using System.IO.Pipes;

namespace MasstransferCommunicate.Process.Client;

public class ProcessHelper
{
    public event Action<string> MessageReceived;

    private readonly string _pipeName;
    private readonly bool _isServer;
    private PipeStream _pipeStream;
    private StreamReader _reader;
    private StreamWriter _writer;
    private CancellationTokenSource _cts;

    private ProcessHelper(string pipeName, bool isServer)
    {
        _pipeName = pipeName;
        _isServer = isServer;
        _cts = new CancellationTokenSource();
    }

    public static async Task<ProcessHelper> CreateServer(string pipeName)
    {
        var helper = new ProcessHelper(pipeName, true);
        await helper.ConnectAsync();
        return helper;
    }

    public static async Task<ProcessHelper> CreateClient(string pipeName)
    {
        var helper = new ProcessHelper(pipeName, false);
        await helper.ConnectAsync();
        return helper;
    }

    private async Task ConnectAsync()
    {
        if (_isServer)
        {
            _pipeStream = new NamedPipeServerStream(_pipeName, PipeDirection.InOut, 1, PipeTransmissionMode.Byte,
                PipeOptions.Asynchronous);
            await ((NamedPipeServerStream)_pipeStream).WaitForConnectionAsync(_cts.Token);
        }
        else
        {
            _pipeStream = new NamedPipeClientStream(".", _pipeName, PipeDirection.InOut, PipeOptions.Asynchronous);
            await ((NamedPipeClientStream)_pipeStream).ConnectAsync(_cts.Token);
        }

        _reader = new StreamReader(_pipeStream);
        _writer = new StreamWriter(_pipeStream) { AutoFlush = true };
        StartListeningAsync();
    }

    public async Task SendMessageAsync(string message)
    {
        try
        {
            await _writer.WriteLineAsync(message);
        }
        catch (IOException)
        {
            await ReconnectAsync();
            await SendMessageAsync(message);
        }
    }

    private void StartListeningAsync()
    {
        Task.Run(async () =>
        {
            while (!_cts.Token.IsCancellationRequested)
            {
                try
                {
                    var message = await _reader.ReadLineAsync();
                    if (message == null) throw new IOException("Pipe disconnected.");
                    MessageReceived?.Invoke(message);
                }
                catch (IOException)
                {
                    // Handle disconnection and retries
                    await ReconnectAsync();
                }
            }
        });
    }

    private async Task ReconnectAsync()
    {
        Close();
        while (!_pipeStream.IsConnected)
        {
            try
            {
                Console.WriteLine("尝试重新连接...");
                await ConnectAsync();
                Console.WriteLine("重新连接成功");
                break;
            }
            catch (Exception)
            {
                Console.WriteLine("重新连接失败，等待 1 秒后重试...");
                await Task.Delay(1000);
            }
        }
    }

    public void Close()
    {
        _cts.Cancel();
        _pipeStream?.Close();
        _cts = new CancellationTokenSource();
    }
}