using System.Collections.Generic;
using System.Linq;
using Unity.Netcode;
using UnityEngine;

namespace Northbound
{
    /// <summary>
    /// 네트워크 연결 및 스폰 관리
    /// </summary>
    public class NetworkConnectionHandler : MonoBehaviour
    {
        [Header("Spawn Settings")]
        public List<Transform> spawnPoints = new List<Transform>();
        public bool useRandomSpawn = false;
        public bool findSpawnPointsAutomatically = true;
        
        private Dictionary<ulong, int> _clientSpawnIndices = new Dictionary<ulong, int>();
        private int _nextSpawnIndex = 0;

        // ⭐ Awake에서 스폰 포인트 먼저 찾고, 콜백 등록
        private void Awake()
        {
            // 1️⃣ 먼저 스폰 포인트 찾기
            if (findSpawnPointsAutomatically)
            {
                FindSpawnPoints();
            }

            // 2️⃣ 그 다음 콜백 등록
            if (NetworkManager.Singleton != null)
            {
                NetworkManager.Singleton.ConnectionApprovalCallback = ApprovalCheck;
                NetworkManager.Singleton.OnServerStarted += OnServerStarted;
                NetworkManager.Singleton.OnClientConnectedCallback += OnClientConnected;
            }
            else
            {
            }
        }

        private void FindSpawnPoints()
        {
            PlayerSpawnPoint[] points = FindObjectsByType<PlayerSpawnPoint>(FindObjectsSortMode.None);
            
            // spawnIndex로 정렬
            var sortedPoints = points.OrderBy(p => p.spawnIndex == -1 ? int.MaxValue : p.spawnIndex);
            
            spawnPoints.Clear();
            foreach (var point in sortedPoints)
            {
                if (point != null && point.transform != null && point.isAvailable)
                {
                    spawnPoints.Add(point.transform);
                }
            }
        }

        private void OnServerStarted()
        {
            
            if (ServerResourceManager.Instance == null)
            {
                GameObject resourceManagerObj = new GameObject("ServerResourceManager");
                ServerResourceManager manager = resourceManagerObj.AddComponent<ServerResourceManager>();
                
                NetworkObject networkObject = resourceManagerObj.GetComponent<NetworkObject>();
                if (networkObject == null)
                {
                    networkObject = resourceManagerObj.AddComponent<NetworkObject>();
                }
                
                networkObject.Spawn();
            }
             
            if (NetworkManager.Singleton.IsHost)
            {
                SpawnPlayer(NetworkManager.Singleton.LocalClientId);
            }
        }

        private void OnClientConnected(ulong clientId)
        {
            if (!NetworkManager.Singleton.IsServer) return;
            if (clientId == NetworkManager.Singleton.LocalClientId) return;

            
            if (!NetworkManager.Singleton.ConnectedClients.TryGetValue(clientId, out var client) || client.PlayerObject != null)
            {
                return;
            }
            
            SpawnPlayer(clientId);
        }

        private void SpawnPlayer(ulong clientId)
        {
            Vector3 spawnPosition = GetSpawnPosition(clientId);
            Quaternion spawnRotation = GetSpawnRotation(clientId);
            
            GameObject playerPrefab = NetworkManager.Singleton.NetworkConfig.PlayerPrefab;
            if (playerPrefab == null)
            {
                return;
            }
            
            GameObject playerObject = Instantiate(playerPrefab, spawnPosition, spawnRotation);
            NetworkObject networkObject = playerObject.GetComponent<NetworkObject>();
            if (networkObject == null)
            {
                return;
            }
             
            networkObject.SpawnAsPlayerObject(clientId);
        }

        private void ApprovalCheck(
            NetworkManager.ConnectionApprovalRequest request,
            NetworkManager.ConnectionApprovalResponse response)
        {
            spawnPoints.RemoveAll(p => p == null);
             
            if (spawnPoints.Count == 0)
            {
            }

            response.Approved = true;
            response.CreatePlayerObject = false;
            response.Position = Vector3.zero;
            response.Rotation = Quaternion.identity;
        }

        private Vector3 GetSpawnPosition(ulong clientId)
        {
            spawnPoints.RemoveAll(p => p == null);
             
            if (spawnPoints.Count == 0)
            {
                return Vector3.zero;
            }

            int spawnIndex;

            if (useRandomSpawn)
            {
                spawnIndex = Random.Range(0, spawnPoints.Count);
            }
            else
            {
                if (!_clientSpawnIndices.ContainsKey(clientId))
                {
                    _clientSpawnIndices[clientId] = _nextSpawnIndex;
                    _nextSpawnIndex = (_nextSpawnIndex + 1) % spawnPoints.Count;
                }
                spawnIndex = _clientSpawnIndices[clientId];
                
                if (spawnIndex >= spawnPoints.Count)
                {
                    spawnIndex = spawnIndex % spawnPoints.Count;
                }
            }

            return spawnPoints[spawnIndex].position;
        }

        private Quaternion GetSpawnRotation(ulong clientId)
        {
            spawnPoints.RemoveAll(p => p == null);
            
            if (spawnPoints.Count == 0)
                return Quaternion.identity;

            int spawnIndex = _clientSpawnIndices.ContainsKey(clientId) 
                ? _clientSpawnIndices[clientId] 
                : 0;
            
            if (spawnIndex >= spawnPoints.Count)
            {
                spawnIndex = spawnIndex % spawnPoints.Count;
            }

            return spawnPoints[spawnIndex].rotation;
        }

        private void OnDestroy()
        {
            if (NetworkManager.Singleton != null)
            {
                NetworkManager.Singleton.ConnectionApprovalCallback = null;
                NetworkManager.Singleton.OnServerStarted -= OnServerStarted;
                NetworkManager.Singleton.OnClientConnectedCallback -= OnClientConnected;
            }
        }
    }
}