SVSimServer/SVSim.BattleNode/Sessions/Dispatch/Handlers/LoadedHandler.cs

using SVSim.BattleNode.Lifecycle;
using SVSim.BattleNode.Protocol;

namespace SVSim.BattleNode.Sessions.Dispatch.Handlers;

internal sealed class LoadedHandler : IFrameHandler
{
    public IReadOnlyList<DispatchRoute> Handle(FrameDispatchContext ctx)
    {
        // case 3: Bot — silent (client populates opponent state from AIBattleStart HTTP data).
        if (ctx.Type == BattleType.Bot && ctx.SenderPhase == BattleSessionPhase.AwaitingLoaded)
        {
            ctx.SenderPhase = BattleSessionPhase.AwaitingSwap;
            return Array.Empty<DispatchRoute>();
        }

        // case 6: general — BattleStart (per-perspective) + Deal to the sender.
        if (ctx.SenderPhase == BattleSessionPhase.AwaitingLoaded)
        {
            // A goes first deterministically (turnState 0); B goes second (turnState 1).
            var turnState = ReferenceEquals(ctx.From, ctx.A) ? 0 : 1;
            var r = new List<DispatchRoute>
            {
                new(ctx.From, ServerBattleFrames.BuildBattleStart(
                    ctx.From.Context, ctx.Other.Context, ctx.From.ViewerId, turnState), false),
                new(ctx.From, ServerBattleFrames.BuildDeal(), false),
            };
            ctx.SenderPhase = BattleSessionPhase.AwaitingSwap;
            return r;
        }

        return Array.Empty<DispatchRoute>();
    }
}