Emberwild/Assets/GAME/Script/Network/NetworkPlayerLookup.cs

using FishNet.Connection;
using FishNet.Object;
using Ashwild.Inventory;

namespace Ashwild.Network
{
    /// <summary>
    /// Server-side lookup of the player systems belonging to a connection. Every server-authoritative
    /// interaction (pickup, harvest, chest, cooking station, build refund) needs the requesting player's
    /// inventory, and they all used to resolve it through <c>conn.FirstObject</c>.
    ///
    /// That is unsafe: a connection owns more than one NetworkObject (the build ghost is spawned with the
    /// player as owner), FishNet stores them in an unordered <c>HashSet</c>, and it re-picks FirstObject
    /// from that set whenever the current one is despawned. FirstObject can therefore resolve to the ghost
    /// instead of the player — a null inventory, and a silently lost grant. Scanning the connection's
    /// objects for the component we actually want removes the guesswork.
    /// </summary>
    public static class NetworkPlayerLookup
    {
        #region Public API

        /// <summary>
        /// Returns the inventory of the player owned by this connection, or null when the connection has
        /// no player object (disconnecting, or not spawned yet).
        /// </summary>
        public static PlayerInventory ResolveInventory(NetworkConnection conn) => Resolve<PlayerInventory>(conn);

        /// <summary>
        /// Returns the first component of the requested type found on any NetworkObject this connection
        /// owns. Checks FirstObject before scanning, since it is the right answer in the common case.
        /// </summary>
        public static T Resolve<T>(NetworkConnection conn) where T : class
        {
            if (conn == null) return null;

            NetworkObject first = conn.FirstObject;
            if (first != null && first.TryGetComponent(out T fromFirst)) return fromFirst;

            foreach (NetworkObject nob in conn.Objects)
            {
                if (nob != null && nob.TryGetComponent(out T component)) return component;
            }
            return null;
        }

        #endregion
    }
}