using System;

using System.Collections.Generic;
using System.Threading.Tasks;
using Newtonsoft.Json;
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.Networking;
using System.Net;
using System.Net.Sockets;
public class DBmanager : MonoBehaviour
{
    public static string phpRoot = "http://38.242.232.13/upf/";

    public static string username = null;
    private static int coins = 0;
    private static int gems = 0;
    public static List<BuildingState> buildingStates = new List<BuildingState>();
    public static UnityEvent OnStateChanged = new UnityEvent();

    public static int Coins => coins;
    public static int Gems => gems;

    public static bool LoggedIn { get { return username != null; } }
    public static void LogOut()
    {
        username = null;
    }

    public static DateTime GetNetworkTime()
    {
        //default Windows time server
        const string ntpServer = "time.windows.com";

        // NTP message size - 16 bytes of the digest (RFC 2030)
        var ntpData = new byte[48];

        //Setting the Leap Indicator, Version Number and Mode values
        ntpData[0] = 0x1B; //LI = 0 (no warning), VN = 3 (IPv4 only), Mode = 3 (Client Mode)

        var addresses = Dns.GetHostEntry(ntpServer).AddressList;

        //The UDP port number assigned to NTP is 123
        var ipEndPoint = new IPEndPoint(addresses[0], 123);
        //NTP uses UDP

        using(var socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp))
        {
            socket.Connect(ipEndPoint);

            //Stops code hang if NTP is blocked
            socket.ReceiveTimeout = 3000;

            socket.Send(ntpData);
            socket.Receive(ntpData);
            socket.Close();
        }

        //Offset to get to the "Transmit Timestamp" field (time at which the reply
        //departed the server for the client, in 64-bit timestamp format."
        const byte serverReplyTime = 40;

        //Get the seconds part
        ulong intPart = BitConverter.ToUInt32(ntpData, serverReplyTime);

        //Get the seconds fraction
        ulong fractPart = BitConverter.ToUInt32(ntpData, serverReplyTime + 4);

        //Convert From big-endian to little-endian
        intPart = SwapEndianness(intPart);
        fractPart = SwapEndianness(fractPart);

        var milliseconds = (intPart * 1000) + ((fractPart * 1000) / 0x100000000L);

        //**UTC** time
        var networkDateTime = (new DateTime(1900, 1, 1, 0, 0, 0, DateTimeKind.Utc)).AddMilliseconds((long)milliseconds);

        return networkDateTime.ToLocalTime();
    }

    // stackoverflow.com/a/3294698/162671
    static uint SwapEndianness(ulong x)
    {
        return (uint) (((x & 0x000000ff) << 24) +
        ((x & 0x0000ff00) << 8) +
        ((x & 0x00ff0000) >> 8) +
        ((x & 0xff000000) >> 24));
    }


    public async static Task SetCoins(int newValue, bool justOffline = false){
        WWWForm form = new WWWForm();
        form.AddField("name", username);
        form.AddField("coins", newValue);
        if(justOffline){coins=newValue; return;}
        using(UnityWebRequest www = UnityWebRequest.Post(phpRoot + "set_coins.php",form)){
            var operation = www.SendWebRequest();
            while(!operation.isDone){
                await Task.Yield();
            }

            if(www.downloadHandler.text=="0"){
                coins = newValue;
            }else{
                Debug.Log("Response : " + www.downloadHandler.text);
                Debug.LogWarning("Failed to set coins to " + newValue);
            }
        }

        GameManagerInstance.gameManager.RefreshData();
    }

    public async static void SetGems(int newValue,bool justOffline=false){
        WWWForm form = new WWWForm();
        form.AddField("name", username);
        form.AddField("gems", newValue);
        if(justOffline){gems=newValue; return;}
        using(UnityWebRequest www = UnityWebRequest.Post(phpRoot + "set_gems.php",form)){
            var operation = www.SendWebRequest();
            while(!operation.isDone){
                await Task.Yield();
            }

            if(www.downloadHandler.text=="0"){
                gems = newValue;
            }else{
                Debug.Log("Response : " + www.downloadHandler.text);
                Debug.LogWarning("Failed to set gems to " + newValue);
            }
        }

        GameManagerInstance.gameManager.RefreshData();
    }

    public static void GetBuildingStates(string rawData){
        try{

           buildingStates = JsonConvert.DeserializeObject<List<BuildingState>>(rawData);
            Debug.Log("Updating buildings data, isNull: " + (buildingStates==null).ToString());
            if(buildingStates==null){
                buildingStates = new List<BuildingState>();
            }
        }catch(Exception e){
            Debug.LogError(e.Message);
            Debug.LogError("Error updating buildings from server, Response:" + rawData);
        }

        OnStateChanged.Invoke();
    }

    public async static Task AddBuilding(BuildingData buildingData){

        foreach (BuildingState buildingState in buildingStates){
            if(buildingState.id == buildingData.buildingName){
                Debug.LogError("Building already exists. Cannot add " + buildingState.id);
                return;
            }
        }

        buildingStates.Add(new BuildingState(buildingData.buildingName, 0,Vector3.zero));
        Debug.Log("Added new building "+ buildingData.buildingName);
        await UpdateBuildingsToServer();

        OnStateChanged.Invoke();
    }

    public async static Task UpgradeBuilding(string id, int newLevel){
        for(int i=0; i < buildingStates.Count; i++){
            if(buildingStates[i].id == id){
                buildingStates[i].level = newLevel;
                Debug.Log("Upgrading " + id + " to " + newLevel);
                break;
            }
        }

        await UpdateBuildingsToServer();

        OnStateChanged.Invoke();
    }

    public async static Task RelocateBuilding(string id, Vector3 newPosition){
        for(int i=0; i < buildingStates.Count; i++){
            if(buildingStates[i].id == id){
                buildingStates[i].position = newPosition;
                Debug.Log("Relocating " + id + " to " + newPosition);
                // break;
            }
        }
        Debug.Log("Going to update to server" + JsonConvert.SerializeObject(buildingStates));
        await UpdateBuildingsToServer();

        OnStateChanged.Invoke();
    }

    public async static Task UpdateBuildingsToServer(){
        string buildingsJson = JsonConvert.SerializeObject(buildingStates);
        Debug.Log(buildingsJson);

        WWWForm form = new WWWForm();
        form.AddField("name", username);
        form.AddField("buildings", buildingsJson);

        using(UnityWebRequest www = UnityWebRequest.Post(phpRoot + "set_buildings.php",form)){
            var operation = www.SendWebRequest();
            while(!operation.isDone){
                await Task.Yield();
            }

            if(www.downloadHandler.text=="0"){

            }else{
                Debug.Log("Response : " + www.downloadHandler.text);
                Debug.LogWarning("Failed to set buildings to " + buildingsJson);
            }
        }
    }

}