add trade validation to prevent accepting invalid trades and update UI accordingly

Reviewed-on: #13

src/components/Collection.tsx

@@ -1,17 +1,25 @@
-import React, { useState, useEffect } from 'react';
+import React, { useState, useEffect, useRef, useCallback } from 'react';
 import { Search, Loader2, Trash2, CheckCircle, XCircle, RefreshCw, Plus, Minus, X } from 'lucide-react';
 import { Card } from '../types';
-import { getUserCollection, getCardsByIds, addCardToCollection } from '../services/api';
+import { getUserCollectionPaginated, getCardsByIds, addCardToCollection, getCollectionTotalValue } from '../services/api';
 import { useAuth } from '../contexts/AuthContext';
 import { supabase } from '../lib/supabase';
 import ConfirmModal from './ConfirmModal';
 
+const PAGE_SIZE = 50;
+
 export default function Collection() {
   const { user } = useAuth();
   const [searchQuery, setSearchQuery] = useState('');
   const [collection, setCollection] = useState<{ card: Card; quantity: number }[]>([]);
   const [filteredCollection, setFilteredCollection] = useState<{ card: Card; quantity: number }[]>([]);
   const [isLoadingCollection, setIsLoadingCollection] = useState(true);
+  const [isLoadingMore, setIsLoadingMore] = useState(false);
+  const [hasMore, setHasMore] = useState(false);
+  const [offset, setOffset] = useState(0);
+  const [totalCount, setTotalCount] = useState(0);
+  const [totalCollectionValue, setTotalCollectionValue] = useState<number>(0);
+  const [isLoadingTotalValue, setIsLoadingTotalValue] = useState(true);
   const [hoveredCard, setHoveredCard] = useState<Card | null>(null);
   const [selectedCard, setSelectedCard] = useState<{ card: Card; quantity: number } | null>(null);
   const [cardFaceIndex, setCardFaceIndex] = useState<Map<string, number>>(new Map());
@@ -22,6 +30,7 @@ export default function Collection() {
     cardId: string;
     cardName: string;
   }>({ isOpen: false, cardId: '', cardName: '' });
+  const observerTarget = useRef<HTMLDivElement>(null);
 
   // Helper function to check if a card has an actual back face (not adventure/split/etc)
   const isDoubleFaced = (card: Card) => {
@@ -62,6 +71,58 @@ export default function Collection() {
     });
   };
 
+  // Calculate total collection value (lightweight query from database)
+  useEffect(() => {
+    const calculateTotalValue = async () => {
+      if (!user) {
+        setIsLoadingTotalValue(false);
+        return;
+      }
+
+      try {
+        setIsLoadingTotalValue(true);
+        // Get total value directly from database (no need to fetch all cards!)
+        const totalValue = await getCollectionTotalValue(user.id);
+        setTotalCollectionValue(totalValue);
+      } catch (error) {
+        console.error('Error calculating total collection value:', error);
+        setTotalCollectionValue(0);
+      } finally {
+        setIsLoadingTotalValue(false);
+      }
+    };
+
+    calculateTotalValue();
+  }, [user]);
+
+  // Subscribe to realtime updates for collection total value
+  useEffect(() => {
+    if (!user) return;
+
+    const profileChannel = supabase
+      .channel('profile-total-value-changes')
+      .on(
+        'postgres_changes',
+        {
+          event: 'UPDATE',
+          schema: 'public',
+          table: 'profiles',
+          filter: `id=eq.${user.id}`,
+        },
+        (payload: any) => {
+          if (payload.new?.collection_total_value !== undefined) {
+            console.log('Collection total value updated:', payload.new.collection_total_value);
+            setTotalCollectionValue(payload.new.collection_total_value);
+          }
+        }
+      )
+      .subscribe();
+
+    return () => {
+      supabase.removeChannel(profileChannel);
+    };
+  }, [user]);
+
   // Load user's collection from Supabase on mount
   useEffect(() => {
     const loadCollection = async () => {
@@ -72,26 +133,33 @@ export default function Collection() {
 
       try {
         setIsLoadingCollection(true);
-        // Get collection from Supabase (returns Map<card_id, quantity>)
-        const collectionMap = await getUserCollection(user.id);
-
-        if (collectionMap.size === 0) {
+        setOffset(0);
         setCollection([]);
+
+        // Get paginated collection from Supabase
+        const result = await getUserCollectionPaginated(user.id, PAGE_SIZE, 0);
+        setTotalCount(result.totalCount);
+        setHasMore(result.hasMore);
+
+        if (result.items.size === 0) {
+          setCollection([]);
+          setFilteredCollection([]);
           return;
         }
 
-        // Get the actual card data from Scryfall for all cards in collection
-        const cardIds = Array.from(collectionMap.keys());
+        // Get the actual card data from Scryfall for all cards in this page
+        const cardIds = Array.from(result.items.keys());
         const cards = await getCardsByIds(cardIds);
 
         // Combine card data with quantities
         const collectionWithCards = cards.map(card => ({
           card,
-          quantity: collectionMap.get(card.id) || 0,
+          quantity: result.items.get(card.id) || 0,
         }));
 
         setCollection(collectionWithCards);
         setFilteredCollection(collectionWithCards);
+        setOffset(PAGE_SIZE);
       } catch (error) {
         console.error('Error loading collection:', error);
         setSnackbar({ message: 'Failed to load collection', type: 'error' });
@@ -103,6 +171,70 @@ export default function Collection() {
     loadCollection();
   }, [user]);
 
+  // Load more cards for infinite scroll
+  const loadMoreCards = useCallback(async () => {
+    if (!user || isLoadingMore || !hasMore) return;
+
+    try {
+      setIsLoadingMore(true);
+
+      // Get next page of collection
+      const result = await getUserCollectionPaginated(user.id, PAGE_SIZE, offset);
+      setHasMore(result.hasMore);
+
+      if (result.items.size === 0) {
+        return;
+      }
+
+      // Get card data from Scryfall
+      const cardIds = Array.from(result.items.keys());
+      const cards = await getCardsByIds(cardIds);
+
+      // Combine card data with quantities
+      const newCards = cards.map(card => ({
+        card,
+        quantity: result.items.get(card.id) || 0,
+      }));
+
+      // Deduplicate: only add cards that aren't already in the collection
+      setCollection(prev => {
+        const existingIds = new Set(prev.map(item => item.card.id));
+        const uniqueNewCards = newCards.filter(item => !existingIds.has(item.card.id));
+        return [...prev, ...uniqueNewCards];
+      });
+
+      setOffset(prev => prev + PAGE_SIZE);
+    } catch (error) {
+      console.error('Error loading more cards:', error);
+      setSnackbar({ message: 'Failed to load more cards', type: 'error' });
+    } finally {
+      setIsLoadingMore(false);
+    }
+  }, [user, offset, hasMore, isLoadingMore]);
+
+  // Intersection Observer for infinite scroll
+  useEffect(() => {
+    const observer = new IntersectionObserver(
+      (entries) => {
+        if (entries[0].isIntersecting && hasMore && !isLoadingMore) {
+          loadMoreCards();
+        }
+      },
+      { threshold: 0.1 }
+    );
+
+    const currentTarget = observerTarget.current;
+    if (currentTarget) {
+      observer.observe(currentTarget);
+    }
+
+    return () => {
+      if (currentTarget) {
+        observer.unobserve(currentTarget);
+      }
+    };
+  }, [hasMore, isLoadingMore, loadMoreCards]);
+
   // Filter collection based on search query
   useEffect(() => {
     if (!searchQuery.trim()) {
@@ -209,9 +341,31 @@ export default function Collection() {
 
         {/* Collection */}
         <div>
-          <h2 className="text-xl font-semibold mb-4">
+          <div className="flex flex-col sm:flex-row sm:items-center sm:justify-between gap-2 mb-4">
+            <h2 className="text-xl font-semibold">
               {searchQuery ? `Found ${filteredCollection.length} card(s)` : `My Cards (${collection.length} unique, ${collection.reduce((acc, c) => acc + c.quantity, 0)} total)`}
             </h2>
+            {/* Collection Value Summary */}
+            <div className="bg-gray-800 border border-gray-700 rounded-lg px-4 py-2">
+              <div className="text-xs text-gray-400 mb-0.5">
+                {searchQuery ? 'Filtered Value' : 'Total Collection Value'}
+              </div>
+              <div className="text-lg font-bold text-green-400">
+                {isLoadingTotalValue ? (
+                  <Loader2 className="animate-spin" size={20} />
+                ) : searchQuery ? (
+                  // For search results, calculate from filtered collection
+                  `$${filteredCollection.reduce((total, { card, quantity }) => {
+                    const price = card.prices?.usd ? parseFloat(card.prices.usd) : 0;
+                    return total + (price * quantity);
+                  }, 0).toFixed(2)}`
+                ) : (
+                  // For full collection, use pre-calculated total
+                  `$${totalCollectionValue.toFixed(2)}`
+                )}
+              </div>
+            </div>
+          </div>
 
           {isLoadingCollection ? (
             <div className="flex items-center justify-center py-12">
@@ -255,6 +409,12 @@ export default function Collection() {
                       <div className="absolute top-1 right-1 bg-blue-600 text-white text-xs sm:text-sm font-bold px-2 py-1 rounded-full shadow-lg">
                         x{quantity}
                       </div>
+                      {/* Price badge */}
+                      {card.prices?.usd && (
+                        <div className="absolute bottom-1 left-1 bg-green-600 text-white text-[10px] sm:text-xs font-bold px-1.5 py-0.5 rounded shadow-lg">
+                          ${card.prices.usd}
+                        </div>
+                      )}
                       {/* Flip button for double-faced cards */}
                       {isMultiFaced && (
                         <button
@@ -279,6 +439,25 @@ export default function Collection() {
               })}
             </div>
           )}
+
+          {/* Infinite scroll loading indicator */}
+          {!searchQuery && isLoadingMore && (
+            <div className="flex justify-center py-8">
+              <Loader2 className="animate-spin text-blue-500" size={32} />
+            </div>
+          )}
+
+          {/* Observer target for infinite scroll */}
+          {!searchQuery && hasMore && !isLoadingMore && (
+            <div ref={observerTarget} className="h-20" />
+          )}
+
+          {/* End of collection indicator */}
+          {!searchQuery && !hasMore && collection.length > 0 && (
+            <div className="text-center py-8 text-gray-500 text-sm">
+              End of collection • {totalCount} total cards
+            </div>
+          )}
         </div>
       </div>
 

src/components/Community.tsx

@@ -1,5 +1,5 @@
-import React, { useState, useEffect } from 'react';
-import { Search, Globe, Users, Eye, ArrowLeftRight, Loader2, Clock, History, UserPlus, UserMinus, Check, X, Send, Settings, Save, ChevronLeft } from 'lucide-react';
+import React, { useState, useEffect, useRef, useCallback } from 'react';
+import { Search, Globe, Users, Eye, ArrowLeftRight, Loader2, Clock, History, UserPlus, UserMinus, Check, X, Send, Settings, Save, ChevronLeft, RefreshCw, Plus, Minus, AlertTriangle } from 'lucide-react';
 import { useAuth } from '../contexts/AuthContext';
 import { useToast } from '../contexts/ToastContext';
 import { supabase } from '../lib/supabase';
@@ -23,7 +23,7 @@ import {
   Trade,
   TradeItem,
 } from '../services/tradesService';
-import { getUserCollection, getCardsByIds } from '../services/api';
+import { getUserCollectionPaginated, getCardsByIds, getCollectionTotalValue } from '../services/api';
 import { Card } from '../types';
 import TradeCreator from './TradeCreator';
 import TradeDetail from './TradeDetail';
@@ -50,6 +50,8 @@ const VISIBILITY_OPTIONS = [
   { value: 'private', label: 'Private', description: 'Only you' },
 ] as const;
 
+const PAGE_SIZE = 50;
+
 export default function Community() {
   const { user } = useAuth();
   const toast = useToast();
@@ -62,8 +64,18 @@ export default function Community() {
   const [selectedUser, setSelectedUser] = useState<UserProfile | null>(null);
   const [selectedUserCollection, setSelectedUserCollection] = useState<CollectionItem[]>([]);
   const [loadingCollection, setLoadingCollection] = useState(false);
+  const [isLoadingMoreUserCards, setIsLoadingMoreUserCards] = useState(false);
+  const [hasMoreUserCards, setHasMoreUserCards] = useState(false);
+  const [userCollectionOffset, setUserCollectionOffset] = useState(0);
+  const [userCollectionTotalCount, setUserCollectionTotalCount] = useState(0);
+  const [userCollectionTotalValue, setUserCollectionTotalValue] = useState<number>(0);
+  const [isLoadingUserTotalValue, setIsLoadingUserTotalValue] = useState(true);
   const [showTradeCreator, setShowTradeCreator] = useState(false);
   const [userCollectionSearch, setUserCollectionSearch] = useState('');
+  const [hoveredUserCard, setHoveredUserCard] = useState<Card | null>(null);
+  const [selectedUserCard, setSelectedUserCard] = useState<CollectionItem | null>(null);
+  const [userCardFaceIndex, setUserCardFaceIndex] = useState<Map<string, number>>(new Map());
+  const userCollectionObserverTarget = useRef<HTMLDivElement>(null);
 
   // Friends state
   const [friendsSubTab, setFriendsSubTab] = useState<FriendsSubTab>('list');
@@ -196,6 +208,7 @@ export default function Community() {
   }, [user]);
 
   // Subscribe to collection changes when viewing someone's collection
+  // Auto-price trigger is disabled, so no more infinite loops!
   useEffect(() => {
     if (!user || !selectedUser) return;
 
@@ -209,10 +222,11 @@ export default function Community() {
           table: 'collections',
         },
         (payload: any) => {
-          // Filter for the selected user's collections
           const data = payload.new || payload.old;
           if (data && data.user_id === selectedUser.id) {
-            console.log('Collection change for viewed user:', payload);
+            console.log('Collection change for viewed user:', payload.eventType);
+            // Reload on any change (INSERT/UPDATE/DELETE)
+            // No more infinite loops since auto-price trigger is disabled
             loadUserCollection(selectedUser.id);
           }
         }
@@ -224,6 +238,44 @@ export default function Community() {
     };
   }, [user, selectedUser]);
 
+  // Helper function to check if a card has an actual back face
+  const isDoubleFaced = (card: Card) => {
+    const backFaceLayouts = ['transform', 'modal_dfc', 'double_faced_token', 'reversible_card'];
+    return card.card_faces && card.card_faces.length > 1 && backFaceLayouts.includes(card.layout);
+  };
+
+  // Helper function to get the current face index for a card
+  const getCurrentFaceIndex = (cardId: string) => {
+    return userCardFaceIndex.get(cardId) || 0;
+  };
+
+  // Helper function to get the image URI for a card
+  const getCardImageUri = (card: Card, faceIndex: number = 0) => {
+    if (isDoubleFaced(card) && card.card_faces) {
+      return card.card_faces[faceIndex]?.image_uris?.normal || card.card_faces[faceIndex]?.image_uris?.small;
+    }
+    return card.image_uris?.normal || card.image_uris?.small;
+  };
+
+  // Helper function to get the large image URI for hover preview
+  const getCardLargeImageUri = (card: Card, faceIndex: number = 0) => {
+    if (isDoubleFaced(card) && card.card_faces) {
+      return card.card_faces[faceIndex]?.image_uris?.large || card.card_faces[faceIndex]?.image_uris?.normal;
+    }
+    return card.image_uris?.large || card.image_uris?.normal;
+  };
+
+  // Toggle card face
+  const toggleCardFace = (cardId: string, totalFaces: number) => {
+    setUserCardFaceIndex(prev => {
+      const newMap = new Map(prev);
+      const currentIndex = prev.get(cardId) || 0;
+      const nextIndex = (currentIndex + 1) % totalFaces;
+      newMap.set(cardId, nextIndex);
+      return newMap;
+    });
+  };
+
   const loadAllData = async () => {
     if (!user) return;
     setLoading(true);
@@ -257,26 +309,138 @@ export default function Community() {
 
   const loadUserCollection = async (userId: string) => {
     setLoadingCollection(true);
-    try {
-      const collectionMap = await getUserCollection(userId);
-      if (collectionMap.size === 0) {
+    setIsLoadingUserTotalValue(true);
     setSelectedUserCollection([]);
+    setUserCollectionOffset(0);
+
+    try {
+      // Load paginated collection for display
+      const result = await getUserCollectionPaginated(userId, PAGE_SIZE, 0);
+      setUserCollectionTotalCount(result.totalCount);
+      setHasMoreUserCards(result.hasMore);
+
+      if (result.items.size === 0) {
+        setSelectedUserCollection([]);
+        setUserCollectionTotalValue(0);
+        setIsLoadingUserTotalValue(false);
         return;
       }
-      const cardIds = Array.from(collectionMap.keys());
+
+      const cardIds = Array.from(result.items.keys());
       const cards = await getCardsByIds(cardIds);
       setSelectedUserCollection(cards.map((card) => ({
         card,
-        quantity: collectionMap.get(card.id) || 0,
+        quantity: result.items.get(card.id) || 0,
       })));
+      setUserCollectionOffset(PAGE_SIZE);
+
+      // Calculate total value (lightweight query from database)
+      const totalValue = await getCollectionTotalValue(userId);
+      setUserCollectionTotalValue(totalValue);
     } catch (error) {
       console.error('Error loading collection:', error);
       setSelectedUserCollection([]);
+      setUserCollectionTotalValue(0);
     } finally {
       setLoadingCollection(false);
+      setIsLoadingUserTotalValue(false);
     }
   };
 
+  // Load more cards for infinite scroll in user collection view
+  const loadMoreUserCards = useCallback(async () => {
+    if (!selectedUser || isLoadingMoreUserCards || !hasMoreUserCards) return;
+
+    try {
+      setIsLoadingMoreUserCards(true);
+
+      const result = await getUserCollectionPaginated(
+        selectedUser.id,
+        PAGE_SIZE,
+        userCollectionOffset
+      );
+      setHasMoreUserCards(result.hasMore);
+
+      if (result.items.size === 0) {
+        return;
+      }
+
+      const cardIds = Array.from(result.items.keys());
+      const cards = await getCardsByIds(cardIds);
+
+      const newCards = cards.map(card => ({
+        card,
+        quantity: result.items.get(card.id) || 0,
+      }));
+
+      // Deduplicate: only add cards that aren't already in the collection
+      setSelectedUserCollection(prev => {
+        const existingIds = new Set(prev.map(item => item.card.id));
+        const uniqueNewCards = newCards.filter(item => !existingIds.has(item.card.id));
+        return [...prev, ...uniqueNewCards];
+      });
+
+      setUserCollectionOffset(prev => prev + PAGE_SIZE);
+    } catch (error) {
+      console.error('Error loading more cards:', error);
+    } finally {
+      setIsLoadingMoreUserCards(false);
+    }
+  }, [selectedUser, userCollectionOffset, hasMoreUserCards, isLoadingMoreUserCards]);
+
+  // Intersection Observer for infinite scroll in user collection view
+  useEffect(() => {
+    if (!selectedUser) return;
+
+    const observer = new IntersectionObserver(
+      (entries) => {
+        if (entries[0].isIntersecting && hasMoreUserCards && !isLoadingMoreUserCards) {
+          loadMoreUserCards();
+        }
+      },
+      { threshold: 0.1 }
+    );
+
+    const currentTarget = userCollectionObserverTarget.current;
+    if (currentTarget) {
+      observer.observe(currentTarget);
+    }
+
+    return () => {
+      if (currentTarget) {
+        observer.unobserve(currentTarget);
+      }
+    };
+  }, [selectedUser, hasMoreUserCards, isLoadingMoreUserCards, loadMoreUserCards]);
+
+  // Subscribe to realtime updates for selected user's collection total value
+  useEffect(() => {
+    if (!selectedUser) return;
+
+    const userProfileChannel = supabase
+      .channel(`user-profile-value-${selectedUser.id}`)
+      .on(
+        'postgres_changes',
+        {
+          event: 'UPDATE',
+          schema: 'public',
+          table: 'profiles',
+          filter: `id=eq.${selectedUser.id}`,
+        },
+        (payload: any) => {
+          if (payload.new?.collection_total_value !== undefined) {
+            console.log(`User ${selectedUser.username}'s collection total value updated:`, payload.new.collection_total_value);
+            setUserCollectionTotalValue(payload.new.collection_total_value);
+          }
+        }
+      )
+      .subscribe();
+
+    return () => {
+      supabase.removeChannel(userProfileChannel);
+    };
+  }, [selectedUser]);
+
   // ============ FRIENDS FUNCTIONS ============
   const loadFriendsData = async () => {
     if (!user) return;
@@ -532,74 +696,313 @@ export default function Community() {
     );
 
     return (
-      <div className="bg-gray-900 text-white min-h-screen">
-        {/* Header */}
-        <div className="sticky top-0 bg-gray-900/95 backdrop-blur border-b border-gray-800 p-3 z-10">
-          <div className="flex items-center justify-between gap-2 mb-3">
+      <div className="relative bg-gray-900 text-white min-h-screen">
+        <div className="max-w-7xl mx-auto p-3 sm:p-6">
+          {/* Header with Back and Trade buttons */}
+          <div className="flex items-center justify-between gap-2 mb-4 md:mb-6">
             <button
-              onClick={() => { setSelectedUser(null); setSelectedUserCollection([]); setUserCollectionSearch(''); }}
-              className="flex items-center gap-1 text-blue-400 text-sm min-w-0"
+              onClick={() => {
+                setSelectedUser(null);
+                setSelectedUserCollection([]);
+                setUserCollectionSearch('');
+                setSelectedUserCard(null);
+                setHoveredUserCard(null);
+              }}
+              className="flex items-center gap-1 text-blue-400 hover:text-blue-300 text-sm"
             >
               <ChevronLeft size={20} />
-              <span className="hidden sm:inline">Back</span>
+              <span>Back</span>
             </button>
-            <h1 className="text-lg font-bold truncate flex-1 text-center">{selectedUser.username}</h1>
+            <h1 className="text-2xl md:text-3xl font-bold truncate flex-1 text-center">{selectedUser.username}'s Collection</h1>
             <button
               onClick={() => setShowTradeCreator(true)}
-              className="flex items-center gap-1 px-3 py-1.5 bg-blue-600 hover:bg-blue-700 rounded-lg text-sm whitespace-nowrap"
+              className="flex items-center gap-2 px-3 py-2 bg-blue-600 hover:bg-blue-700 rounded-lg text-sm whitespace-nowrap"
             >
               <ArrowLeftRight size={16} />
-              <span className="hidden sm:inline">Trade</span>
+              <span className="hidden sm:inline">Propose Trade</span>
+              <span className="sm:hidden">Trade</span>
             </button>
           </div>
+
           {/* Search input */}
+          <div className="mb-8">
             <div className="relative">
-            <Search className="absolute left-3 top-1/2 -translate-y-1/2 text-gray-400" size={16} />
+              <Search className="absolute left-3 top-1/2 transform -translate-y-1/2 text-gray-400" size={20} />
               <input
                 type="text"
                 value={userCollectionSearch}
                 onChange={(e) => setUserCollectionSearch(e.target.value)}
-              placeholder="Search cards..."
-              className="w-full pl-9 pr-8 py-2 bg-gray-700 border border-gray-600 rounded-lg text-sm focus:ring-2 focus:ring-blue-500 focus:border-transparent"
+                placeholder="Search cards by name, type, or text..."
+                className="w-full pl-10 pr-4 py-2 bg-gray-800 border border-gray-700 rounded-lg focus:ring-2 focus:ring-blue-500 focus:border-transparent"
               />
-            {userCollectionSearch && (
-              <button
-                onClick={() => setUserCollectionSearch('')}
-                className="absolute right-2 top-1/2 -translate-y-1/2 text-gray-400 hover:text-white"
+            </div>
+          </div>
+
+          {/* Collection */}
+          <div>
+            <div className="flex flex-col sm:flex-row sm:items-center sm:justify-between gap-2 mb-4">
+              <h2 className="text-xl font-semibold">
+                {userCollectionSearch
+                  ? `Found ${filteredUserCollection.length} card(s)`
+                  : `Cards (${selectedUserCollection.length} unique, ${selectedUserCollection.reduce((acc, c) => acc + c.quantity, 0)} total)`
+                }
+              </h2>
+              {/* Collection Value Summary */}
+              <div className="bg-gray-800 border border-gray-700 rounded-lg px-4 py-2">
+                <div className="text-xs text-gray-400 mb-0.5">
+                  {userCollectionSearch ? 'Filtered Value' : 'Total Collection Value'}
+                </div>
+                <div className="text-lg font-bold text-green-400">
+                  {isLoadingUserTotalValue ? (
+                    <Loader2 className="animate-spin" size={20} />
+                  ) : userCollectionSearch ? (
+                    // For search results, calculate from filtered collection
+                    `$${filteredUserCollection.reduce((total, { card, quantity }) => {
+                      const price = card.prices?.usd ? parseFloat(card.prices.usd) : 0;
+                      return total + (price * quantity);
+                    }, 0).toFixed(2)}`
+                  ) : (
+                    // For full collection, use pre-calculated total
+                    `$${userCollectionTotalValue.toFixed(2)}`
+                  )}
+                </div>
+              </div>
+            </div>
+
+            {loadingCollection ? (
+              <div className="flex items-center justify-center py-12">
+                <Loader2 className="animate-spin text-blue-500" size={48} />
+              </div>
+            ) : selectedUserCollection.length === 0 ? (
+              <div className="text-center py-12 text-gray-400">
+                <p className="text-lg">Empty collection</p>
+              </div>
+            ) : filteredUserCollection.length === 0 ? (
+              <div className="text-center py-12 text-gray-400">
+                <p className="text-lg mb-2">No cards found</p>
+                <p className="text-sm">Try a different search term</p>
+              </div>
+            ) : (
+              <div className="grid grid-cols-3 sm:grid-cols-4 md:grid-cols-6 lg:grid-cols-8 xl:grid-cols-10 gap-1.5 sm:gap-2">
+                {filteredUserCollection.map(({ card, quantity }) => {
+                  const currentFaceIndex = getCurrentFaceIndex(card.id);
+                  const isMultiFaced = isDoubleFaced(card);
+                  const displayName = isMultiFaced && card.card_faces
+                    ? card.card_faces[currentFaceIndex]?.name || card.name
+                    : card.name;
+
+                  return (
+                    <div
+                      key={card.id}
+                      className="relative group cursor-pointer"
+                      onMouseEnter={() => setHoveredUserCard(card)}
+                      onMouseLeave={() => setHoveredUserCard(null)}
+                      onClick={() => setSelectedUserCard({ card, quantity })}
                     >
-                <X size={16} />
+                      {/* Card thumbnail */}
+                      <div className="relative rounded-lg overflow-hidden shadow-lg transition-all group-hover:ring-2 group-hover:ring-blue-500">
+                        <img
+                          src={getCardImageUri(card, currentFaceIndex)}
+                          alt={displayName}
+                          className="w-full h-auto"
+                        />
+                        {/* Quantity badge */}
+                        <div className="absolute top-1 right-1 bg-blue-600 text-white text-xs sm:text-sm font-bold px-2 py-1 rounded-full shadow-lg">
+                          x{quantity}
+                        </div>
+                        {/* Price badge */}
+                        {card.prices?.usd && (
+                          <div className="absolute bottom-1 left-1 bg-green-600 text-white text-[10px] sm:text-xs font-bold px-1.5 py-0.5 rounded shadow-lg">
+                            ${card.prices.usd}
+                          </div>
+                        )}
+                        {/* Flip button for double-faced cards */}
+                        {isMultiFaced && (
+                          <button
+                            onClick={(e) => {
+                              e.stopPropagation();
+                              toggleCardFace(card.id, card.card_faces!.length);
+                            }}
+                            className="absolute bottom-1 right-1 bg-purple-600 hover:bg-purple-700 text-white p-1 rounded-full shadow-lg transition-all"
+                            title="Flip card"
+                          >
+                            <RefreshCw size={12} />
                           </button>
                         )}
                       </div>
+
+                      {/* Card name below thumbnail */}
+                      <div className="mt-1 text-xs text-center truncate px-1">
+                        {displayName}
+                      </div>
+                    </div>
+                  );
+                })}
+              </div>
+            )}
+
+            {/* Infinite scroll loading indicator */}
+            {!userCollectionSearch && isLoadingMoreUserCards && (
+              <div className="flex justify-center py-8">
+                <Loader2 className="animate-spin text-blue-500" size={32} />
+              </div>
+            )}
+
+            {/* Observer target for infinite scroll */}
+            {!userCollectionSearch && hasMoreUserCards && !isLoadingMoreUserCards && (
+              <div ref={userCollectionObserverTarget} className="h-20" />
+            )}
+
+            {/* End of collection indicator */}
+            {!userCollectionSearch && !hasMoreUserCards && selectedUserCollection.length > 0 && (
+              <div className="text-center py-8 text-gray-500 text-sm">
+                End of collection • {userCollectionTotalCount} total cards
+              </div>
+            )}
+          </div>
         </div>
 
-        {/* Collection Grid */}
-        <div className="p-3">
-          {loadingCollection ? (
-            <div className="flex justify-center py-12">
-              <Loader2 className="animate-spin text-blue-500" size={32} />
-            </div>
-          ) : selectedUserCollection.length === 0 ? (
-            <p className="text-gray-400 text-center py-12">Empty collection</p>
-          ) : filteredUserCollection.length === 0 ? (
-            <p className="text-gray-400 text-center py-12">No cards match "{userCollectionSearch}"</p>
-          ) : (
-            <div className="grid grid-cols-3 sm:grid-cols-4 md:grid-cols-6 lg:grid-cols-8 gap-2">
-              {filteredUserCollection.map(({ card, quantity }) => (
-                <div key={card.id} className="relative">
+        {/* Hover Card Preview - desktop only, only show if no card is selected */}
+        {hoveredUserCard && !selectedUserCard && (() => {
+          const currentFaceIndex = getCurrentFaceIndex(hoveredUserCard.id);
+          const isMultiFaced = isDoubleFaced(hoveredUserCard);
+          const currentFace = isMultiFaced && hoveredUserCard.card_faces
+            ? hoveredUserCard.card_faces[currentFaceIndex]
+            : null;
+
+          const displayName = currentFace?.name || hoveredUserCard.name;
+          const displayTypeLine = currentFace?.type_line || hoveredUserCard.type_line;
+          const displayOracleText = currentFace?.oracle_text || hoveredUserCard.oracle_text;
+
+          return (
+            <div className="hidden lg:block fixed top-1/2 right-8 transform -translate-y-1/2 z-30 pointer-events-none">
+              <div className="bg-gray-800 rounded-lg shadow-2xl p-4 max-w-md">
+                <div className="relative">
                   <img
-                    src={card.image_uris?.small || card.image_uris?.normal}
-                    alt={card.name}
-                    className="w-full h-auto rounded-lg"
+                    src={getCardLargeImageUri(hoveredUserCard, currentFaceIndex)}
+                    alt={displayName}
+                    className="w-full h-auto rounded-lg shadow-lg"
                   />
-                  <span className="absolute top-1 right-1 bg-blue-600 text-white text-[10px] font-bold px-1.5 py-0.5 rounded-full">
-                    x{quantity}
-                  </span>
-                </div>
-              ))}
+                  {isMultiFaced && (
+                    <div className="absolute top-2 right-2 bg-purple-600 text-white text-xs font-bold px-2 py-1 rounded-full shadow-lg">
+                      Face {currentFaceIndex + 1}/{hoveredUserCard.card_faces!.length}
                     </div>
                   )}
                 </div>
+                <div className="mt-3 space-y-2">
+                  <h3 className="text-xl font-bold">{displayName}</h3>
+                  <p className="text-sm text-gray-400">{displayTypeLine}</p>
+                  {displayOracleText && (
+                    <p className="text-sm text-gray-300 border-t border-gray-700 pt-2">
+                      {displayOracleText}
+                    </p>
+                  )}
+                  {hoveredUserCard.prices?.usd && (
+                    <div className="text-sm text-green-400 font-semibold border-t border-gray-700 pt-2">
+                      ${hoveredUserCard.prices.usd}
+                    </div>
+                  )}
+                </div>
+              </div>
+            </div>
+          );
+        })()}
+
+        {/* Card Detail Panel - slides in from right */}
+        {selectedUserCard && (() => {
+          const currentFaceIndex = getCurrentFaceIndex(selectedUserCard.card.id);
+          const isMultiFaced = isDoubleFaced(selectedUserCard.card);
+          const currentFace = isMultiFaced && selectedUserCard.card.card_faces
+            ? selectedUserCard.card.card_faces[currentFaceIndex]
+            : null;
+
+          const displayName = currentFace?.name || selectedUserCard.card.name;
+          const displayTypeLine = currentFace?.type_line || selectedUserCard.card.type_line;
+          const displayOracleText = currentFace?.oracle_text || selectedUserCard.card.oracle_text;
+
+          return (
+            <>
+              {/* Backdrop */}
+              <div
+                className="fixed inset-0 bg-black bg-opacity-50 z-[110] transition-opacity duration-300"
+                onClick={() => setSelectedUserCard(null)}
+              />
+
+              {/* Sliding Panel */}
+              <div className="fixed top-0 right-0 h-full w-full md:w-96 bg-gray-800 shadow-2xl z-[120] overflow-y-auto animate-slide-in-right">
+                {/* Close button */}
+                <button
+                  onClick={() => setSelectedUserCard(null)}
+                  className="fixed top-4 right-4 bg-gray-700 hover:bg-gray-600 text-white p-2 md:p-1.5 rounded-full transition-colors z-[130] shadow-lg"
+                  aria-label="Close"
+                >
+                  <X size={24} className="md:w-5 md:h-5" />
+                </button>
+
+                <div className="p-4 sm:p-6">
+                  {/* Card Image */}
+                  <div className="relative mb-4 max-w-sm mx-auto">
+                    <img
+                      src={getCardLargeImageUri(selectedUserCard.card, currentFaceIndex)}
+                      alt={displayName}
+                      className="w-full h-auto rounded-lg shadow-lg"
+                    />
+                    {isMultiFaced && (
+                      <>
+                        <div className="absolute top-2 right-2 bg-purple-600 text-white text-xs font-bold px-2 py-1 rounded-full shadow-lg">
+                          Face {currentFaceIndex + 1}/{selectedUserCard.card.card_faces!.length}
+                        </div>
+                        <button
+                          onClick={() => toggleCardFace(selectedUserCard.card.id, selectedUserCard.card.card_faces!.length)}
+                          className="absolute bottom-2 right-2 bg-purple-600 hover:bg-purple-700 text-white p-2 rounded-full shadow-lg transition-all"
+                          title="Flip card"
+                        >
+                          <RefreshCw size={20} />
+                        </button>
+                      </>
+                    )}
+                  </div>
+
+                  {/* Card Info */}
+                  <div className="space-y-4">
+                    <div>
+                      <h2 className="text-xl md:text-2xl font-bold text-white mb-2">{displayName}</h2>
+                      <p className="text-xs sm:text-sm text-gray-400">{displayTypeLine}</p>
+                    </div>
+
+                    {displayOracleText && (
+                      <div className="border-t border-gray-700 pt-3">
+                        <p className="text-sm text-gray-300">{displayOracleText}</p>
+                      </div>
+                    )}
+
+                    {selectedUserCard.card.prices?.usd && (
+                      <div className="border-t border-gray-700 pt-3">
+                        <div className="text-lg text-green-400 font-semibold">
+                          ${selectedUserCard.card.prices.usd} each
+                        </div>
+                        <div className="text-sm text-gray-400">
+                          Total value: ${(parseFloat(selectedUserCard.card.prices.usd) * selectedUserCard.quantity).toFixed(2)}
+                        </div>
+                      </div>
+                    )}
+
+                    {/* Quantity Display */}
+                    <div className="border-t border-gray-700 pt-3">
+                      <h3 className="text-lg font-semibold mb-3">Quantity in Collection</h3>
+                      <div className="flex items-center justify-center bg-gray-900 rounded-lg p-4">
+                        <div className="text-center">
+                          <div className="text-3xl font-bold">{selectedUserCard.quantity}</div>
+                          <div className="text-xs text-gray-400">copies</div>
+                        </div>
+                      </div>
+                    </div>
+                  </div>
+                </div>
+              </div>
+            </>
+          );
+        })()}
 
         {showTradeCreator && (
           <TradeCreator
@@ -1009,10 +1412,15 @@ export default function Community() {
                             With: <strong>{otherUser?.username}</strong>
                           </span>
                         </div>
+                        <div className="flex items-center gap-1.5">
+                          {trade.status === 'pending' && !trade.is_valid && (
+                            <AlertTriangle size={14} className="text-red-400" title="Trade no longer valid" />
+                          )}
                           <span className={`text-xs capitalize ${statusColors[trade.status]}`}>
                             {trade.status}
                           </span>
                         </div>
+                      </div>
 
                       {/* Items */}
                       <div className="grid grid-cols-2 gap-2 text-sm">

src/components/TradeDetail.tsx

@@ -1,5 +1,5 @@
 import React, { useState, useEffect } from 'react';
-import { X, Check, ArrowLeftRight, DollarSign, Loader2, Edit, RefreshCcw, History } from 'lucide-react';
+import { X, Check, ArrowLeftRight, DollarSign, Loader2, Edit, RefreshCcw, History, AlertTriangle } from 'lucide-react';
 import { useAuth } from '../contexts/AuthContext';
 import { useToast } from '../contexts/ToastContext';
 import { Trade, TradeHistoryEntry, getTradeVersionHistory } from '../services/tradesService';
@@ -222,6 +222,18 @@ export default function TradeDetail({
             </div>
           ) : (
             <div className="space-y-4">
+              {/* Invalid Trade Warning */}
+              {trade.status === 'pending' && !trade.is_valid && (
+                <div className="bg-red-900/30 border border-red-600 rounded-lg p-3 flex items-start gap-2">
+                  <AlertTriangle size={20} className="text-red-400 flex-shrink-0 mt-0.5" />
+                  <div>
+                    <h4 className="font-semibold text-red-400 text-sm">Trade No Longer Valid</h4>
+                    <p className="text-red-200 text-xs mt-1">
+                      One or more cards in this trade are no longer available in the required quantities. This trade cannot be accepted until it is updated.
+                    </p>
+                  </div>
+                </div>
+              )}
               <div className="grid grid-cols-1 lg:grid-cols-2 gap-4">
                 {/* Your Side */}
                 <div className="space-y-3">
@@ -367,8 +379,9 @@ export default function TradeDetail({
                 <div className="flex gap-2">
                   <button
                     onClick={handleAccept}
-                    disabled={processing}
-                    className="flex-1 flex items-center justify-center gap-2 px-4 py-3 bg-green-600 hover:bg-green-700 disabled:bg-gray-600 rounded-lg font-medium transition"
+                    disabled={processing || !trade.is_valid}
+                    className="flex-1 flex items-center justify-center gap-2 px-4 py-3 bg-green-600 hover:bg-green-700 disabled:bg-gray-600 disabled:cursor-not-allowed rounded-lg font-medium transition"
+                    title={!trade.is_valid ? 'This trade is no longer valid' : ''}
                   >
                     {processing ? (
                       <Loader2 className="animate-spin" size={18} />
@@ -431,8 +444,9 @@ export default function TradeDetail({
                     <div className="flex gap-2">
                       <button
                         onClick={handleAccept}
-                        disabled={processing}
-                        className="flex-1 flex items-center justify-center gap-2 px-4 py-3 bg-green-600 hover:bg-green-700 disabled:bg-gray-600 rounded-lg font-medium transition"
+                        disabled={processing || !trade.is_valid}
+                        className="flex-1 flex items-center justify-center gap-2 px-4 py-3 bg-green-600 hover:bg-green-700 disabled:bg-gray-600 disabled:cursor-not-allowed rounded-lg font-medium transition"
+                        title={!trade.is_valid ? 'This trade is no longer valid' : ''}
                       >
                         {processing ? (
                           <Loader2 className="animate-spin" size={18} />

src/services/api.ts

@@ -75,10 +75,76 @@ export const getUserCollection = async (userId: string): Promise<Map<string, num
   return collectionMap;
 };
 
+// Paginated collection API
+export interface PaginatedCollectionResult {
+  items: Map<string, number>; // card_id -> quantity
+  totalCount: number;
+  hasMore: boolean;
+}
+
+// Get total collection value from user profile (pre-calculated by triggers)
+export const getCollectionTotalValue = async (userId: string): Promise<number> => {
+  const { data, error } = await supabase
+    .from('profiles')
+    .select('collection_total_value')
+    .eq('id', userId)
+    .single();
+
+  if (error) {
+    console.error('Error fetching collection total value:', error);
+    return 0;
+  }
+
+  return data?.collection_total_value || 0;
+};
+
+export const getUserCollectionPaginated = async (
+  userId: string,
+  pageSize: number = 50,
+  offset: number = 0
+): Promise<PaginatedCollectionResult> => {
+  // First, get the total count
+  const { count: totalCount, error: countError } = await supabase
+    .from('collections')
+    .select('*', { count: 'exact', head: true })
+    .eq('user_id', userId);
+
+  if (countError) {
+    console.error('Error counting user collection:', countError);
+    throw countError;
+  }
+
+  // Then get the paginated data
+  const { data, error } = await supabase
+    .from('collections')
+    .select('card_id, quantity')
+    .eq('user_id', userId)
+    .order('created_at', { ascending: false })
+    .range(offset, offset + pageSize - 1);
+
+  if (error) {
+    console.error('Error fetching user collection:', error);
+    throw error;
+  }
+
+  // Create a map of card_id to quantity for easy lookup
+  const collectionMap = new Map<string, number>();
+  data?.forEach((item) => {
+    collectionMap.set(item.card_id, item.quantity);
+  });
+
+  return {
+    items: collectionMap,
+    totalCount: totalCount || 0,
+    hasMore: offset + pageSize < (totalCount || 0),
+  };
+};
+
 export const addCardToCollection = async (
   userId: string,
   cardId: string,
-  quantity: number = 1
+  quantity: number = 1,
+  priceUsd: number = 0
 ): Promise<void> => {
   // Check if card already exists in collection
   const { data: existing, error: fetchError } = await supabase
@@ -94,11 +160,12 @@ export const addCardToCollection = async (
   }
 
   if (existing) {
-    // Update existing card quantity
+    // Update existing card quantity and price
     const { error: updateError } = await supabase
       .from('collections')
       .update({
         quantity: existing.quantity + quantity,
+        price_usd: priceUsd,
         updated_at: new Date().toISOString()
       })
       .eq('id', existing.id);
@@ -112,6 +179,7 @@ export const addCardToCollection = async (
         user_id: userId,
         card_id: cardId,
         quantity: quantity,
+        price_usd: priceUsd,
       });
 
     if (insertError) throw insertError;
@@ -120,7 +188,7 @@ export const addCardToCollection = async (
 
 export const addMultipleCardsToCollection = async (
   userId: string,
-  cards: { cardId: string; quantity: number }[]
+  cards: { cardId: string; quantity: number; priceUsd?: number }[]
 ): Promise<void> => {
   // Fetch existing cards in collection
   const cardIds = cards.map(c => c.cardId);
@@ -146,6 +214,7 @@ export const addMultipleCardsToCollection = async (
       toUpdate.push({
         id: existing.id,
         quantity: existing.quantity + card.quantity,
+        price_usd: card.priceUsd || 0,
         updated_at: new Date().toISOString(),
       });
     } else {
@@ -153,6 +222,7 @@ export const addMultipleCardsToCollection = async (
         user_id: userId,
         card_id: card.cardId,
         quantity: card.quantity,
+        price_usd: card.priceUsd || 0,
       });
     }
   }
@@ -170,7 +240,11 @@ export const addMultipleCardsToCollection = async (
     for (const update of toUpdate) {
       const { error: updateError } = await supabase
         .from('collections')
-        .update({ quantity: update.quantity, updated_at: update.updated_at })
+        .update({
+          quantity: update.quantity,
+          price_usd: update.price_usd,
+          updated_at: update.updated_at
+        })
         .eq('id', update.id);
 
       if (updateError) throw updateError;

src/services/tradesService.ts

@@ -18,6 +18,7 @@ export interface Trade {
   updated_at: string | null;
   version: number;
   editor_id: string | null;
+  is_valid: boolean;
   user1?: { username: string | null };
   user2?: { username: string | null };
   items?: TradeItem[];
@@ -160,6 +161,25 @@ export async function createTrade(params: CreateTradeParams): Promise<Trade> {
 
 // Accept a trade (executes the card transfer)
 export async function acceptTrade(tradeId: string): Promise<boolean> {
+  // First check if the trade is valid
+  const { data: trade, error: tradeError } = await supabase
+    .from('trades')
+    .select('is_valid, status')
+    .eq('id', tradeId)
+    .single();
+
+  if (tradeError) throw tradeError;
+
+  // Prevent accepting invalid trades
+  if (!trade.is_valid) {
+    throw new Error('This trade is no longer valid. One or more cards are no longer available in the required quantities.');
+  }
+
+  // Prevent accepting non-pending trades
+  if (trade.status !== 'pending') {
+    throw new Error('This trade has already been processed.');
+  }
+
   const { data, error } = await supabase.rpc('execute_trade', {
     trade_id: tradeId,
   });

supabase/migrations/20250127000000_add_price_to_collections.sql

@@ -0,0 +1,9 @@
+-- Add price_usd column to collections table
+ALTER TABLE collections
+ADD COLUMN IF NOT EXISTS price_usd DECIMAL(10, 2) DEFAULT 0;
+
+-- Create index for faster price calculations
+CREATE INDEX IF NOT EXISTS idx_collections_price ON collections(price_usd);
+
+-- Add comment
+COMMENT ON COLUMN collections.price_usd IS 'USD price of the card at time of addition/update';

supabase/migrations/20250127000001_add_trade_validation.sql

@@ -0,0 +1,101 @@
+-- Add is_valid column to trades table
+ALTER TABLE public.trades
+ADD COLUMN IF NOT EXISTS is_valid BOOLEAN DEFAULT true;
+
+-- Create index for filtering by validity
+CREATE INDEX IF NOT EXISTS idx_trades_is_valid ON public.trades(is_valid);
+
+-- Function to validate if a trade can still be executed based on current collections
+CREATE OR REPLACE FUNCTION public.validate_trade(p_trade_id uuid)
+RETURNS boolean
+LANGUAGE plpgsql
+SECURITY DEFINER
+AS $$
+DECLARE
+  v_item RECORD;
+  v_collection_quantity integer;
+BEGIN
+  -- Check each item in the trade
+  FOR v_item IN
+    SELECT owner_id, card_id, quantity
+    FROM public.trade_items
+    WHERE trade_id = p_trade_id
+  LOOP
+    -- Get the quantity of this card in the owner's collection
+    SELECT COALESCE(quantity, 0) INTO v_collection_quantity
+    FROM public.collections
+    WHERE user_id = v_item.owner_id
+    AND card_id = v_item.card_id;
+
+    -- If owner doesn't have enough of this card, trade is invalid
+    IF v_collection_quantity < v_item.quantity THEN
+      RETURN false;
+    END IF;
+  END LOOP;
+
+  -- All items are available, trade is valid
+  RETURN true;
+END;
+$$;
+
+-- Function to check and update validity of affected trades when collections change
+CREATE OR REPLACE FUNCTION public.update_affected_trades_validity()
+RETURNS TRIGGER
+LANGUAGE plpgsql
+SECURITY DEFINER
+AS $$
+DECLARE
+  v_user_id uuid;
+  v_card_id text;
+  v_trade RECORD;
+  v_is_valid boolean;
+BEGIN
+  -- Get the user_id and card_id from the changed row
+  IF (TG_OP = 'DELETE') THEN
+    v_user_id := OLD.user_id;
+    v_card_id := OLD.card_id;
+  ELSE
+    v_user_id := NEW.user_id;
+    v_card_id := NEW.card_id;
+  END IF;
+
+  -- Find all pending trades that involve this card from this user
+  FOR v_trade IN
+    SELECT DISTINCT t.id
+    FROM public.trades t
+    JOIN public.trade_items ti ON ti.trade_id = t.id
+    WHERE t.status = 'pending'
+    AND ti.owner_id = v_user_id
+    AND ti.card_id = v_card_id
+  LOOP
+    -- Validate the trade
+    v_is_valid := public.validate_trade(v_trade.id);
+
+    -- Update the trade's validity
+    UPDATE public.trades
+    SET is_valid = v_is_valid,
+        updated_at = now()
+    WHERE id = v_trade.id;
+  END LOOP;
+
+  IF (TG_OP = 'DELETE') THEN
+    RETURN OLD;
+  ELSE
+    RETURN NEW;
+  END IF;
+END;
+$$;
+
+-- Create trigger to auto-update trade validity when collections change
+CREATE TRIGGER update_trades_on_collection_change
+AFTER UPDATE OR DELETE ON public.collections
+FOR EACH ROW
+EXECUTE FUNCTION public.update_affected_trades_validity();
+
+-- Add comment
+COMMENT ON COLUMN public.trades.is_valid IS 'Indicates if the trade can still be executed based on current collections. Auto-updated when collections change.';
+
+-- Initial validation: set is_valid for all existing pending trades
+UPDATE public.trades
+SET is_valid = public.validate_trade(id)
+WHERE status = 'pending';