using MLAPI;
using MLAPI.Messaging;
using MLAPI.Transports.UNET;
using MLAPI.Spawning;
using UnityEngine;
using UnityEngine.SceneManagement;
using System.Collections;
using System.Collections.Generic;

public class ServerModule : NetworkBehaviour
{
    public static ServerModule Singleton { get; protected set; }
    public GameObject FoodPrefab;
    public GameObject BossPrefab;
    private GameLiftServer GameLift;

    private Dictionary<string, string> PlayerSessionMap = new Dictionary<string, string>();

    public bool LocalTest = false;

    private void Awake()
    {
        if (Singleton != null)
        {
            Destroy(gameObject);
            return;
        }
        DontDestroyOnLoad(gameObject);
        Singleton = this;
        GameLift = new GameLiftServer();
    }

    // Start is called before the first frame update
    void Start()
    {
        NetworkManager.Singleton.NetworkConfig.ConnectionApproval = true;
        NetworkManager.Singleton.OnServerStarted += OnServerStarted;
        NetworkManager.Singleton.OnClientConnectedCallback += OnClientConnected;
        NetworkManager.Singleton.OnClientDisconnectCallback += OnClientDisconnect;
        NetworkManager.Singleton.ConnectionApprovalCallback += OnConnectionApproved;

        if (Application.isBatchMode)
        {
            string activeSceneName = SceneManager.GetActiveScene().name;
            if (activeSceneName == "Map001")
            {
                //Connect to server from Client
                NetworkManager.Singleton.GetComponent<UNetTransport>().ConnectAddress = "0.0.0.0";
                NetworkManager.Singleton.GetComponent<UNetTransport>().ServerListenPort = 7777;

                const int port = 7777;
                LogModule.WriteToLogFile("[ServerModule] Server Module Start at Port :7777 ");

                // Only run on Server mode
                if (LocalTest)
                {
                    NetworkManager.Singleton.StartServer();
                }
                else
                {
                    if (GameLift.GameLiftStart(port))
                    {
                        NetworkManager.Singleton.StartServer();
                    }
                }
            }
            else if (activeSceneName == "Map002")
            {
                //Connect to server from Client
                NetworkManager.Singleton.GetComponent<UNetTransport>().ConnectAddress = "0.0.0.0";
                NetworkManager.Singleton.GetComponent<UNetTransport>().ServerListenPort = 8888;

                const int port = 8888;
                LogModule.WriteToLogFile("[ServerModule] Server Module Start at Port :8888 ");

                // Only run on Server mode
                if (LocalTest)
                {
                    NetworkManager.Singleton.StartServer();
                }
                else
                {
                    if (GameLift.GameLiftStart(port))
                    {
                        NetworkManager.Singleton.StartServer();
                    }
                }
            }
        }
    }

    // Update is called once per frame
    void Update()
    {
    }

    private void OnServerStarted()
    {
        //This runs at Server side
        LogModule.WriteToLogFile("[ServerModule] On Server Started");
        if (IsServer)
        {
            StartCoroutine(SpawnFood());
            if (SceneManager.GetActiveScene().name == "Map002")
            {
                StartCoroutine(SpawnBoss());
            }
        }
    }

    private void OnClientConnected(ulong clientId)
    {
        //Called when Client connected
        if (IsServer)
        {
            LogModule.WriteToLogFile("[ServerModule] On Client Connected - " + clientId);
        }
    }

    private void OnClientDisconnect(ulong clientId)
    {
        //Called when Client disconnected
        if (PlayerSessionMap.ContainsKey("" + clientId))
        {
            string playerSessionId = PlayerSessionMap["" + clientId];
            PlayerSessionMap.Remove("" + clientId);
#if UNITY_EDITOR
#else
            if (!LocalTest)
            {
                GameLift.RemovePlayer(playerSessionId);
            }
#endif
        }
    }

    private void OnConnectionApproved(byte[] connectionData, ulong clientId, MLAPI.NetworkManager.ConnectionApprovedDelegate callback)
    {
        LogModule.WriteToLogFile("[ServerModule] On Connection Approved");

        string connectionString = System.Text.Encoding.UTF8.GetString(connectionData);
        LogModule.WriteToLogFile("[ServerModule] Connection String - " + connectionString);

        string playerSessionId = connectionString;

        //If approve is true, the connection will be added. If it is false, the client gets disconnected
        bool approve = !string.IsNullOrEmpty(connectionString);

        if (!LocalTest)
        {
            if (!approve || !GameLift.AcceptPlayer(playerSessionId))
            {
                LogModule.WriteToLogFile("[ServerModule] Disconnect Client from server - clientId : " + clientId + ", playerSessionId : " + playerSessionId);
                approve = false;
            }
            else
            {
                approve = true;
            }
        }
        bool createPlayerObject = approve;

        float z = 0;
        float x = Random.Range
            (Camera.main.ScreenToWorldPoint(new Vector3(0, 0, z)).x, Camera.main.ScreenToWorldPoint(new Vector3(Screen.width, 0, z)).x);
        float y = Random.Range
            (Camera.main.ScreenToWorldPoint(new Vector3(0, 0, z)).y, Camera.main.ScreenToWorldPoint(new Vector3(0, Screen.height, z)).y);
        Vector3 randomPos = new Vector3(x, y, z);

        Vector3 spawnPosition = randomPos;
        if (approve)
        {
            LogModule.WriteToLogFile("[ServerModule] Spawn Position from Server - " + spawnPosition);
            PlayerSessionMap["" + clientId] = playerSessionId;
        }

        callback(createPlayerObject, null, approve, spawnPosition, null);
    }

    private IEnumerator SpawnFood()
    {
        while (true)
        {
            int playerCount = NetworkManager.Singleton.ConnectedClients.Count;
            int foodCount = NetworkSpawnManager.SpawnedObjectsList.Count;
            //Debug.Log("PlayerCount - " + playerCount + ", Food Count - " + foodCount);
            if (foodCount < 10 || playerCount > foodCount / 2)
            {
                //Spawn food only the number of players is more than foodCount/2
                int x = UnityEngine.Random.Range(0, Camera.main.pixelWidth);
                int y = UnityEngine.Random.Range(0, Camera.main.pixelHeight);

                Vector3 pos = Camera.main.ScreenToWorldPoint(new Vector3(x, y, 0));
                pos.z = 0;

                //Implement Custom Prefab Spawning
                GameObject foodObj = Instantiate(FoodPrefab, pos, Quaternion.identity);
                //Spawn Food Management
                foodObj.GetComponent<NetworkObject>().Spawn();
            }
            yield return new WaitForSeconds(5.0f);
        }
    }

    private IEnumerator SpawnBoss()
    {
        int x = UnityEngine.Random.Range(0, Camera.main.pixelWidth);
        int y = UnityEngine.Random.Range(0, Camera.main.pixelHeight);

        Vector3 pos = Camera.main.ScreenToWorldPoint(new Vector3(x, y, 0));
        pos.z = 0;

        //Implement Custom Prefab Spawning
        GameObject bossObj = Instantiate(BossPrefab, pos, Quaternion.identity);
        //Spawn Food Management
        bossObj.GetComponent<NetworkObject>().Spawn();

        yield return new WaitForSeconds(1.0f);
    }

    public void CloseServer()
    {
        if (IsServer)
        {
            StartCoroutine(CloseServerRoutine());
        }
    }

    private IEnumerator CloseServerRoutine()
    {
        LogModule.WriteToLogFile("[ServerModule] Server will soon restart");
        yield return new WaitForSeconds(10.0f);
        PlayerSessionMap.Clear();
#if UNITY_EDITOR
#else
        Application.Quit();
#endif
    }

    public void OnApplicationQuit()
    {
        LogModule.WriteToLogFile("[ServerModule] On Application Quit");
#if UNITY_EDITOR
#else
        if (Application.isBatchMode && !LocalTest)
        {
            GameLift.EndProcess();
        }
#endif
    }
}