using System;
using System.Collections.Generic;
using System.Threading;

using Microsoft.VisualStudio.TestTools.UnitTesting;

using Moq;

using Renci.SshNet.Channels;
using Renci.SshNet.Common;
using Renci.SshNet.Messages.Connection;

namespace Renci.SshNet.Tests.Classes.Channels
{
    [TestClass]
    public class ChannelSessionTest_Open_ExceptionWaitingOnOpenConfirmation : ChannelSessionTestBase
    {
        private ChannelSession _channel;
        private uint _localChannelNumber;
        private uint _localWindowSize;
        private uint _localPacketSize;
        private IList<ChannelEventArgs> _channelClosedRegister;
        private List<ExceptionEventArgs> _channelExceptionRegister;
        private SemaphoreSlim _sessionSemaphore;
        private int _initialSessionSemaphoreCount;
        private Exception _waitOnConfirmationException;
        private SystemException _actualException;

        protected override void SetupData()
        {
            var random = new Random();

            _localChannelNumber = (uint)random.Next(0, int.MaxValue);
            _localWindowSize = (uint)random.Next(2000, 3000);
            _localPacketSize = (uint)random.Next(1000, 2000);
            _initialSessionSemaphoreCount = random.Next(10, 20);
            _sessionSemaphore = new SemaphoreSlim(_initialSessionSemaphoreCount);
            _channelClosedRegister = new List<ChannelEventArgs>();
            _channelExceptionRegister = new List<ExceptionEventArgs>();
            _waitOnConfirmationException = new SystemException();
        }

        protected override void SetupMocks()
        {
            var sequence = new MockSequence();

            SessionMock.InSequence(sequence).Setup(p => p.ConnectionInfo).Returns(ConnectionInfoMock.Object);
            ConnectionInfoMock.InSequence(sequence).Setup(p => p.RetryAttempts).Returns(2);
            SessionMock.Setup(p => p.SessionSemaphore).Returns(_sessionSemaphore);
            SessionMock.InSequence(sequence)
                        .Setup(
                            p =>
                                p.SendMessage(
                                    It.Is<ChannelOpenMessage>(
                                        m =>
                                            m.LocalChannelNumber == _localChannelNumber &&
                                            m.InitialWindowSize == _localWindowSize && m.MaximumPacketSize == _localPacketSize &&
                                            m.Info is SessionChannelOpenInfo)));
            SessionMock.InSequence(sequence)
                        .Setup(p => p.WaitOnHandle(It.IsNotNull<WaitHandle>()))
                        .Throws(_waitOnConfirmationException);
        }

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

            _channel = new ChannelSession(SessionMock.Object, _localChannelNumber, _localWindowSize, _localPacketSize);
            _channel.Closed += (sender, args) => _channelClosedRegister.Add(args);
            _channel.Exception += (sender, args) => _channelExceptionRegister.Add(args);
        }

        protected override void Act()
        {
            try
            {
                _channel.Open();
            }
            catch (SystemException ex)
            {
                _actualException = ex;
            }
        }

        [TestMethod]
        public void OpenShouldHaveRethrownExceptionThrownByWaitOnHandle()
        {
            Assert.IsNotNull(_actualException);
            Assert.AreSame(_waitOnConfirmationException, _actualException);
        }

        [TestMethod]
        public void CurrentCountOfSessionSemaphoreShouldBeEqualToInitialCount()
        {
            Assert.AreEqual(_initialSessionSemaphoreCount, _sessionSemaphore.CurrentCount);
        }

        [TestMethod]
        public void ExceptionShouldNeverHaveFired()
        {
            Assert.AreEqual(0, _channelExceptionRegister.Count);
        }

        [TestMethod]
        public void ClosedEventShouldNeverHaveFired()
        {
            Assert.AreEqual(0, _channelClosedRegister.Count);
        }

        [TestMethod]
        public void IsOpenShouldReturnFalse()
        {
            Assert.IsFalse(_channel.IsOpen);
        }
    }
}