using AcDream.App.Physics;
using AcDream.App.Rendering;
using AcDream.Core.Net;
using AcDream.Core.Physics.Motion;
using AcDream.Core.World;

namespace AcDream.App.Physics;

/// <summary>
/// Narrow reverse seam for collaborators constructed before the live network
/// owner. It carries no state or identity: every call resolves the one bound
/// update-thread owner, and use before bind fails immediately.
/// </summary>
internal interface ILiveEntityMotionRuntimeBindings
{
    (float Radius, float Height) GetSetupCylinder(uint serverGuid, WorldEntity entity);
    bool RouteServerMoveTo(
        MovementManager movement,
        uint cellId,
        WorldSession.EntityMotionUpdate update);
    void StickToObjectFromWire(IPhysicsObjHost? host, uint targetGuid);
    void ClearTargetForHiddenEntity(uint serverGuid);
    IPhysicsObjHost? ResolvePhysicsHost(uint serverGuid);
}

internal sealed class DeferredLiveEntityMotionRuntimeBindings
    : ILiveEntityMotionRuntimeBindings
{
    private ILiveEntityMotionRuntimeBindings? _target;

    public void Bind(ILiveEntityMotionRuntimeBindings target)
    {
        ArgumentNullException.ThrowIfNull(target);
        if (_target is not null)
        {
            throw new InvalidOperationException(
                "Live entity motion runtime bindings are already bound.");
        }
        _target = target;
    }

    private ILiveEntityMotionRuntimeBindings Target =>
        _target ?? throw new InvalidOperationException(
            "Live entity motion runtime bindings were used before binding.");

    public (float Radius, float Height) GetSetupCylinder(
        uint serverGuid,
        WorldEntity entity) => Target.GetSetupCylinder(serverGuid, entity);

    public bool RouteServerMoveTo(
        MovementManager movement,
        uint cellId,
        WorldSession.EntityMotionUpdate update) =>
        Target.RouteServerMoveTo(movement, cellId, update);

    public void StickToObjectFromWire(IPhysicsObjHost? host, uint targetGuid) =>
        Target.StickToObjectFromWire(host, targetGuid);

    public void ClearTargetForHiddenEntity(uint serverGuid) =>
        Target.ClearTargetForHiddenEntity(serverGuid);

    public IPhysicsObjHost? ResolvePhysicsHost(uint serverGuid) =>
        Target.ResolvePhysicsHost(serverGuid);
}