using UnityEngine;
using Unity.Netcode;
using Unity.Netcode.Transports.UTP;

namespace Northbound
{
    public class ConnectionDiagnostics : MonoBehaviour
    {
        [Header("Auto-Diagnosis")]
        [SerializeField] private bool runOnStart = true;
        [SerializeField] private bool autoFixIssues = true;
        
        private NetworkManager _networkManager;
        private UnityTransport _transport;

        private void Start()
        {
            if (runOnStart)
            {
                RunDiagnostics();
            }
        }

        public void RunDiagnostics()
        {
            Debug.Log("<color=yellow>=== RUNNING CONNECTION DIAGNOSTICS ===</color>");
            
            InitializeComponents();
            CheckNetworkManager();
            CheckTransport();
            CheckPlayerPrefab();
            CheckConnectionApproval();
            
            if (autoFixIssues)
            {
                FixCommonIssues();
            }
            
            GenerateReport();
            Debug.Log("<color=yellow>=== DIAGNOSTICS COMPLETE ===</color>");
        }

        private void InitializeComponents()
        {
            _networkManager = NetworkManager.Singleton;
            if (_networkManager == null)
            {
                Debug.LogError("<color=red>[Diagnostics] NetworkManager not found!</color>");
                return;
            }

            _transport = _networkManager.GetComponent<UnityTransport>();
            if (_transport == null)
            {
                Debug.LogError("<color=red>[Diagnostics] UnityTransport not found!</color>");
                return;
            }
        }

        private void CheckNetworkManager()
        {
            Debug.Log("<color=cyan>[1/5] Checking NetworkManager...</color>");
            
            if (_networkManager == null)
            {
                Debug.LogError("✗ NetworkManager is NULL");
                return;
            }
            
            Debug.Log("✓ NetworkManager exists");
            Debug.Log("  IsServer: " + _networkManager.IsServer);
            Debug.Log("  IsClient: " + _networkManager.IsClient);
            Debug.Log("  IsHost: " + _networkManager.IsHost);
            Debug.Log("  IsConnectedClient: " + _networkManager.IsConnectedClient);
        }

        private void CheckTransport()
        {
            Debug.Log("<color=cyan>[2/5] Checking UnityTransport...</color>");
            
            if (_transport == null)
            {
                Debug.LogError("✗ UnityTransport is NULL");
                return;
            }
            
            Debug.Log("✓ UnityTransport exists");
            Debug.Log("  Connection Address: " + _transport.ConnectionData.Address);
            Debug.Log("  Connection Port: " + _transport.ConnectionData.Port);
            Debug.Log("  Server Listen Address: " + _transport.ConnectionData.ServerListenAddress);
            
            int timeout = _transport.ConnectTimeoutMS;
            if (timeout < 10000)
            {
                Debug.LogWarning("⚠ Connect timeout too low: " + timeout + "ms (recommended: 15000ms)");
            }
            else
            {
                Debug.Log("✓ Connect timeout is adequate: " + timeout + "ms");
            }
            
            ushort port = _transport.ConnectionData.Port;
            if (port <= 0 || port > 65535)
            {
                Debug.LogError("✗ Invalid port: " + port);
            }
            else
            {
                Debug.Log("✓ Port is valid: " + port);
            }
        }

        private void CheckPlayerPrefab()
        {
            Debug.Log("<color=cyan>[3/5] Checking Player Prefab...</color>");
            
            if (_networkManager == null || _networkManager.NetworkConfig == null)
            {
                Debug.LogError("✗ NetworkConfig not accessible");
                return;
            }
            
            GameObject playerPrefab = _networkManager.NetworkConfig.PlayerPrefab;
            if (playerPrefab == null)
            {
                Debug.LogError("✗ Player Prefab is NOT assigned!");
                Debug.LogError("  → Players will not spawn");
                Debug.LogError("  → Fix: Assign Player Prefab in NetworkManager");
                return;
            }
            
            Debug.Log("✓ Player Prefab assigned: " + playerPrefab.name);
            
            NetworkObject networkObject = playerPrefab.GetComponent<NetworkObject>();
            if (networkObject == null)
            {
                Debug.LogError("✗ Player Prefab has no NetworkObject component!");
            }
            else
            {
                Debug.Log("✓ Player Prefab has NetworkObject");
            }
        }

        private void CheckConnectionApproval()
        {
            Debug.Log("<color=cyan>[4/5] Checking Connection Approval...</color>");
            
            if (_networkManager == null || _networkManager.NetworkConfig == null)
            {
                Debug.LogError("✗ NetworkConfig not accessible");
                return;
            }
            
            bool approval = _networkManager.NetworkConfig.ConnectionApproval;
            Debug.Log("Connection Approval: " + approval);
            
            if (approval)
            {
                Debug.Log("✓ Connection approval is enabled");
                Debug.Log("  → Ensure ConnectionApprovalCallback is set");
            }
            else
            {
                Debug.LogWarning("⚠ Connection approval is disabled");
                Debug.Log("  → Players may auto-connect without approval");
            }
            
            NetworkConnectionHandler handler = FindObjectOfType<NetworkConnectionHandler>();
            if (handler != null)
            {
                Debug.Log("✓ NetworkConnectionHandler found");
            }
            else
            {
                Debug.LogWarning("⚠ NetworkConnectionHandler not found");
                Debug.Log("  → Manual player spawning may not work");
            }
        }

        private void FixCommonIssues()
        {
            Debug.Log("<color=cyan>[5/5] Fixing Common Issues...</color>");
            
            if (_transport == null) return;
            
            bool fixedSomething = false;
            
            if (_transport.ConnectTimeoutMS < 10000)
            {
                _transport.ConnectTimeoutMS = 15000;
                Debug.Log("✓ Fixed: Increased timeout to 15000ms");
                fixedSomething = true;
            }
            
            if (_transport.MaxConnectAttempts < 5)
            {
                _transport.MaxConnectAttempts = 10;
                Debug.Log("✓ Fixed: Increased max connect attempts to 10");
                fixedSomething = true;
            }
            
            ushort port = _transport.ConnectionData.Port;
            if (port <= 0)
            {
                _transport.SetConnectionData("0.0.0.0", 7777);
                Debug.Log("✓ Fixed: Set default port to 7777");
                fixedSomething = true;
            }
            
            if (!fixedSomething)
            {
                Debug.Log("✓ No issues found to fix");
            }
        }

        private void GenerateReport()
        {
            Debug.Log("<color=green>=== DIAGNOSTICS REPORT ===</color>");
            
            string status = GetOverallStatus();
            Color color = GetStatusColor(status);
            
            Debug.Log("<color=" + ColorToHex(color) + ">" + status + "</color>");
            
            if (status != "System Healthy")
            {
                Debug.Log("Review warnings and errors above");
            }
            Debug.Log("=========================");
        }

        private string GetOverallStatus()
        {
            if (_networkManager == null || _transport == null)
                return "Critical Errors Found";
            
            if (_networkManager.NetworkConfig?.PlayerPrefab == null)
                return "Configuration Error";
            
            if (_transport.ConnectTimeoutMS < 10000)
                return "Performance Issue";
            
            return "System Healthy";
        }

        private Color GetStatusColor(string status)
        {
            switch (status)
            {
                case "System Healthy":
                    return Color.green;
                case "Performance Issue":
                    return Color.yellow;
                case "Configuration Error":
                    return new Color(1f, 0.5f, 0f);
                case "Critical Errors Found":
                    return Color.red;
                default:
                    return Color.gray;
            }
        }

        private string ColorToHex(Color color)
        {
            return "#" + ColorUtility.ToHtmlStringRGBA(color);
        }

        [ContextMenu("Run Diagnostics")]
        public void ManualRunDiagnostics()
        {
            RunDiagnostics();
        }

        [ContextMenu("Check Connection Status")]
        public void CheckConnectionStatus()
        {
            if (_networkManager == null)
            {
                Debug.LogError("NetworkManager not found");
                return;
            }
            
            Debug.Log("=== CONNECTION STATUS ===");
            Debug.Log("IsServer: " + _networkManager.IsServer);
            Debug.Log("IsClient: " + _networkManager.IsClient);
            Debug.Log("IsHost: " + _networkManager.IsHost);
            Debug.Log("IsConnectedClient: " + _networkManager.IsConnectedClient);
            Debug.Log("LocalClientId: " + _networkManager.LocalClientId);
            Debug.Log("ConnectedClients: " + _networkManager.ConnectedClients.Count);
            
            if (_transport != null)
            {
                Debug.Log("Listening on: " + _transport.ConnectionData.Address + ":" + _transport.ConnectionData.Port);
            }
            
            if (_networkManager.IsHost || _networkManager.IsServer)
            {
                Debug.Log("Connected Players:");
                foreach (var client in _networkManager.ConnectedClients)
                {
                    string playerInfo = client.Value.PlayerObject != null ? 
                        client.Value.PlayerObject.name : "No Player Object";
                    Debug.Log("  Client " + client.Key + ": " + playerInfo);
                }
            }
            Debug.Log("=======================");
        }
    }
}