oecs-sharp/Game.Blackjack/Systems/DealSystem.cs

using OECS;

namespace Game.Blackjack;

/// <summary>
/// Deals initial two cards to player and dealer when entering the dealing phase.
/// Advances to player turn after dealing.
/// </summary>
public class DealSystem : ISystem
{
    public void RunImpl(World world)
    {
        var state = world.ReadSingleton<GameState>();
        if (state.Phase != GamePhase.Dealing)
            return;

        ref var mutableState = ref world.GetSingleton<GameState>();

        // Deal two cards to player, then two to dealer.
        HitCommand.DrawCard<PlayerHand>(world);
        HitCommand.DrawCard<PlayerHand>(world);
        HitCommand.DrawCard<DealerHand>(world);
        HitCommand.DrawCard<DealerHand>(world);

        mutableState.Phase = GamePhase.PlayerTurn;
    }
}

internal static class PlayerHandTag { public static readonly PlayerHand Instance = new(); }
internal static class DealerHandTag { public static readonly DealerHand Instance = new(); }