.json();
        // Fetch thumbnail cards for each collection
        const collectionsWithThumbnails = await Promise.all(
          data.map(async (collection) => {
            try {
              const identifier = collection.slug || collection.id;
              const thumbnailResponse = await fetch(`/api/collections/${identifier}/thumbnails`);
              const thumbnails = thumbnailResponse.ok ? await thumbnailResponse.json() : [];
              return { ...collection, thumbnails };
            } catch (error) {
              console.error(`Error fetching thumbnails for collection ${collection.slug || collection.id}:`, error);
              return { ...collection, thumbnails: [] };
            }
          })
        );
        setCollections(collectionsWithThumbnails);
      } else {
        console.error('Failed to fetch collections');
        setCollections([]); // Empty array on error
      }
    } catch (error) {
      console.error('Error fetching collections:', error);
      setCollections([]); // Empty array on error
    } finally {
      setLoading(false);
    }
  };

  const sortOptions = [
    { value: 'name', label: 'Name (A-Z)' },
    { value: 'value', label: 'Value (High to Low)' },
    { value: 'cardCount', label: 'Card Count (High to Low)' },
    { value: 'createdAt', label: 'Date Created (Newest)' }
  ];

  const sortCollections = (collections, sortBy) => {
    return [...collections].sort((a, b) => {
      switch (sortBy) {
        case 'name':
          return a.name.localeCompare(b.name);
        case 'value':
          return b.value - a.value;
        case 'cardCount':
          return b.cardCount - a.cardCount;
        case 'createdAt':
          return new Date(b.createdAt) - new Date(a.createdAt);
        default:
          return 0;
      }
    });
  };

  const filteredCollections = collections.filter(collection => {
    const matchesSearch = collection.name.toLowerCase().includes(searchQuery.toLowerCase()) ||
                         collection.description.toLowerCase().includes(searchQuery.toLowerCase());
    return matchesSearch;
  });

  const sortedCollections = sortCollections(filteredCollections, sortBy);

  const handleCreateCollection = async () => {
    try {
      const response = await fetch('/api/collections', {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
        },
        body: JSON.stringify({
          name: newCollection.name,
          description: newCollection.description,
          isPublic: newCollection.isPublic,
          image: newCollection.image,
          tags: newCollection.tags
        })
      });

      if (response.ok) {
        const createdCollection = await response.json();
        setCreatedCollection(createdCollection);
        setShowCreateModal(false);
        setShowSuccessModal(true);
        
        // Reset form
        setNewCollection({ 
          name: '', 
          description: '', 
          isPublic: false, 
          image: '', 
          tags: [] 
        });
        
        // Refresh collections list
        fetchCollections();
      } else {
        const error = await response.json();
        alert(error.error || 'Failed to create collection');
      }
    } catch (error) {
      console.error('Error creating collection:', error);
      alert('Network error. Please try again.');
    }
  };

  const handleUpdateCollection = () => {
    setCollections(collections.map(c => 
      c.id === editingCollection.id ? editingCollection : c
    ));
    setEditingCollection(null);
  };

  const handleDeleteCollection = (id) => {
    if (confirm('Are you sure you want to delete this collection?')) {
      setCollections(collections.filter(c => c.id !== id));
    }
  };

  const formatCurrency = (amount) => {
    return new Intl.NumberFormat('en-US', {
      style: 'currency',
      currency: 'USD'
    }).format(amount);
  };

  const formatDate = (dateString) => {
    return new Date(dateString).toLocaleDateString();
  };

  const CollectionThumbnail = ({ collection }) => {
    const { thumbnails = [], image } = collection;
    
    // If collection has a custom hero image, use it
    if (image) {
      return (
        <div className="w-full h-48 rounded-xl overflow-hidden mb-4" style={{ backgroundColor: 'var(--bg-tertiary)' }}>
          <img 
            src={image} 
            alt={collection.name}
            className="w-full h-full object-cover"
          />
        </div>
      );
    }

    // If no thumbnails available, show placeholder
    if (!thumbnails || thumbnails.length === 0) {
      return (
        <div className="w-full h-48 rounded-xl mb-4 flex items-center justify-center" style={{ backgroundColor: 'var(--bg-tertiary)' }}>
          <div className="text-center">
            <div className="text-4xl mb-2">📦</div>
            <p className="text-sm" style={{ color: 'var(--text-secondary)' }}>No cards yet</p>
          </div>
        </div>
      );
    }

    // Show main card (rarest) and grid of 4 others
    const mainCard = thumbnails[0]; // Rarest card
    const gridCards = thumbnails.slice(1, 5); // Next 4 cards

    return (
      <div className="w-full h-48 rounded-xl overflow-hidden mb-4 flex gap-2">
        {/* Main card (rarest) - takes up 2/3 of the space */}
        <div className="flex-2 h-full relative group">
          {mainCard ? (
            <div className="relative h-full">
              <img 
                src={mainCard.image_url || mainCard.stock_image_url || '/placeholder-card.png'} 
                alt={mainCard.name}
                className="w-full h-full object-cover rounded-lg"
              />
              {/* Rarity glow effect */}
              <div className={`absolute inset-0 rounded-lg rarity-glow-${mainCard.rarity?.toLowerCase() || 'common'}`}></div>
              {/* Card name overlay */}
              <div className="absolute bottom-0 left-0 right-0 bg-gradient-to-t from-black/70 to-transparent p-2 rounded-b-lg">
                <p className="text-white text-xs font-medium truncate">{mainCard.name}</p>
                <p className="text-white/80 text-xs capitalize">{mainCard.rarity}</p>
              </div>
            </div>
          ) : (
            <div className="w-full h-full bg-gray-200 dark:bg-gray-700 rounded-lg flex items-center justify-center">
              <span className="text-gray-400 text-xs">No image</span>
            </div>
          )}
        </div>

        {/* Grid of 4 other cards - takes up 1/3 of the space */}
        <div className="flex-1 h-full">
          <div className="grid grid-cols-2 gap-1 h-full">
            {Array.from({ length: 4 }).map((_, index) => {
              const card = gridCards[index];
              return (
                <div key={index} className="relative group">
                  {card ? (
                    <div className="relative h-full">
                      <img 
                        src={card.image_url || card.stock_image_url || '/placeholder-card.png'} 
                        alt={card.name}
                        className="w-full h-full object-cover rounded"
                      />
                      {/* Subtle rarity glow for grid cards */}
                      <div className={`absolute inset-0 rounded rarity-glow-${card.rarity?.toLowerCase() || 'common'} opacity-50`}></div>
                    </div>
                  ) : (
                    <div className="w-full h-full bg-gray-100 dark:bg-gray-800 rounded flex items-center justify-center">
                      <span className="text-gray-300 text-xs">+</span>
                    </div>
                  )}
                </div>
              );
            })}
          </div>
        </div>
      </div>
    );
  };

  // Show loading spinner while auth is loading or data is loading
  if (authLoading || loading) {
    return (
      <Layout user={user}>
        <div className="flex items-center justify-center min-h-screen">
          <div className="animate-spin rounded-full h-32 w-32 border-b-2" style={{ borderColor: 'var(--accent-ember)' }}></div>
        </div>
      </Layout>
    );
  }

  // Redirect to login if not authenticated (handled by useEffect, but this is a fallback)
  if (!user) {
    return null;
  }

  return (
    <Layout user={user}>
      {/* Header */}
      <div className="p-6" style={{ backgroundColor: 'var(--bg-secondary)', borderBottom: '1px solid var(--border)' }}>
        <div className="flex items-center justify-between">
          <div>
            <h1 className="text-3xl font-bold mb-2" style={{ color: 'var(--text-primary)' }}>
              My Collections
            </h1>
            <p className="text-lg" style={{ color: 'var(--text-secondary)' }}>
              Organize and manage your card collections
            </p>
          </div>
          <button 
            onClick={() => setShowCreateModal(true)}
            className="px-6 py-3 rounded-xl font-medium transition-all duration-200 hover:shadow-md flex items-center space-x-2"
            style={{ 
              backgroundColor: 'var(--accent-ember)',
              color: 'white'
            }}
          >
            <svg className="h-5 w-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 6v6m0 0v6m0-6h6m-6 0H6" />
            </svg>
            <span>Create Collection</span>
          </button>
        </div>
      </div>

      {/* Filters and Search */}
      <div className="p-6" style={{ backgroundColor: 'var(--bg-secondary)' }}>
        <div className="flex flex-col md:flex-row gap-4">
          <div className="flex-1">
            <input
              type="text"
              placeholder="Search collections..."
              className="input-field w-full"
              value={searchQuery}
              onChange={(e) => setSearchQuery(e.target.value)}
            />
          </div>
          <div className="flex gap-4">
            <select
              value={sortBy}
              onChange={(e) => setSortBy(e.target.value)}
              className="input-field w-48"
            >
              {sortOptions.map(option => (
                <option key={option.value} value={option.value}>
                  {option.label}
                </option>
              ))}
            </select>
          </div>
        </div>
      </div>

      {/* Collections Grid */}
      <div className="p-6">
        {sortedCollections.length === 0 ? (
          <div className="text-center py-12">
            <div className="text-6xl mb-4">📦</div>
            <h3 className="text-xl font-semibold mb-2" style={{ color: 'var(--text-primary)' }}>
              {searchQuery ? 'No collections found' : 'No collections yet'}
            </h3>
            <p className="mb-6" style={{ color: 'var(--text-secondary)' }}>
              {searchQuery 
                ? 'Try adjusting your search terms'
                : 'Create your first collection to get started'
              }
            </p>
            {!searchQuery && (
              <button 
                onClick={() => setShowCreateModal(true)}
                className="px-6 py-3 rounded-xl font-medium transition-all duration-200 hover:shadow-md"
                style={{ 
                  backgroundColor: 'var(--accent-ember)',
                  color: 'white'
                }}
              >
                Create Collection
              </button>
            )}
          </div>
        ) : (
          <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 xl:grid-cols-4 gap-6">
            {sortedCollections.map(collection => (
              <div 
                key={collection.id} 
                className="card hover:shadow-xl transition-all duration-300 cursor-pointer group"
                onClick={() => router.push(`/collection/${collection.slug || collection.id}`)}
              >
                {/* Thumbnail Section */}
                <CollectionThumbnail collection={collection} />
                
                {/* Collection Info */}
                <div className="space-y-3">
                  {/* Header with name and actions */}
                  <div className="flex items-start justify-between">
                    <div className="flex-1 min-w-0">
                      <h3 className="text-lg font-semibold truncate" style={{ color: 'var(--text-primary)' }}>
                        {collection.name}
                      </h3>
                      {collection.description && (
                        <p className="text-sm mt-1 line-clamp-2" style={{ color: 'var(--text-secondary)' }}>
                          {collection.description}
                        </p>
                      )}
                    </div>
                    <div className="flex items-center space-x-1 ml-2">
                      <PermissionIndicator 
                        userRole={collection.userRole} 
                        isPublic={collection.isPublic}
                        showTooltip={false}
                      />
                      <div className="opacity-0 group-hover:opacity-100 transition-opacity flex space-x-1">
                        <button
                          onClick={(e) => {
                            e.stopPropagation();
                            setEditingCollection(collection);
                          }}
                          className="p-1.5 rounded-lg transition-colors hover:scale-105" 
                          style={{ 
                            backgroundColor: 'var(--bg-tertiary)', 
                            color: 'var(--text-secondary)' 
                          }}
                        >
                          <svg className="h-3.5 w-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M11 5H6a2 2 0 00-2 2v11a2 2 0 002 2h11a2 2 0 002-2v-5m-1.414-9.414a2 2 0 112.828 2.828L11.828 15H9v-2.828l8.586-8.586z" />
                          </svg>
                        </button>
                        <button
                          onClick={(e) => {
                            e.stopPropagation();
                            handleDeleteCollection(collection.id);
                          }}
                          className="p-1.5 rounded-lg transition-colors hover:scale-105" 
                          style={{ 
                            backgroundColor: 'var(--bg-tertiary)', 
                            color: '#ef4444' 
                          }}
                        >
                          <svg className="h-3.5 w-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 7l-.867 12.142A2 2 0 0116.138 21H7.862a2 2 0 01-1.995-1.858L5 7m5 4v6m4-6v6m1-10V4a1 1 0 00-1-1h-4a1 1 0 00-1 1v3M4 7h16" />
                          </svg>
                        </button>
                      </div>
                    </div>
                  </div>
                  
                  {/* Compact Stats */}
                  <div className="flex items-center justify-between text-sm" style={{ color: 'var(--text-secondary)' }}>
                    <div className="flex items-center space-x-4">
                      <span className="font-medium" style={{ color: 'var(--text-primary)' }}>
                        {collection.cardCount} cards
                      </span>
                      <span className="font-medium" style={{ color: 'var(--accent-ember)' }}>
                        {formatCurrency(collection.value)}
                      </span>
                    </div>
                    <span className="text-xs">
                      {formatDate(collection.createdAt)}
                    </span>
                  </div>
                  
                  {/* Tags */}
                  {collection.tags && collection.tags.length > 0 && (
                    <div className="flex flex-wrap gap-1">
                      {collection.tags.slice(0, 2).map(tag => (
                        <span 
                          key={tag} 
                          className="px-2 py-1 text-xs rounded-full"
                          style={{ 
                            backgroundColor: 'var(--bg-tertiary)', 
                            color: 'var(--text-secondary)' 
                          }}
                        >
                          {tag}
                        </span>
                      ))}
                      {collection.tags.length > 2 && (
                        <span className="px-2 py-1 text-xs rounded-full" style={{ 
                          backgroundColor: 'var(--bg-tertiary)', 
                          color: 'var(--text-secondary)' 
                        }}>
                          +{collection.tags.length - 2}
                        </span>
                      )}
                    </div>
                  )}
                </div>
              </div>
            ))}
          </div>
        )}
      </div>

      {/* Create Collection Modal */}
      {showCreateModal && (
        <div className="fixed inset-0 bg-black bg-opacity-50 flex items-center justify-center z-50">
          <div className="card max-w-md w-full mx-4">
            <h2 className="text-2xl font-bold mb-4" style={{ color: 'var(--text-primary)' }}>
              Create New Collection
            </h2>
            <div className="space-y-4">
              <div>
                <label className="block text-sm font-medium mb-2" style={{ color: 'var(--text-primary)' }}>
                  Collection Name
                </label>
                <input
                  type="text"
                  className="input-field w-full"
                  value={newCollection.name}
                  onChange={(e) => setNewCollection({...newCollection, name: e.target.value})}
                  placeholder="Enter collection name"
                />
              </div>
              <div>
                <label className="block text-sm font-medium mb-2" style={{ color: 'var(--text-primary)' }}>
                  Description
                </label>
                <textarea
                  className="input-field w-full"
                  rows="3"
                  value={newCollection.description}
                  onChange={(e) => setNewCollection({...newCollection, description: e.target.value})}
                  placeholder="Describe your collection"
                />
              </div>
              <div>
                <label className="block text-sm font-medium mb-2" style={{ color: 'var(--text-primary)' }}>
                  Hero Image (Optional)
                </label>
                <input
                  type="url"
                  className="input-field w-full"
                  value={newCollection.image}
                  onChange={(e) => setNewCollection({...newCollection, image: e.target.value})}
                  placeholder="Enter image URL or upload later"
                />
                <p className="text-xs mt-1" style={{ color: 'var(--text-secondary)' }}>
                  Add a custom thumbnail image, or we'll use your rarest cards
                </p>
              </div>
              <div className="flex items-center justify-between p-4 rounded-lg border" style={{ borderColor: 'var(--border)' }}>
                <div>
                  <label className="text-sm font-medium" style={{ color: 'var(--text-primary)' }}>
                    Public Collection
                  </label>
                  <p className="text-xs mt-1" style={{ color: 'var(--text-secondary)' }}>
                    Make this collection discoverable by other users
                  </p>
                </div>
                <button
                  type="button"
                  onClick={() => setNewCollection({...newCollection, isPublic: !newCollection.isPublic})}
                  className={`relative inline-flex h-6 w-11 items-center rounded-full transition-colors ${
                    newCollection.isPublic ? 'bg-green-600' : 'bg-gray-300 dark:bg-gray-600'
                  }`}
                >
                  <span
                    className={`inline-block h-4 w-4 transform rounded-full bg-white transition-transform ${
                      newCollection.isPublic ? 'translate-x-6' : 'translate-x-1'
                    }`}
                  />
                </button>
              </div>
            </div>
            <div className="flex space-x-3 mt-6">
              <button
                onClick={() => setShowCreateModal(false)}
                className="flex-1 py-2 px-4 rounded-xl border transition-colors"
                style={{ 
                  borderColor: 'var(--border)', 
                  color: 'var(--text-secondary)' 
                }}
              >
                Cancel
              </button>
              <button
                onClick={handleCreateCollection}
                disabled={!newCollection.name.trim()}
                className="flex-1 py-2 px-4 rounded-xl font-medium transition-all duration-200 hover:shadow-md disabled:opacity-50"
                style={{ 
                  backgroundColor: 'var(--accent-ember)',
                  color: 'white'
                }}
              >
                Create Collection
              </button>
            </div>
          </div>
        </div>
      )}

      {/* Success Modal */}
      {showSuccessModal && createdCollection && (
        <div className="fixed inset-0 bg-black bg-opacity-50 flex items-center justify-center z-50">
          <div className="card max-w-md w-full mx-4 text-center">
            <div className="text-6xl mb-4">🎉</div>
            <h2 className="text-2xl font-bold mb-4" style={{ color: 'var(--text-primary)' }}>
              Collection Created!
            </h2>
            <p className="mb-6" style={{ color: 'var(--text-secondary)' }}>
              Your collection "{createdCollection.name}" has been created successfully.
            </p>
            <div className="space-y-3">
              <button
                onClick={() => {
                  setShowSuccessModal(false);
                  router.push(`/collection/${createdCollection.slug || createdCollection.id}`);
                }}
                className="w-full py-2 px-4 rounded-xl font-medium transition-all duration-200 hover:shadow-md"
                style={{ 
                  backgroundColor: 'var(--accent-ember)',
                  color: 'white'
                }}
              >
                View Collection
              </button>
              <button
                onClick={() => setShowSuccessModal(false)}
                className="w-full py-2 px-4 rounded-xl border transition-colors"
                style={{ 
                  borderColor: 'var(--border)', 
                  color: 'var(--text-secondary)' 
                }}
              >
                Stay on Collections Page
              </button>
            </div>
          </div>
        </div>
      )}

      {/* Edit Collection Modal */}
      {editingCollection && (
        <div className="fixed inset-0 bg-black bg-opacity-50 flex items-center justify-center z-50">
          <div className="card max-w-md w-full mx-4">
            <h2 className="text-2xl font-bold mb-4" style={{ color: 'var(--text-primary)' }}>
              Edit Collection
            </h2>
            <div className="space-y-4">
              <div>
                <label className="block text-sm font-medium mb-2" style={{ color: 'var(--text-primary)' }}>
                  Collection Name
                </label>
                <input
                  type="text"
                  className="input-field w-full"
                  value={editingCollection.name}
                  onChange={(e) => setEditingCollection({...editingCollection, name: e.target.value})}
                />
              </div>
              <div>
                <label className="block text-sm font-medium mb-2" style={{ color: 'var(--text-primary)' }}>
                  Description
                </label>
                <textarea
                  className="input-field w-full"
                  rows="3"
                  value={editingCollection.description}
                  onChange={(e) => setEditingCollection({...editingCollection, description: e.target.value})}
                />
              </div>
              <div>
                <label className="block text-sm font-medium mb-2" style={{ color: 'var(--text-primary)' }}>
                  Hero Image
                </label>
                <input
                  type="url"
                  className="input-field w-full"
                  value={editingCollection.image || ''}
                  onChange={(e) => setEditingCollection({...editingCollection, image: e.target.value})}
                  placeholder="Enter image URL"
                />
              </div>
              <div className="flex items-center justify-between p-4 rounded-lg border" style={{ borderColor: 'var(--border)' }}>
                <div>
                  <label className="text-sm font-medium" style={{ color: 'var(--text-primary)' }}>
                    Public Collection
                  </label>
                  <p className="text-xs mt-1" style={{ color: 'var(--text-secondary)' }}>
                    Make this collection discoverable by other users
                  </p>
                </div>
                <button
                  type="button"
                  onClick={() => setEditingCollection({...editingCollection, isPublic: !editingCollection.isPublic})}
                  className={`relative inline-flex h-6 w-11 items-center rounded-full transition-colors ${
                    editingCollection.isPublic ? 'bg-green-600' : 'bg-gray-300 dark:bg-gray-600'
                  }`}
                >
                  <span
                    className={`inline-block h-4 w-4 transform rounded-full bg-white transition-transform ${
                      editingCollection.isPublic ? 'translate-x-6' : 'translate-x-1'
                    }`}
                  />
                </button>
              </div>
            </div>
            <div className="flex space-x-3 mt-6">
              <button
                onClick={() => setEditingCollection(null)}
                className="flex-1 py-2 px-4 rounded-xl border transition-colors"
                style={{ 
                  borderColor: 'var(--border)', 
                  color: 'var(--text-secondary)' 
                }}
              >
                Cancel
              </button>
              <button
                onClick={handleUpdateCollection}
                disabled={!editingCollection.name.trim()}
                className="flex-1 py-2 px-4 rounded-xl font-medium transition-all duration-200 hover:shadow-md disabled:opacity-50"
                style={{ 
                  backgroundColor: 'var(--accent-ember)',
                  color: 'white'
                }}
              >
                Update Collection
              </button>
            </div>
          </div>
        </div>
      )}
    </Layout>
  );
}