using System.Net;
using System.Net.NetworkInformation;
using System.Net.Sockets;
using System.Text;
using System.Text.Json;
using InnovEnergy.App.SinexcelCommunication.DataTypes;

namespace InnovEnergy.App.SinexcelCommunication.MiddlewareClasses;

public static class MiddlewareAgent
{
    private static UdpClient   _udpListener = null!;
    private static IPAddress? _controllerIpAddress;
    private static EndPoint? _endPoint;
    
    public static bool InitializeCommunicationToMiddleware()
    {
        try
        {
            _controllerIpAddress = FindVpnIp();
            if (Equals(IPAddress.None, _controllerIpAddress))
            {
                Console.WriteLine("There is no VPN interface.");
                _udpListener = null;
                return false;
            }

            const int udpPort = 9000;
            _endPoint = new IPEndPoint(_controllerIpAddress, udpPort);

            _udpListener?.Close();
            _udpListener?.Dispose();

            _udpListener = new UdpClient();
            _udpListener.Client.Blocking = false;
            _udpListener.Client.Bind(_endPoint);

            Console.WriteLine($"UDP listener bound to {_endPoint}");
            return true;
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Failed to initialize middleware communication: {ex}");
            _udpListener = null;
            return false;
        }
    }
    
    private static IPAddress FindVpnIp()
    {
        const String interfaceName = "innovenergy";
        
        var networkInterfaces = NetworkInterface.GetAllNetworkInterfaces();
        
        foreach (var networkInterface in networkInterfaces)
        {
            if (networkInterface.Name == interfaceName)
            {
                var ipProps         = networkInterface.GetIPProperties();
                var uniCastIPs      = ipProps.UnicastAddresses;
                var controllerIpAddress = uniCastIPs[0].Address;

                Console.WriteLine("VPN IP is: "+ uniCastIPs[0].Address);
                return controllerIpAddress;
            }
        }

        return IPAddress.None;
    }
    public static Configuration? SetConfigurationFile()
    {
        try
        {
            // Ensure listener is initialized
            if (_udpListener == null)
            {
                Console.WriteLine("UDP listener not initialized, trying to initialize...");
                InitializeCommunicationToMiddleware();
    
                if (_udpListener == null)
                {
                    Console.WriteLine("Failed to initialize UDP listener.");
                    return null;
                }
            }
    
            // Check if data is available
            if (_udpListener.Available <= 0)
                return null;
    
            IPEndPoint? serverEndpoint = null;
    
            var udpMessage = _udpListener.Receive(ref serverEndpoint);
            var message = Encoding.UTF8.GetString(udpMessage);
    
            Console.WriteLine($"Received raw UDP message from {serverEndpoint}: {message}");
    
            var config = JsonSerializer.Deserialize<Configuration>(message);
    
            if (config != null)
            {
                Console.WriteLine(
                    $"Received a configuration message:\n" +
                    $"MinimumSoC: {config.MinimumSoC}\n" +
                    $"OperatingPriority: {config.OperatingPriority}\n" +
                    $"Number of batteries: {config.BatteriesCount}\n" +
                    $"Maximum Charging current: {config.MaximumChargingCurrent}\n" +
                    $"Maximum Discharging current: {config.MaximumDischargingCurrent}\n" +
                    $"StartTimeChargeandDischargeDayandTime: {config.StartTimeChargeandDischargeDayandTime}\n" +
                    $"StopTimeChargeandDischargeDayandTime: {config.StopTimeChargeandDischargeDayandTime}\n" +
                    $"TimeChargeandDischargePower: {config.TimeChargeandDischargePower}\n" +
                    $"ControlPermission: {config.ControlPermission}"
                );
    
                // Send ACK
                var replyMessage = "ACK";
                var replyData = Encoding.UTF8.GetBytes(replyMessage);
    
                _udpListener.Send(replyData, replyData.Length, serverEndpoint);
                Console.WriteLine($"Replied to {serverEndpoint}: {replyMessage}");
    
                return config;
            }
            else
            {
                Console.WriteLine("Received UDP message but failed to deserialize Configuration.");
                return null;
            }
        }
        catch (SocketException ex)
        {
            Console.WriteLine($"Socket error in SetConfigurationFile: {ex}");
    
            // Recover by reinitializing
            try
            {
                _udpListener?.Close();
                _udpListener?.Dispose();
            }
            catch
            {
                // ignored
            }

            _udpListener = null;
            InitializeCommunicationToMiddleware();
    
            return null;
        }
        catch (JsonException ex)
        {
            Console.WriteLine($"JSON deserialization error: {ex}");
            return null;
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Unexpected error in SetConfigurationFile: {ex}");
            return null;
        }
    }

}