using RobotNet10.Script.IO;
using System.Net.Sockets;

namespace RobotNet10.ScriptEngine.IO;

/// <summary>
/// Implementation of ProfiNet connection.
/// Note: This is a basic implementation. Full ProfiNet support may require additional libraries.
/// </summary>
public class ProfiNetConnection : IProfiNetConnection
{
    private TcpClient? _tcpClient;
    private NetworkStream? _stream;
    private bool _disposed;

    public string IpAddress { get; }
    public int Slot { get; }
    public int Subslot { get; }
    public bool IsConnected { get; private set; }

    public ProfiNetConnection(string ipAddress, int slot = 1, int subslot = 1)
    {
        IpAddress = ipAddress;
        Slot = slot;
        Subslot = subslot;
        IsConnected = false;
    }

    public async Task ConnectAsync()
    {
        if (IsConnected)
            return;

        try
        {
            _tcpClient = new TcpClient();
            await _tcpClient.ConnectAsync(IpAddress, 34964); // Standard ProfiNet port
            _stream = _tcpClient.GetStream();
            IsConnected = true;
            
            // TODO: Implement ProfiNet DCP (Discovery and Configuration Protocol) handshake
            // This requires implementing the ProfiNet protocol stack
        }
        catch
        {
            Disconnect();
            throw;
        }
    }

    public Task DisconnectAsync()
    {
        Disconnect();
        return Task.CompletedTask;
    }

    private void Disconnect()
    {
        IsConnected = false;
        _stream?.Close();
        _stream = null;
        _tcpClient?.Close();
        _tcpClient?.Dispose();
        _tcpClient = null;
    }

    public async Task<byte[]> ReadAsync(int index, int length)
    {
        EnsureConnected();
        
        // TODO: Implement ProfiNet read operation
        // This requires implementing the ProfiNet IO data exchange protocol
        await Task.CompletedTask;
        throw new NotImplementedException("ProfiNet read operation is not yet fully implemented. Full ProfiNet support requires additional protocol implementation.");
    }

    public async Task WriteAsync(int index, byte[] data)
    {
        EnsureConnected();
        
        // TODO: Implement ProfiNet write operation
        // This requires implementing the ProfiNet IO data exchange protocol
        await Task.CompletedTask;
        throw new NotImplementedException("ProfiNet write operation is not yet fully implemented. Full ProfiNet support requires additional protocol implementation.");
    }

    private void EnsureConnected()
    {
        if (!IsConnected || _stream == null)
        {
            throw new InvalidOperationException("ProfiNet connection is not connected. Call ConnectAsync() first.");
        }
    }

    public void Dispose()
    {
        if (!_disposed)
        {
            Disconnect();
            _disposed = true;
        }
        GC.SuppressFinalize(this);
    }
}