// Copyright (c) .NET Foundation. All rights reserved. See License.txt in the project root for license information.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Security.Claims;
using System.Text;
using System.Threading.Tasks;
using Microsoft.AspNet.Authentication.OAuth;
using Microsoft.AspNet.Builder;
using Microsoft.AspNet.DataProtection;
using Microsoft.AspNet.Http;
using Microsoft.AspNet.Http.Authentication;
using Microsoft.AspNet.TestHost;
using Microsoft.Framework.DependencyInjection;
using Microsoft.Framework.WebEncoders;
using Newtonsoft.Json;
using Xunit;

namespace Microsoft.AspNet.Authentication.Google
{
    public class GoogleMiddlewareTests
    {
        [Fact]
        public async Task ChallengeWillTriggerRedirection()
        {
            var server = CreateServer(options =>
            {
                options.ClientId = "Test Id";
                options.ClientSecret = "Test Secret";
            });
            var transaction = await server.SendAsync("https://example.com/challenge");
            Assert.Equal(HttpStatusCode.Redirect, transaction.Response.StatusCode);
            var location = transaction.Response.Headers.Location.ToString();
            Assert.Contains("https://accounts.google.com/o/oauth2/auth?response_type=code", location);
            Assert.Contains("&client_id=", location);
            Assert.Contains("&redirect_uri=", location);
            Assert.Contains("&scope=", location);
            Assert.Contains("&state=", location);

            Assert.DoesNotContain("access_type=", location);
            Assert.DoesNotContain("approval_prompt=", location);
            Assert.DoesNotContain("login_hint=", location);
        }

        [Fact]
        public async Task SignInThrows()
        {
            var server = CreateServer(options =>
            {
                options.ClientId = "Test Id";
                options.ClientSecret = "Test Secret";
            });
            var transaction = await server.SendAsync("https://example.com/signIn");
            Assert.Equal(HttpStatusCode.OK, transaction.Response.StatusCode);
        }

        [Fact]
        public async Task SignOutThrows()
        {
            var server = CreateServer(options =>
            {
                options.ClientId = "Test Id";
                options.ClientSecret = "Test Secret";
            });
            var transaction = await server.SendAsync("https://example.com/signOut");
            Assert.Equal(HttpStatusCode.OK, transaction.Response.StatusCode);
        }

        [Fact]
        public async Task ForbidThrows()
        {
            var server = CreateServer(options =>
            {
                options.ClientId = "Test Id";
                options.ClientSecret = "Test Secret";
            });
            var transaction = await server.SendAsync("https://example.com/signOut");
            Assert.Equal(HttpStatusCode.OK, transaction.Response.StatusCode);
        }

        [Fact]
        public async Task Challenge401WillTriggerRedirection()
        {
            var server = CreateServer(options =>
            {
                options.ClientId = "Test Id";
                options.ClientSecret = "Test Secret";
                options.AutomaticAuthentication = true;
            });
            var transaction = await server.SendAsync("https://example.com/401");
            Assert.Equal(HttpStatusCode.Redirect, transaction.Response.StatusCode);
            var location = transaction.Response.Headers.Location.ToString();
            Assert.Contains("https://accounts.google.com/o/oauth2/auth?response_type=code", location);
            Assert.Contains("&client_id=", location);
            Assert.Contains("&redirect_uri=", location);
            Assert.Contains("&scope=", location);
            Assert.Contains("&state=", location);
        }

        [Fact]
        public async Task ChallengeWillSetCorrelationCookie()
        {
            var server = CreateServer(options =>
            {
                options.ClientId = "Test Id";
                options.ClientSecret = "Test Secret";
            });
            var transaction = await server.SendAsync("https://example.com/challenge");
            Assert.Contains(".AspNet.Correlation.Google=", transaction.SetCookie.Single());
        }

        [Fact]
        public async Task Challenge401WillSetCorrelationCookie()
        {
            var server = CreateServer(options =>
            {
                options.ClientId = "Test Id";
                options.ClientSecret = "Test Secret";
                options.AutomaticAuthentication = true;
            });
            var transaction = await server.SendAsync("https://example.com/401");
            Assert.Contains(".AspNet.Correlation.Google=", transaction.SetCookie.Single());
        }

        [Fact]
        public async Task ChallengeWillSetDefaultScope()
        {
            var server = CreateServer(options =>
            {
                options.ClientId = "Test Id";
                options.ClientSecret = "Test Secret";
            });
            var transaction = await server.SendAsync("https://example.com/challenge");
            Assert.Equal(HttpStatusCode.Redirect, transaction.Response.StatusCode);
            var query = transaction.Response.Headers.Location.Query;
            Assert.Contains("&scope=" + UrlEncoder.Default.UrlEncode("openid profile email"), query);
        }

        [Fact]
        public async Task Challenge401WillSetDefaultScope()
        {
            var server = CreateServer(options =>
            {
                options.ClientId = "Test Id";
                options.ClientSecret = "Test Secret";
                options.AutomaticAuthentication = true;
            });
            var transaction = await server.SendAsync("https://example.com/401");
            Assert.Equal(HttpStatusCode.Redirect, transaction.Response.StatusCode);
            var query = transaction.Response.Headers.Location.Query;
            Assert.Contains("&scope=" + UrlEncoder.Default.UrlEncode("openid profile email"), query);
        }

        [Fact]
        public async Task ChallengeWillUseAuthenticationPropertiesAsParameters()
        {
            var server = CreateServer(options =>
            {
                options.ClientId = "Test Id";
                options.ClientSecret = "Test Secret";
                options.AutomaticAuthentication = true;
            },
            context =>
                {
                    var req = context.Request;
                    var res = context.Response;
                    if (req.Path == new PathString("/challenge2"))
                    {
                        return context.Authentication.ChallengeAsync("Google", new AuthenticationProperties(
                            new Dictionary<string, string>()
                            {
                                { "scope", "https://www.googleapis.com/auth/plus.login" },
                                { "access_type", "offline" },
                                { "approval_prompt", "force" },
                                { "login_hint", "test@example.com" }
                            }));
                    }

                    return Task.FromResult<object>(null);
                });
            var transaction = await server.SendAsync("https://example.com/challenge2");
            Assert.Equal(HttpStatusCode.Redirect, transaction.Response.StatusCode);
            var query = transaction.Response.Headers.Location.Query;
            Assert.Contains("scope=" + UrlEncoder.Default.UrlEncode("https://www.googleapis.com/auth/plus.login"), query);
            Assert.Contains("access_type=offline", query);
            Assert.Contains("approval_prompt=force", query);
            Assert.Contains("login_hint=" + UrlEncoder.Default.UrlEncode("test@example.com"), query);
        }

        [Fact]
        public async Task ChallengeWillTriggerApplyRedirectEvent()
        {
            var server = CreateServer(options =>
            {
                options.ClientId = "Test Id";
                options.ClientSecret = "Test Secret";
                options.Events = new OAuthEvents
                {
                    OnApplyRedirect = context =>
                    {
                        context.Response.Redirect(context.RedirectUri + "&custom=test");
                        return Task.FromResult(0);
                    }
                };
            });
            var transaction = await server.SendAsync("https://example.com/challenge");
            Assert.Equal(HttpStatusCode.Redirect, transaction.Response.StatusCode);
            var query = transaction.Response.Headers.Location.Query;
            Assert.Contains("custom=test", query);
        }

        [Fact]
        public async Task ReplyPathWithoutStateQueryStringWillBeRejected()
        {
            var server = CreateServer(options =>
            {
                options.ClientId = "Test Id";
                options.ClientSecret = "Test Secret";
            });
            var transaction = await server.SendAsync("https://example.com/signin-google?code=TestCode");
            Assert.Equal(HttpStatusCode.InternalServerError, transaction.Response.StatusCode);
        }

        [Theory]
        [InlineData(null)]
        [InlineData("CustomIssuer")]
        public async Task ReplyPathWillAuthenticateValidAuthorizeCodeAndState(string claimsIssuer)
        {
            var stateFormat = new PropertiesDataFormat(new EphemeralDataProtectionProvider().CreateProtector("GoogleTest"));
            var server = CreateServer(options =>
            {
                options.ClientId = "Test Id";
                options.ClientSecret = "Test Secret";
                options.StateDataFormat = stateFormat;
                options.ClaimsIssuer = claimsIssuer;
                options.BackchannelHttpHandler = new TestHttpMessageHandler
                {
                    Sender = req =>
                    {
                        if (req.RequestUri.AbsoluteUri == "https://accounts.google.com/o/oauth2/token")
                        {
                            return ReturnJsonResponse(new
                            {
                                access_token = "Test Access Token",
                                expires_in = 3600,
                                token_type = "Bearer"
                            });
                        }
                        else if (req.RequestUri.GetLeftPart(UriPartial.Path) == "https://www.googleapis.com/plus/v1/people/me")
                        {
                            return ReturnJsonResponse(new
                            {
                                id = "Test User ID",
                                displayName = "Test Name",
                                name = new
                                {
                                    familyName = "Test Family Name",
                                    givenName = "Test Given Name"
                                },
                                url = "Profile link",
                                emails = new[]
                                {
                                    new
                                    {
                                        value = "Test email",
                                        type = "account"
                                    }
                                }
                            });
                        }

                        return null;
                    }
                };
            });
            var properties = new AuthenticationProperties();
            var correlationKey = ".AspNet.Correlation.Google";
            var correlationValue = "TestCorrelationId";
            properties.Items.Add(correlationKey, correlationValue);
            properties.RedirectUri = "/me";
            var state = stateFormat.Protect(properties);
            var transaction = await server.SendAsync(
                "https://example.com/signin-google?code=TestCode&state=" + UrlEncoder.Default.UrlEncode(state),
                correlationKey + "=" + correlationValue);
            Assert.Equal(HttpStatusCode.Redirect, transaction.Response.StatusCode);
            Assert.Equal("/me", transaction.Response.Headers.GetValues("Location").First());
            Assert.Equal(2, transaction.SetCookie.Count);
            Assert.Contains(correlationKey, transaction.SetCookie[0]);
            Assert.Contains(".AspNet." + TestExtensions.CookieAuthenticationScheme, transaction.SetCookie[1]);

            var authCookie = transaction.AuthenticationCookieValue;
            transaction = await server.SendAsync("https://example.com/me", authCookie);
            Assert.Equal(HttpStatusCode.OK, transaction.Response.StatusCode);
            var expectedIssuer = claimsIssuer ?? GoogleDefaults.AuthenticationScheme;
            Assert.Equal("Test Name", transaction.FindClaimValue(ClaimTypes.Name, expectedIssuer));
            Assert.Equal("Test User ID", transaction.FindClaimValue(ClaimTypes.NameIdentifier, expectedIssuer));
            Assert.Equal("Test Given Name", transaction.FindClaimValue(ClaimTypes.GivenName, expectedIssuer));
            Assert.Equal("Test Family Name", transaction.FindClaimValue(ClaimTypes.Surname, expectedIssuer));
            Assert.Equal("Test email", transaction.FindClaimValue(ClaimTypes.Email, expectedIssuer));

            // Ensure claims transformation 
            Assert.Equal("yup", transaction.FindClaimValue("xform"));
        }

        [Fact]
        public async Task ReplyPathWillRejectIfCodeIsInvalid()
        {
            var stateFormat = new PropertiesDataFormat(new EphemeralDataProtectionProvider().CreateProtector("GoogleTest"));
            var server = CreateServer(options =>
            {
                options.ClientId = "Test Id";
                options.ClientSecret = "Test Secret";
                options.StateDataFormat = stateFormat;
                options.BackchannelHttpHandler = new TestHttpMessageHandler
                {
                    Sender = req =>
                    {
                        return new HttpResponseMessage(HttpStatusCode.BadRequest);
                    }
                };
            });
            var properties = new AuthenticationProperties();
            var correlationKey = ".AspNet.Correlation.Google";
            var correlationValue = "TestCorrelationId";
            properties.Items.Add(correlationKey, correlationValue);
            properties.RedirectUri = "/me";
            var state = stateFormat.Protect(properties);
            var transaction = await server.SendAsync(
                "https://example.com/signin-google?code=TestCode&state=" + UrlEncoder.Default.UrlEncode(state),
                correlationKey + "=" + correlationValue);
            Assert.Equal(HttpStatusCode.Redirect, transaction.Response.StatusCode);
            Assert.Contains("error=access_denied", transaction.Response.Headers.Location.ToString());
        }

        [Fact]
        public async Task ReplyPathWillRejectIfAccessTokenIsMissing()
        {
            var stateFormat = new PropertiesDataFormat(new EphemeralDataProtectionProvider().CreateProtector("GoogleTest"));
            var server = CreateServer(options =>
            {
                options.ClientId = "Test Id";
                options.ClientSecret = "Test Secret";
                options.StateDataFormat = stateFormat;
                options.BackchannelHttpHandler = new TestHttpMessageHandler
                {
                    Sender = req =>
                    {
                        return ReturnJsonResponse(new object());
                    }
                };
            });
            var properties = new AuthenticationProperties();
            var correlationKey = ".AspNet.Correlation.Google";
            var correlationValue = "TestCorrelationId";
            properties.Items.Add(correlationKey, correlationValue);
            properties.RedirectUri = "/me";
            var state = stateFormat.Protect(properties);
            var transaction = await server.SendAsync(
                "https://example.com/signin-google?code=TestCode&state=" + UrlEncoder.Default.UrlEncode(state),
                correlationKey + "=" + correlationValue);
            Assert.Equal(HttpStatusCode.Redirect, transaction.Response.StatusCode);
            Assert.Contains("error=access_denied", transaction.Response.Headers.Location.ToString());
        }

        [Fact]
        public async Task AuthenticatedEventCanGetRefreshToken()
        {
            var stateFormat = new PropertiesDataFormat(new EphemeralDataProtectionProvider().CreateProtector("GoogleTest"));
            var server = CreateServer(options =>
            {
                options.ClientId = "Test Id";
                options.ClientSecret = "Test Secret";
                options.StateDataFormat = stateFormat;
                options.BackchannelHttpHandler = new TestHttpMessageHandler
                {
                    Sender = req =>
                    {
                        if (req.RequestUri.AbsoluteUri == "https://accounts.google.com/o/oauth2/token")
                        {
                            return ReturnJsonResponse(new
                            {
                                access_token = "Test Access Token",
                                expires_in = 3600,
                                token_type = "Bearer",
                                refresh_token = "Test Refresh Token"
                            });
                        }
                        else if (req.RequestUri.GetLeftPart(UriPartial.Path) == "https://www.googleapis.com/plus/v1/people/me")
                        {
                            return ReturnJsonResponse(new
                            {
                                id = "Test User ID",
                                displayName = "Test Name",
                                name = new
                                {
                                    familyName = "Test Family Name",
                                    givenName = "Test Given Name"
                                },
                                url = "Profile link",
                                emails = new[]
                                    {
                                        new
                                        {
                                            value = "Test email",
                                            type = "account"
                                        }
                                    }
                            });
                        }

                        return null;
                    }
                };
                options.Events = new OAuthEvents
                {
                    OnAuthenticated = context =>
                    {
                        var refreshToken = context.RefreshToken;
                        context.Principal.AddIdentity(new ClaimsIdentity(new Claim[] { new Claim("RefreshToken", refreshToken, ClaimValueTypes.String, "Google") }, "Google"));
                        return Task.FromResult<object>(null);
                    }
                };
            });
            var properties = new AuthenticationProperties();
            var correlationKey = ".AspNet.Correlation.Google";
            var correlationValue = "TestCorrelationId";
            properties.Items.Add(correlationKey, correlationValue);
            properties.RedirectUri = "/me";
            var state = stateFormat.Protect(properties);
            var transaction = await server.SendAsync(
                "https://example.com/signin-google?code=TestCode&state=" + UrlEncoder.Default.UrlEncode(state),
                correlationKey + "=" + correlationValue);
            Assert.Equal(HttpStatusCode.Redirect, transaction.Response.StatusCode);
            Assert.Equal("/me", transaction.Response.Headers.GetValues("Location").First());
            Assert.Equal(2, transaction.SetCookie.Count);
            Assert.Contains(correlationKey, transaction.SetCookie[0]);
            Assert.Contains(".AspNet." + TestExtensions.CookieAuthenticationScheme, transaction.SetCookie[1]);

            var authCookie = transaction.AuthenticationCookieValue;
            transaction = await server.SendAsync("https://example.com/me", authCookie);
            Assert.Equal(HttpStatusCode.OK, transaction.Response.StatusCode);
            Assert.Equal("Test Refresh Token", transaction.FindClaimValue("RefreshToken"));
        }

        [Fact]
        public async Task ValidateAuthenticatedContext()
        {
            var stateFormat = new PropertiesDataFormat(new EphemeralDataProtectionProvider().CreateProtector("GoogleTest"));
            var server = CreateServer(options =>
            {
                options.ClientId = "Test Id";
                options.ClientSecret = "Test Secret";
                options.StateDataFormat = stateFormat;
                options.AccessType = "offline";
                options.Events = new OAuthEvents()
                {
                    OnAuthenticated = context =>
                    {
                        Assert.NotNull(context.User);
                        Assert.Equal(context.AccessToken, "Test Access Token");
                        Assert.Equal(context.RefreshToken, "Test Refresh Token");
                        Assert.Equal(context.ExpiresIn, TimeSpan.FromSeconds(3600));
                        Assert.Equal(GoogleHelper.GetEmail(context.User), "Test email");
                        Assert.Equal(GoogleHelper.GetId(context.User), "Test User ID");
                        Assert.Equal(GoogleHelper.GetName(context.User), "Test Name");
                        Assert.Equal(GoogleHelper.GetFamilyName(context.User), "Test Family Name");
                        Assert.Equal(GoogleHelper.GetGivenName(context.User), "Test Given Name");
                        return Task.FromResult(0);
                    }
                };
                options.BackchannelHttpHandler = new TestHttpMessageHandler
                {
                    Sender = req =>
                    {
                        if (req.RequestUri.AbsoluteUri == "https://accounts.google.com/o/oauth2/token")
                        {
                            return ReturnJsonResponse(new
                            {
                                access_token = "Test Access Token",
                                expires_in = 3600,
                                token_type = "Bearer",
                                refresh_token = "Test Refresh Token"
                            });
                        }
                        else if (req.RequestUri.GetLeftPart(UriPartial.Path) == "https://www.googleapis.com/plus/v1/people/me")
                        {
                            return ReturnJsonResponse(new
                            {
                                id = "Test User ID",
                                displayName = "Test Name",
                                name = new
                                {
                                    familyName = "Test Family Name",
                                    givenName = "Test Given Name"
                                },
                                url = "Profile link",
                                emails = new[]
                                    {
                                        new
                                        {
                                            value = "Test email",
                                            type = "account"
                                        }
                                    }
                            });
                        }

                        return null;
                    }
                };
            });

            var properties = new AuthenticationProperties();
            var correlationKey = ".AspNet.Correlation.Google";
            var correlationValue = "TestCorrelationId";
            properties.Items.Add(correlationKey, correlationValue);
            properties.RedirectUri = "/foo";
            var state = stateFormat.Protect(properties);

            //Post a message to the Google middleware
            var transaction = await server.SendAsync(
                "https://example.com/signin-google?code=TestCode&state=" + UrlEncoder.Default.UrlEncode(state),
                correlationKey + "=" + correlationValue);

            Assert.Equal(HttpStatusCode.Redirect, transaction.Response.StatusCode);
            Assert.Equal("/foo", transaction.Response.Headers.GetValues("Location").First());
        }


        private static HttpResponseMessage ReturnJsonResponse(object content)
        {
            var res = new HttpResponseMessage(HttpStatusCode.OK);
            var text = JsonConvert.SerializeObject(content);
            res.Content = new StringContent(text, Encoding.UTF8, "application/json");
            return res;
        }

        private static TestServer CreateServer(Action<GoogleOptions> configureOptions, Func<HttpContext, Task> testpath = null)
        {
            return TestServer.Create(app =>
            {
                app.UseCookieAuthentication(options =>
                {
                    options.AuthenticationScheme = TestExtensions.CookieAuthenticationScheme;
                    options.AutomaticAuthentication = true;
                });
                app.UseGoogleAuthentication(configureOptions);
                app.UseClaimsTransformation(p =>
                {
                    var id = new ClaimsIdentity("xform");
                    id.AddClaim(new Claim("xform", "yup"));
                    p.AddIdentity(id);
                    return Task.FromResult(p);
                });
                app.Use(async (context, next) =>
                {
                    var req = context.Request;
                    var res = context.Response;
                    if (req.Path == new PathString("/challenge"))
                    {
                        await context.Authentication.ChallengeAsync("Google");
                    }
                    else if (req.Path == new PathString("/me"))
                    {
                        res.Describe(context.User);
                    }
                    else if (req.Path == new PathString("/unauthorized"))
                    {
                        // Simulate Authorization failure 
                        var result = await context.Authentication.AuthenticateAsync("Google");
                        await context.Authentication.ChallengeAsync("Google");
                    }
                    else if (req.Path == new PathString("/unauthorizedAuto"))
                    {
                        var result = await context.Authentication.AuthenticateAsync("Google");
                        await context.Authentication.ChallengeAsync();
                    }
                    else if (req.Path == new PathString("/401"))
                    {
                        res.StatusCode = 401;
                    }
                    else if (req.Path == new PathString("/signIn"))
                    {
                        await Assert.ThrowsAsync<NotSupportedException>(() => context.Authentication.SignInAsync("Google", new ClaimsPrincipal()));
                    }
                    else if (req.Path == new PathString("/signOut"))
                    {
                        await Assert.ThrowsAsync<NotSupportedException>(() => context.Authentication.SignOutAsync("Google"));
                    }
                    else if (req.Path == new PathString("/forbid"))
                    {
                        await Assert.ThrowsAsync<NotSupportedException>(() => context.Authentication.ForbidAsync("Google"));
                    }
                    else if (testpath != null)
                    {
                        await testpath(context);
                    }
                    else
                    {
                        await next();
                    }
                });
            },
            services =>
            {
                services.AddAuthentication(options => options.SignInScheme = TestExtensions.CookieAuthenticationScheme);
            });
        }
    }
}