using System;
using System.Diagnostics;
using System.Net;
using System.Net.Sockets;

using Microsoft.VisualStudio.TestTools.UnitTesting;

using Moq;

using Renci.SshNet.Tests.Common;

namespace Renci.SshNet.Tests.Classes.Connection
{
    [TestClass]
    public class DirectConnectorTest_Connect_ConnectionSucceeded : DirectConnectorTestBase
    {
        private ConnectionInfo _connectionInfo;
        private AsyncSocketListener _server;
        private Socket _clientSocket;
        private Stopwatch _stopWatch;
        private bool _disconnected;
        private Socket _actual;

        protected override void SetupData()
        {
            base.SetupData();

            var random = new Random();

            _connectionInfo = CreateConnectionInfo(IPAddress.Loopback.ToString());
            _connectionInfo.Timeout = TimeSpan.FromMilliseconds(random.Next(50, 200));
            _stopWatch = new Stopwatch();
            _disconnected = false;

            _clientSocket = SocketFactory.Create(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

            _server = new AsyncSocketListener(new IPEndPoint(IPAddress.Loopback, _connectionInfo.Port));
            _server.Disconnected += (socket) => _disconnected = true;
            _server.Connected += (socket) => socket.Send(new byte[1] { 0x44 });
            _server.Start();
        }

        protected override void SetupMocks()
        {
            _ = SocketFactoryMock.Setup(p => p.Create(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp))
                                 .Returns(_clientSocket);
        }

        protected override void TearDown()
        {
            base.TearDown();

            _server?.Dispose();
            _clientSocket?.Dispose();
        }

        protected override void Act()
        {
            _stopWatch.Start();

            try
            {
                _actual = Connector.Connect(_connectionInfo);
            }
            finally
            {
                _stopWatch.Stop();
            }
        }

        [TestMethod]
        public void ConnectShouldHaveReturnedSocketCreatedUsingSocketFactory()
        {
            Assert.IsNotNull(_actual);
            Assert.AreSame(_clientSocket, _actual);
        }

        [TestMethod]
        public void ConnectShouldHaveRespectedTimeout()
        {
            var errorText = string.Format("Elapsed: {0}, Timeout: {1}",
                                          _stopWatch.ElapsedMilliseconds,
                                          _connectionInfo.Timeout.TotalMilliseconds);

            // Compare elapsed time with configured timeout, allowing for a margin of error
            Assert.IsTrue(_stopWatch.ElapsedMilliseconds < _connectionInfo.Timeout.TotalMilliseconds + 100, errorText);
        }

        [TestMethod]
        public void ClientSocketShouldBeConnected()
        {
            Assert.IsTrue(_clientSocket.Connected);
            Assert.IsFalse(_disconnected);
        }

        [TestMethod]
        public void NoBytesShouldHaveBeenReadFromSocket()
        {
            var buffer = new byte[1];

            var bytesRead = _clientSocket.Receive(buffer);
            Assert.AreEqual(1, bytesRead);
            Assert.AreEqual(0x44, buffer[0]);
        }

        [TestMethod]
        public void CreateOnSocketFactoryShouldHaveBeenInvokedOnce()
        {
            SocketFactoryMock.Verify(p => p.Create(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp),
                                     Times.Once());
        }
    }
}
