using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Security.Principal;
using System.Web;
using System.Web.Mvc;
using System.Web.Security;
using System.Web.UI;
using NerdDinner.Helpers;

namespace NerdDinner.Controllers {

	  [HandleErrorWithELMAH]
    public class AccountController : Controller {

        // This constructor is used by the MVC framework to instantiate the controller using
        // the default forms authentication and membership providers.

        public AccountController()
            : this(null, null) {
        }

        // This constructor is not used by the MVC framework but is instead provided for ease
        // of unit testing this type. See the comments at the end of this file for more
        // information.
        public AccountController(IFormsAuthentication formsAuth, IMembershipService service) {
            FormsAuth = formsAuth ?? new FormsAuthenticationService();
            MembershipService = service ?? new AccountMembershipService();
        }

        public IFormsAuthentication FormsAuth {
            get;
            private set;
        }

        public IMembershipService MembershipService {
            get;
            private set;
        }

        public ActionResult LogOn() {

            return View();
        }

        [HttpPost]
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1054:UriParametersShouldNotBeStrings",
            Justification = "Needs to take same parameter type as Controller.Redirect()")]
        public ActionResult LogOn(string userName, string password, bool rememberMe, string returnUrl) {

            if (!ValidateLogOn(userName, password)) {
                ViewData["rememberMe"] = rememberMe;
                return View();
            }

            // Make sure we have the username with the right capitalization
            // since we do case sensitive checks for OpenID Claimed Identifiers later.
            userName = this.MembershipService.GetCanonicalUsername(userName);

            FormsAuthenticationTicket authTicket = new
                            FormsAuthenticationTicket(1, //version
                            userName, // user name
                            DateTime.Now,             //creation
                            DateTime.Now.AddMinutes(30), //Expiration
                            rememberMe, //Persistent
                            userName); //since Classic logins don't have a "Friendly Name"

            string encTicket = FormsAuthentication.Encrypt(authTicket);
            this.Response.Cookies.Add(new HttpCookie(FormsAuthentication.FormsCookieName, encTicket));

            if (!String.IsNullOrEmpty(returnUrl)) {
                return Redirect(returnUrl);
            }
            else {
                return RedirectToAction("Index", "Home");
            }
        }

        public ActionResult LogOff() {

            FormsAuth.SignOut();

            return RedirectToAction("Index", "Home");
        }

        public ActionResult Register() {

            ViewData["PasswordLength"] = MembershipService.MinPasswordLength;

            return View();
        }

        [HttpPost]
        public ActionResult Register(string userName, string email, string password, string confirmPassword) {

            ViewData["PasswordLength"] = MembershipService.MinPasswordLength;

            if (ValidateRegistration(userName, email, password, confirmPassword)) {
                // Attempt to register the user
                MembershipCreateStatus createStatus = MembershipService.CreateUser(userName, password, email);

                if (createStatus == MembershipCreateStatus.Success) {
                    FormsAuth.SignIn(userName, false /* createPersistentCookie */);
                    return RedirectToAction("Index", "Home");
                }
                else {
                    ModelState.AddModelError("_FORM", ErrorCodeToString(createStatus));
                }
            }

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

        [Authorize]
        public ActionResult ChangePassword() {

            ViewData["PasswordLength"] = MembershipService.MinPasswordLength;

            return View();
        }

        [Authorize]
        [HttpPost]
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes",
            Justification = "Exceptions result in password not being changed.")]
        public ActionResult ChangePassword(string currentPassword, string newPassword, string confirmPassword) {

            ViewData["PasswordLength"] = MembershipService.MinPasswordLength;

            if (!ValidateChangePassword(currentPassword, newPassword, confirmPassword)) {
                return View();
            }

            try {
                if (MembershipService.ChangePassword(User.Identity.Name, currentPassword, newPassword)) {
                    return RedirectToAction("ChangePasswordSuccess");
                }
                else {
                    ModelState.AddModelError("_FORM", "The current password is incorrect or the new password is invalid.");
                    return View();
                }
            }
            catch {
                ModelState.AddModelError("_FORM", "The current password is incorrect or the new password is invalid.");
                return View();
            }
        }

        public ActionResult ChangePasswordSuccess() {

            return View();
        }

        protected override void OnActionExecuting(ActionExecutingContext filterContext)
        {
            if (filterContext.HttpContext.User.Identity is WindowsIdentity) {
                throw new InvalidOperationException("Windows authentication is not supported.");
            }
        }

        #region Validation Methods

        private bool ValidateChangePassword(string currentPassword, string newPassword, string confirmPassword) {
            if (String.IsNullOrEmpty(currentPassword)) {
                ModelState.AddModelError("currentPassword", "You must specify a current password.");
            }
            if (newPassword == null || newPassword.Length < MembershipService.MinPasswordLength) {
                ModelState.AddModelError("newPassword",
                    String.Format(CultureInfo.CurrentCulture,
                         "You must specify a new password of {0} or more characters.",
                         MembershipService.MinPasswordLength));
            }

            if (!String.Equals(newPassword, confirmPassword, StringComparison.Ordinal)) {
                ModelState.AddModelError("_FORM", "The new password and confirmation password do not match.");
            }

            return ModelState.IsValid;
        }

        private bool ValidateLogOn(string userName, string password) {
            if (String.IsNullOrEmpty(userName)) {
                ModelState.AddModelError("username", "You must specify a username.");
            }
            if (String.IsNullOrEmpty(password)) {
                ModelState.AddModelError("password", "You must specify a password.");
            }
            if (!MembershipService.ValidateUser(userName, password)) {
                ModelState.AddModelError("_FORM", "The username or password provided is incorrect.");
            }

            return ModelState.IsValid;
        }

        private bool ValidateRegistration(string userName, string email, string password, string confirmPassword) {
            if (String.IsNullOrEmpty(userName)) {
                ModelState.AddModelError("username", "You must specify a username.");
            }
            if (String.IsNullOrEmpty(email)) {
                ModelState.AddModelError("email", "You must specify an email address.");
            }
            if (password == null || password.Length < MembershipService.MinPasswordLength) {
                ModelState.AddModelError("password",
                    String.Format(CultureInfo.CurrentCulture,
                         "You must specify a password of {0} or more characters.",
                         MembershipService.MinPasswordLength));
            }
            if (!String.Equals(password, confirmPassword, StringComparison.Ordinal)) {
                ModelState.AddModelError("_FORM", "The new password and confirmation password do not match.");
            }
            return ModelState.IsValid;
        }

        private static string ErrorCodeToString(MembershipCreateStatus createStatus) {
            // See http://msdn.microsoft.com/en-us/library/system.web.security.membershipcreatestatus.aspx for
            // a full list of status codes.
            switch (createStatus) {
                case MembershipCreateStatus.DuplicateUserName:
                    return "Username already exists. Please enter a different user name.";

                case MembershipCreateStatus.DuplicateEmail:
                    return "A username for that e-mail address already exists. Please enter a different e-mail address.";

                case MembershipCreateStatus.InvalidPassword:
                    return "The password provided is invalid. Please enter a valid password value.";

                case MembershipCreateStatus.InvalidEmail:
                    return "The e-mail address provided is invalid. Please check the value and try again.";

                case MembershipCreateStatus.InvalidAnswer:
                    return "The password retrieval answer provided is invalid. Please check the value and try again.";

                case MembershipCreateStatus.InvalidQuestion:
                    return "The password retrieval question provided is invalid. Please check the value and try again.";

                case MembershipCreateStatus.InvalidUserName:
                    return "The user name provided is invalid. Please check the value and try again.";

                case MembershipCreateStatus.ProviderError:
                    return "The authentication provider returned an error. Please verify your entry and try again. If the problem persists, please contact your system administrator.";

                case MembershipCreateStatus.UserRejected:
                    return "The user creation request has been canceled. Please verify your entry and try again. If the problem persists, please contact your system administrator.";

                default:
                    return "An unknown error occurred. Please verify your entry and try again. If the problem persists, please contact your system administrator.";
            }
        }
        #endregion
    }

    // The FormsAuthentication type is sealed and contains static members, so it is difficult to
    // unit test code that calls its members. The interface and helper class below demonstrate
    // how to create an abstract wrapper around such a type in order to make the AccountController
    // code unit testable.

    public interface IFormsAuthentication {
        void SignIn(string userName, bool createPersistentCookie);
        void SignOut();
    }

    public class FormsAuthenticationService : IFormsAuthentication {
        public void SignIn(string userName, bool createPersistentCookie) {
            FormsAuthentication.SetAuthCookie(userName, createPersistentCookie);
        }
        public void SignOut() {
            FormsAuthentication.SignOut();
        }
    }

    public interface IMembershipService {
        int MinPasswordLength { get; }

        bool ValidateUser(string userName, string password);
        string GetCanonicalUsername(string userName);
        MembershipCreateStatus CreateUser(string userName, string password, string email);
        bool ChangePassword(string userName, string oldPassword, string newPassword);
    }

    public class AccountMembershipService : IMembershipService {
        private MembershipProvider _provider;

        public AccountMembershipService()
            : this(null) {
        }

        public AccountMembershipService(MembershipProvider provider) {
            _provider = provider ?? Membership.Provider;
        }

        public int MinPasswordLength {
            get {
                return _provider.MinRequiredPasswordLength;
            }
        }

        public bool ValidateUser(string userName, string password) {
            return _provider.ValidateUser(userName, password);
        }

        public string GetCanonicalUsername(string userName)
        {
            var user = _provider.GetUser(userName, true);
            if (user != null)
            {
               return user.UserName;
            }

            return null;
        }

        public MembershipCreateStatus CreateUser(string userName, string password, string email) {
            MembershipCreateStatus status;
            _provider.CreateUser(userName, password, email, null, null, true, null, out status);
            return status;
        }

        public bool ChangePassword(string userName, string oldPassword, string newPassword) {
            MembershipUser currentUser = _provider.GetUser(userName, true /* userIsOnline */);
            return currentUser.ChangePassword(oldPassword, newPassword);
        }
    }
}
