// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System;
using System.Net;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Connections;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;

namespace Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv.Internal
{
  internal class LibuvTransportFactory : IConnectionListenerFactory
  {
    private readonly LibuvTransportContext _baseTransportContext;

    public LibuvTransportFactory(
      IOptions<LibuvTransportOptions> options,
      IHostApplicationLifetime applicationLifetime,
      ILoggerFactory loggerFactory)
    {
      if (options == null) throw new ArgumentNullException(nameof(options));
      if (applicationLifetime == null) throw new ArgumentNullException(nameof(applicationLifetime));
      if (loggerFactory == null) throw new ArgumentNullException(nameof(loggerFactory));

      var logger = loggerFactory.CreateLogger("Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv");
      var trace = new LibuvTrace(logger);

      var threadCount = options.Value.ThreadCount;

      if (threadCount <= 0)
        throw new ArgumentOutOfRangeException(nameof(threadCount),
          threadCount,
          "ThreadCount must be positive.");

      if (!LibuvConstants.ECONNRESET.HasValue) trace.LogWarning("Unable to determine ECONNRESET value on this platform.");

      if (!LibuvConstants.EADDRINUSE.HasValue) trace.LogWarning("Unable to determine EADDRINUSE value on this platform.");

      _baseTransportContext = new LibuvTransportContext
      {
        Options = options.Value,
        AppLifetime = applicationLifetime,
        Log = trace,
      };
    }

    public async ValueTask<IConnectionListener> BindAsync(EndPoint endpoint, CancellationToken cancellationToken = default)
    {
      var transportContext = new LibuvTransportContext
      {
        Options = _baseTransportContext.Options,
        AppLifetime = _baseTransportContext.AppLifetime,
        Log = _baseTransportContext.Log
      };

      var transport = new LibuvConnectionListener(transportContext, endpoint);
      await transport.BindAsync();
      return transport;
    }
  }
}