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

namespace InnovEnergy.App.GrowattCommunication.MiddlewareClasses;

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

        const Int32 udpPort = 9000;
        _endPoint = new IPEndPoint(_controllerIpAddress, udpPort);

        _udpListener = new UdpClient();
        _udpListener.Client.Blocking = false;
        _udpListener.Client.Bind(_endPoint);
    }
    
    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()
    {
        if (_udpListener.Available > 0)
        {
            IPEndPoint? serverEndpoint = null;

            var replyMessage = "ACK";
            var replyData    = Encoding.UTF8.GetBytes(replyMessage);

            var udpMessage = _udpListener.Receive(ref serverEndpoint);
            var message    = Encoding.UTF8.GetString(udpMessage);

            var config = JsonSerializer.Deserialize<Configuration>(message);

            if (config != null)
            {
                Console.WriteLine($"Received a configuration message: GridSetPoint is " + config.GridSetPoint +
                                  ", MinimumSoC is " + config.MinimumSoC + " and operating priorty is " +config.OperatingPriority + "Number of batteries is " + config.BatteriesCount );

                // Send the reply to the sender's endpoint
                _udpListener.Send(replyData, replyData.Length, serverEndpoint);
                Console.WriteLine($"Replied to {serverEndpoint}: {replyMessage}");
                return config;
            }
        }

        if (_endPoint != null && !_endPoint.Equals(_udpListener.Client.LocalEndPoint as IPEndPoint))
        {
            Console.WriteLine("UDP address has changed, rebinding...");
            InitializeCommunicationToMiddleware();
        }
        return null;
    }

}