using System.IO.Ports;
using Microsoft.Extensions.Options;
using YD_TrainingCompetition_Api.Options;

namespace YD_TrainingCompetition_Api.Serial;

public sealed class SerialGateway : ISerialGateway
{
    private readonly SerialPort _serialPort;

    public SerialGateway(IOptions<Serial24GOptions> options)
    {
        var cfg = options.Value;
        _serialPort = new SerialPort
        {
            PortName = cfg.PortName,
            BaudRate = cfg.BaudRate,
            DataBits = cfg.DataBits,
            StopBits = StopBits.One,
            Parity = Parity.None,
            ReadBufferSize = cfg.ReadBufferSize,
            WriteBufferSize = cfg.WriteBufferSize
        };

        _serialPort.DataReceived += (_, _) =>
        {
            try
            {
                var len = _serialPort.BytesToRead;
                if (len <= 0)
                {
                    return;
                }

                var buf = new byte[len];
                _serialPort.Read(buf, 0, len);
                DataReceived?.Invoke(this, buf);
            }
            catch
            {
            }
        };
    }

    public event EventHandler<byte[]>? DataReceived;
    public bool IsOpen => _serialPort.IsOpen;
    public string? CurrentPort => _serialPort.IsOpen ? _serialPort.PortName : null;

    public string[] GetAvailablePorts() => SerialPort.GetPortNames().OrderBy(x => x, StringComparer.OrdinalIgnoreCase).ToArray();

    public Task OpenAsync(string portName, CancellationToken cancellationToken = default)
    {
        if (_serialPort.IsOpen)
        {
            _serialPort.Close();
        }

        _serialPort.PortName = portName;
        _serialPort.Open();
        return Task.CompletedTask;
    }

    public Task CloseAsync(CancellationToken cancellationToken = default)
    {
        if (_serialPort.IsOpen)
        {
            _serialPort.Close();
        }

        return Task.CompletedTask;
    }

    public Task SendAsync(byte[] data, CancellationToken cancellationToken = default)
    {
        if (!_serialPort.IsOpen)
        {
            throw new InvalidOperationException("Serial port is not open");
        }

        _serialPort.Write(data, 0, data.Length);
        return Task.CompletedTask;
    }
}