// 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.Threading.Tasks;
using Microsoft.AspNetCore.Builder.Internal;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Routing;
using Microsoft.Extensions.DependencyInjection;
using Moq;
using Xunit;

namespace Microsoft.AspNetCore.Builder
{
    public class RoutingBuilderExtensionsTest
    {
        [Fact]
        public void UseRouter_IRouter_ThrowsWithoutCallingAddRouting()
        {
            // Arrange
            var app = new ApplicationBuilder(Mock.Of<IServiceProvider>());

            // Act
            var ex = Assert.Throws<InvalidOperationException>(() => app.UseRouter(Mock.Of<IRouter>()));

            // Assert
            Assert.Equal(
                "Unable to find the required services. " +
                "Please add all the required services by calling 'IServiceCollection.AddRouting' " +
                "inside the call to 'ConfigureServices(...)' in the application startup code.",
                ex.Message);
        }

        [Fact]
        public void UseRouter_Action_ThrowsWithoutCallingAddRouting()
        {
            // Arrange
            var app = new ApplicationBuilder(Mock.Of<IServiceProvider>());

            // Act
            var ex = Assert.Throws<InvalidOperationException>(() => app.UseRouter(b => { }));

            // Assert
            Assert.Equal(
                "Unable to find the required services. " +
                "Please add all the required services by calling 'IServiceCollection.AddRouting' " +
                "inside the call to 'ConfigureServices(...)' in the application startup code.",
                ex.Message);
        }

        [Fact]
        public async Task UseRouter_IRouter_CallsRoute()
        {
            // Arrange
            var services = CreateServices();

            var app = new ApplicationBuilder(services);

            var router = new Mock<IRouter>(MockBehavior.Strict);
            router
                .Setup(r => r.RouteAsync(It.IsAny<RouteContext>()))
                .Returns(Task.FromResult(0))
                .Verifiable();

            app.UseRouter(router.Object);

            var appFunc = app.Build();

            // Act
            await appFunc(new DefaultHttpContext());

            // Assert
            router.Verify();
        }

        [Fact]
        public async Task UseRouter_Action_CallsRoute()
        {
            // Arrange
            var services = CreateServices();

            var app = new ApplicationBuilder(services);

            var router = new Mock<IRouter>(MockBehavior.Strict);
            router
                .Setup(r => r.RouteAsync(It.IsAny<RouteContext>()))
                .Returns(Task.FromResult(0))
                .Verifiable();

            app.UseRouter(b =>
            {
                b.Routes.Add(router.Object);
            });

            var appFunc = app.Build();

            // Act
            await appFunc(new DefaultHttpContext());

            // Assert
            router.Verify();
        }

        private IServiceProvider CreateServices()
        {
            var services = new ServiceCollection();

            services.AddLogging();
            services.AddOptions();
            services.AddRouting();

            return services.BuildServiceProvider();
        }
    }
}