'use client';

import { faction } from '@/game/catalog';
import { coalitionAllies } from '@/game/coalition-alliance';
import type { GameView } from '@/game/engine';

/** Alliance membership is public; a staged larger alliance has no scalar
 * player.ally value, so use its authoritative public membership ledger. */
export function RosterAlliance({game, playerId}: {
  game: Pick<GameView, 'players' | 'coalitionState'>;
  playerId: string;
}) {
  const player = game.players.find(seat => seat.id === playerId);
  if (!player) return null;
  const ids = game.coalitionState
    ? coalitionAllies(game.players, game.coalitionState, playerId)
    : player.ally ? [player.ally] : [];
  const names = ids.flatMap(id => {
    const ally = game.players.find(seat => seat.id === id);
    return ally ? [faction(ally.faction).name] : [];
  });
  return names.length ? <div className="fine">Allied with {names.join(' and ')}</div> : null;
}