using System.Collections.Generic;
using Game.Scripts.Runtime.Data;
using Game.Scripts.Runtime.Game;
using Game.Scripts.Runtime.Pooling;
using Game.Scripts.Runtime.Spawning;
using Steamworks;
using UnityEngine;

namespace MegaKoop.Game.Networking
{
    [DefaultExecutionOrder(-120)]
    [DisallowMultipleComponent]
    public class SteamEnemySpawnerNetworkBridge : MonoBehaviour
    {
        [Header("References")]
        [SerializeField] private EnemySpawner spawner;
        [SerializeField] private GameController gameController;
        [SerializeField] private ObjectPooler pooler;
        [SerializeField] private List<EnemyDefinition> additionalDefinitions = new();

        [Header("Behaviour")]
        [SerializeField] private bool autoFindReferences = true;

        private SteamCoopNetworkManager networkManager;
        private bool handlersRegistered;
        private bool spawnerSubscribed;
        private bool poolerSubscribed;
        private bool cachedAuthority;
        private bool hasPendingRemoteSpawn;
        private EnemySpawnMessage pendingRemoteSpawn;

        private void Awake()
        {
            if (autoFindReferences)
            {
                spawner ??= GetComponent<EnemySpawner>();
                gameController ??= GetComponent<GameController>();
                pooler ??= spawner != null ? spawner.Pool : ObjectPooler.SharedInstance;
            }

            cachedAuthority = DetermineAuthority();
            ApplyAuthorityOverride(cachedAuthority);
            RegisterDefinitionsFromSpawner();
            RegisterAdditionalDefinitions();
        }

        private void OnEnable()
        {
            RefreshNetworkManager();
            RegisterHandlers();
            SubscribeEvents();
            cachedAuthority = DetermineAuthority();
            ApplyAuthorityOverride(cachedAuthority);
            RegisterDefinitionsFromSpawner();
        }

        private void OnDisable()
        {
            UnsubscribeEvents();
            UnregisterHandlers();
        }

        private void Update()
        {
            RefreshNetworkManager();

            bool authority = DetermineAuthority();
            if (authority != cachedAuthority)
            {
                cachedAuthority = authority;
                ApplyAuthorityOverride(authority);
            }

            if (!handlersRegistered)
            {
                RegisterHandlers();
            }
        }

        private void SubscribeEvents()
        {
            if (spawner != null && !spawnerSubscribed)
            {
                spawner.OnEnemySpawned += HandleEnemySpawned;
                spawnerSubscribed = true;
            }

            if (pooler != null && !poolerSubscribed)
            {
                pooler.InstanceDespawned += HandleInstanceDespawned;
                poolerSubscribed = true;
            }
        }

        private void UnsubscribeEvents()
        {
            if (spawner != null && spawnerSubscribed)
            {
                spawner.OnEnemySpawned -= HandleEnemySpawned;
                spawnerSubscribed = false;
            }

            if (pooler != null && poolerSubscribed)
            {
                pooler.InstanceDespawned -= HandleInstanceDespawned;
                poolerSubscribed = false;
            }
        }

        private void RegisterHandlers()
        {
            if (handlersRegistered)
            {
                return;
            }

            RefreshNetworkManager();
            if (networkManager == null)
            {
                return;
            }

            networkManager.RegisterHandler(NetworkMessageType.EnemySpawn, HandleEnemySpawnMessage);
            networkManager.RegisterHandler(NetworkMessageType.EnemyDespawn, HandleEnemyDespawnMessage);
            handlersRegistered = true;
        }

        private void UnregisterHandlers()
        {
            if (!handlersRegistered || networkManager == null)
            {
                return;
            }

            networkManager.UnregisterHandler(NetworkMessageType.EnemySpawn, HandleEnemySpawnMessage);
            networkManager.UnregisterHandler(NetworkMessageType.EnemyDespawn, HandleEnemyDespawnMessage);
            handlersRegistered = false;
        }

        private void RefreshNetworkManager()
        {
            if (networkManager == null)
            {
                networkManager = SteamCoopNetworkManager.Instance;
            }
        }

        private bool DetermineAuthority()
        {
            RefreshNetworkManager();
            if (networkManager == null)
            {
                return true;
            }

            if (!networkManager.IsConnected)
            {
                return true;
            }

            return networkManager.IsHost;
        }

        private void ApplyAuthorityOverride(bool authority)
        {
            spawner?.SetAuthorityOverride(authority);
        }

        private void RegisterDefinitionsFromSpawner()
        {
            if (spawner == null)
            {
                return;
            }

            var table = spawner.ActiveTable;
            if (table?.Entries == null)
            {
                return;
            }

            foreach (var entry in table.Entries)
            {
                if (entry?.Def == null)
                {
                    continue;
                }

                EnemyDefinitionRegistry.Register(entry.Def);
            }
        }

        private void RegisterAdditionalDefinitions()
        {
            if (additionalDefinitions == null)
            {
                return;
            }

            foreach (var definition in additionalDefinitions)
            {
                EnemyDefinitionRegistry.Register(definition);
            }
        }

        private void HandleEnemySpawned(GameObject instance, EnemyDefinition definition)
        {
            if (definition != null)
            {
                EnemyDefinitionRegistry.Register(definition);
            }

            if (!IsHostClient() || networkManager == null)
            {
                if (hasPendingRemoteSpawn)
                {
                    ApplyPendingRemoteSpawn(instance, definition);
                }

                return;
            }

            if (instance == null || definition == null)
            {
                return;
            }

            string definitionId = EnemyDefinitionRegistry.ResolveId(definition);
            var identity = instance.GetComponent<NetworkIdentity>();
            int networkId = identity != null ? identity.NetworkId : 0;
            Vector3 spawnRootPosition = instance.transform.position - definition.PrefabPivotOffset;
            Quaternion rotation = instance.transform.rotation;
            bool isBoss = definition.IsBoss;
            int waveIndex = spawner != null ? spawner.CurrentWaveIndex : -1;
            float timestamp = gameController != null ? gameController.Elapsed : Time.time;

            var message = new EnemySpawnMessage(definitionId, spawnRootPosition, rotation, networkId, isBoss, waveIndex, timestamp);
            byte[] payload = EnemySpawnMessage.Serialize(message);
            networkManager.SendToAll(NetworkMessageType.EnemySpawn, payload, EP2PSend.k_EP2PSendReliable);
        }

        private void HandleInstanceDespawned(GameObject instance, EnemyDefinition definition)
        {
            if (!IsHostClient() || networkManager == null)
            {
                return;
            }

            if (instance == null)
            {
                return;
            }

            var identity = instance.GetComponent<NetworkIdentity>();
            if (identity == null || identity.NetworkId == 0)
            {
                return;
            }

            var message = new EnemyDespawnMessage(identity.NetworkId);
            byte[] payload = EnemyDespawnMessage.Serialize(message);
            SteamCharacterStateCache.RemoveState(identity.NetworkId);
            networkManager.SendToAll(NetworkMessageType.EnemyDespawn, payload, EP2PSend.k_EP2PSendReliable);
        }

        private void HandleEnemySpawnMessage(NetworkMessage message)
        {
            if (IsHostClient())
            {
                return;
            }

            pendingRemoteSpawn = EnemySpawnMessage.Deserialize(message.Payload);
            hasPendingRemoteSpawn = true;

            if (!EnemyDefinitionRegistry.TryGet(pendingRemoteSpawn.DefinitionId, out var definition))
            {
                Debug.LogWarning($"[SteamEnemySpawnerNetworkBridge] Missing EnemyDefinition for id '{pendingRemoteSpawn.DefinitionId}'.");
                hasPendingRemoteSpawn = false;
                return;
            }
            EnemyDefinitionRegistry.Register(definition);

            if (pendingRemoteSpawn.NetworkId != 0 && NetworkIdentity.TryGet(pendingRemoteSpawn.NetworkId, out var existingIdentity) && existingIdentity != null)
            {
                var existingInstance = existingIdentity.gameObject;
                if (existingInstance != null)
                {
                    existingInstance.SetActive(true);
                    existingInstance.transform.SetPositionAndRotation(pendingRemoteSpawn.Position + definition.PrefabPivotOffset, pendingRemoteSpawn.Rotation);
                    hasPendingRemoteSpawn = false;
                }
                return;
            }

            bool success = spawner != null && spawner.TrySpawn(definition, pendingRemoteSpawn.Position);
            if (success)
            {
                return;
            }

            GameObject instance = pooler != null
                ? pooler.Spawn(definition, pendingRemoteSpawn.Position, pendingRemoteSpawn.Rotation)
                : null;

            if (instance == null)
            {
                Debug.LogWarning($"[SteamEnemySpawnerNetworkBridge] Fallback spawn failed for '{pendingRemoteSpawn.DefinitionId}'.");
                hasPendingRemoteSpawn = false;
                return;
            }

            ApplyPendingRemoteSpawn(instance, definition);
        }

        private void HandleEnemyDespawnMessage(NetworkMessage message)
        {
            if (IsHostClient())
            {
                return;
            }

            EnemyDespawnMessage despawnMessage = EnemyDespawnMessage.Deserialize(message.Payload);
            if (despawnMessage.NetworkId == 0)
            {
                return;
            }

            if (!NetworkIdentity.TryGet(despawnMessage.NetworkId, out var identity) || identity == null)
            {
                return;
            }

            SteamCharacterStateCache.RemoveState(identity.NetworkId);

            var pooled = identity.GetComponent<PooledInstance>();
            if (pooled != null)
            {
                pooled.ReturnToPool();
            }
            else
            {
                identity.gameObject.SetActive(false);
            }
        }

        private void ApplyPendingRemoteSpawn(GameObject instance, EnemyDefinition definition)
        {
            if (!hasPendingRemoteSpawn || instance == null)
            {
                return;
            }

            hasPendingRemoteSpawn = false;
            instance.transform.rotation = pendingRemoteSpawn.Rotation;
            if (definition != null)
            {
                EnemyDefinitionRegistry.Register(definition);
            }

            var identity = instance.GetComponent<NetworkIdentity>();
            if (identity != null && pendingRemoteSpawn.NetworkId != 0 && identity.NetworkId != pendingRemoteSpawn.NetworkId)
            {
                identity.SetNetworkId(pendingRemoteSpawn.NetworkId);
            }
        }

        private bool IsHostClient()
        {
            RefreshNetworkManager();
            return networkManager != null && networkManager.IsHost;
        }
    }
}