// 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.Text;
using System.Text.Encodings.Web;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc.Abstractions;
using Microsoft.AspNetCore.Routing;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.ObjectPool;
using Xunit;

namespace Microsoft.AspNetCore.Mvc.Routing
{
    public class UrlHelperBaseTest
    {
        public static TheoryData GeneratePathFromRoute_HandlesLeadingAndTrailingSlashesData =>
            new TheoryData<string, string, string>
            {
                {  null, "", "/" },
                {  null, "/", "/"  },
                {  null, "Hello", "/Hello" },
                {  null, "/Hello", "/Hello" },
                { "/", "", "/" },
                { "/", "hello", "/hello" },
                { "/", "/hello", "/hello" },
                { "/hello", "", "/hello" },
                { "/hello/", "", "/hello/" },
                { "/hello", "/", "/hello/" },
                { "/hello/", "world", "/hello/world" },
                { "/hello/", "/world", "/hello/world" },
                { "/hello/", "/world 123", "/hello/world 123" },
                { "/hello/", "/world%20123", "/hello/world%20123" },
            };

        [Theory]
        [MemberData(nameof(GeneratePathFromRoute_HandlesLeadingAndTrailingSlashesData))]
        public void AppendPathAndFragment_HandlesLeadingAndTrailingSlashes(
            string appBase,
            string virtualPath,
            string expected)
        {
            // Arrange
            var services = CreateServices();
            var httpContext = CreateHttpContext(services, appBase, host: null, protocol: null);
            var builder = new StringBuilder();

            // Act
            UrlHelperBase.AppendPathAndFragment(builder, httpContext.Request.PathBase, virtualPath, string.Empty);

            // Assert
            Assert.Equal(expected, builder.ToString());
        }

        [Theory]
        [MemberData(nameof(GeneratePathFromRoute_HandlesLeadingAndTrailingSlashesData))]
        public void AppendPathAndFragment_AppendsFragments(
            string appBase,
            string virtualPath,
            string expected)
        {
            // Arrange
            var fragmentValue = "fragment-value";
            expected += $"#{fragmentValue}";
            var services = CreateServices();
            var httpContext = CreateHttpContext(services, appBase, host: null, protocol: null);
            var builder = new StringBuilder();

            // Act
            UrlHelperBase.AppendPathAndFragment(builder, httpContext.Request.PathBase, virtualPath, fragmentValue);

            // Assert
            Assert.Equal(expected, builder.ToString());
        }

        [Theory]
        [InlineData(null, null, null, "/", null, "/")]
        [InlineData(null, null, null, "/Hello", null, "/Hello")]
        [InlineData(null, null, null, "Hello", null, "/Hello")]
        [InlineData("/", null, null, "", null, "/")]
        [InlineData("/hello/", null, null, "/world", null, "/hello/world")]
        [InlineData("/hello/", "https", "myhost", "/world", "fragment-value", "https://myhost/hello/world#fragment-value")]
        public void GenerateUrl_FastAndSlowPathsReturnsExpected(
            string appBase,
            string protocol,
            string host,
            string virtualPath,
            string fragment,
            string expected)
        {
            // Arrange
            var services = CreateServices();
            var httpContext = CreateHttpContext(services, appBase, host, protocol);
            var actionContext = CreateActionContext(httpContext);
            var urlHelper = new TestUrlHelper(actionContext);

            // Act
            var url = urlHelper.GenerateUrl(protocol, host, virtualPath, fragment);

            // Assert
            Assert.Equal(expected, url);
        }

        private static IServiceProvider CreateServices()
        {
            var services = new ServiceCollection();
            services.AddOptions();
            services.AddLogging();
            services.AddRouting();
            services
                .AddSingleton<ObjectPoolProvider, DefaultObjectPoolProvider>()
                .AddSingleton<UrlEncoder>(UrlEncoder.Default);

            return services.BuildServiceProvider();
        }

        private static HttpContext CreateHttpContext(
           IServiceProvider services,
           string appRoot,
           string host,
           string protocol)
        {
            appRoot = string.IsNullOrEmpty(appRoot) ? string.Empty : appRoot;
            host = string.IsNullOrEmpty(host) ? "localhost" : host;

            var context = new DefaultHttpContext();
            context.RequestServices = services;
            context.Request.PathBase = new PathString(appRoot);
            context.Request.Host = new HostString(host);
            context.Request.Scheme = protocol;
            return context;
        }

        private static ActionContext CreateActionContext(HttpContext context)
        {
            return new ActionContext(context, new RouteData(), new ActionDescriptor());
        }

        private class TestUrlHelper : UrlHelperBase
        {
            public TestUrlHelper(ActionContext actionContext) :
                base(actionContext)
            {
            }

            public override string Action(UrlActionContext actionContext)
            {
                throw new NotImplementedException();
            }

            public override string RouteUrl(UrlRouteContext routeContext)
            {
                throw new NotImplementedException();
            }

            public new string GenerateUrl(
                string protocol,
                string host,
                string virtualPath,
                string fragment)
            {
                return base.GenerateUrl(
                    protocol,
                    host,
                    virtualPath,
                    fragment);
            }
        }
    }
}