using System.Net.Sockets;

namespace Dlhis.Middle.Services.Implements;

public class HealthCheckService : IHealthCheckService
{
    private bool _isOffline;
    private readonly string _hostName;
    private readonly ILogger<HealthCheckService> _logger;
    private int _successRetry;
    private int _retry;

    public HealthCheckService(ILogger<HealthCheckService> logger, IConfiguration configuration)
    {
        _logger = logger;
        _hostName = configuration.GetSection("HostName").Value;
    }

    public bool GetIsOffline()
    {
        return _isOffline;
    }

    public async Task DoHealthCheckAsync()
    {
        var cancellationTokenSource = new CancellationTokenSource(3000);
        var tcpClient = new TcpClient();

        try
        {
            _logger.LogDebug("tcp connecting {host} {port}", _hostName, 443);
            await tcpClient.ConnectAsync(_hostName, 443, cancellationTokenSource.Token);
            _retry++;
            _logger.LogDebug("retry {retry}", _retry);
            if (tcpClient.Connected)
            {
                _successRetry++;
                _logger.LogDebug("success connected {count}", _successRetry);
                if (_successRetry == 4)
                {
                    _isOffline = false;
                    _successRetry = 0;
                    _retry = 0;
                    _logger.LogInformation("current is {status}", "healthy");
                }
                else
                {
                    _logger.LogDebug("wait next check in {waitTime}", _successRetry * 1000);
                    await Task.Delay(_successRetry * 1000, cancellationTokenSource.Token);
                }
            }
            else
            {
                _successRetry = 0;
                _isOffline = true;
                _logger.LogDebug("current is {status}", "unavailable");
                await Task.Delay(500);
            }
        }
        catch (Exception ex)
        {
            _logger.LogError("fail cause :{reason}", ex.Message);
            _isOffline = true;
        }
    }
}