using FishNet.Object;
using UnityEngine;

namespace Ashwild.Network
{
    /// <summary>
    /// Splits the player's visible body by viewpoint. The local owner's third-person body is
    /// moved onto a dedicated "local body" layer that his own first-person camera excludes from
    /// its culling mask, so he never sees his own torso/head clip through the view — while every
    /// remote client still renders that same body normally. The layer change is purely local and
    /// never travels over the network, so hiding your body from yourself does not hide it from
    /// anyone else. The Animator/NetworkAnimator are left untouched, so the third-person animation
    /// keeps replicating to other players even while the mesh is culled from the owner's own view.
    /// </summary>
    [DisallowMultipleComponent]
    public class PlayerBodyVisibility : NetworkBehaviour
    {
        #region Serialized Fields

        [Header("Body")]
        [Tooltip("Root of the third-person body mesh hierarchy (skinned mesh + bones).")]
        [SerializeField] private GameObject bodyRoot;

        [Header("Local hiding")]
        [Tooltip("Layer the owner's own body is moved to. The first-person camera must exclude this layer from its culling mask.")]
        [SerializeField] private string localBodyLayer = "LocalBody";

        #endregion

        #region Network Lifecycle

        /// <summary>
        /// Once ownership is resolved, relayers the third-person body so the owning player's own
        /// camera stops rendering it. Remote copies return early and keep the body on its authored
        /// (visible) layer, which is why other players still see it.
        /// </summary>
        public override void OnStartClient()
        {
            base.OnStartClient();

            if (!base.IsOwner) return;

            if (bodyRoot == null)
            {
                Debug.LogError($"[PlayerBodyVisibility] '{name}' has no bodyRoot assigned — cannot hide the local body.", this);
                return;
            }

            int layer = LayerMask.NameToLayer(localBodyLayer);
            if (layer < 0)
            {
                Debug.LogError($"[PlayerBodyVisibility] '{name}' — layer '{localBodyLayer}' does not exist. Add it in Project Settings ▸ Tags and Layers, then exclude it from the first-person camera's culling mask.", this);
                return;
            }

            SetLayerRecursively(bodyRoot, layer);
        }

        #endregion

        #region Internal Helpers

        /// <summary>
        /// Applies a layer to a GameObject and every descendant, since a skinned body spans many
        /// child renderers and bones that must all move together for the camera cull to hide it fully.
        /// </summary>
        private static void SetLayerRecursively(GameObject root, int layer)
        {
            root.layer = layer;
            foreach (Transform child in root.transform)
                SetLayerRecursively(child.gameObject, layer);
        }

        #endregion
    }
}