// 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.IO;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;
using Microsoft.AspNet.Builder;
using Microsoft.AspNet.Hosting;
using Microsoft.AspNet.Hosting.Startup;
using Microsoft.AspNet.Http;
using Microsoft.Framework.Configuration;
using Microsoft.Framework.DependencyInjection;
using Microsoft.Framework.Logging;
using Xunit;

namespace Microsoft.AspNet.TestHost
{
    public class TestServerTests
    {
        [Fact]
        public void CreateWithDelegate()
        {
            // Arrange
            // Act & Assert (Does not throw)
            TestServer.Create(app => { });
        }

        [Fact]
        public void ThrowsIfNoApplicationEnvironmentIsRegisteredWithTheProvider()
        {
            // Arrange
            var services = new ServiceCollection().BuildServiceProvider();

            // Act & Assert
            Assert.Throws<InvalidOperationException>(
                () => TestServer.Create(
                    services,
                    new ConfigurationBuilder().Build(), new Startup().Configure, configureServices: null));
        }

        [Fact]
        public async Task RequestServicesAutoCreated()
        {
            TestServer server = TestServer.Create(app =>
            {
                app.Run(context =>
                {
                    return context.Response.WriteAsync("RequestServices:" + (context.RequestServices != null));
                });
            });

            string result = await server.CreateClient().GetStringAsync("/path");
            Assert.Equal("RequestServices:True", result);
        }

        public class TestService { }

        public class TestRequestServiceMiddleware
        {
            private RequestDelegate _next;

            public TestRequestServiceMiddleware(RequestDelegate next)
            {
                _next = next;
            }

            public Task Invoke(HttpContext httpContext)
            {
                var services = new ServiceCollection();
                services.AddTransient<TestService>();
                httpContext.RequestServices = services.BuildServiceProvider();

                return _next.Invoke(httpContext);
            }
        }

        public class RequestServicesFilter : IStartupFilter
        {
            public Action<IApplicationBuilder> Configure(Action<IApplicationBuilder> next)
            {
                return builder =>
                {
                    builder.UseMiddleware<TestRequestServiceMiddleware>();
                    next(builder);
                };
            }
        }

        [Fact]
        public async Task ExistingRequestServicesWillNotBeReplaced()
        {
            var server = TestServer.Create(app =>
            {
                app.Run(context =>
                {
                    var service = context.RequestServices.GetService<TestService>();
                    return context.Response.WriteAsync("Found:" + (service != null));
                });
            },
            services => services.AddTransient<IStartupFilter, RequestServicesFilter>());
            string result = await server.CreateClient().GetStringAsync("/path");
            Assert.Equal("Found:True", result);
        }


        [Fact]
        public async Task CanAccessLogger()
        {
            var server = TestServer.Create(app =>
            {
                app.Run(context =>
                {
                    var logger = app.ApplicationServices.GetRequiredService<ILogger<HttpContext>>();
                    return context.Response.WriteAsync("FoundLogger:" + (logger != null));
                });
            });

            string result = await server.CreateClient().GetStringAsync("/path");
            Assert.Equal("FoundLogger:True", result);
        }

        [Fact]
        public async Task CanAccessHttpContext()
        {
            TestServer server = TestServer.Create(app =>
            {
                app.Run(context =>
                {
                    var accessor = app.ApplicationServices.GetRequiredService<IHttpContextAccessor>();
                    return context.Response.WriteAsync("HasContext:"+(accessor.HttpContext != null));
                });
            });

            string result = await server.CreateClient().GetStringAsync("/path");
            Assert.Equal("HasContext:True", result);
        }

        public class ContextHolder
        {
            public ContextHolder(IHttpContextAccessor accessor)
            {
                Accessor = accessor;
            }

            public IHttpContextAccessor Accessor { get; set; }
        }

        [Fact]
        public async Task CanAddNewHostServices()
        {
            TestServer server = TestServer.Create(app =>
            {
                app.Run(context =>
                {
                    var accessor = app.ApplicationServices.GetRequiredService<ContextHolder>();
                    return context.Response.WriteAsync("HasContext:" + (accessor.Accessor.HttpContext != null));
                });
            },
            services => services.AddSingleton<ContextHolder>());

            string result = await server.CreateClient().GetStringAsync("/path");
            Assert.Equal("HasContext:True", result);
        }

        [Fact]
        public async Task CreateInvokesApp()
        {
            TestServer server = TestServer.Create(app =>
            {
                app.Run(context =>
                {
                    return context.Response.WriteAsync("CreateInvokesApp");
                });
            });

            string result = await server.CreateClient().GetStringAsync("/path");
            Assert.Equal("CreateInvokesApp", result);
        }

        [Fact]
        public void WebRootCanBeResolvedWhenNotInTheProjectJson()
        {
            TestServer server = TestServer.Create(app =>
            {
                var env = app.ApplicationServices.GetRequiredService<IHostingEnvironment>();
                Assert.Equal(Directory.GetCurrentDirectory(), env.WebRootPath);
            });
        }

        [Fact]
        public async Task DisposeStreamIgnored()
        {
            TestServer server = TestServer.Create(app =>
            {
                app.Run(async context =>
                {
                    await context.Response.WriteAsync("Response");
                    context.Response.Body.Dispose();
                });
            });

            HttpResponseMessage result = await server.CreateClient().GetAsync("/");
            Assert.Equal(HttpStatusCode.OK, result.StatusCode);
            Assert.Equal("Response", await result.Content.ReadAsStringAsync());
        }

        [Fact]
        public async Task DisposedServerThrows()
        {
            TestServer server = TestServer.Create(app =>
            {
                app.Run(async context =>
                {
                    await context.Response.WriteAsync("Response");
                    context.Response.Body.Dispose();
                });
            });

            HttpResponseMessage result = await server.CreateClient().GetAsync("/");
            Assert.Equal(HttpStatusCode.OK, result.StatusCode);
            server.Dispose();
            await Assert.ThrowsAsync<ObjectDisposedException>(() => server.CreateClient().GetAsync("/"));
        }

        [Fact]
        public void CancelAborts()
        {
            TestServer server = TestServer.Create(app =>
            {
                app.Run(context =>
                {
                    TaskCompletionSource<int> tcs = new TaskCompletionSource<int>();
                    tcs.SetCanceled();
                    return tcs.Task;
                });
            });

            Assert.Throws<AggregateException>(() => { string result = server.CreateClient().GetStringAsync("/path").Result; });
        }

        [Fact]
        public async Task CanCreateViaStartupType()
        {
            TestServer server = new TestServer(TestServer.CreateBuilder().UseStartup<TestStartup>());
            HttpResponseMessage result = await server.CreateClient().GetAsync("/");
            Assert.Equal(HttpStatusCode.OK, result.StatusCode);
            Assert.Equal("FoundService:True", await result.Content.ReadAsStringAsync());
        }

        [Fact]
        public async Task CanCreateViaStartupTypeAndSpecifyEnv()
        {
            TestServer server = new TestServer(TestServer.CreateBuilder()
                    .UseStartup<TestStartup>()
                    .UseEnvironment("Foo"));
            HttpResponseMessage result = await server.CreateClient().GetAsync("/");
            Assert.Equal(HttpStatusCode.OK, result.StatusCode);
            Assert.Equal("FoundFoo:False", await result.Content.ReadAsStringAsync());
        }

        public class Startup
        {
            public void Configure(IApplicationBuilder builder)
            {
                builder.Run(ctx => ctx.Response.WriteAsync("Startup"));
            }
        }

        public class SimpleService
        {
            public SimpleService()
            {
            }

            public string Message { get; set; }
        }

        public class TestStartup
        {
            public void ConfigureServices(IServiceCollection services)
            {
                services.AddSingleton<SimpleService>();
            }

            public void ConfigureFooServices(IServiceCollection services)
            {
            }

            public void Configure(IApplicationBuilder app)
            {
                app.Run(context =>
                {
                    var service = app.ApplicationServices.GetRequiredService<SimpleService>();
                    return context.Response.WriteAsync("FoundService:" + (service != null));
                });
            }

            public void ConfigureFoo(IApplicationBuilder app)
            {
                app.Run(context =>
                {
                    var service = app.ApplicationServices.GetService<SimpleService>();
                    return context.Response.WriteAsync("FoundFoo:" + (service != null));
                });
            }
        }
    }
}