// <copyright file="HttpClientTests.netcore31.cs" company="OpenTelemetry Authors">
// Copyright The OpenTelemetry Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// </copyright>
#if NETCOREAPP3_1_OR_GREATER
using System;
using System.Collections.Generic;
using System.Collections.Immutable;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Net.Http;
using System.Reflection;
using System.Threading.Tasks;
using Moq;
using Newtonsoft.Json;
using OpenTelemetry.Metrics;
using OpenTelemetry.Tests;
using OpenTelemetry.Trace;
using Xunit;

namespace OpenTelemetry.Instrumentation.Http.Tests
{
    public partial class HttpClientTests
    {
        public static int Counter;

        public static IEnumerable<object[]> TestData => HttpTestData.ReadTestCases();

        [Theory]
        [MemberData(nameof(TestData))]
        public async Task HttpOutCallsAreCollectedSuccessfullyAsync(HttpTestData.HttpOutTestCase tc)
        {
            var serverLifeTime = TestHttpServer.RunServer(
                (ctx) =>
                {
                    ctx.Response.StatusCode = tc.ResponseCode == 0 ? 200 : tc.ResponseCode;
                    ctx.Response.OutputStream.Close();
                },
                out var host,
                out var port);

            var processor = new Mock<BaseProcessor<Activity>>();
            tc.Url = HttpTestData.NormalizeValues(tc.Url, host, port);

            var metricItems = new List<Metric>();
            var metricExporter = new TestExporter<Metric>(ProcessExport);

            void ProcessExport(Batch<Metric> batch)
            {
                foreach (var metricItem in batch)
                {
                    metricItems.Add(metricItem);
                }
            }

            var metricReader = new BaseExportingMetricReader(metricExporter)
            {
                PreferredAggregationTemporality = AggregationTemporality.Cumulative,
            };
            var meterProvider = Sdk.CreateMeterProviderBuilder()
                .AddHttpClientInstrumentation()
                .AddMetricReader(metricReader)
                .Build();

            using (serverLifeTime)

            using (Sdk.CreateTracerProviderBuilder()
                               .AddHttpClientInstrumentation((opt) =>
                               {
                                   opt.SetHttpFlavor = tc.SetHttpFlavor;
                                   opt.Enrich = ActivityEnrichment;
                                   opt.RecordException = tc.RecordException.HasValue ? tc.RecordException.Value : false;
                               })
                               .AddProcessor(processor.Object)
                               .Build())
            {
                try
                {
                    using var c = new HttpClient();
                    var request = new HttpRequestMessage
                    {
                        RequestUri = new Uri(tc.Url),
                        Method = new HttpMethod(tc.Method),
                        Version = new Version(2, 0),
                    };

                    if (tc.Headers != null)
                    {
                        foreach (var header in tc.Headers)
                        {
                            request.Headers.Add(header.Key, header.Value);
                        }
                    }

                    await c.SendAsync(request);
                }
                catch (Exception)
                {
                    // test case can intentionally send request that will result in exception
                }
            }

            meterProvider.Dispose();

            var requestMetrics = metricItems
                .Where(metric => metric.Name == "http.client.duration")
                .ToArray();

            Assert.Equal(5, processor.Invocations.Count); // SetParentProvider/OnStart/OnEnd/OnShutdown/Dispose called.
            var activity = (Activity)processor.Invocations[2].Arguments[0];

            Assert.Equal(ActivityKind.Client, activity.Kind);
            Assert.Equal(tc.SpanName, activity.DisplayName);

            // Assert.Equal(tc.SpanStatus, d[span.Status.CanonicalCode]);
            Assert.Equal(
                    tc.SpanStatus,
                    activity.GetTagValue(SpanAttributeConstants.StatusCodeKey) as string);

            if (tc.SpanStatusHasDescription.HasValue)
            {
                var desc = activity.GetTagValue(SpanAttributeConstants.StatusDescriptionKey) as string;
                Assert.Equal(tc.SpanStatusHasDescription.Value, !string.IsNullOrEmpty(desc));
            }

            var normalizedAttributes = activity.TagObjects.Where(kv => !kv.Key.StartsWith("otel.")).ToImmutableSortedDictionary(x => x.Key, x => x.Value.ToString());
            var normalizedAttributesTestCase = tc.SpanAttributes.ToDictionary(x => x.Key, x => HttpTestData.NormalizeValues(x.Value, host, port));

            Assert.Equal(normalizedAttributesTestCase.Count, normalizedAttributes.Count);

            foreach (var kv in normalizedAttributesTestCase)
            {
                Assert.Contains(activity.TagObjects, i => i.Key == kv.Key && i.Value.ToString().Equals(kv.Value, StringComparison.InvariantCultureIgnoreCase));
            }

            if (tc.RecordException.HasValue && tc.RecordException.Value)
            {
                Assert.Single(activity.Events.Where(evt => evt.Name.Equals("exception")));
            }

            if (tc.ResponseExpected)
            {
                Assert.Single(requestMetrics);

                var metric = requestMetrics[0];
                Assert.NotNull(metric);
                Assert.True(metric.MetricType == MetricType.Histogram);

                var metricPoints = new List<MetricPoint>();
                foreach (var p in metric.GetMetricPoints())
                {
                    metricPoints.Add(p);
                }

                Assert.Single(metricPoints);
                var metricPoint = metricPoints[0];
                Assert.Equal(1L, metricPoint.LongValue);
                Assert.Equal(activity.Duration.TotalMilliseconds, metricPoint.DoubleValue);

                var attributes = new KeyValuePair<string, object>[metricPoint.Keys.Length];
                for (int i = 0; i < attributes.Length; i++)
                {
                    attributes[i] = new KeyValuePair<string, object>(metricPoint.Keys[i], metricPoint.Values[i]);
                }

                var method = new KeyValuePair<string, object>(SemanticConventions.AttributeHttpMethod, tc.Method);
                var scheme = new KeyValuePair<string, object>(SemanticConventions.AttributeHttpScheme, "http");
                var statusCode = new KeyValuePair<string, object>(SemanticConventions.AttributeHttpStatusCode, tc.ResponseCode == 0 ? 200 : tc.ResponseCode);
                var flavor = new KeyValuePair<string, object>(SemanticConventions.AttributeHttpFlavor, "2.0");
                Assert.Contains(method, attributes);
                Assert.Contains(scheme, attributes);
                Assert.Contains(statusCode, attributes);
                Assert.Contains(flavor, attributes);
                Assert.Equal(4, attributes.Length);
            }
            else
            {
                Assert.Single(requestMetrics);
                var metricPoints = new List<MetricPoint>();
                foreach (var p in requestMetrics[0].GetMetricPoints())
                {
                    metricPoints.Add(p);
                }

                Assert.Empty(metricPoints);
            }
        }

        [Fact]
        public async Task DebugIndividualTestAsync()
        {
            var serializer = new JsonSerializer();
            var input = serializer.Deserialize<HttpTestData.HttpOutTestCase[]>(new JsonTextReader(new StringReader(@"
[
  {
    ""name"": ""Response code: 399"",
    ""method"": ""GET"",
    ""url"": ""http://{host}:{port}/"",
    ""responseCode"": 399,
    ""responseExpected"": true,
    ""spanName"": ""HTTP GET"",
    ""spanStatus"": ""UNSET"",
    ""spanKind"": ""Client"",
    ""spanAttributes"": {
      ""http.method"": ""GET"",
      ""http.host"": ""{host}:{port}"",
      ""http.status_code"": ""399"",
      ""http.url"": ""http://{host}:{port}/""
    }
  }
]
")));

            var t = (Task)this.GetType().InvokeMember(nameof(this.HttpOutCallsAreCollectedSuccessfullyAsync), BindingFlags.InvokeMethod, null, this, HttpTestData.GetArgumentsFromTestCaseObject(input).First());
            await t;
        }

        [Fact]
        public async Task CheckEnrichmentWhenSampling()
        {
            await CheckEnrichment(new AlwaysOffSampler(), 0).ConfigureAwait(false);
            await CheckEnrichment(new AlwaysOnSampler(), 2).ConfigureAwait(false);
        }

        private static async Task CheckEnrichment(Sampler sampler, int expect)
        {
            Counter = 0;
            var processor = new Mock<BaseProcessor<Activity>>();
            using (Sdk.CreateTracerProviderBuilder()
                .SetSampler(sampler)
                .AddHttpClientInstrumentation(options => options.Enrich = ActivityEnrichmentCounter)
                .AddProcessor(processor.Object)
                .Build())
            {
                using var c = new HttpClient();
                using var r = await c.GetAsync("https://opentelemetry.io/").ConfigureAwait(false);
            }

            Assert.Equal(expect, Counter);
        }

        private static void ActivityEnrichmentCounter(Activity activity, string method, object obj)
        {
            Counter++;
        }
    }
}
#endif