Implement Harkonnen Nexus exchanges with durable traitor declarations

game/nexus-traitor-options.ts

@@ -0,0 +1,145 @@
+import type { Action, GameView } from './engine';
+import { nexusCardMode } from './nexus-cards';
+import { CHEAP_HERO_TRAITOR, matchingTraitor } from './traitors';
+
+function quiet(game: GameView): boolean {
+  return (
+    game.status === 'playing' &&
+    !game.automaticContinuationPending &&
+    !game.truthtrance &&
+    !game.response &&
+    !game.decision &&
+    !game.phaseOpening &&
+    !game.nexusCards?.waiting.length
+  );
+}
+
+/** The private server offer, not another player's hand, authorizes a draw. */
+export function nexusTraitorDrawAction(
+  game: GameView,
+  event: string,
+  mode: 'cunning' | 'secretAlly' | 'betrayal',
+): Action | null {
+  const offer = game.nexusTraitors?.offer;
+  const owner = game.players.find((player) => player.id === game.me);
+  if (
+    game.status !== 'playing' ||
+    game.truthtrance ||
+    game.nexusCards?.waiting.length ||
+    game.nexusTraitors?.pending ||
+    !owner ||
+    !event ||
+    !offer ||
+    offer.event !== event ||
+    offer.mode !== mode ||
+    offer.blocked ||
+    mode === 'betrayal' ||
+    game.nexusCards?.card !== 'harkonnen' ||
+    owner.ally ||
+    nexusCardMode(
+      'harkonnen',
+      owner.faction,
+      game.players.map((player) => player.faction),
+    ) !== mode ||
+    offer.draw !== (mode === 'cunning' ? 1 : 2) ||
+    (mode === 'secretAlly' && game.phase !== 8)
+  )
+    return null;
+  return { type: 'nexusTraitorDraw', event, mode };
+}
+
+/** Return only the explicitly projected physical choices, never a reconstructed
+ * traitor/Face Dancer hand. A returned new draw is as legal as an old identity. */
+export function nexusTraitorReturnAction(
+  game: GameView,
+  event: string,
+  cards: readonly string[],
+): Action | null {
+  const pending = game.nexusTraitors?.pending;
+  if (
+    game.status !== 'playing' ||
+    game.truthtrance ||
+    !pending ||
+    pending.owner !== game.me ||
+    !event ||
+    pending.event !== event ||
+    !game.players.some((player) => player.id === game.me) ||
+    !['cunning', 'secretAlly'].includes(pending.mode) ||
+    pending.count !== (pending.mode === 'cunning' ? 1 : 2) ||
+    (pending.mode === 'secretAlly' && game.phase !== 8) ||
+    cards.length !== pending.count ||
+    new Set(cards).size !== cards.length ||
+    !cards.every((id) => pending.choices.some((choice) => choice.id === id))
+  )
+    return null;
+  return { type: 'nexusTraitorReturn', event, cards: [...cards] };
+}
+
+function returnPreference(game: GameView, id: string): number {
+  const owner = game.players.find((player) => player.id === game.me)!;
+  const battle = game.battle;
+  if (
+    battle?.revealed &&
+    [battle.attacker, battle.defender].includes(owner.id)
+  ) {
+    const target =
+      battle.attacker === owner.id ? battle.defender : battle.attacker;
+    const leader = battle.plans[target]?.leader;
+    if (
+      leader &&
+      matchingTraitor(
+        [id],
+        leader,
+        battle.cards.find((card) => card.id === leader),
+      )
+    )
+      return 1000;
+  }
+  if (id === CHEAP_HERO_TRAITOR) return 0;
+  const identity = game.allLeaders.find((leader) => leader.id === id);
+  const publicLeader = game.players
+    .flatMap((player) => player.leaders)
+    .find((leader) => leader.id === id);
+  return (
+    (identity?.faction === owner.faction ? -100 : 0) +
+    (publicLeader?.dead ? -20 : 0) +
+    (identity?.strength ?? 0)
+  );
+}
+
+/** Shared legal policy only; ranking uses public leaders and this viewer's
+ * authorized choices. It makes no claim of calibrated faction strategy. */
+export function nexusTraitorBotActions(game: GameView): Action[] {
+  const pending = game.nexusTraitors?.pending;
+  if (pending) {
+    if (
+      pending.owner !== game.me ||
+      game.truthtrance ||
+      game.status !== 'playing'
+    )
+      return [];
+    const cards = [...pending.choices]
+      .sort(
+        (one, two) =>
+          returnPreference(game, one.id) - returnPreference(game, two.id),
+      )
+      .slice(0, pending.count)
+      .map((choice) => choice.id);
+    const action = nexusTraitorReturnAction(game, pending.event, cards);
+    return action ? [action] : [];
+  }
+  const offer = game.nexusTraitors?.offer;
+  if (!offer || !quiet(game)) return [];
+  if (offer.mode === 'cunning') {
+    const battle = game.battle;
+    const beforeCall =
+      game.phase === 6 &&
+      battle?.revealed &&
+      [battle.attacker, battle.defender].includes(game.me) &&
+      battle.traitorVoters.includes(game.me) &&
+      !battle.traitorSubmitted.includes(game.me);
+    if (!beforeCall && game.phase !== 8) return [];
+  }
+  const action = nexusTraitorDrawAction(game, offer.event, offer.mode);
+  return action ? [action] : [];
+}