using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Ocelot.Configuration.File;
using Shouldly;
using TestStack.BDDfy;
using Xunit;

namespace Ocelot.AcceptanceTests
{
    public class HttpDelegatingHandlersTests
    {
        private IWebHost _builder;
        private readonly Steps _steps;
        private string _downstreamPath;

        public HttpDelegatingHandlersTests()
        {
            _steps = new Steps();
        }

        [Fact]
        public void should_call_handlers()
        {
            var configuration = new FileConfiguration
            {
                ReRoutes = new List<FileReRoute>
                {
                    new FileReRoute
                    {
                        DownstreamPathTemplate = "/",
                        DownstreamScheme = "http",
                        DownstreamHostAndPorts = new List<FileHostAndPort>
                        {
                            new FileHostAndPort
                            {
                                Host = "localhost",
                                Port = 61879,
                            }
                        },
                        UpstreamPathTemplate = "/",
                        UpstreamHttpMethod = new List<string> { "Get" },
                    }
                }
            };

            var handlerOne = new FakeHandler();
            var handlerTwo = new FakeHandler();

            this.Given(x => x.GivenThereIsAServiceRunningOn("http://localhost:61879", "/", 200, "Hello from Laura"))
                .And(x => _steps.GivenThereIsAConfiguration(configuration))
                .And(x => _steps.GivenOcelotIsRunningWithHandlers(handlerOne, handlerTwo))
                .When(x => _steps.WhenIGetUrlOnTheApiGateway("/"))
                .Then(x => _steps.ThenTheStatusCodeShouldBe(HttpStatusCode.OK))
                .And(x => _steps.ThenTheResponseBodyShouldBe("Hello from Laura"))
                .And(x => ThenTheHandlersAreCalledCorrectly(handlerOne, handlerTwo))
                .BDDfy();
        }

        private void ThenTheHandlersAreCalledCorrectly(FakeHandler one, FakeHandler two)
        {
            one.TimeCalled.ShouldBeLessThan(two.TimeCalled);
        }

        class FakeHandler : DelegatingHandler
        {
  
            public DateTime TimeCalled { get; private set; }

            protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
            {
                TimeCalled = DateTime.Now;
                return await base.SendAsync(request, cancellationToken);
            }
        }

        private void GivenThereIsAServiceRunningOn(string baseUrl, string basePath, int statusCode, string responseBody)
        {
            _builder = new WebHostBuilder()
                .UseUrls(baseUrl)
                .UseKestrel()
                .UseContentRoot(Directory.GetCurrentDirectory())
                .UseIISIntegration()
                .Configure(app =>
                {
                    app.UsePathBase(basePath);
                    app.Run(async context =>
                    {
                        _downstreamPath = !string.IsNullOrEmpty(context.Request.PathBase.Value) ? context.Request.PathBase.Value : context.Request.Path.Value;

                        if (_downstreamPath != basePath)
                        {
                            context.Response.StatusCode = statusCode;
                            await context.Response.WriteAsync("downstream path didnt match base path");
                        }
                        else
                        {
                            context.Response.StatusCode = statusCode;
                            await context.Response.WriteAsync(responseBody);
                        }
                    });
                })
                .Build();

            _builder.Start();
        }

    }
}