using Microsoft.Extensions.Configuration;
using Microsoft.IdentityModel.Tokens;

using MongoDB.Entities;

using PrivaPub.ClientModels;
using PrivaPub.Models.Group;
using PrivaPub.Models.User;
using PrivaPub.Tests.Support;
using PrivaPub.Tests.Support.Host;

using System.IdentityModel.Tokens.Jwt;
using System.Net;
using System.Security.Claims;
using System.Text;
using System.Text.Json.Nodes;

using GroupEntity = PrivaPub.Models.Group.Group;

namespace PrivaPub.Tests.Http
{
	[Trait("Category", "Integration")]
	public sealed class ClientApiAccountsTests : IAsyncLifetime
	{
		const string NewPassword = "Other-Pass-2!";

		PrivaPubHost _host;

		public async ValueTask InitializeAsync()
		{
			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
			_host = await PrivaPubHost.Shared();
		}

		public ValueTask DisposeAsync() => ValueTask.CompletedTask;

		static string Name(string prefix) => $"{prefix}{Guid.NewGuid():N}"[..20];

		async Task<HttpResponseMessage> LogIn(string userName, string password)
		{
			using var client = _host.Client();
			return await client.PostJson("/clientapi/user/login", new { userName, password });
		}

		async Task<HttpStatusCode> Settings(string jwt)
		{
			using var client = _host.As(jwt);
			return (await client.GetAsync("/clientapi/user/settings", TestContext.Current.CancellationToken)).StatusCode;
		}

		static async Task<string> Message(HttpResponseMessage response)
		{
			var body = await response.JsonBody();
			return body["errorMessage"]?.GetValue<string>() ?? body["title"]?.GetValue<string>();
		}

		string Jwt(string rootId, string userName, DateTime expires, string key = default)
		{
			var configuration = _host.Get<IConfiguration>();
			var signing = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(key ?? configuration["AppConfiguration:Jwt:Key"]!));
			var token = new JwtSecurityToken(configuration["AppConfiguration:Jwt:Issuer"], configuration["AppConfiguration:Jwt:Audience"],
				new[] { new Claim(ClaimTypes.UserData, rootId), new Claim(ClaimTypes.Name, userName), new Claim(Policies.IsUser, "true") },
				notBefore: expires.AddHours(-1), expires: expires, signingCredentials: new SigningCredentials(signing, SecurityAlgorithms.HmacSha512));
			return new JwtSecurityTokenHandler().WriteToken(token);
		}

		[Fact]
		public async Task Signing_up_answers_a_token_for_the_new_root()
		{
			var userName = Name("Signup");
			using var client = _host.Client();

			var response = await client.PostJson("/clientapi/user/signup", new { userName, password = Accounts.Password });

			Assert.Equal(HttpStatusCode.OK, response.StatusCode);
			var jwt = await response.JsonBody();
			Assert.Equal(userName.ToLowerInvariant(), jwt["username"]!.GetValue<string>());
			Assert.Equal(new[] { Policies.IsUser }, jwt["policies"]!.AsArray().Select(p => p!.GetValue<string>()));
			Assert.Equal(HttpStatusCode.OK, await Settings(jwt["token"]!.GetValue<string>()));
			var stored = await DB.Default.Find<RootUser>().MatchID(jwt["userId"]!.GetValue<string>()).ExecuteFirstAsync(TestContext.Current.CancellationToken);
			Assert.NotEqual(Accounts.Password, stored.HashedPassword);
		}

		[Fact]
		public async Task A_taken_username_is_refused_whatever_its_case()
		{
			var root = await _host.SignUp("taken");
			using var client = _host.Client();

			var again = await client.PostJson("/clientapi/user/signup", new { userName = root.UserName, password = Accounts.Password });
			var shouted = await client.PostJson("/clientapi/user/signup", new { userName = root.UserName.ToUpperInvariant(), password = Accounts.Password });

			Assert.Equal(HttpStatusCode.BadRequest, again.StatusCode);
			Assert.Contains("already taken", await Message(again));
			Assert.Equal(HttpStatusCode.BadRequest, shouted.StatusCode);
			Assert.Equal(1, await DB.Default.CountAsync<RootUser>(u => u.UserName == root.UserName, TestContext.Current.CancellationToken));
		}

		public static TheoryData<string> InvalidSignUps() => new()
		{
			"{}",
			"{\"userName\":\"ab\",\"password\":\"Test-Pass-1!\"}",
			"{\"userName\":\"has space\",\"password\":\"Test-Pass-1!\"}",
			"{\"userName\":\"validname\",\"password\":\"short\"}",
			"{\"userName\":\"validname\",\"password\":\"nouppercase1\"}",
			"{\"userName\":\"validname\",\"password\":\"Has Space1\"}",
			"{\"userName\":\"validname\",\"password\":\"Test-Pass-1!\",\"lightThemeIndexColour\":400}",
			"{\"userName\":\"" + new string('a', 40) + "\",\"password\":\"Test-Pass-1!\"}",
			"not json"
		};

		[Theory]
		[MemberData(nameof(InvalidSignUps))]
		public async Task An_invalid_sign_up_answers_400_with_a_message(string body)
		{
			using var client = _host.Client();

			var response = await client.PostAsync("/clientapi/user/signup", new StringContent(body, Encoding.UTF8, "application/json"), TestContext.Current.CancellationToken);

			Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
			Assert.False(string.IsNullOrEmpty(await Message(response)));
		}

		[Fact]
		public async Task Logging_in_and_out()
		{
			var root = await _host.SignUp("login");

			var ok = await LogIn(root.UserName, root.Password);
			var wrong = await LogIn(root.UserName, "Wrong-Pass-1!");
			var unknown = await LogIn(Name("nobody"), root.Password);
			using var signedIn = _host.As((await ok.JsonBody())["token"]!.GetValue<string>());
			var logout = await signedIn.GetAsync("/clientapi/user/logout", TestContext.Current.CancellationToken);
			using var anonymous = _host.Client();
			var anonymousLogout = await anonymous.GetAsync("/clientapi/user/logout", TestContext.Current.CancellationToken);

			Assert.Equal(HttpStatusCode.OK, ok.StatusCode);
			Assert.Equal(root.Id, (await ok.JsonBody())["userId"]!.GetValue<string>());
			Assert.Equal(HttpStatusCode.BadRequest, wrong.StatusCode);
			Assert.Equal("Wrong password.", await Message(wrong));
			Assert.Equal(HttpStatusCode.BadRequest, unknown.StatusCode);
			Assert.Equal(HttpStatusCode.OK, logout.StatusCode);
			Assert.Equal(HttpStatusCode.Unauthorized, anonymousLogout.StatusCode);
		}

		[Fact]
		public async Task Update_sets_the_recovery_email_and_refuses_one_in_use()
		{
			var root = await _host.SignUp("email");
			var other = await _host.SignUp("email");
			var email = $"{Guid.NewGuid():N}@example.test";
			using var client = _host.As(root.Jwt);
			using var otherClient = _host.As(other.Jwt);

			var set = await client.PostJson("/clientapi/user/update", new { email });
			var taken = await otherClient.PostJson("/clientapi/user/update", new { email });
			var invalid = await otherClient.PostJson("/clientapi/user/update", new { email = "not an email" });

			Assert.Equal(HttpStatusCode.OK, set.StatusCode);
			Assert.Equal(email, (await DB.Default.Find<RootUser>().MatchID(root.Id).ExecuteFirstAsync(TestContext.Current.CancellationToken)).Email);
			Assert.Equal(HttpStatusCode.BadRequest, taken.StatusCode);
			Assert.Contains("already taken", await Message(taken));
			Assert.Equal(HttpStatusCode.BadRequest, invalid.StatusCode);
			Assert.Null((await DB.Default.Find<RootUser>().MatchID(other.Id).ExecuteFirstAsync(TestContext.Current.CancellationToken)).Email);
		}

		[Fact]
		public async Task Settings_round_trip()
		{
			var root = await _host.SignUp("settings");
			using var client = _host.As(root.Jwt);

			var updated = await client.PostJson("/clientapi/user/update/settings", new
			{
				languageCode = "it",
				lightThemeIndexColour = 100,
				darkThemeIndexColour = 200,
				iconsThemeIndexColour = 50,
				themeIsDarkMode = true,
				themeIsDarkGray = true
			});
			var settings = await (await client.GetAsync("/clientapi/user/settings", TestContext.Current.CancellationToken)).JsonBody();
			var unsupported = await client.PostJson("/clientapi/user/update/settings", new { languageCode = "xx" });
			var outOfRange = await client.PostJson("/clientapi/user/update/settings", new { languageCode = "en", lightThemeIndexColour = 360 });

			Assert.Equal(HttpStatusCode.OK, updated.StatusCode);
			Assert.Equal("it", settings["languageCode"]!.GetValue<string>());
			Assert.Equal(100, settings["lightThemeIndexColour"]!.GetValue<int>());
			Assert.Equal(200, settings["darkThemeIndexColour"]!.GetValue<int>());
			Assert.Equal(50, settings["iconsThemeIndexColour"]!.GetValue<int>());
			Assert.True(settings["themeIsDarkMode"]!.GetValue<bool>());
			Assert.True(settings["themeIsDarkGray"]!.GetValue<bool>());
			Assert.Equal(HttpStatusCode.BadRequest, unsupported.StatusCode);
			Assert.Contains("unsupported", await Message(unsupported));
			Assert.Equal(HttpStatusCode.BadRequest, outOfRange.StatusCode);
			Assert.Equal("it", (await DB.Default.Find<RootUser>().MatchID(root.Id).ExecuteFirstAsync(TestContext.Current.CancellationToken)).Settings.LanguageCode);
		}

		[Fact]
		public async Task Changing_the_password_needs_the_old_one()
		{
			var root = await _host.SignUp("password");
			using var client = _host.As(root.Jwt);

			var wrongOld = await client.PostJson("/clientapi/user/update/password", new { oldPassword = "Wrong-Pass-1!", newPassword = NewPassword, repeatedPassword = NewPassword });
			var mismatch = await client.PostJson("/clientapi/user/update/password", new { oldPassword = root.Password, newPassword = NewPassword, repeatedPassword = "Something-3!" });
			var weak = await client.PostJson("/clientapi/user/update/password", new { oldPassword = root.Password, newPassword = "weak", repeatedPassword = "weak" });
			var changed = await client.PostJson("/clientapi/user/update/password", new { oldPassword = root.Password, newPassword = NewPassword, repeatedPassword = NewPassword });

			Assert.Equal(HttpStatusCode.BadRequest, wrongOld.StatusCode);
			Assert.Equal("Wrong password.", await Message(wrongOld));
			Assert.Equal(HttpStatusCode.BadRequest, mismatch.StatusCode);
			Assert.Equal(HttpStatusCode.BadRequest, weak.StatusCode);
			Assert.Equal(HttpStatusCode.OK, changed.StatusCode);
			Assert.Equal(HttpStatusCode.BadRequest, (await LogIn(root.UserName, root.Password)).StatusCode);
			Assert.Equal(HttpStatusCode.OK, (await LogIn(root.UserName, NewPassword)).StatusCode);
		}

		[Fact]
		public async Task An_invitation_signs_up_a_root_with_a_persona_in_the_group()
		{
			var owner = await _host.Persona(await _host.SignUp("owner"), "owner");
			var group = await _host.Group(owner, community: false, password: "door-Pass-1");
			var invitationCode = group["invitationCode"]!.GetValue<string>();
			var userName = Name("invited");
			var avatarUserName = Name("guest");
			using var client = _host.Client();

			var wrongPassword = await client.PostJson("/clientapi/user/invitation/signup", new { userName, password = Accounts.Password, invitationCode, invitationPassword = "nope", avatarUserName });
			var wrongCode = await client.PostJson("/clientapi/user/invitation/signup", new { userName, password = Accounts.Password, invitationCode = $"{Guid.NewGuid():N}{Guid.NewGuid():N}", invitationPassword = "door-Pass-1", avatarUserName });
			var response = await client.PostJson("/clientapi/user/invitation/signup", new { userName, password = Accounts.Password, invitationCode, invitationPassword = "door-Pass-1", avatarUserName, avatarName = "Guest" });

			Assert.Equal(HttpStatusCode.NotAcceptable, wrongPassword.StatusCode);
			Assert.Equal(HttpStatusCode.NotFound, wrongCode.StatusCode);
			Assert.Equal(HttpStatusCode.OK, response.StatusCode);
			var jwt = await response.JsonBody();
			using var invited = _host.As(jwt["token"]!.GetValue<string>());
			var avatars = await (await invited.GetAsync("/clientapi/avatar/private/list", TestContext.Current.CancellationToken)).JsonItems();
			var avatar = Assert.Single(avatars)!;
			Assert.Equal(avatarUserName, avatar["userName"]!.GetValue<string>());
			Assert.Equal("Guest", avatar["name"]!.GetValue<string>());
			var stored = await DB.Default.Find<GroupEntity>().MatchID(group["id"]!.GetValue<string>()).ExecuteFirstAsync(TestContext.Current.CancellationToken);
			Assert.Contains(stored.Members, m => !m.IsForeign && m.AvatarId == avatar["id"]!.GetValue<string>() && m.Role == GroupRole.Member);
		}

		[Fact]
		public async Task An_invitation_never_names_the_persona_after_the_login()
		{
			var owner = await _host.Persona(await _host.SignUp("owner"), "owner");
			var invitationCode = (await _host.Group(owner, community: true))["invitationCode"]!.GetValue<string>();
			var userName = Name("same");
			using var client = _host.Client();

			var same = await client.PostJson("/clientapi/user/invitation/signup", new { userName, password = Accounts.Password, invitationCode, avatarUserName = userName });
			var shouted = await client.PostJson("/clientapi/user/invitation/signup", new { userName = userName.ToUpperInvariant(), password = Accounts.Password, invitationCode, avatarUserName = userName });
			var missing = await client.PostJson("/clientapi/user/invitation/signup", new { userName, password = Accounts.Password, invitationCode });

			Assert.Equal(HttpStatusCode.BadRequest, same.StatusCode);
			Assert.Equal("Your persona's username must differ from your login.", await Message(same));
			Assert.Equal(HttpStatusCode.BadRequest, shouted.StatusCode);
			Assert.Equal("Your persona's username must differ from your login.", await Message(shouted));
			Assert.Equal(HttpStatusCode.BadRequest, missing.StatusCode);
			Assert.False(await DB.Default.Find<RootUser>().Match(u => u.UserName == userName).ExecuteAnyAsync(TestContext.Current.CancellationToken));
			Assert.False(await DB.Default.Find<Avatar>().Match(a => a.UserName == userName).ExecuteAnyAsync(TestContext.Current.CancellationToken));
		}

		[Fact]
		public async Task An_existing_root_joins_through_an_invitation_with_a_new_persona()
		{
			var owner = await _host.Persona(await _host.SignUp("owner"), "owner");
			var group = await _host.Group(owner, community: true);
			var root = await _host.SignUp("joiner");
			var avatarUserName = Name("joined");
			using var client = _host.Client();

			var response = await client.PostJson("/clientapi/user/invitation/login", new
			{
				userName = root.UserName,
				password = root.Password,
				invitationCode = group["invitationCode"]!.GetValue<string>(),
				avatarUserName
			});

			Assert.Equal(HttpStatusCode.OK, response.StatusCode);
			using var joined = _host.As(root.Jwt);
			var avatar = Assert.Single(await (await joined.GetAsync("/clientapi/avatar/private/list", TestContext.Current.CancellationToken)).JsonItems())!;
			Assert.Equal(avatarUserName, avatar["userName"]!.GetValue<string>());
			var groups = await (await joined.GetAsync("/clientapi/group/list?avatarId=" + avatar["id"]!.GetValue<string>(), TestContext.Current.CancellationToken)).JsonItems();
			Assert.Equal(group["id"]!.GetValue<string>(), Assert.Single(groups)!["id"]!.GetValue<string>());
		}

		[Fact]
		public async Task Recovery_without_an_email_is_refused()
		{
			var root = await _host.SignUp("noemail");
			using var client = _host.Client();

			var response = await client.PostJson("/clientapi/user/recover/password", new { userName = root.UserName });
			var unknown = await client.PostJson("/clientapi/user/recover/password", new { userName = Name("nobody") });
			var neither = await client.PostJson("/clientapi/user/recover/password", new { });

			Assert.Equal(HttpStatusCode.Locked, response.StatusCode);
			Assert.Contains("doesn't have an email", await Message(response));
			Assert.False(await DB.Default.Find<EmailRecovery>().Match(r => r.RootUserId == root.Id).ExecuteAnyAsync(TestContext.Current.CancellationToken));
			Assert.Equal(HttpStatusCode.NotFound, unknown.StatusCode);
			Assert.Equal(HttpStatusCode.BadRequest, neither.StatusCode);
		}

		[Fact]
		public async Task Recovery_through_an_unreachable_mail_server_says_so_and_nothing_more()
		{
			var root = await _host.SignUp("smtp");
			var email = $"{Guid.NewGuid():N}@example.test";
			using (var signedIn = _host.As(root.Jwt))
				Assert.Equal(HttpStatusCode.OK, (await signedIn.PostJson("/clientapi/user/update", new { email })).StatusCode);
			using var client = _host.Client();

			var byName = await client.PostJson("/clientapi/user/recover/password", new { userName = root.UserName });
			var byEmail = await client.PostJson("/clientapi/user/recover/password", new { email });

			foreach (var response in new[] { byName, byEmail })
			{
				var body = await response.Content.ReadAsStringAsync(TestContext.Current.CancellationToken);
				Assert.Equal(HttpStatusCode.ServiceUnavailable, response.StatusCode);
				Assert.Equal("Failed to send email.", JsonNode.Parse(body)!["errorMessage"]!.GetValue<string>());
				foreach (var leak in new[] { "xception", "efused", "ocket", "127.0.0.1", "smtp", "SMTP", "  at " })
					Assert.DoesNotContain(leak, body);
			}
		}

		[Fact]
		public async Task A_wrong_recovery_code_changes_nothing()
		{
			using var client = _host.Client();
			var code = Guid.NewGuid().ToString("N");

			var valid = await client.PostAsync("/clientapi/user/recover/valid", new StringContent($"\"{code}\"", Encoding.UTF8, "application/json"), TestContext.Current.CancellationToken);
			var change = await client.PostJson("/clientapi/user/recover/update/password", new { newPassword = NewPassword, repeatedPassword = NewPassword, recoveryCode = code });

			Assert.Equal(HttpStatusCode.OK, valid.StatusCode);
			Assert.Equal("false", await valid.Content.ReadAsStringAsync(TestContext.Current.CancellationToken));
			Assert.Equal(HttpStatusCode.NotFound, change.StatusCode);
			Assert.Equal("Invalid recovery code.", await Message(change));
		}

		[Fact]
		public async Task A_valid_recovery_code_resets_the_password_once()
		{
			var root = await _host.SignUp("recover");
			var code = Guid.NewGuid().ToString("N") + Guid.NewGuid().ToString("N");
			await DB.Default.SaveAsync(new EmailRecovery { RootUserId = root.Id, RecoveryCode = code }, TestContext.Current.CancellationToken);
			using var client = _host.Client();

			var valid = await client.PostAsync("/clientapi/user/recover/valid", new StringContent($"\"{code}\"", Encoding.UTF8, "application/json"), TestContext.Current.CancellationToken);
			var change = await client.PostJson("/clientapi/user/recover/update/password", new { newPassword = NewPassword, repeatedPassword = NewPassword, recoveryCode = code });
			var again = await client.PostJson("/clientapi/user/recover/update/password", new { newPassword = "Third-Pass-3!", repeatedPassword = "Third-Pass-3!", recoveryCode = code });

			Assert.Equal("true", await valid.Content.ReadAsStringAsync(TestContext.Current.CancellationToken));
			Assert.True(change.IsSuccessStatusCode);
			Assert.Equal(HttpStatusCode.NotFound, again.StatusCode);
			Assert.Equal(HttpStatusCode.BadRequest, (await LogIn(root.UserName, root.Password)).StatusCode);
			Assert.Equal(HttpStatusCode.OK, (await LogIn(root.UserName, NewPassword)).StatusCode);
			Assert.False(await DB.Default.Find<EmailRecovery>().Match(r => r.RootUserId == root.Id).ExecuteAnyAsync(TestContext.Current.CancellationToken));
		}

		[Fact]
		public async Task Sniffing_again_answers_a_fresh_token()
		{
			var root = await _host.SignUp("sniff");
			using var client = _host.As(root.Jwt);

			var response = await client.GetAsync("/clientapi/user/sniff/again", TestContext.Current.CancellationToken);
			using var anonymous = _host.Client();
			var refused = await anonymous.GetAsync("/clientapi/user/sniff/again", TestContext.Current.CancellationToken);

			Assert.Equal(HttpStatusCode.OK, response.StatusCode);
			var jwt = await response.JsonBody();
			Assert.Equal(root.Id, jwt["userId"]!.GetValue<string>());
			Assert.Equal(root.UserName, jwt["username"]!.GetValue<string>());
			Assert.True(jwt["expiration"]!.GetValue<long>() > DateTime.UtcNow.Ticks);
			Assert.Equal(HttpStatusCode.OK, await Settings(jwt["token"]!.GetValue<string>()));
			Assert.Equal(HttpStatusCode.Unauthorized, refused.StatusCode);
		}

		[Fact]
		public async Task The_eleventh_sign_up_from_one_address_in_a_minute_is_refused()
		{
			using var client = _host.ClientAt("198.51.100.21");
			for (var attempt = 1; attempt <= 10; attempt++)
				Assert.Equal(HttpStatusCode.BadRequest, (await client.PostJson("/clientapi/user/signup", new { })).StatusCode);

			var eleventh = await client.PostJson("/clientapi/user/signup", new { userName = Name("limited"), password = Accounts.Password });

			Assert.Equal(HttpStatusCode.TooManyRequests, eleventh.StatusCode);
		}

		[Fact]
		public async Task A_bad_token_answers_401_with_a_json_body()
		{
			var root = await _host.SignUp("badjwt");
			var tokens = new[]
			{
				"not-a-jwt",
				Jwt(root.Id, root.UserName, DateTime.UtcNow.AddHours(-1)),
				Jwt(root.Id, root.UserName, DateTime.UtcNow.AddHours(1), key: "another-key-entirely-0123456789abcdef0123456789abcdef0123456789abcdef")
			};

			foreach (var token in tokens)
			{
				using var client = _host.As(token);
				var response = await client.GetAsync("/clientapi/user/settings", TestContext.Current.CancellationToken);

				Assert.Equal(HttpStatusCode.Unauthorized, response.StatusCode);
				Assert.Equal("application/json", response.Content.Headers.ContentType!.MediaType);
				var body = await response.JsonBody();
				Assert.Equal(401, body["statusCode"]!.GetValue<int>());
				Assert.False(body["isValid"]!.GetValue<bool>());
				Assert.Contains("invalid_token", response.Headers.WwwAuthenticate.ToString());
			}
			Assert.Equal(HttpStatusCode.OK, await Settings(Jwt(root.Id, root.UserName, DateTime.UtcNow.AddHours(1))));
		}

		[Fact]
		public async Task A_banned_or_removed_root_loses_the_client_api_at_once()
		{
			var banned = await _host.SignUp("banned");
			var removed = await _host.SignUp("removed");
			Assert.Equal(HttpStatusCode.OK, await Settings(banned.Jwt));
			Assert.Equal(HttpStatusCode.OK, await Settings(removed.Jwt));

			await ClientApi.Ban(banned.Id);
			await DB.Default.Update<RootUser>().MatchID(removed.Id).Modify(u => u.DeletedAt, DateTime.UtcNow).ExecuteAsync(TestContext.Current.CancellationToken);

			Assert.Equal(HttpStatusCode.Unauthorized, await Settings(banned.Jwt));
			Assert.Equal(HttpStatusCode.Unauthorized, await Settings(removed.Jwt));
			using (var client = _host.As(banned.Jwt))
			{
				Assert.Equal(HttpStatusCode.Unauthorized, (await client.GetAsync("/clientapi/user/sniff/again", TestContext.Current.CancellationToken)).StatusCode);
				Assert.Equal(HttpStatusCode.Unauthorized, (await client.PostJson("/clientapi/avatar/private/insert", new { userName = Name("late"), name = "late", biography = "testing" })).StatusCode);
			}
			await ClientApi.Ban(banned.Id, banned: false);
			Assert.Equal(HttpStatusCode.OK, await Settings(banned.Jwt));
		}
	}
}