using System;
using EasyNetQ.Logging;
using Microsoft.Extensions.Logging;

// use like this...
// LogProvider.SetCurrentLogProvider(new EasyNetQMicrosoftExtensionsLogProvider(loggerProvider));
// RabbitHutch.CreateBus(..);

namespace Logging
{
    public class EasyNetQMicrosoftExtensionsLogProvider : ILogProvider
    {
        private readonly ILoggerProvider loggerProvider;

        public EasyNetQMicrosoftExtensionsLogProvider(ILoggerProvider loggerProvider)
        {
            this.loggerProvider = loggerProvider ?? throw new ArgumentNullException(nameof(loggerProvider));
        }

        public Logger GetLogger(string name)
        {
            var logger = loggerProvider.CreateLogger(name);

            return (logLevel, messageFunc, exception, formatParameters) =>
            {
                if (messageFunc == null)
                {
                    return true;
                }

                var msLogLevel = logLevel switch 
                { 
                    EasyNetQ.Logging.LogLevel.Debug => Microsoft.Extensions.Logging.LogLevel.Debug,
                    EasyNetQ.Logging.LogLevel.Error => Microsoft.Extensions.Logging.LogLevel.Error,
                    EasyNetQ.Logging.LogLevel.Fatal => Microsoft.Extensions.Logging.LogLevel.Critical,
                    EasyNetQ.Logging.LogLevel.Info => Microsoft.Extensions.Logging.LogLevel.Information,
                    EasyNetQ.Logging.LogLevel.Trace => Microsoft.Extensions.Logging.LogLevel.Trace,
                    EasyNetQ.Logging.LogLevel.Warn => Microsoft.Extensions.Logging.LogLevel.Warning,
                    _ => Microsoft.Extensions.Logging.LogLevel.None
                };

                var message = messageFunc();

                if(exception is Exception)
                {
                    logger.Log(msLogLevel, exception, message, formatParameters);
                }
                else
                {
                    logger.Log(msLogLevel, message, formatParameters);
                }

                return true;
            };
        }

        public IDisposable OpenMappedContext(string key, object value, bool destructure = false)
            => NullDisposable.Instance;

        public IDisposable OpenNestedContext(string message)
            => NullDisposable.Instance;

        private class NullDisposable : IDisposable
        {
            internal static readonly IDisposable Instance = new NullDisposable();

            public void Dispose()
            { }
        }

    }

    public class EasyNetQLogger { }
}