using ProjectM.Simulation;
using Unity.Entities;
using Unity.NetCode;
using UnityEngine;

namespace ProjectM.Client
{
    /// <summary>
    /// Client-side route-pick sender: a static enqueue (the Step-14 map panel's option buttons / execute_code)
    /// drained into <see cref="RouteSelectRequest"/> RPCs. The request is stamped from the CLIENT's replicated
    /// <see cref="RunInfo"/>: <c>ForRunEpoch = (int)RunSeed</c> (the re-meaned run-identity token — the server-only
    /// RunEpoch is not client-knowable) and <c>ForLayer = CurrentRoom</c> VERBATIM (during a gate that is still the
    /// just-cleared layer — never +1). The server re-validates everything; a stale/possessed pick is simply dropped.
    /// Statics reset on play-enter (the stale-bridge hazard).
    /// </summary>
    [WorldSystemFilter(WorldSystemFilterFlags.ClientSimulation)]
    public partial class RouteSendSystem : SystemBase
    {
        static int s_Pending;
        static byte s_PendingIndex;

        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.SubsystemRegistration)]
        static void ResetStatics()
        {
            s_Pending = 0;
            s_PendingIndex = 0;
        }

        /// <summary>Queue a route pick (0..RouteOptionCount-1). HUD map panel + execute_code drive this.</summary>
        public static void PickRoute(byte optionIndex)
        {
            s_PendingIndex = optionIndex;
            s_Pending++;
        }

        protected override void OnCreate()
        {
            RequireForUpdate<NetworkId>();
            RequireForUpdate<RunInfo>();
        }

        protected override void OnUpdate()
        {
            if (s_Pending == 0)
                return;
            var runInfo = SystemAPI.GetSingleton<RunInfo>();
            while (s_Pending > 0)
            {
                s_Pending--;
                var req = EntityManager.CreateEntity(typeof(RouteSelectRequest), typeof(SendRpcCommandRequest));
                EntityManager.SetComponentData(req, new RouteSelectRequest
                {
                    OptionIndex = s_PendingIndex,
                    ForRunEpoch = (int)runInfo.RunSeed, // the re-meaned replicated run token
                    ForLayer = runInfo.CurrentRoom,     // the gate's un-incremented cleared layer
                });
            }
        }
    }
}