// 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.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using System.Xml.Linq;
using Microsoft.AspNetCore.Server.IIS.FunctionalTests.Utilities;
using Microsoft.AspNetCore.Server.IntegrationTesting;
using Microsoft.AspNetCore.Server.IntegrationTesting.IIS;
using Microsoft.AspNetCore.Testing.xunit;
using Microsoft.Extensions.Logging;
using Xunit;

namespace Microsoft.AspNetCore.Server.IISIntegration.FunctionalTests
{
    [Collection(PublishedSitesCollection.Name)]
    public class FrebTests : LogFileTestBase
    {
        private readonly PublishedSitesFixture _fixture;
        public FrebTests(PublishedSitesFixture fixture)
        {
            _fixture = fixture;
        }

        public static IList<FrebLogItem> FrebChecks()
        {
            var list = new List<FrebLogItem>();
            list.Add(new FrebLogItem("ANCM_INPROC_EXECUTE_REQUEST_START"));
            list.Add(new FrebLogItem("ANCM_INPROC_EXECUTE_REQUEST_COMPLETION", "1"));
            list.Add(new FrebLogItem("ANCM_INPROC_ASYNC_COMPLETION_START"));
            list.Add(new FrebLogItem("ANCM_INPROC_ASYNC_COMPLETION_COMPLETION", "0"));
            list.Add(new FrebLogItem("ANCM_INPROC_MANAGED_REQUEST_COMPLETION"));
            return list;
        }

        [ConditionalFact]
        [RequiresIIS(IISCapability.FailedRequestTracingModule)]
        public async Task CheckCommonFrebEvents()
        {
            var result = await SetupFrebApp();

            await result.HttpClient.GetAsync("HelloWorld");

            StopServer();

            AssertFrebLogs(result, FrebChecks());
        }

        [ConditionalFact]
        [RequiresNewShim]
        [RequiresIIS(IISCapability.FailedRequestTracingModule)]
        public async Task FrebIncludesHResultFailures()
        {
            var parameters = _fixture.GetBaseDeploymentParameters(publish: true);
            parameters.TransformArguments((args, _) => string.Empty);
            var result = await SetupFrebApp(parameters);

            await result.HttpClient.GetAsync("HelloWorld");

            StopServer();

            AssertFrebLogs(result, new FrebLogItem("ANCM_HRESULT_FAILED"), new FrebLogItem("ANCM_EXCEPTION_CAUGHT"));
        }

        [ConditionalFact]
        [RequiresIIS(IISCapability.FailedRequestTracingModule)]
        public async Task CheckFailedRequestEvents()
        {
            var result = await SetupFrebApp();

            await result.HttpClient.GetAsync("Throw");

            StopServer();

            AssertFrebLogs(result, new FrebLogItem("ANCM_INPROC_ASYNC_COMPLETION_COMPLETION", "2"));
        }

        [ConditionalFact]
        [RequiresIIS(IISCapability.FailedRequestTracingModule)]
        public async Task CheckFrebDisconnect()
        {
            var result = await SetupFrebApp();

            using (var connection = new TestConnection(result.HttpClient.BaseAddress.Port))
            {
                await connection.Send(
                    "GET /WaitForAbort HTTP/1.1",
                    "Host: localhost",
                    "Connection: close",
                    "",
                    "");
                await result.HttpClient.RetryRequestAsync("/WaitingRequestCount", async message => await message.Content.ReadAsStringAsync() == "1");
            }

            StopServer();

            // The order of freb logs is based on when the requests are complete.
            // This is non-deterministic here, so we need to check both freb files for a request that was disconnected.
            AssertFrebLogs(result, new FrebLogItem("ANCM_INPROC_REQUEST_DISCONNECT"), new FrebLogItem("ANCM_INPROC_MANAGED_REQUEST_COMPLETION"));
        }

        private async Task<IISDeploymentResult> SetupFrebApp(IISDeploymentParameters parameters = null)
        {
            parameters = parameters ?? _fixture.GetBaseDeploymentParameters(publish: true);
            parameters.EnableFreb("Verbose", _logFolderPath);

            Directory.CreateDirectory(_logFolderPath);
            var result = await DeployAsync(parameters);
            return result;
        }

        private void AssertFrebLogs(IISDeploymentResult result, params FrebLogItem[] expectedFrebEvents)
        {
            AssertFrebLogs(result, (IEnumerable<FrebLogItem>)expectedFrebEvents);
        }

        private void AssertFrebLogs(IISDeploymentResult result, IEnumerable<FrebLogItem> expectedFrebEvents)
        {
            var frebEvent = GetFrebLogItems(result);
            foreach (var expectedEvent in expectedFrebEvents)
            {
                Assert.Contains(expectedEvent, frebEvent);
            }
        }

        private IEnumerable<FrebLogItem> GetFrebLogItems(IISDeploymentResult result)
        {
            var folderPath = Helpers.GetFrebFolder(_logFolderPath, result);
            var xmlFiles = Directory.GetFiles(folderPath).Where(f => f.EndsWith("xml"));
            var frebEvents = new List<FrebLogItem>();

            foreach (var xmlFile in xmlFiles)
            {
                var xDocument = XDocument.Load(xmlFile).Root;
                var nameSpace = (XNamespace)"http://schemas.microsoft.com/win/2004/08/events/event";
                var eventElements = xDocument.Descendants(nameSpace + "Event");
                foreach (var eventElement in eventElements)
                {
                    var eventElementWithOpCode = eventElement.Descendants(nameSpace + "RenderingInfo").Single().Descendants(nameSpace + "Opcode").Single();
                    var requestStatus = eventElement.Element(nameSpace + "EventData").Descendants().Where(el => el.Attribute("Name").Value == "requestStatus").SingleOrDefault();
                    frebEvents.Add(new FrebLogItem(eventElementWithOpCode.Value, requestStatus?.Value));
                }
            }

            return frebEvents;
        }

        public class FrebLogItem
        {
            private string _opCode;
            private string _requestStatus;

            public FrebLogItem(string opCode)
            {
                _opCode = opCode;
            }

            public FrebLogItem(string opCode, string requestStatus)
            {
                _opCode = opCode;
                _requestStatus = requestStatus;
            }

            public override bool Equals(object obj)
            {
                var item = obj as FrebLogItem;
                return item != null &&
                       _opCode == item._opCode &&
                       _requestStatus == item._requestStatus;
            }

            public override int GetHashCode()
            {
                return HashCode.Combine(_opCode, _requestStatus);
            }
        }
    }
}