using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Diagnostics;
using System.Linq;
using System.Security.Claims;
using System.Threading.Tasks;
using System.Web.Mvc;
using Abp.Auditing;
using Abp.Configuration.Startup;
using Abp.Domain.Uow;
using Abp.Extensions;
using Abp.Localization;
using Abp.Runtime.Session;
using Abp.Threading;
using Abp.Timing;
using Abp.UI;
using Abp.Web.Models;
using Abp.Web.Security.AntiForgery;
using WePlatform.Authorization;
using WePlatform.Authorization.Roles;
using WePlatform.Authorization.Users;
using WePlatform.BaseSystem.Sessions.Dto;
using WePlatform.Configuration;
using WePlatform.Controllers.Results;
using WePlatform.MultiTenancy;
using WePlatform.Models;
using WePlatform.Models.Account;
using IwbZero.Auditing;
using IwbZero.Authorization.Base;
using IwbZero.Authorization.Base.Users;
using IwbZero.Authorization.Users;
using IwbZero.MultiTenancy;
using IwbZero.ToolCommon.LogHelpers;
using Microsoft.AspNet.Identity;
using Microsoft.AspNet.Identity.Owin;
using Microsoft.Owin.Security;

namespace WePlatform.Controllers
{
    [AuditLog("用户账号"), AllowAnonymous]
    public class AccountController : IwbControllerBase
    {
        private readonly TenantManager _tenantManager;
        private readonly UserManager _userManager;
        private readonly RoleManager _roleManager;
        private readonly IUnitOfWorkManager _unitOfWorkManager;
        private readonly IMultiTenancyConfig _multiTenancyConfig;
        private readonly LogInManager _logInManager;
        private readonly ILanguageManager _languageManager;
        private readonly ITenantCache _tenantCache;
        private readonly IAuthenticationManager _authenticationManager;
        private readonly IAuditingHelper _auditingHelper;
        private readonly IAuditInfoProvider _auditInfoProvider;

        public AccountController(
            TenantManager tenantManager,
            UserManager userManager,
            RoleManager roleManager,
            IUnitOfWorkManager unitOfWorkManager,
            IMultiTenancyConfig multiTenancyConfig,
            LogInManager logInManager,
            ILanguageManager languageManager,
            ITenantCache tenantCache,
            IAuthenticationManager authenticationManager, IAuditingHelper auditingHelper, IAuditInfoProvider auditInfoProvider)
        {
            _tenantManager = tenantManager;
            _userManager = userManager;
            _roleManager = roleManager;
            _unitOfWorkManager = unitOfWorkManager;
            _multiTenancyConfig = multiTenancyConfig;
            _logInManager = logInManager;
            _languageManager = languageManager;
            _tenantCache = tenantCache;
            _authenticationManager = authenticationManager;
            _auditingHelper = auditingHelper;
            _auditInfoProvider = auditInfoProvider;
        }

        #region Login / Logout
        [DisableAuditing]
        [AuditLog("登陆")]
        public async Task<ActionResult> Index(string returnUrl = "")
        {
            if (string.IsNullOrWhiteSpace(returnUrl))
            {
                returnUrl = Request.ApplicationPath;
            }

            ViewBag.IsMultiTenancyEnabled = _multiTenancyConfig.IsEnabled;
            TenantLoginInfoDto tenantDto = null;
            List<SelectListItem> tenantList = new List<SelectListItem>();
            if (_multiTenancyConfig.IsEnabled)
            {
                if (AbpSession.TenantId.HasValue)
                {
                    var tenant = await _tenantManager.GetByIdAsync(AbpSession.GetTenantId());
                    tenant = await GetActiveTenantAsync(tenant.TenancyName);
                    tenantDto = ObjectMapper.Map<TenantLoginInfoDto>(tenant);
                }
                var tenants = await _tenantManager.GeTenants();
                tenantList.Add(new SelectListItem() { Value = "", Text = L("NotSelected") });
                foreach (var t in tenants)
                {
                    tenantList.Add(new SelectListItem() { Value = t.TenancyName, Text = t.Name });
                }
            }

            ViewBag.TenantList = tenantList;
            return View("Login", new LoginFormViewModel
            {
                Tenant = tenantDto,
                ReturnUrl = returnUrl,
                IsMultiTenancyEnabled = _multiTenancyConfig.IsEnabled,
                IsSelfRegistrationAllowed = false,
                MultiTenancySide = AbpSession.MultiTenancySide
            });
        }

        [HttpPost]
        [DisableAuditing]
        [AuditLog("登陆")]
        public async Task<JsonResult> Login(LoginViewModel loginModel, string returnUrl = "", string returnUrlHash = "")
        {
            var actionStopwatch = Stopwatch.StartNew();
            CheckModelState();

            var loginResult = await GetLoginResultAsync(
                loginModel.UsernameOrEmailAddress,
                loginModel.Password,
                GetTenancyNameOrNull()
                );

            await SignInAsync(loginResult.User, loginResult.Identity, loginModel.RememberMe);

            if (string.IsNullOrWhiteSpace(returnUrl))
            {
                returnUrl = Request.ApplicationPath;
            }

            if (!string.IsNullOrWhiteSpace(returnUrlHash))
            {
                returnUrl = returnUrl + returnUrlHash;
            }
            actionStopwatch.Stop();
            await WriteLoginLog(loginResult, actionStopwatch);
            return Json(new AjaxResponse { TargetUrl = returnUrl });
        }

        private async Task<IwbLoginResult<Tenant, User>> GetLoginResultAsync(string usernameOrEmailAddress, string password, string tenancyName)
        {
            var loginResult = await _logInManager.LoginAsync(usernameOrEmailAddress, password, tenancyName);

            switch (loginResult.Result)
            {
                case IwbLoginResultType.Success:
                    return loginResult;
                default:
                    throw CreateExceptionForFailedLoginAttempt(loginResult.Result, usernameOrEmailAddress, tenancyName);
            }
        }

        private async Task SignInAsync(User user, ClaimsIdentity identity = null, bool rememberMe = false)
        {
            if (identity == null)
            {
                identity = await _userManager.CreateIdentityAsync(user, IwbAuthenticationTypes.ApplicationCookie);
            }

            _authenticationManager.SignOut(IwbAuthenticationTypes.ApplicationCookie);
            // Many browsers do not clean up session cookies when you close them. So the rule of thumb must be:
            // For having a consistent behaviour across all browsers, don't rely solely on browser behaviour for proper clean-up
            // of session cookies. It is safer to use non-session cookies (IsPersistent == true) in bundle with an expiration date.
            // See http://blog.petersondave.com/cookies/Session-Cookies-in-Chrome-Firefox-and-Sitecore/
            if (rememberMe)
            {
                _authenticationManager.SignIn(new AuthenticationProperties { IsPersistent = true }, identity);
            }
            else
            {
                _authenticationManager.SignIn(
                    new AuthenticationProperties
                    {
                        IsPersistent = true,
                        ExpiresUtc = DateTimeOffset.UtcNow.AddMinutes(int.Parse(System.Configuration.ConfigurationManager.AppSettings["AuthSession.ExpireTimeInMinutes.WhenNotPersistent"] ?? "30"))
                    },
                    identity);
            }
        }

        private Exception CreateExceptionForFailedLoginAttempt(IwbLoginResultType result, string usernameOrEmailAddress, string tenancyName)
        {
            switch (result)
            {
                case IwbLoginResultType.Success:
                    return new ApplicationException("Don't call this method with a success result!");
                case IwbLoginResultType.InvalidUserNameOrEmailAddress:
                case IwbLoginResultType.InvalidPassword:
                    return new UserFriendlyException(L("LoginFailed"), L("InvalidUserNameOrPassword"));
                case IwbLoginResultType.InvalidTenancyName:
                    return new UserFriendlyException(L("LoginFailed"), L("ThereIsNoTenantDefinedWithName{0}", tenancyName));
                case IwbLoginResultType.TenantIsNotActive:
                    return new UserFriendlyException(L("LoginFailed"), L("TenantIsNotActive", tenancyName));
                case IwbLoginResultType.UserIsNotActive:
                    return new UserFriendlyException(L("LoginFailed"), L("UserIsNotActiveAndCanNotLogin", usernameOrEmailAddress));
                case IwbLoginResultType.UserEmailIsNotConfirmed:
                    return new UserFriendlyException(L("LoginFailed"), "UserEmailIsNotConfirmedAndCanNotLogin");
                case IwbLoginResultType.LockedOut:
                    return new UserFriendlyException(L("LoginFailed"), L("UserLockedOutMessage"));
                default: //Can not fall to default actually. But other result types can be added in the future and we may forget to handle it
                    Logger.Warn("Unhandled login fail reason: " + result);
                    return new UserFriendlyException(L("LoginFailed"));
            }
        }

        public ActionResult Logout()
        {
            _authenticationManager.SignOut();
            return RedirectToAction("Index");
        }

        private async Task WriteLoginLog(IwbLoginResult<Tenant, User> loginResult, Stopwatch actionStopwatch)
        {
            try
            {
                var auditInfo = new AuditInfo
                {
                    TenantId = loginResult.User.TenantId,
                    UserId = loginResult.User.Id,
                    ImpersonatorUserId = AbpSession.ImpersonatorUserId,
                    ImpersonatorTenantId = AbpSession.ImpersonatorTenantId,
                    ServiceName = "AccountController",
                    MethodName = "Login",
                    Parameters = "",
                    ExecutionTime = Clock.Now,
                    ExecutionDuration = Convert.ToInt32(actionStopwatch.Elapsed.TotalMilliseconds)
                };
                _auditInfoProvider.Fill(auditInfo);
                await _auditingHelper.SaveAsync(auditInfo);
            }
            catch (Exception e)
            {
                this.LogError(e);
            }
        }

        #endregion

        #region Register

        public ActionResult Register()
        {
            return RegisterView(new RegisterViewModel());
        }

        private ActionResult RegisterView(RegisterViewModel model)
        {
            ViewBag.IsMultiTenancyEnabled = _multiTenancyConfig.IsEnabled;

            return View("Register", model);
        }

        //private bool IsSelfRegistrationEnabled()
        //{
        //    if (!AbpSession.TenantId.HasValue)
        //    {
        //        return false; //No registration enabled for host users!
        //    }

        //    return true;
        //}

        [HttpPost]
        public virtual async Task<ActionResult> Register(RegisterViewModel model)
        {
            try
            {
                CheckModelState();

                //Create user
                var user = new User
                {
                    Name = model.Name,
                    Surname = model.Surname,
                    EmailAddress = model.EmailAddress,
                    IsActive = true
                };

                //Get external login info if possible
                ExternalLoginInfo externalLoginInfo = null;
                if (model.IsExternalLogin)
                {
                    externalLoginInfo = await _authenticationManager.GetExternalLoginInfoAsync();
                    if (externalLoginInfo == null)
                    {
                        throw new ApplicationException("Can not external login!");
                    }

                    user.Logins = new List<UserLogin>
                    {
                        new UserLogin
                        {
                            LoginProvider = externalLoginInfo.Login.LoginProvider,
                            ProviderKey = externalLoginInfo.Login.ProviderKey
                        }
                    };

                    if (model.UserName.IsNullOrEmpty())
                    {
                        model.UserName = model.EmailAddress;
                    }

                    model.Password = Authorization.Users.User.CreateRandomPassword();

                    if (string.Equals(externalLoginInfo.Email, model.EmailAddress, StringComparison.InvariantCultureIgnoreCase))
                    {
                        user.IsEmailConfirmed = true;
                    }
                }
                else
                {
                    //Username and Password are required if not external login
                    if (model.UserName.IsNullOrEmpty() || model.Password.IsNullOrEmpty())
                    {
                        throw new UserFriendlyException(L("FormIsNotValidMessage"));
                    }
                }

                user.UserName = model.UserName;
                user.Password = new PasswordHasher().HashPassword(model.Password);

                //Switch to the tenant
                _unitOfWorkManager.Current.EnableFilter(AbpDataFilters.MayHaveTenant); //TODO: Needed?
                _unitOfWorkManager.Current.SetTenantId(AbpSession.GetTenantId());

                //Add default roles
                user.Roles = new List<UserRole>();
                foreach (var defaultRole in await _roleManager.Roles.Where(r => r.IsDefault).ToListAsync())
                {
                    user.Roles.Add(new UserRole { RoleId = defaultRole.Id });
                }

                //Save user
                CheckErrors(await _userManager.CreateAsync(user));
                await _unitOfWorkManager.Current.SaveChangesAsync();

                //Directly login if possible
                if (user.IsActive)
                {
                    IwbLoginResult<Tenant, User> loginResult;
                    if (externalLoginInfo != null)
                    {
                        loginResult = await _logInManager.LoginAsync(externalLoginInfo.Login, GetTenancyNameOrNull());
                    }
                    else
                    {
                        loginResult = await GetLoginResultAsync(user.UserName, model.Password, GetTenancyNameOrNull());
                    }

                    if (loginResult.Result == IwbLoginResultType.Success)
                    {
                        await SignInAsync(loginResult.User, loginResult.Identity);
                        return Redirect(Url.Action("Index", "Home"));
                    }

                    Logger.Warn("New registered user could not be login. This should not be normally. login result: " + loginResult.Result);
                }

                //If can not login, show a register result page
                return View("RegisterResult", new RegisterResultViewModel
                {
                    TenancyName = GetTenancyNameOrNull(),
                    NameAndSurname = user.Name + " " + user.Surname,
                    UserName = user.UserName,
                    EmailAddress = user.EmailAddress,
                    IsActive = user.IsActive
                });
            }
            catch (UserFriendlyException ex)
            {
                ViewBag.IsMultiTenancyEnabled = _multiTenancyConfig.IsEnabled;
                ViewBag.ErrorMessage = ex.Message;

                return View("Register", model);
            }
        }

        #endregion

        #region External Login

        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult ExternalLogin(string provider, string returnUrl)
        {
            return new ChallengeResult(
                provider,
                Url.Action(
                    "ExternalLoginCallback",
                    "Account",
                    new
                    {
                        ReturnUrl = returnUrl,
                        tenancyName = GetTenancyNameOrNull()
                    })
            );
        }

        [UnitOfWork]
        [DisableAbpAntiForgeryTokenValidation]
        public virtual async Task<ActionResult> ExternalLoginCallback(string returnUrl, string tenancyName = "")
        {
            var loginInfo = await _authenticationManager.GetExternalLoginInfoAsync();
            if (loginInfo == null)
            {
                return RedirectToAction("Login");
            }

            //Try to find tenancy name
            if (tenancyName.IsNullOrEmpty())
            {
                var tenants = await FindPossibleTenantsOfUserAsync(loginInfo.Login);
                switch (tenants.Count)
                {
                    case 0:
                        return await RegisterView(loginInfo);
                    case 1:
                        tenancyName = tenants[0].TenancyName;
                        break;
                    default:
                        return View("TenantSelection", model: new TenantSelectionViewModel
                        {
                            Action = Url.Action("ExternalLoginCallback", "Account", new { returnUrl }),
                            Tenants = ObjectMapper.Map<List<TenantSelectionViewModel.TenantInfo>>(tenants)

                        });
                }
            }

            var loginResult = await _logInManager.LoginAsync(loginInfo.Login, tenancyName);

            switch (loginResult.Result)
            {
                case IwbLoginResultType.Success:
                    await SignInAsync(loginResult.User, loginResult.Identity);

                    if (string.IsNullOrWhiteSpace(returnUrl))
                    {
                        returnUrl = Url.Action("Index", "Home");
                    }

                    return Redirect(returnUrl);
                case IwbLoginResultType.UnknownExternalLogin:
                    return await RegisterView(loginInfo, tenancyName);
                default:
                    throw CreateExceptionForFailedLoginAttempt(loginResult.Result, loginInfo.Email ?? loginInfo.DefaultUserName, tenancyName);
            }
        }

        private async Task<ActionResult> RegisterView(ExternalLoginInfo loginInfo, string tenancyName = null)
        {
            var name = loginInfo.DefaultUserName;
            var surname = loginInfo.DefaultUserName;

            var extractedNameAndSurname = TryExtractNameAndSurnameFromClaims(loginInfo.ExternalIdentity.Claims.ToList(), ref name, ref surname);

            var viewModel = new RegisterViewModel
            {
                EmailAddress = loginInfo.Email,
                Name = name,
                Surname = surname,
                IsExternalLogin = true
            };

            if (!tenancyName.IsNullOrEmpty() && extractedNameAndSurname)
            {
                return await Register(viewModel);
            }

            return RegisterView(viewModel);
        }

        protected virtual async Task<List<Tenant>> FindPossibleTenantsOfUserAsync(UserLoginInfo login)
        {
            List<User> allUsers;
            using (_unitOfWorkManager.Current.DisableFilter(AbpDataFilters.MayHaveTenant))
            {
                allUsers = await _userManager.FindAllAsync(login);
            }

            return allUsers
                .Where(u => u.TenantId != null)
                .Select(u => AsyncHelper.RunSync(() => _tenantManager.FindByIdAsync(u.TenantId.Value)))
                .ToList();
        }

        private static bool TryExtractNameAndSurnameFromClaims(List<Claim> claims, ref string name, ref string surname)
        {
            string foundName = null;
            string foundSurname = null;

            var givennameClaim = claims.FirstOrDefault(c => c.Type == ClaimTypes.GivenName);
            if (givennameClaim != null && !givennameClaim.Value.IsNullOrEmpty())
            {
                foundName = givennameClaim.Value;
            }

            var surnameClaim = claims.FirstOrDefault(c => c.Type == ClaimTypes.Surname);
            if (surnameClaim != null && !surnameClaim.Value.IsNullOrEmpty())
            {
                foundSurname = surnameClaim.Value;
            }

            if (foundName == null || foundSurname == null)
            {
                var nameClaim = claims.FirstOrDefault(c => c.Type == ClaimTypes.Name);
                if (nameClaim != null)
                {
                    var nameSurName = nameClaim.Value;
                    if (!nameSurName.IsNullOrEmpty())
                    {
                        var lastSpaceIndex = nameSurName.LastIndexOf(' ');
                        if (lastSpaceIndex < 1 || lastSpaceIndex > (nameSurName.Length - 2))
                        {
                            foundName = foundSurname = nameSurName;
                        }
                        else
                        {
                            foundName = nameSurName.Substring(0, lastSpaceIndex);
                            foundSurname = nameSurName.Substring(lastSpaceIndex);
                        }
                    }
                }
            }

            if (!foundName.IsNullOrEmpty())
            {
                name = foundName;
            }

            if (!foundSurname.IsNullOrEmpty())
            {
                surname = foundSurname;
            }

            return foundName != null && foundSurname != null;
        }

        #endregion

        #region Common private methods

        private async Task<Tenant> GetActiveTenantAsync(string tenancyName)
        {
            var tenant = await _tenantManager.FindByTenancyNameAsync(tenancyName);
            if (tenant == null)
            {
                throw new UserFriendlyException(L("ThereIsNoTenantDefinedWithName{0}", tenancyName));
            }

            if (!tenant.IsActive)
            {
                throw new UserFriendlyException(L("TenantIsNotActive", tenancyName));
            }

            return tenant;
        }

        private string GetTenancyNameOrNull()
        {
            if (!AbpSession.TenantId.HasValue)
            {
                return null;
            }

            return _tenantCache.GetOrNull(AbpSession.TenantId.Value)?.TenancyName;
        }

        #endregion

        #region Common Partial Views

        [ChildActionOnly]
        public PartialViewResult _AccountLanguages()
        {
            var model = new LanguageSelectionViewModel
            {
                CurrentLanguage = _languageManager.CurrentLanguage,
                Languages = _languageManager.GetLanguages().Where(l => !l.IsDisabled).ToList()
                    .Where(l => !l.IsDisabled)
                    .ToList(),
                CurrentUrl = Request.Path
            };

            return PartialView("_AccountLanguages", model);
        }

        #endregion
    }
}