﻿using System.Collections.Generic;
using System.Security.Claims;
using System.Threading.Tasks;
using System.Web;
using System.Web.Mvc;
using Microsoft.AspNet.Identity;
using Microsoft.AspNet.Identity.EntityFramework;
using Microsoft.AspNet.Identity.Owin;
using Microsoft.Owin.Security;
using _3NET_SyncWorld.Models;

namespace _3NET_SyncWorld.Controllers
{
    [Authorize]
    public class AccountController : Controller
    {
        public AccountController()
            : this(new UserManager<ApplicationUser>(new UserStore<ApplicationUser>(new ApplicationDbContext())))
        {
        }

        public AccountController(UserManager<ApplicationUser> userManager)
        {
            UserManager = userManager;
        }

        public UserManager<ApplicationUser> UserManager { get; private set; }

        //
        // GET: /Account/Login
        [AllowAnonymous]
        public ActionResult Login(string returnUrl)
        {
            ViewBag.ReturnUrl = returnUrl;
            return View();
        }

        //
        // POST: /Account/Login
        [HttpPost]
        [AllowAnonymous]
        [ValidateAntiForgeryToken]
        public async Task<ActionResult> Login(LoginViewModel model, string returnUrl)
        {
            if (ModelState.IsValid)
            {
                ApplicationUser user = await UserManager.FindAsync(model.UserName, model.Password);
                if (user != null)
                {
                    await SignInAsync(user, model.RememberMe);
                    return RedirectToLocal(returnUrl);
                }
                ModelState.AddModelError("", "Invalid username or password.");
            }

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

        //
        // GET: /Account/Register
        [AllowAnonymous]
        public ActionResult Register()
        {
            return View();
        }

        //
        // POST: /Account/Register
        [HttpPost]
        [AllowAnonymous]
        [ValidateAntiForgeryToken]
        public async Task<ActionResult> Register(RegisterViewModel model)
        {
            if (ModelState.IsValid)
            {
                var user = new ApplicationUser {UserName = model.UserName, Name = model.Name};
                IdentityResult result = await UserManager.CreateAsync(user, model.Password);
                if (result.Succeeded)
                {
                    await SignInAsync(user, false);
                    return RedirectToAction("Index", "Home");
                }
                AddErrors(result);
            }

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

        //
        // POST: /Account/Disassociate
        [HttpPost]
        [ValidateAntiForgeryToken]
        public async Task<ActionResult> Disassociate(string loginProvider, string providerKey)
        {
            ManageMessageId? message = null;
            IdentityResult result =
                await
                    UserManager.RemoveLoginAsync(User.Identity.GetUserId(),
                        new UserLoginInfo(loginProvider, providerKey));
            if (result.Succeeded)
            {
                message = ManageMessageId.RemoveLoginSuccess;
            }
            else
            {
                message = ManageMessageId.Error;
            }
            return RedirectToAction("Manage", new {Message = message});
        }

        //
        // GET: /Account/Manage
        public ActionResult Manage(ManageMessageId? message)
        {
            ViewBag.StatusMessage =
                message == ManageMessageId.ChangePasswordSuccess
                    ? "Your password has been changed."
                    : message == ManageMessageId.SetPasswordSuccess
                        ? "Your password has been set."
                        : message == ManageMessageId.RemoveLoginSuccess
                            ? "The external login was removed."
                            : message == ManageMessageId.Error
                                ? "An error has occurred."
                                : "";
            ViewBag.HasLocalPassword = HasPassword();
            ViewBag.ReturnUrl = Url.Action("Manage");
            return View();
        }

        // GET: /Account/Edit
        public ActionResult Edit(ManageMessageId? Message = null)
        {
            var db = new ApplicationDbContext();

            ApplicationUser @user = db.Users.Find(User.Identity.GetUserId());
            //UserManager.Update(@user);
            if (@user == null)
            {
                return HttpNotFound();
            }
            return View("Edit", new EditViewModel {UserName = @user.UserName, Name = @user.Name});
        }

        // POST: /Event/Edit
        // To protect from overposting attacks, please enable the specific properties you want to bind to, for 
        // more details see http://go.microsoft.com/fwlink/?LinkId=317598.
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Edit(EditViewModel editViewModel)
        {
            ApplicationUser user = UserManager.FindById(User.Identity.GetUserId());

            if (ModelState.IsValid)
            {
                user.UserName = editViewModel.UserName;
                user.Name = editViewModel.Name;
                UserManager.Update(user);
                return RedirectToAction("Edit");
            }
            return View("Edit", new EditViewModel {UserName = @user.UserName, Name = @user.Name});
        }

        //
        // POST: /Account/Manage
        [HttpPost]
        [ValidateAntiForgeryToken]
        public async Task<ActionResult> Manage(ManageUserViewModel model)
        {
            bool hasPassword = HasPassword();
            ViewBag.HasLocalPassword = hasPassword;
            ViewBag.ReturnUrl = Url.Action("Manage");
            if (hasPassword)
            {
                if (ModelState.IsValid)
                {
                    IdentityResult result =
                        await
                            UserManager.ChangePasswordAsync(User.Identity.GetUserId(), model.OldPassword,
                                model.NewPassword);
                    if (result.Succeeded)
                    {
                        return RedirectToAction("Manage", new {Message = ManageMessageId.ChangePasswordSuccess});
                    }
                    AddErrors(result);
                }
            }
            else
            {
                // User does not have a password so remove any validation errors caused by a missing OldPassword field
                ModelState state = ModelState["OldPassword"];
                if (state != null)
                {
                    state.Errors.Clear();
                }

                if (ModelState.IsValid)
                {
                    IdentityResult result =
                        await UserManager.AddPasswordAsync(User.Identity.GetUserId(), model.NewPassword);
                    if (result.Succeeded)
                    {
                        return RedirectToAction("Manage", new {Message = ManageMessageId.SetPasswordSuccess});
                    }
                    AddErrors(result);
                }
            }

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

        //
        // POST: /Account/LinkLogin
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult LinkLogin(string provider)
        {
            // Request a redirect to the external login provider to link a login for the current user
            return new ChallengeResult(provider, Url.Action("LinkLoginCallback", "Account"), User.Identity.GetUserId());
        }

        //
        // GET: /Account/LinkLoginCallback
        public async Task<ActionResult> LinkLoginCallback()
        {
            ExternalLoginInfo loginInfo =
                await AuthenticationManager.GetExternalLoginInfoAsync(XsrfKey, User.Identity.GetUserId());
            if (loginInfo == null)
            {
                return RedirectToAction("Manage", new {Message = ManageMessageId.Error});
            }
            IdentityResult result = await UserManager.AddLoginAsync(User.Identity.GetUserId(), loginInfo.Login);
            if (result.Succeeded)
            {
                return RedirectToAction("Manage");
            }
            return RedirectToAction("Manage", new {Message = ManageMessageId.Error});
        }


        //
        // POST: /Account/LogOff
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult LogOff()
        {
            AuthenticationManager.SignOut();
            return RedirectToAction("Index", "Home");
        }

        //
        // GET: /Account/ExternalLoginFailure
        [AllowAnonymous]
        public ActionResult ExternalLoginFailure()
        {
            return View();
        }

        [ChildActionOnly]
        public ActionResult RemoveAccountList()
        {
            IList<UserLoginInfo> linkedAccounts = UserManager.GetLogins(User.Identity.GetUserId());
            ViewBag.ShowRemoveButton = HasPassword() || linkedAccounts.Count > 1;
            return PartialView("_RemoveAccountPartial", linkedAccounts);
        }

        protected override void Dispose(bool disposing)
        {
            if (disposing && UserManager != null)
            {
                UserManager.Dispose();
                UserManager = null;
            }
            base.Dispose(disposing);
        }

        #region Helpers

        // Used for XSRF protection when adding external logins
        public enum ManageMessageId
        {
            ChangePasswordSuccess,
            SetPasswordSuccess,
            RemoveLoginSuccess,
            Error
        }

        private const string XsrfKey = "XsrfId";

        private IAuthenticationManager AuthenticationManager
        {
            get { return HttpContext.GetOwinContext().Authentication; }
        }

        private async Task SignInAsync(ApplicationUser user, bool isPersistent)
        {
            AuthenticationManager.SignOut(DefaultAuthenticationTypes.ExternalCookie);
            ClaimsIdentity identity =
                await UserManager.CreateIdentityAsync(user, DefaultAuthenticationTypes.ApplicationCookie);
            AuthenticationManager.SignIn(new AuthenticationProperties {IsPersistent = isPersistent}, identity);
        }

        private void AddErrors(IdentityResult result)
        {
            foreach (string error in result.Errors)
            {
                ModelState.AddModelError("", error);
            }
        }

        private bool HasPassword()
        {
            ApplicationUser user = UserManager.FindById(User.Identity.GetUserId());
            if (user != null)
            {
                return user.PasswordHash != null;
            }
            return false;
        }

        private ActionResult RedirectToLocal(string returnUrl)
        {
            if (Url.IsLocalUrl(returnUrl))
            {
                return Redirect(returnUrl);
            }
            return RedirectToAction("Index", "Home");
        }

        private class ChallengeResult : HttpUnauthorizedResult
        {
            public ChallengeResult(string provider, string redirectUri) : this(provider, redirectUri, null)
            {
            }

            public ChallengeResult(string provider, string redirectUri, string userId)
            {
                LoginProvider = provider;
                RedirectUri = redirectUri;
                UserId = userId;
            }

            public string LoginProvider { get; set; }
            public string RedirectUri { get; set; }
            public string UserId { get; set; }

            public override void ExecuteResult(ControllerContext context)
            {
                var properties = new AuthenticationProperties {RedirectUri = RedirectUri};
                if (UserId != null)
                {
                    properties.Dictionary[XsrfKey] = UserId;
                }
                context.HttpContext.GetOwinContext().Authentication.Challenge(properties, LoginProvider);
            }
        }

        #endregion
    }
}