using OECS;

namespace Game.CardWars;

/// <summary>
/// One-time setup: creates players, leaders, banners, decks, castles, and deals starting hands.
/// </summary>
public class GameSetupSystem : ISystem
{
    private readonly int _playerCount;
    private readonly string _cardDataCsv;
    private bool _hasRun;

    public GameSetupSystem(int playerCount, string cardDataCsv)
    {
        _playerCount = playerCount;
        _cardDataCsv = cardDataCsv;
    }

    public void Run(World world)
    {
        if (_hasRun) return;
        _hasRun = true;

        var state = world.ReadSingleton<GameState>();
        ref var mutable = ref world.GetSingleton<GameState>();
        mutable.PlayerCount = _playerCount;
        mutable.Phase = GamePhase.PlayPhase;
        mutable.CurrentPlayerIndex = 0;
        mutable.StartingPlayerIndex = 0;
        mutable.RoundNumber = 1;
        world.MarkModified<GameState>(World.SingletonEntity);

        // Register card effects.
        CardEffectRegistry.Add<WarriorEffect>();
        CardEffectRegistry.Add<ArcherEffect>();
        CardEffectRegistry.Add<MercenaryEffect>();
        CardEffectRegistry.Add<MerchantEffect>();
        CardEffectRegistry.Add<DancerEffect>();
        CardEffectRegistry.Add<PaladinEffect>();
        CardEffectRegistry.Add<PrincessEffect>();
        CardEffectRegistry.Add<DuelistEffect>();
        CardEffectRegistry.Add<NunEffect>();
        CardEffectRegistry.Add<ScoutEffect>();
        CardEffectRegistry.Add<WitchEffect>();
        CardEffectRegistry.Add<ThiefEffect>();
        CardEffectRegistry.Add<PegasusEffect>();
        CardEffectRegistry.Add<CurseMasterEffect>();
        CardEffectRegistry.Add<MageEffect>();
        CardEffectRegistry.Freeze();

        // Create public deck.
        var publicDeck = world.CreateEntity();
        world.AddComponent(publicDeck, new PublicDeck());

        // Load card definitions and create card instances for the public deck.
        var defs = CardDataLoader.LoadDefinitions(world, _cardDataCsv);
        foreach (var (defEntity, _) in defs)
        {
            world.AddComponent(defEntity, new InDeck { Target = publicDeck });
        }

        // Shuffle public deck.
        var seed = state.Seed;
        GameUtil.ShuffleDeck(world, publicDeck, ref seed);

        // Create the first castle.
        var castle = world.CreateEntity();
        world.AddComponent(castle, new Castle { Color = CastleColor.Black });

        // Create players.
        for (int i = 0; i < _playerCount; i++)
        {
            var player = world.CreateEntity();
            world.AddComponent(player, new Player { Index = i });

            // Create leader card (always on field, rank 0 placeholder).
            var leader = world.CreateEntity();
            world.AddComponent(leader, new Leader());
            world.AddComponent(leader, new CardDef { Name = $"领袖{i}", Ranks = new[] { 0 }, Effect = CardEffect.None, Kind = CardKind.Faction });
            world.AddComponent(leader, new Card { Rank = 0, FaceDown = false });
            world.AddComponent(leader, new OnField { Target = player });

            // Create banner.
            var banner = world.CreateEntity();
            world.AddComponent(banner, new Banner());
            world.AddComponent(banner, new OnField { Target = player });

            // Create faction deck.
            var factionDeck = world.CreateEntity();
            world.AddComponent(factionDeck, new FactionDeck());
        }

        // Deal starting hands: 3 public cards per player.
        foreach (var player in GameUtil.FindAllEntities<Player>(world))
        {
            for (int i = 0; i < 3; i++)
                GameUtil.DrawCard(world, publicDeck, player);
        }

        mutable.Seed = seed;
        world.MarkModified<GameState>(World.SingletonEntity);
    }
}