using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using RabbitMQ.Client;
using SPMS.Application.Settings;

namespace SPMS.Infrastructure.Messaging;

public class RabbitMQConnection : IAsyncDisposable
{
    private readonly RabbitMQSettings _settings;
    private readonly ILogger<RabbitMQConnection> _logger;
    private readonly SemaphoreSlim _semaphore = new(1, 1);
    private IConnection? _connection;

    public RabbitMQConnection(
        IOptions<RabbitMQSettings> settings,
        ILogger<RabbitMQConnection> logger)
    {
        _settings = settings.Value;
        _logger = logger;
    }

    public async Task<IConnection> GetConnectionAsync(CancellationToken cancellationToken = default)
    {
        if (_connection is { IsOpen: true })
            return _connection;

        await _semaphore.WaitAsync(cancellationToken);
        try
        {
            if (_connection is { IsOpen: true })
                return _connection;

            var factory = new ConnectionFactory
            {
                HostName = _settings.HostName,
                Port = _settings.Port,
                UserName = _settings.UserName,
                Password = _settings.Password,
                VirtualHost = _settings.VirtualHost,
                AutomaticRecoveryEnabled = true,
                NetworkRecoveryInterval = TimeSpan.FromSeconds(10),
                RequestedHeartbeat = TimeSpan.FromSeconds(60)
            };

            _connection = await factory.CreateConnectionAsync(cancellationToken);
            _logger.LogInformation("RabbitMQ 연결 성공: {HostName}:{Port}", _settings.HostName, _settings.Port);

            return _connection;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "RabbitMQ 연결 실패: {HostName}:{Port}", _settings.HostName, _settings.Port);
            throw;
        }
        finally
        {
            _semaphore.Release();
        }
    }

    public async Task<IChannel> CreateChannelAsync(CancellationToken cancellationToken = default)
    {
        var connection = await GetConnectionAsync(cancellationToken);
        return await connection.CreateChannelAsync(cancellationToken: cancellationToken);
    }

    public async ValueTask DisposeAsync()
    {
        if (_connection is not null)
        {
            await _connection.CloseAsync();
            _connection.Dispose();
            _connection = null;
        }

        _semaphore.Dispose();
    }
}