using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Entity;
using System.Linq;
using System.Net;
using System.Threading.Tasks;
using System.Web;
using System.Web.Mvc;
using Microsoft.AspNet.Identity;
using Microsoft.AspNet.Identity.Owin;
using Project_Unite.Models;

namespace Project_Unite.Controllers
{
    //We have a custom ACL implementation so we do not need to use the ASP.NET role system to check if a user has an ACL rule.
    [Authorize]
    public class AdminController : Controller
    {
        private ApplicationDbContext db = new ApplicationDbContext();

        public ActionResult Index()
        {
            ViewBag.Admin = true;
            return View();
        }


        public ActionResult DeleteForum(string id)
        {
            var frm = db.ForumCategories.FirstOrDefault(x => x.Id == id);
            if (frm == null)
                return new HttpStatusCodeResult(404);

            //Purge ALL DATA RELATED TO THIS CATEGORY.
            DeleteCategoryRecursive(frm);
            db.SaveChanges();

            return RedirectToAction("Forums");
        }


        public void DeleteCategoryRecursive(ForumCategory start)
        {
            foreach (var c in start.Children.ToArray())
            {
                DeleteCategoryRecursive(c);
            }

            foreach (var topic in start.Topics.ToArray())
            {
                DeleteTopic(topic);
            }
            db.ForumCategories.Remove(db.ForumCategories.FirstOrDefault(x => x.Id == start.Id));

        }

        public void DeleteTopic(ForumTopic topic)
        {
            foreach(var post in topic.Posts.ToArray())
            {
                DeletePost(post);
            }
            db.ForumTopics.Remove(topic);
        }

        public ActionResult AccessControl()
        {
            var model = new Dictionary<string, ForumPermission[]>();
            var db = new ApplicationDbContext();
            var forums = db.ForumCategories.ToArray();
            foreach(var forum in forums)
            {
                ACL.UpdateACLDefinitions(forum.Id);
                if(forum.Id != "root")
                {
                    if (!model.ContainsKey(forum.Id))
                    {
                        model.Add(forum.Id, forum.Permissions);
                    }
                }
            }
            return View(new AdminAccessControlViewModel(model));  
        }

        public ActionResult SetPermission(string id, string role, string permission)
        {
            if (!ACL.Granted(User.Identity.Name, "CanAccessAdminCP"))
                return new HttpStatusCodeResult(403);
            if (!ACL.Granted(User.Identity.Name, "CanEditRoles"))
                return new HttpStatusCodeResult(403);
            if (!ACL.Granted(User.Identity.Name, "CanEditForumCategories"))
                return new HttpStatusCodeResult(403);

            var db = new ApplicationDbContext();
            var frm = db.ForumCategories.FirstOrDefault(x => x.Id == id);
            if (frm == null)
                return new HttpStatusCodeResult(403);
            var rolePerm = db.ForumPermissions.Where(x => x.CategoryId == frm.Id).FirstOrDefault(x => x.RoleId == role);
            if (rolePerm == null)
                return new HttpStatusCodeResult(404);

            rolePerm.Permissions = (PermissionPreset)Enum.Parse(typeof(PermissionPreset), permission);

            db.AuditLogs.Add(new Models.AuditLog(User.Identity.GetUserId(), AuditLogLevel.Admin, "User altered the ACL definition for forum ID " + id + ", role ID " + role + ", to permission \"" + permission + "\"."));
            db.SaveChanges();

            return RedirectToAction("AccessControl");

        }

        public void DeletePost(ForumPost post)
        {
            db.ForumPosts.Remove(post);
        }


        // GET: Admin/Forums
        public ActionResult Forums()
        {
            ViewBag.Admin = true;
            var cats = db.ForumCategories.First(x => x.Id == "root").Children.Where(x=>x.Id != "root");
            return View(cats);
        }



        public ActionResult AddForumCategory(string parentId)
        {
            ViewBag.Admin = true;
            if (parentId == null)
                parentId = "root";

            var model = new AddForumCategoryViewModel();
            model.PossibleParents = GetForumCategories();
            model.Parent = (parentId);
            return View(model);
        }

        public ActionResult RaisePriority(string id)
        {
            var uid = User.Identity.Name;
            if(ACL.Granted(uid, "CanEditRoles"))
            {
                var db = new ApplicationDbContext();
                var role = db.Roles.FirstOrDefault(x => x.Id == id) as Role;
                if (role == null)
                    return new HttpStatusCodeResult(HttpStatusCode.BadRequest);

                if (role.Priority == db.Roles.Count() - 1)
                    return new HttpStatusCodeResult(HttpStatusCode.BadRequest);

                Role higherUp = null;
                foreach(var r in db.Roles)
                {
                    if ((r as Role).Priority == role.Priority + 1)
                        higherUp = r as Role;
                }

                higherUp.Priority--;
                role.Priority++;
                db.SaveChanges();

                return RedirectToAction("Roles");
            }
            else
            {
                return new HttpStatusCodeResult(403);
            }
        }

        public async Task<ActionResult> RemoveUserFromRole(string id, string usr)
        {
            if(ACL.CanManageRole(User.Identity.Name, id))
            {
                var uman = HttpContext.GetOwinContext().GetUserManager<ApplicationUserManager>();
                await uman.RemoveFromRoleAsync(usr, id);
                return RedirectToAction("RoleDetails", new { @id = id });
            }
            else
            {
                return new HttpStatusCodeResult(403);
            }
        }

        public ActionResult LowerPriority(string id)
        {
            var uid = User.Identity.Name;
            if (ACL.Granted(uid, "CanEditRoles"))
            {
                var db = new ApplicationDbContext();
                var role = db.Roles.FirstOrDefault(x => x.Id == id) as Role;
                if (role == null)
                    return new HttpStatusCodeResult(HttpStatusCode.BadRequest);

                if (role.Priority == 0)
                    return new HttpStatusCodeResult(HttpStatusCode.BadRequest);

                Role higherUp = null;
                foreach (var r in db.Roles)
                {
                    if ((r as Role).Priority == role.Priority - 1)
                        higherUp = r as Role;
                }

                if(higherUp != null)
                    higherUp.Priority++;
                role.Priority--;
                db.SaveChanges();

                return RedirectToAction("Roles");
            }
            else
            {
                return new HttpStatusCodeResult(403);
            }
        }


        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult AddForumCategory(AddForumCategoryViewModel model)
        {
            try
            {
                if (model == null)
                    return new HttpStatusCodeResult(HttpStatusCode.BadRequest);

                if (string.IsNullOrWhiteSpace(model.Name))
                {
                    ViewBag.Error = "Please specify a name for this forum category.";
                    return View(model);
                }

                string DisallowedChars = "/.,\\][;':\"|?><!@#$%^&*()_+-=`~}{ ";

                string id = model.Name.ToLower();

                foreach (var c in DisallowedChars)
                {
                    id = id.Replace(c, '_');
                }


                var frm = new ForumCategory();

                frm.Name = model.Name;
                frm.Id = id;

                frm.Description = model.Description;
                frm.LinkUrl = null;
                frm.Parent = db.ForumCategories.FirstOrDefault(x => x.Id == model.Parent).Id;
                db.ForumCategories.Add(frm);

                db.SaveChanges();
                if (model.StealPermissionsFrom != "root")
                {
                    var frmToSteal = db.ForumCategories.FirstOrDefault(x => x.Id == model.StealPermissionsFrom);
                    ACL.UpdateACLDefinitions(frmToSteal.Id); //Just to be sure..
                    foreach(var perm in frmToSteal.Permissions)
                    {
                        var aclEntry = new ForumPermission();
                        aclEntry.CategoryId = frm.Id;
                        aclEntry.RoleId = perm.RoleId;
                        aclEntry.Permissions = perm.Permissions;
                        aclEntry.Id = Guid.NewGuid().ToString();
                        db.ForumPermissions.Add(aclEntry);
                    }
                    db.SaveChanges();
                }
                else
                {
                    ACL.UpdateACLDefinitions(frm.Id);
                    //This sets the permission data to the default values.
                }


                
                return RedirectToAction("Forums");
            }
            catch (Exception ex)
            {
                ViewBag.Error = ex.ToString();
                return View(model);
            }
        }

        public ActionResult AnonymizeUser(string id)
        {
            if (!ACL.Granted(User.Identity.Name, "CanAcessAdminCP"))
                return new HttpStatusCodeResult(HttpStatusCode.Forbidden);
            if (!ACL.Granted(User.Identity.Name, "CanAnonymizeUser"))
                return new HttpStatusCodeResult(HttpStatusCode.Forbidden);
            var db = new ApplicationDbContext();
            var user = db.Users.FirstOrDefault(x => x.Id == id);
            if (user == null)
                return new HttpStatusCodeResult(404);

            user.UserName = Guid.NewGuid().ToString() + "@system";
            user.Email = Guid.NewGuid().ToString() + "@system";
            user.PasswordHash = Guid.NewGuid().ToString();
            user.EmailConfirmed = false;
            user.Hobbies = "";
            user.Interests = "";
            user.Bio = @"# User anonymized.

This user has been anonymized by an administrator.";
            user.AvatarUrl = "";
            user.BannerUrl = "";
            var uman = HttpContext.GetOwinContext().GetUserManager<ApplicationUserManager>();
            foreach(var role in user.Roles)
            {
                uman.RemoveFromRole(user.Id, role.RoleId);
            }
            uman.AddToRole(user.Id, ACL.LowestPriorityRole().Id);
            db.SaveChanges();
            return RedirectToAction("Users");
        }


        public ActionResult Logs()
        {
            if (!ACL.Granted(User.Identity.Name, "CanAccessAdminCP"))
                return new HttpStatusCodeResult(403);

            var db = new ApplicationDbContext();

            return View(db.AuditLogs);
        }


        public ActionResult Users()
        {
            return View(new ApplicationDbContext().Users);
        }

        public ActionResult EditForum(string id)
        {
            ViewBag.Admin = true;
            var frm = db.ForumCategories.FirstOrDefault(x => x.Id == id);
            if (frm == null)
                return new HttpStatusCodeResult(404);

            var m = new AddForumCategoryViewModel();
            m.Id = frm.Id;
            m.Parent = frm.Parent;
            m.Description = frm.Description;
            m.Name = frm.Name;
            m.PossibleParents = GetForumCategories();
            return View(m);
        }

        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult EditForum(string id, AddForumCategoryViewModel m)
        {
            try
            {
                m.Id = id;
                var frm = db.ForumCategories.FirstOrDefault(x => x.Id == id);

                frm.Name = m.Name;
                frm.Description = m.Description;



                frm.Parent = m.Parent;
                db.SaveChanges();
                
                return RedirectToAction("Forums");
            }
            catch (Exception ex)
            {
                ViewBag.Error = ex.ToString();
                return View(m);
            }
        }






        // GET: Admin
        public ActionResult Roles()
        {
            ViewBag.Admin = true;
            return View(db.IdentityRoles.ToList());
        }

        // GET: Admin/RoleDetails/5
        public ActionResult RoleDetails(string id)
        {
            ViewBag.Admin = true;
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
            Role role = db.IdentityRoles.Find(id);
            if (role == null)
            {
                return HttpNotFound();
            }
            return View(role);
        }

        // GET: Admin/Create
        public ActionResult CreateRole()
        {
            ViewBag.Admin = true;
            return View();
        }

        // POST: Admin/Create
        // 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 CreateRole(Role role)
        {
            if (ModelState.IsValid)
            {
                db.IdentityRoles.Add(role);
                db.SaveChanges();
                return RedirectToAction("Roles");
            }

            return View(role);
        }

        // GET: Admin/AddUserToRole
        public ActionResult AddUserToRole()
        {
            ViewBag.Admin = true;
            return View(new AddUserToRoleViewModel());
        }

        // POST: Admin/AddUserToRole
        [HttpPost]
        public async Task<ActionResult> AddUserToRole(AddUserToRoleViewModel model)
        {
            var r = db.Roles.FirstOrDefault(role => role.Name == model.RoleId);
            var user = db.Users.FirstOrDefault(u => u.DisplayName == model.Username);
            var uMan = HttpContext.GetOwinContext().GetUserManager<ApplicationUserManager>();

            var isInRole = await uMan.IsInRoleAsync(user.Id, r.Id);
            
            if(isInRole)
            {
                ViewBag.Error = $"{model.Username} is already in the {r.Name} role.";
                return View(model);
            }
            else
            {
                await uMan.AddToRoleAsync(user.Id, r.Name);
                return RedirectToAction("Roles");
            }


        }

        // GET: Admin/Edit/5
        public ActionResult EditRole(string id)
        {
            ViewBag.Admin = true;
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
            Role role = db.IdentityRoles.Find(id);
            if (role == null)
            {
                return HttpNotFound();
            }
            return View(role);
        }

        // POST: Admin/Edit/5
        // 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 EditRole(Role role)
        {
            if (ModelState.IsValid)
            {
                db.Entry(role).State = EntityState.Modified;
                db.SaveChanges();
                return RedirectToAction("Index");
            }
            return View(role);
        }

        // GET: Admin/Delete/5
        public ActionResult DeleteRole(string id)
        {
            ViewBag.Admin = true;
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
            Role role = db.IdentityRoles.Find(id);
            if (role == null)
            {
                return HttpNotFound();
            }
            return View(role);
        }

        // POST: Admin/Delete/5
        [HttpPost, ActionName("Delete")]
        [ValidateAntiForgeryToken]
        public ActionResult DeleteRoleConfirmed(string id)
        {
            Role role = db.IdentityRoles.Find(id);
            db.IdentityRoles.Remove(role);
            db.SaveChanges();
            return RedirectToAction("Index");
        }

        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                db.Dispose();
            }
            base.Dispose(disposing);
        }

        public List<SelectListItem> GetForumCategories()
        {
            var items = new List<SelectListItem>();
            items.Add(new SelectListItem
            {
                Value = "root",
                Text = "Top Level"
            });

            foreach(var cat in getChildren("root", 1))
            {
                items.Add(cat);
            }

            return items;

        }

        private IEnumerable<SelectListItem> getChildren(string id, int dashcount)
        {
            var lst = new List<SelectListItem>();
            db = new ApplicationDbContext();
            foreach (var cat in db.ForumCategories.FirstOrDefault(c => c.Id == id).Children.Where(x=>x.Id != "root"))
            {
                string dashes = "";
                for (int i = 0; i <= dashcount; i++)
                    dashes += "-";
                lst.Add(new SelectListItem
                {
                    Text = dashes + " " + cat.Name,
                    Value = cat.Id,
                });
                lst.AddRange(getChildren(cat.Id, dashcount + 1));
            }
            return lst;
        }
    }
}