using System.Diagnostics;
using System.IO;
using System.Text;
using Azaion.Common.Database;
using Azaion.Common.Extensions;
using Azaion.CommonSecurity;
using Azaion.CommonSecurity.DTO;
using Azaion.CommonSecurity.DTO.Commands;
using Azaion.CommonSecurity.Exceptions;
using Azaion.CommonSecurity.Services;
using MessagePack;
using Microsoft.Extensions.Options;
using NetMQ;
using NetMQ.Sockets;

namespace Azaion.Common.Services;

public interface IInferenceClient : IDisposable
{
    event EventHandler<RemoteCommand> BytesReceived;
    event EventHandler<RemoteCommand>? InferenceDataReceived;
    event EventHandler<RemoteCommand>? AIAvailabilityReceived;
    void Send(RemoteCommand create);
    void Stop();
}

public class InferenceClient : IInferenceClient, IResourceLoader
{
    private CancellationTokenSource _waitFileCancelSource = new();

    public event EventHandler<RemoteCommand>? BytesReceived;
    public event EventHandler<RemoteCommand>? InferenceDataReceived;
    public event EventHandler<RemoteCommand>? AIAvailabilityReceived;

    private readonly DealerSocket _dealer = new();
    private readonly NetMQPoller _poller = new();
    private readonly Guid _clientId = Guid.NewGuid();
    private readonly InferenceClientConfig _inferenceClientConfig;

    public InferenceClient(IOptions<InferenceClientConfig> config, CancellationToken ct)
    {
        _inferenceClientConfig = config.Value;
        Start(ct);
    }

    private void Start(CancellationToken ct = default)
    {
        try
        {
            using var process = new Process();
            process.StartInfo = new ProcessStartInfo
            {
                FileName = SecurityConstants.EXTERNAL_INFERENCE_PATH,
                Arguments = $"--port {_inferenceClientConfig.ZeroMqPort} --api {_inferenceClientConfig.ApiUrl}",
                //RedirectStandardOutput = true,
                //RedirectStandardError = true,
                //CreateNoWindow = true
            };

            process.OutputDataReceived += (_, e) => { if (e.Data != null) Console.WriteLine(e.Data); };
            process.ErrorDataReceived += (_, e) => { if (e.Data != null) Console.WriteLine(e.Data); };
            process.Start();
        }
        catch (Exception e)
        {
            Console.WriteLine(e);
            //throw;
        }

        _dealer.Options.Identity = Encoding.UTF8.GetBytes(_clientId.ToString("N"));
        _dealer.Connect($"tcp://{_inferenceClientConfig.ZeroMqHost}:{_inferenceClientConfig.ZeroMqPort}");

        _dealer.ReceiveReady += (_, e) => ProcessClientCommand(e.Socket, ct);
        _poller.Add(_dealer);
        _ = Task.Run(() => _poller.RunAsync(), ct);
    }

    private void ProcessClientCommand(NetMQSocket socket, CancellationToken ct = default)
    {
        while (socket.TryReceiveFrameBytes(TimeSpan.Zero, out var bytes))
        {
            if (bytes?.Length == 0)
                continue;

            var remoteCommand = MessagePackSerializer.Deserialize<RemoteCommand>(bytes, cancellationToken: ct);
            switch (remoteCommand.CommandType)
            {
                case CommandType.DataBytes:
                    BytesReceived?.Invoke(this, remoteCommand);
                    break;
                case CommandType.InferenceData:
                    InferenceDataReceived?.Invoke(this, remoteCommand);
                    break;
                case CommandType.AIAvailabilityResult:
                    AIAvailabilityReceived?.Invoke(this, remoteCommand);
                    break;
            }

        }
    }

    public void Stop()
    {

    }

    public void Send(RemoteCommand command)
    {
        _dealer.SendFrame(MessagePackSerializer.Serialize(command));
    }

    public MemoryStream LoadFile(string fileName, string? folder = null, TimeSpan? timeout = null)
    {
        //TODO: Bad solution, look for better implementation
        byte[] bytes = [];
        Exception? exception = null;
        _waitFileCancelSource = new CancellationTokenSource();
        Send(RemoteCommand.Create(CommandType.Load, new LoadFileData(fileName, folder)));
        BytesReceived += OnBytesReceived;

        void OnBytesReceived(object? sender, RemoteCommand command)
        {
            if (command.Data is null)
            {
                exception = new BusinessException(command.Message ?? "File is empty");
                _waitFileCancelSource.Cancel();
            }

            bytes = command.Data!;
            _waitFileCancelSource.Cancel();
        }
        _waitFileCancelSource.Token.WaitForCancel(timeout ?? TimeSpan.FromSeconds(15));
        BytesReceived -= OnBytesReceived;
        if (exception != null)
            throw exception;
        return new MemoryStream(bytes);
    }

    public void Dispose()
    {
        _waitFileCancelSource.Dispose();
        _poller.Stop();
        _poller.Dispose();

        _dealer.SendFrame(MessagePackSerializer.Serialize(new RemoteCommand(CommandType.Exit)));
        _dealer.Disconnect($"tcp://{_inferenceClientConfig.ZeroMqHost}:{_inferenceClientConfig.ZeroMqPort}");
        _dealer.Close();
        _dealer.Dispose();
    }
}