megakoop/Game/Scripts/Networking/NetworkIdentity.cs

using System.Collections.Generic;
using UnityEngine;

namespace MegaKoop.Game.Networking
{
    [DisallowMultipleComponent]
    public class NetworkIdentity : MonoBehaviour
    {
        private static readonly Dictionary<int, NetworkIdentity> registry = new();
        private static int nextId = 1;

        [SerializeField] private int networkId;
        [SerializeField] private bool assignOnAwake = true;

        public int NetworkId => networkId;

        private void Awake()
        {
            if (assignOnAwake && networkId == 0)
            {
                networkId = nextId++;
            }

            Register();
        }

        private void OnDestroy()
        {
            if (registry.TryGetValue(networkId, out NetworkIdentity existing) && existing == this)
            {
                registry.Remove(networkId);
            }
        }

        private void Register()
        {
            if (networkId == 0)
            {
                Debug.LogWarning($"[NetworkIdentity] {name} has no network id and won't be tracked.");
                return;
            }

            if (registry.TryGetValue(networkId, out NetworkIdentity existing) && existing != this)
            {
                Debug.LogWarning($"[NetworkIdentity] Duplicate network id {networkId} detected. Overwriting reference.");
            }

            registry[networkId] = this;
        }

        public static bool TryGet(int id, out NetworkIdentity identity) => registry.TryGetValue(id, out identity);

        /// <summary>
        /// Allows deterministic assignment so IDs match across clients.
        /// </summary>
        public void SetNetworkId(int id)
        {
            if (id == 0)
            {
                Debug.LogWarning("[NetworkIdentity] Cannot assign network id 0.");
                return;
            }

            if (networkId == id)
            {
                return;
            }

            if (registry.TryGetValue(networkId, out NetworkIdentity existing) && existing == this)
            {
                registry.Remove(networkId);
            }

            networkId = id;
            Register();
        }
    }
}