feat: add label random and animations to web interface

data/target_interaction.js

@@ -43,7 +43,50 @@
     };
   }
 
-  const api = { createTargetActivator };
+  function detectFeedback(previous, next, viewer) {
+    if (!previous || !next || previous.gameId !== next.gameId || next.version <= previous.version) return undefined;
+    const player = viewer === 'player1' ? 0 : viewer === 'player2' ? 1 : -1;
+    if (previous.phase !== next.phase && next.phase === 'finished') {
+      if (player < 0) return { type: 'finish' };
+      return { type: next.winner === player ? 'victory' : 'defeat' };
+    }
+    if (previous.phase !== 'in_progress' && next.phase === 'in_progress') return { type: 'start' };
+    if (!Array.isArray(previous.boards) || !Array.isArray(next.boards)) return undefined;
+
+    let best;
+    for (let board = 0; board < 2; board += 1) {
+      if (typeof previous.boards[board] !== 'string' || typeof next.boards[board] !== 'string') continue;
+      for (let cell = 0; cell < 100; cell += 1) {
+        const before = previous.boards[board][cell];
+        const after = next.boards[board][cell];
+        if (before === after) continue;
+        const perspective = player < 0 ? 'watch' : board === player ? 'damage' : 'attack';
+        if (after === '4') best = { type: perspective === 'damage' ? 'sunk-damage' : perspective === 'attack' ? 'sunk' : 'watch-sunk' };
+        else if (!best && after === '3') best = { type: perspective === 'damage' ? 'damage' : perspective === 'attack' ? 'hit' : 'watch-hit' };
+        else if (!best && after === '2') best = { type: perspective === 'attack' ? 'miss' : perspective === 'damage' ? 'dodged' : 'watch-miss' };
+      }
+    }
+    if (best) return best;
+    if (player >= 0 && previous.turn !== next.turn && next.turn === viewer) return { type: 'turn' };
+    return undefined;
+  }
+
+  function createReactionPicker(catalog, random = Math.random) {
+    const previousByType = new Map();
+    return type => {
+      const variants = catalog[type];
+      if (!Array.isArray(variants) || variants.length === 0) return undefined;
+      if (variants.length === 1) return variants[0];
+      const previous = previousByType.get(type);
+      const candidateCount = previous === undefined ? variants.length : variants.length - 1;
+      let index = Math.min(candidateCount - 1, Math.max(0, Math.floor(random() * candidateCount)));
+      if (previous !== undefined && index >= previous) index += 1;
+      previousByType.set(type, index);
+      return variants[index];
+    };
+  }
+
+  const api = { createTargetActivator, detectFeedback, createReactionPicker };
   if (typeof module !== 'undefined' && module.exports) module.exports = api;
   else globalThis.BattleshipTargetInteraction = api;
 })();