using UnityEngine;

namespace MegaKoop.Game.Networking
{
    internal static class NetworkIdAllocator
    {
        public const int PlayerIdStart = 1;
        public const int EnemyIdStart = 10000;
        private const int EnemyIdRange = 10000;

        private static int nextEnemyId = EnemyIdStart;
        private static readonly System.Collections.Generic.HashSet<int> ActiveEnemyIds = new();

        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.BeforeSceneLoad)]
        private static void ResetOnLoad()
        {
            Reset();
        }

        public static void Reset()
        {
            nextEnemyId = EnemyIdStart;
            ActiveEnemyIds.Clear();
        }

        public static int AllocateEnemyId()
        {
            if (nextEnemyId < EnemyIdStart)
            {
                nextEnemyId = EnemyIdStart;
            }

            const int maxAttempts = EnemyIdRange;
            int attempts = 0;
            while ((ActiveEnemyIds.Contains(nextEnemyId) || NetworkIdRegistry.IsIdRegistered(nextEnemyId) || NetworkIdRegistry.IsIdReserved(nextEnemyId)) && attempts < maxAttempts)
            {
                AdvanceEnemyCursor();
                attempts++;
            }

            int allocated = nextEnemyId;
            AdvanceEnemyCursor();
            ActiveEnemyIds.Add(allocated);
            return allocated;
        }

        public static bool IsPlayerId(int id) => id >= PlayerIdStart && id < EnemyIdStart;

        public static bool IsEnemyId(int id) => id >= EnemyIdStart;

        public static void SyncEnemyCursor(int id)
        {
            if (id >= EnemyIdStart && id >= nextEnemyId)
            {
                nextEnemyId = id + 1;
            }
            if (id >= EnemyIdStart)
            {
                ActiveEnemyIds.Add(id);
            }
        }

        public static void ReleaseEnemyId(int id)
        {
            if (id >= EnemyIdStart)
            {
                ActiveEnemyIds.Remove(id);
            }
        }

        private static void AdvanceEnemyCursor()
        {
            nextEnemyId++;
            if (nextEnemyId >= EnemyIdStart + EnemyIdRange)
            {
                nextEnemyId = EnemyIdStart;
            }
        }
    }
}