feat: implement mana cost parsing and auto-tap calculation with visual preview in game view

src/client/src/modules/game/GameView.tsx

@@ -17,6 +17,7 @@ import { MulliganView } from './MulliganView';
 import { RadialMenu, RadialOption } from './RadialMenu';
 import { InspectorOverlay } from './InspectorOverlay';
 import { SidePanelPreview } from '../../components/SidePanelPreview';
+import { calculateAutoTap } from '../../utils/manaUtils';
 
 // --- DnD Helpers ---
 const DraggableCardWrapper = ({ children, card, disabled }: { children: React.ReactNode, card: CardInstance, disabled?: boolean }) => {
@@ -76,6 +77,7 @@ export const GameView: React.FC<GameViewProps> = ({ gameState, currentPlayerId }
   const [viewingZone, setViewingZone] = useState<string | null>(null);
   const [hoveredCard, setHoveredCard] = useState<CardInstance | null>(null);
   const [dragAnimationMode, setDragAnimationMode] = useState<'start' | 'end'>('end');
+  const [previewTappedIds, setPreviewTappedIds] = useState<Set<string>>(new Set());
 
   // Auto-Pass Priority if Yielding
   useEffect(() => {
@@ -418,6 +420,21 @@ export const GameView: React.FC<GameViewProps> = ({ gameState, currentPlayerId }
     const card = gameState.cards[cardId];
     if (card && card.zone === 'hand') {
       setDragAnimationMode('start');
+
+      // PREVIEW AUTO TAP
+      // If no cost (Land), do nothing.
+      if (card.manaCost && myPlayer) {
+        const myLands = Object.values(gameState.cards).filter(c =>
+          c.controllerId === currentPlayerId &&
+          c.zone === 'battlefield' &&
+          (c.types?.includes('Land') || c.typeLine?.includes('Land'))
+        );
+        const toTap = calculateAutoTap(card.manaCost, myPlayer, myLands);
+        if (toTap.size > 0) {
+          setPreviewTappedIds(toTap);
+        }
+      }
+
       // Trigger animation to shrink
       setTimeout(() => {
         setDragAnimationMode('end');
@@ -431,6 +448,7 @@ export const GameView: React.FC<GameViewProps> = ({ gameState, currentPlayerId }
 
   const handleDragEnd = (event: DragEndEvent) => {
     setActiveDragId(null);
+    setPreviewTappedIds(new Set()); // Clear preview
     document.body.style.cursor = '';
     const { active, over } = event;
 
@@ -700,6 +718,7 @@ export const GameView: React.FC<GameViewProps> = ({ gameState, currentPlayerId }
                     const renderCard = (card: CardInstance) => {
                       const isAttacking = proposedAttackers.has(card.instanceId);
                       const blockingTargetId = proposedBlockers.get(card.instanceId);
+                      const isPreviewTapped = previewTappedIds.has(card.instanceId);
 
                       return (
                         <div
@@ -711,8 +730,11 @@ export const GameView: React.FC<GameViewProps> = ({ gameState, currentPlayerId }
                               ? 'translateY(-40px) scale(1.1) rotateX(10deg)'
                               : blockingTargetId
                                 ? 'translateY(-20px) scale(1.05)'
-                                : 'none',
+                                : isPreviewTapped
-                            boxShadow: isAttacking ? '0 20px 40px -10px rgba(239, 68, 68, 0.5)' : 'none'
+                                  ? 'rotate(10deg)'  // Preview Tap Rotation
+                                  : 'none',
+                            boxShadow: isAttacking ? '0 20px 40px -10px rgba(239, 68, 68, 0.5)' : 'none',
+                            opacity: isPreviewTapped ? 0.7 : 1 // Preview Tap Opacity
                           }}
                         >
                           <DraggableCardWrapper card={card} disabled={!hasPriority}>

src/client/src/utils/manaUtils.ts

@@ -0,0 +1,147 @@
+
+import { CardInstance, PlayerState } from '../types/game';
+
+// Helper to determine land color identity from type line or name
+export const getLandColor = (card: CardInstance): string | null => {
+  const typeLine = card.typeLine || '';
+  const types = card.types || [];
+
+  if (!typeLine.includes('Land') && !types.includes('Land')) return null;
+
+  if (typeLine.includes('Plains')) return 'W';
+  if (typeLine.includes('Island')) return 'U';
+  if (typeLine.includes('Swamp')) return 'B';
+  if (typeLine.includes('Mountain')) return 'R';
+  if (typeLine.includes('Forest')) return 'G';
+
+  // TODO: Wastes
+  return null;
+};
+
+export const parseManaCost = (manaCost: string): { generic: number, colors: Record<string, number>, hybrids: string[][] } => {
+  const cost = { generic: 0, colors: { W: 0, U: 0, B: 0, R: 0, G: 0, C: 0 } as Record<string, number>, hybrids: [] as string[][] };
+
+  if (!manaCost) return cost;
+
+  const matches = manaCost.match(/{[^{}]+}/g);
+  if (!matches) return cost;
+
+  matches.forEach(symbol => {
+    const content = symbol.replace(/[{}]/g, '');
+
+    if (!isNaN(Number(content))) {
+      cost.generic += Number(content);
+    }
+    else if (content.includes('/')) {
+      const parts = content.split('/');
+      const options = parts.filter(p => ['W', 'U', 'B', 'R', 'G', 'C'].includes(p));
+      if (options.length >= 1) {
+        cost.hybrids.push(options);
+      }
+    }
+    else {
+      if (['W', 'U', 'B', 'R', 'G', 'C'].includes(content)) {
+        cost.colors[content]++;
+      }
+    }
+  });
+
+  return cost;
+};
+
+// Returns a set of card IDs to tap
+export const calculateAutoTap = (
+  costStr: string,
+  player: PlayerState,
+  myLands: CardInstance[]
+): Set<string> => {
+  const landsToTap = new Set<string>();
+  const cost = parseManaCost(costStr);
+
+  // Clone pool so we don't mutate state locally
+  const pool = { ...player.manaPool };
+  if (!pool.W) pool.W = 0; if (!pool.U) pool.U = 0; if (!pool.B) pool.B = 0;
+  if (!pool.R) pool.R = 0; if (!pool.G) pool.G = 0; if (!pool.C) pool.C = 0;
+
+  // Filter usable lands (untapped)
+  // We only consider lands that haven't been marked for tap yet (initially none)
+  const availableLands = myLands.filter(l => !l.tapped);
+
+  // 1. Pay Colored Costs
+  for (const color of ['W', 'U', 'B', 'R', 'G', 'C']) {
+    let required = cost.colors[color];
+    if (required <= 0) continue;
+
+    // Pool First
+    if (pool[color] >= required) {
+      pool[color] -= required;
+      required = 0;
+    } else {
+      required -= pool[color];
+      pool[color] = 0;
+    }
+
+    // Lands
+    if (required > 0) {
+      const producers = availableLands.filter(l => !landsToTap.has(l.instanceId) && getLandColor(l) === color);
+      if (producers.length >= required) {
+        for (let i = 0; i < required; i++) {
+          landsToTap.add(producers[i].instanceId);
+        }
+        required = 0;
+      } else {
+        // Cannot pay strictly
+        return new Set(); // Fail
+      }
+    }
+  }
+
+  // 2. Pay Hybrid (Greedy)
+  for (const options of cost.hybrids) {
+    let paid = false;
+    for (const color of options) {
+      if (pool[color] > 0) {
+        pool[color]--;
+        paid = true;
+        break;
+      }
+      const land = availableLands.find(l => !landsToTap.has(l.instanceId) && getLandColor(l) === color);
+      if (land) {
+        landsToTap.add(land.instanceId);
+        paid = true;
+        break;
+      }
+    }
+    // If greedy fail, we might fail overall. 
+    // Real auto-tapper might backtrack, but for preview/MVP we match server greedy logic.
+    if (!paid) return new Set();
+  }
+
+  // 3. Pay Generic
+  let genericRequired = cost.generic;
+  if (genericRequired > 0) {
+    // Pool
+    for (const color of Object.keys(pool)) {
+      if (genericRequired <= 0) break;
+      const available = pool[color];
+      if (available > 0) {
+        const take = Math.min(available, genericRequired);
+        pool[color] -= take;
+        genericRequired -= take;
+      }
+    }
+    // Lands
+    if (genericRequired > 0) {
+      const unusedLands = availableLands.filter(l => !landsToTap.has(l.instanceId) && getLandColor(l) !== null);
+      if (unusedLands.length >= genericRequired) {
+        for (let i = 0; i < genericRequired; i++) {
+          landsToTap.add(unusedLands[i].instanceId);
+        }
+      } else {
+        return new Set(); // Fail
+      }
+    }
+  }
+
+  return landsToTap;
+};