using Unity.Burst;
using Unity.Entities;
using Unity.NetCode;

namespace ProjectM.Simulation
{
    /// <summary>
    /// Bridges replicated <see cref="PlayerInput"/> + data-driven <see cref="EffectiveCharacterStats"/> into
    /// the CC processor's per-tick <see cref="CharacterControl"/>. Replaces the M5 <c>PlayerMoveSystem</c>:
    /// instead of writing PhysicsVelocity, it writes the desired world velocity that
    /// <see cref="CharacterProcessor"/> lerps toward inside the fixed-step character update. Runs in
    /// <see cref="PredictedSimulationSystemGroup"/> after <see cref="StatRecomputeSystem"/> (fresh MoveSpeed)
    /// and before the predicted fixed-step group (where the character physics steps). Derived purely from
    /// replicated input + recomputed stats → identical on server, owning client, and across rollback.
    /// Filtered to <see cref="Simulate"/> for predicted ghosts only.
    /// </summary>
    [UpdateInGroup(typeof(PredictedSimulationSystemGroup))]
    [UpdateAfter(typeof(StatRecomputeSystem))]
    [BurstCompile]
    public partial struct PlayerControlSystem : ISystem
    {
        [BurstCompile]
        public void OnUpdate(ref SystemState state)
        {
            foreach (var (control, input, stats) in
                     SystemAPI.Query<RefRW<CharacterControl>, RefRO<PlayerInput>, RefRO<EffectiveCharacterStats>>()
                         .WithAll<Simulate>())
            {
                control.ValueRW.MoveVelocity =
                    CharacterControlMath.DesiredMovement(input.ValueRO.Move, stats.ValueRO.MoveSpeed);
            }
        }
    }
}