using System;
using System.Globalization;
using System.Threading.Tasks;
using gehGassi.Core.Interfaces;
using gehGassi.Domain.Users;
using gehGassi.Web.Auth;
using gehGassi.Web.Helper;
using gehGassi.Web.Models;
using gehGassi.Web.Services;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Localization;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;

namespace gehGassi.Web.Controllers
{
    /// <summary>
    /// Controller für die Verwaltung von Logins, Logouts usw.
    /// </summary>
    [Authorize]
    public class AccountController : BaseController
    {
        private readonly SignInManager<ApplicationUser> _signInManager;
        private readonly ILogger<AccountController> _logger;
        private readonly IStringLocalizer<AccountController> _localizer;
        private readonly IEmailSender _emailSender;
        private readonly IUserService _userService;
        private readonly IOptions<LicenseOptions> _licenseOptions;
        private readonly UserManager<ApplicationUser> _userManager;
        private readonly IOptions<SessionSettings> _sessionSettings;

        /// <summary>
        /// Erstellt eine Istanz
        /// </summary>
        /// <param name="signInManager">Instanz eines SignInManager</param>
        /// <param name="logger">Instanz eines ILogger</param>
        /// <param name="localizer">Instanz eines IStringLocalizer</param>
        /// <param name="emailSender">Instanz eines IEmailSender</param>
        /// <param name="userService">Isntanz eines IUserService</param>
        /// <param name="licenseOptions">Instanz eines IOptions LicenseOptions</param>
        /// <param name="userManager">Instanz eines UserManager</param>
        /// <param name="sessionSettings">Instanz eines IOptions SessionSettings</param>
        public AccountController(SignInManager<ApplicationUser> signInManager, ILogger<AccountController> logger, IStringLocalizer<AccountController> localizer,
            IEmailSender emailSender, IUserService userService, IOptions<LicenseOptions> licenseOptions, UserManager<ApplicationUser> userManager,
            IOptions<SessionSettings> sessionSettings)
        {
            _signInManager = signInManager;
            _logger = logger;
            _localizer = localizer;
            _emailSender = emailSender;
            _userService = userService;
            _licenseOptions = licenseOptions;
            _userManager = userManager;
            _sessionSettings = sessionSettings;
        }

        /// <summary>
        /// Zeigt eine View zur Anmeldung an
        /// </summary>
        /// <param name="returnUrl">Optional: Return URL</param>
        /// <returns>View</returns>
        [AllowAnonymous]
        public IActionResult Login(string returnUrl)
        {
            var model = new LoginVm();
#if DEBUG
            //model.UserName = "office@creativebits.com";
            //model.Password = "!eLearningFox#321";
#endif
            ViewBag.ReturnUrl = returnUrl;
            return View(model);
        }

        /// <summary>
        /// Login
        /// </summary>
        /// <param name="model">Benutzerdaten</param>
        /// <param name="returnUrl">Optional: ReturnUrl</param>
        /// <returns>Redirect oder View</returns>
        [AllowAnonymous]
        [HttpPost]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> Login(LoginVm model, string returnUrl)
        {
            if (ModelState.IsValid)
            {
                //Hundebesitzer und hundeausführer düfen nicht in das Backend.
                //Ausser es sind Admins oder Poweruser mit Test-Rollen
                var userCheck = await _signInManager.UserManager.FindByNameAsync(model.UserName);
                if (userCheck != null)
                {
                    var roles = await _userManager.GetRolesAsync(userCheck);
                    if (!roles.Contains("Administrator"))
                    {
                        if (!roles.Contains("PowerUser"))
                        {
                            if (roles.Contains("DogOwner") || roles.Contains("DogWalker"))
                            {
                                return Redirect("https://gehgassi.com");
                            }
                        }
                    }
                }
                
                var result = await _signInManager.PasswordSignInAsync(model.UserName, model.Password, _sessionSettings.Value.PersistentCookie, lockoutOnFailure: true);
                if (result.Succeeded)
                {

                    _logger.LogInformation("User logged in.");
                    var user = await _userService.GetByUsernameAsync(model.UserName);
                    user.LastLoginDate = DateTimeOffset.UtcNow;
                    await _userService.CommitAsync(user.UserName);

                    var roles = await _userManager.GetRolesAsync(user);

                    CultureInfo.CurrentCulture = new CultureInfo(user.PreferredLanguage);
                    if (roles.Contains("Administrator"))
                        return RedirectToAction("Index", "Home", new { culture = CultureInfo.CurrentCulture.TwoLetterISOLanguageName });
                    if (roles.Contains("PowerUser"))
                        return RedirectToAction("Index", "Home", new { culture = CultureInfo.CurrentCulture.TwoLetterISOLanguageName });
                    else if (roles.Contains("Customer"))
                        return RedirectToAction("IndexCustomer", "Home", new { culture = CultureInfo.CurrentCulture.TwoLetterISOLanguageName });
                    else if (roles.Contains("AppUser"))
                    {
                        await _signInManager.SignOutAsync();
                        return RedirectToAction("Login", "Account", new { culture = CultureInfo.CurrentCulture.TwoLetterISOLanguageName });
                        //return RedirectToAction("IndexAppUser", "Home", new { culture = CultureInfo.CurrentCulture.TwoLetterISOLanguageName });
                    }
                    else if (roles.Contains("ApiUser"))
                    {
                        await _signInManager.SignOutAsync();
                        return RedirectToAction("Login", "Account", new { culture = CultureInfo.CurrentCulture.TwoLetterISOLanguageName });
                    }
                    else
                        return RedirectToAction("Status401", "Home", new { culture = CultureInfo.CurrentCulture.TwoLetterISOLanguageName });
                }
                if (result.RequiresTwoFactor)
                {
                    return RedirectToAction("VerifyAuthenticatorCode");
                }
                if (result.IsLockedOut)
                {
                    _logger.LogWarning("User account locked out.");
                    return RedirectToAction("Lockout");
                }
                else
                {
                    //Prüfen ob die Email-Adresse noch nicht bestätigt wurde....
                    bool errorAdded = false;
                    var user = await _userManager.FindByEmailAsync(model.UserName);
                    if (user != null)
                    {
                        if (await _userManager.IsEmailConfirmedAsync(user) == false)
                        {
                            ModelState.AddModelError(string.Empty, _localizer["Err_Login_EmailNotConfirmed"]);
                            ViewBag.ShowEmailConfirmation = true;
                            errorAdded = true;
                        }
                    }
                    if (!errorAdded)
                        ModelState.AddModelError(string.Empty, _localizer["Err_Login_Invalid"]);
                }
            }
            ViewBag.ReturnUrl = returnUrl;
            return View(model);
        }

        /// <summary>
        /// Abmelden eines Benutzers
        /// </summary>
        /// <returns>Redirect</returns>
        [HttpPost]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> Logout()
        {
            await _signInManager.SignOutAsync();
            _logger.LogInformation("User logged out.");
            return RedirectToAction("Login", "Account", new { culture = CultureInfo.CurrentCulture.TwoLetterISOLanguageName });
        }

        /// <summary>
        /// Zeigt eine View an die über eine Sperre informiert
        /// </summary>
        /// <returns>View</returns>
        [AllowAnonymous]
        public IActionResult Lockout()
        {
            var timeLockedInMinutes = (int)_signInManager.Options.Lockout.DefaultLockoutTimeSpan.TotalMinutes;
            return View(timeLockedInMinutes);
        }

        /// <summary>
        /// Zeigt eine View für Passwort-Vergessen an
        /// </summary>
        /// <returns>View</returns>
        [HttpGet]
        [AllowAnonymous]
        public IActionResult ForgotPassword()
        {
            return View();
        }

        /// <summary>
        /// Handling für Passwort Vergessen
        /// </summary>
        /// <param name="model">Benutzereingaben</param>
        /// <returns>Redirect oder View</returns>
        [HttpPost]
        [AllowAnonymous]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> ForgotPassword(ForgotPasswordVm model)
        {
            if (ModelState.IsValid)
            {
                try
                {
                    var user = await _signInManager.UserManager.FindByNameAsync(model.Email);
                    if (user != null && (await _signInManager.UserManager.IsEmailConfirmedAsync(user)))
                    {
                        var token = await _signInManager.UserManager.GeneratePasswordResetTokenAsync(user);
                        var callbackUrl = Url.ResetPasswordCallbackLink(user.Id, token, Request.Scheme);
                        await _emailSender.SendPasswordResetAsync(model.Email, callbackUrl, _localizer, _licenseOptions);
                    }
                }
                catch { }

                return RedirectToAction(nameof(ForgotPasswordConfirmation));
            }

            // If we got this far, something failed, redisplay form
            return View(model);
        }

        /// <summary>
        /// Zeigt die Bestätigung für Passwort vergessen an
        /// </summary>
        /// <returns>View</returns>
        [HttpGet]
        [AllowAnonymous]
        public IActionResult ForgotPasswordConfirmation()
        {
            return View();
        }

        /// <summary>
        /// Zeigt eine View zum Zurücksetzen des Passwortes an
        /// </summary>
        /// <param name="code">Rücksetzcode</param>
        /// <returns>View</returns>
        [HttpGet]
        [AllowAnonymous]
        public IActionResult ResetPassword(string code = null)
        {
            if (code == null)
            {
                throw new ApplicationException("A code must be supplied for password reset.");
            }
            var model = new ResetPasswordVm() { Code = code };
            return View(model);
        }

        /// <summary>
        /// Zurücksetzen des Passwortes eines Benutzers
        /// </summary>
        /// <param name="model">Benutzereingaben</param>
        /// <returns></returns>
        [HttpPost]
        [AllowAnonymous]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> ResetPassword(ResetPasswordVm model)
        {
            if (!ModelState.IsValid)
            {
                return View(model);
            }

            if (await _userService.IsUsernameAvailableAsync(model.Email))
            {
                // Don't reveal that the user does not exist
                return RedirectToAction(nameof(ResetPasswordConfirmation));
            }
            try
            {
                var user = await _signInManager.UserManager.FindByNameAsync(model.Email);
                if (user != null)
                {
                    var result = await _signInManager.UserManager.ResetPasswordAsync(user, model.Code, model.Password);
                    if (result.Succeeded)
                    {
                        return RedirectToAction(nameof(ResetPasswordConfirmation));
                    }
                    foreach (var error in result.Errors)
                    {
                        ModelState.AddModelError(string.Empty, error.Description);
                    }
                }
            }
            catch { }
            return View(model);
        }

        /// <summary>
        /// Anzeigen eines Erfolgs-Views für das Zurücksetzen eines Passwortes
        /// </summary>
        /// <returns></returns>
        [HttpGet]
        [AllowAnonymous]
        public IActionResult ResetPasswordConfirmation()
        {
            return View();
        }

        #region Reset Password für API

        /// <summary>
        /// Zeigt eine View zum Zurücksetzen des Passwortes an
        /// </summary>
        /// <param name="code">Rücksetzcode</param>
        /// <returns>View</returns>
        [HttpGet]
        [AllowAnonymous]
        public IActionResult ResetPasswordApp(string code = null)
        {
            if (code == null)
            {
                throw new ApplicationException("A code must be supplied for password reset.");
            }
            var model = new ResetPasswordVm() { Code = code };
            return View(model);
        }

        /// <summary>
        /// Zurücksetzen des Passwortes eines Benutzers
        /// </summary>
        /// <param name="model">Benutzereingaben</param>
        /// <returns></returns>
        [HttpPost]
        [AllowAnonymous]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> ResetPasswordApp(ResetPasswordVm model)
        {
            if (!ModelState.IsValid)
            {
                return View(model);
            }

            if (await _userService.IsUsernameAvailableAsync(model.Email))
            {
                // Don't reveal that the user does not exist
                return RedirectToAction(nameof(ResetPasswordConfirmationApp));
            }
            try
            {
                var user = await _signInManager.UserManager.FindByNameAsync(model.Email);
                if (user != null)
                {
                    var result = await _signInManager.UserManager.ResetPasswordAsync(user, model.Code, model.Password);
                    if (result.Succeeded)
                    {
                        return RedirectToAction(nameof(ResetPasswordConfirmationApp));
                    }
                    foreach (var error in result.Errors)
                    {
                        ModelState.AddModelError(string.Empty, error.Description);
                    }
                }
            }
            catch { }
            return View(model);
        }

        /// <summary>
        /// Anzeigen eines Erfolgs-Views für das Zurücksetzen eines Passwortes
        /// </summary>
        /// <returns></returns>
        [HttpGet]
        [AllowAnonymous]
        public IActionResult ResetPasswordConfirmationApp()
        {
            return View();
        }

        #endregion

        [HttpGet]
        [AllowAnonymous]
        public IActionResult AccessDenied(string returnUrl)
        {
            return View();
        }

        /// <summary>
        /// Anzeige der email-Bestätigung der Email-Adresse
        /// </summary>
        /// <param name="userId"></param>
        /// <param name="code"></param>
        /// <returns></returns>
        [HttpGet]
        [AllowAnonymous]
        public async Task<IActionResult> ConfirmEmail(string userId, string code)
        {
            var model = new LoginVm();
            if (userId == null || code == null)
            {
                ViewBag.ShowEmailConfirmation = true;
                ModelState.AddModelError(string.Empty, _localizer["Common_ConfirmEmailFailed_Desc"]);
                return View("Login", model);
            }
            var user = await _userManager.FindByIdAsync(userId);
            if (user == null)
            {
                ViewBag.ShowEmailConfirmation = true;
                ModelState.AddModelError(string.Empty, _localizer["Common_ConfirmEmailFailed_Desc"]);
                return View("Login", model);
            }
            var result = await _userManager.ConfirmEmailAsync(user, code);
            if (!result.Succeeded)
            {
                ViewBag.ShowEmailConfirmation = true;
                ModelState.AddModelError(string.Empty, _localizer["Common_ConfirmEmailFailed_Desc"]);
                return View("Login", model);
            }

            ViewBag.ShowEmailConfirmationSuccess = true;
            return View("Login", model);
        }

        /// <summary>
        /// Anzeige der email-Bestätigung der Email-Adresse für die App
        /// </summary>
        /// <param name="userId"></param>
        /// <param name="code"></param>
        /// <returns></returns>
        [HttpGet]
        [AllowAnonymous]
        public async Task<IActionResult> ConfirmEmailApp(string userId, string code)
        {
            var model = _localizer["Common_ConfirmEmail_Success"].Value;
            if (userId == null || code == null)
            {
                model = _localizer["Common_ConfirmEmailFailed_Desc"].Value;
            }
            var user = await _userManager.FindByIdAsync(userId);
            if (user == null)
            {
                model = _localizer["Common_ConfirmEmailFailed_Desc"].Value;
            }
            var result = await _userManager.ConfirmEmailAsync(user, code);
            if (!result.Succeeded)
            {
                model = _localizer["Common_ConfirmEmailFailed_Desc"].Value;
            }
            
            return View("ConfirmEmailApp", model);
        }

        /// <summary>
        /// Zeigt eine View für das erneute Senden des Email-Bestätigungscodes an
        /// </summary>
        /// <returns>View</returns>
        [HttpGet]
        [AllowAnonymous]
        public IActionResult SendEmailConfirmation()
        {
            return View();
        }

        /// <summary>
        /// Handling für Email-Bestätigung neu senden
        /// </summary>
        /// <param name="model">Benutzereingaben</param>
        /// <returns>Redirect oder View</returns>
        [HttpPost]
        [AllowAnonymous]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> SendEmailConfirmation(ForgotPasswordVm model)
        {
            if (ModelState.IsValid)
            {
                try
                {
                    var user = await _signInManager.UserManager.FindByNameAsync(model.Email);
                    if (user != null && (await _signInManager.UserManager.IsEmailConfirmedAsync(user)) == false)
                    {
                        var code = await _signInManager.UserManager.GenerateEmailConfirmationTokenAsync(user);
                        var callbackUrl = Url.Action("ConfirmEmail", "Account", new { userId = user.Id, code = code }, protocol: HttpContext.Request.Scheme);
                        await _emailSender.SendEmailConfirmationAsync(user.UserName, callbackUrl, _localizer, LicenseOptions);
                    }
                }
                catch { }

                return RedirectToAction(nameof(SendEmailConfirmationDone));
            }

            // If we got this far, something failed, redisplay form
            return View(model);
        }

        /// <summary>
        /// Zeigt die Bestätigung für das erneute Senden des Email-Bestätigungscodes an
        /// </summary>
        /// <returns>View</returns>
        [HttpGet]
        [AllowAnonymous]
        public IActionResult SendEmailConfirmationDone()
        {
            return View();
        }

        /// <summary>
        /// View für den 2 Faktor Auth-Code
        /// </summary>
        /// <returns>View</returns>
        [HttpGet]
        [AllowAnonymous]
        public async Task<IActionResult> VerifyAuthenticatorCode()
        {
            // Require that the user has already logged in via username/password or external login
            var user = await _signInManager.GetTwoFactorAuthenticationUserAsync();
            if (user == null)
            {
                return View("Error");
            }
            return View(new VerifyAuthenticatorCodeViewModel());
        }

        /// <summary>
        /// View für den 2 Faktor Auth-Code
        /// </summary>
        /// <returns>View</returns>
        [HttpPost]
        [AllowAnonymous]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> VerifyAuthenticatorCode(VerifyAuthenticatorCodeViewModel model)
        {
            if (!ModelState.IsValid)
            {
                return View(model);
            }

            // The following code protects for brute force attacks against the two factor codes.
            // If a user enters incorrect codes for a specified amount of time then the user account
            // will be locked out for a specified amount of time.
            var result = await _signInManager.TwoFactorAuthenticatorSignInAsync(model.Code, false, false);
            if (result.Succeeded)
            {
                _logger.LogInformation("User logged in.");
                var user = await _signInManager.GetTwoFactorAuthenticationUserAsync();
                user.LastLoginDate = DateTimeOffset.UtcNow;
                await _userService.CommitAsync(user.UserName);

                var roles = await _userManager.GetRolesAsync(user);

                CultureInfo.CurrentCulture = new CultureInfo(user.PreferredLanguage);
                if (roles.Contains("Administrator"))
                    return RedirectToAction("Index", "Home", new { culture = CultureInfo.CurrentCulture.TwoLetterISOLanguageName });
                if (roles.Contains("PowerUser"))
                    return RedirectToAction("Index", "Home", new { culture = CultureInfo.CurrentCulture.TwoLetterISOLanguageName });
                else if (roles.Contains("Customer"))
                    return RedirectToAction("IndexCustomer", "Home", new { culture = CultureInfo.CurrentCulture.TwoLetterISOLanguageName });
                else if (roles.Contains("AppUser"))
                    return RedirectToAction("IndexAppUser", "Home", new { culture = CultureInfo.CurrentCulture.TwoLetterISOLanguageName });
                else
                    return RedirectToAction("Status401", "Home", new { culture = CultureInfo.CurrentCulture.TwoLetterISOLanguageName });
            }
            if (result.IsLockedOut)
            {
                return View("Lockout");
            }
            else
            {
                ModelState.AddModelError("Code", _localizer["Err_Invalid_Code"]);
                return View(model);
            }
        }
    }
}