using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;
using Tango.BL;
using Tango.BL.Entities;
using Tango.Core.Commands;
using Tango.MachineStudio.Common;
using Tango.MachineStudio.Common.Notifications;
using Tango.MachineStudio.UsersAndRoles.Navigation;
using Tango.MachineStudio.UsersAndRoles.Providers;
using Tango.SharedUI;
using System.Data.Entity;
using Tango.BL.Builders;
using Tango.BL.ActionLogs;
using Tango.BL.DTO;
using Tango.BL.Enumerations;
using Tango.MachineStudio.Common.Authentication;

namespace Tango.MachineStudio.UsersAndRoles.ViewModels
{
    public class MainViewVM : StudioViewModel
    {
        private ObservablesContext _organizationsContext;
        private ObservablesContext _manageContext;
        private ObservablesContext _userContext;
        private UsersAndRolesNavigationManager _navigation;
        private INotificationProvider _notification;
        private IActionLogManager _actionLogManager;
        private OrganizationDTO _organizationBeforeSave;
        private IAuthenticationProvider _authenticationProvider;
        private UserDTO _userBeforeSave;

        private ObservableCollection<Organization> _organizations;
        public ObservableCollection<Organization> Organizations
        {
            get { return _organizations; }
            set { _organizations = value; RaisePropertyChangedAuto(); }
        }

        private Organization _selectedOrganization;
        public Organization SelectedOrganization
        {
            get { return _selectedOrganization; }
            set { _selectedOrganization = value; RaisePropertyChangedAuto(); }
        }

        private Organization _managedOrganization;
        public Organization ManagedOrganization
        {
            get { return _managedOrganization; }
            set { _managedOrganization = value; RaisePropertyChangedAuto(); }
        }

        private ObservableCollection<Role> _roles;
        public ObservableCollection<Role> Roles
        {
            get { return _roles; }
            set { _roles = value; RaisePropertyChangedAuto(); }
        }

        private ObservableCollection<Role> _managedUserRoles;
        public ObservableCollection<Role> ManagedUserRoles
        {
            get { return _managedUserRoles; }
            set { _managedUserRoles = value; RaisePropertyChangedAuto(); }
        }

        private User _selectedUser;
        public User SelectedUser
        {
            get { return _selectedUser; }
            set { _selectedUser = value; RaisePropertyChangedAuto(); }
        }

        private User _managedUser;
        public User ManagedUser
        {
            get { return _managedUser; }
            set { _managedUser = value; RaisePropertyChangedAuto(); }
        }

        private Place _selectedUserPlace;
        public Place SelectedUserPlace
        {
            get { return _selectedUserPlace; }
            set
            {
                _selectedUserPlace = value;

                if (_selectedUserPlace != null && _selectedUserPlace.Address != null)
                {
                    SetUserPlace(value);
                }
            }
        }

        private Place _selectedOrganizationPlace;
        public Place SelectedOrganizationPlace
        {
            get { return _selectedOrganizationPlace; }
            set
            {
                _selectedOrganizationPlace = value;

                if (_selectedOrganizationPlace != null && _selectedOrganizationPlace.Address != null)
                {
                    SetOrganizationPlace(value);
                }
            }
        }

        private bool _showDeleted;
        public bool ShowDeleted
        {
            get { return _showDeleted; }
            set
            {
                _showDeleted = value;
                if (_showDeleted)
                {
                    //ShowDeletedUsers();
                }
            }
        }


        public RelayCommand ManageOrganizationCommand { get; set; }

        public RelayCommand BackToOrganizationsCommand { get; set; }

        public RelayCommand ManageUserCommand { get; set; }

        public RelayCommand SaveOrganizationCommand { get; set; }

        public RelayCommand AddOrganizationCommand { get; set; }

        public RelayCommand RemoveOrganizationCommand { get; set; }

        public RelayCommand BackToManagedOrganizationCommand { get; set; }

        public RelayCommand<Role> RemoveRoleCommand { get; set; }

        public RelayCommand SaveManagedUserCommand { get; set; }

        public RelayCommand RestoreAndSaveManagedUserCommand { get; set; }

        public RelayCommand AddUserCommand { get; set; }

        public RelayCommand RemoveUserCommand { get; set; }

        public MainViewVM(UsersAndRolesNavigationManager navigation, INotificationProvider notification, IActionLogManager actionLogManager, IAuthenticationProvider authenticationProvider)
        {
            _navigation = navigation;
            _notification = notification;
            _actionLogManager = actionLogManager;
            _authenticationProvider = authenticationProvider;

            ManageOrganizationCommand = new RelayCommand(LoadSelectedOrganization, () => SelectedOrganization != null);
            BackToOrganizationsCommand = new RelayCommand(BackToOrganizations);
            ManageUserCommand = new RelayCommand(LoadSelectedUser, () => SelectedUser != null);
            SaveOrganizationCommand = new RelayCommand(SaveOrganization);
            AddOrganizationCommand = new RelayCommand(AddOrganization);
            RemoveOrganizationCommand = new RelayCommand(RemoveOrganization, () => SelectedOrganization != null);
            BackToManagedOrganizationCommand = new RelayCommand(BackToManagedOrganization);
            RemoveRoleCommand = new RelayCommand<Role>(RemoveUserRole);
            SaveManagedUserCommand = new RelayCommand(SaveManagedUser);
            RestoreAndSaveManagedUserCommand = new RelayCommand(RestoreAndSaveManagedUser);
            AddUserCommand = new RelayCommand(AddNewUser);
            RemoveUserCommand = new RelayCommand(RemoveSelectedUser, () => SelectedUser != null);
            _showDeleted = false;
        }

        public override void OnApplicationReady()
        {
            LoadOrganizations();
        }

        private async void AddOrganization()
        {
            String name = _notification.ShowTextInput("Enter organization name", "Name");

            if (!String.IsNullOrWhiteSpace(name))
            {
                using (_notification.PushTaskItem("Adding new organization..."))
                {
                    Organization org = new Organization();
                    org.Name = name;
                    org.Address = new Address();
                    org.Contact = new Contact();
                    _organizationsContext.Organizations.Add(org);
                    await org.SaveAsync(_organizationsContext);
                    _actionLogManager.InsertLog(ActionLogType.OrganizationCreated, _authenticationProvider.CurrentUser, org.Name, org, "Organization created using Machine Studio.");
                    Organizations = _organizationsContext.Organizations.ToObservableCollection();
                    SelectedOrganization = org;
                    LoadSelectedOrganization();
                }
            }
        }

        private async void RemoveOrganization()
        {
            if (_notification.ShowQuestion("Are you sure you want to remove " + SelectedOrganization.Name + " organization?"))
            {

                using (ObservablesContext db = ObservablesContext.CreateDefault())
                {
                    var usersCount = db.Users.Count(x => x.OrganizationGuid == SelectedOrganization.Guid);

                    if (usersCount > 0)
                    {
                        _notification.ShowError($"The organization cannot be removed as it contains {usersCount} users.");
                        return;
                    }

                    var machinesCount = db.Machines.Count(x => x.OrganizationGuid == SelectedOrganization.Guid);

                    if (machinesCount > 0)
                    {
                        _notification.ShowError($"The organization cannot be removed as it contains {machinesCount} machines.");
                        return;
                    }

                    var sitesCount = db.Sites.Count(x => x.OrganizationGuid == SelectedOrganization.Guid);

                    if (sitesCount > 0)
                    {
                        _notification.ShowError($"The organization cannot be removed as it contains {sitesCount} sites.");
                        return;
                    }
                }


                using (_notification.PushTaskItem("Removing organization..."))
                {
                    await SelectedOrganization.DeleteCascadeAsync(_organizationsContext);
                    _actionLogManager.InsertLog(ActionLogType.OrganizationDeleted, _authenticationProvider.CurrentUser, SelectedOrganization.Name, SelectedOrganization, "Organization deleted using Machine Studio.");
                    await LoadOrganizations();
                }
            }
        }

        private async void SaveOrganization()
        {
            using (_notification.PushTaskItem("Saving organization address and contact..."))
            {
                var organizationAfter = OrganizationDTO.FromObservable(ManagedOrganization);

                await ManagedOrganization.SaveAsync(_manageContext);
                _actionLogManager.InsertLog(ActionLogType.OrganizationSaved, _authenticationProvider.CurrentUser, ManagedOrganization.Name, _organizationBeforeSave, organizationAfter, "Organization saved using Machine Studio.");

                _organizationBeforeSave = organizationAfter;

                await LoadOrganizations();
                SelectedOrganization = Organizations.SingleOrDefault(x => x.Guid == ManagedOrganization.Guid);
            }
        }

        private async void LoadSelectedUser()
        {
            using (_notification.PushTaskItem("Loading user details..."))
            {
                await Task.Factory.StartNew(() =>
                {
                    _userContext = ObservablesContext.CreateDefault();

                    Roles = new RolesCollectionBuilder(_userContext).SetAll().WithPermission().Build();
                    ManagedUser = new UserBuilder(_userContext).WithDeleted().Set(SelectedUser.Guid).WithRolesAndPermissions().Build();
                    ManagedUserRoles = ManagedUser.Roles.ToObservableCollection();

                    _userBeforeSave = UserDTO.FromObservable(ManagedUser);
                });

                _navigation.NavigateTo(UsersAndRolesNavigationView.UserManagementView);
            }
        }

        private void BackToOrganizations()
        {
            _navigation.NavigateTo(UsersAndRolesNavigationView.OrganizationSelectionView);
        }

        private void BackToManagedOrganization()
        {
            _navigation.NavigateTo(UsersAndRolesNavigationView.OrganizationManagementView);
        }

        private void RemoveUserRole(Role role)
        {
            ManagedUserRoles.Remove(role);

            foreach (var userRole in ManagedUser.UsersRoles.Where(x => x.Role == role).ToList())
            {
                _userContext.UsersRoles.Remove(userRole);
            }
        }

        private async void SaveManagedUser()
        {
            try
            {
                ManagedUser.Validate(_userContext);

                if (ManagedUser.Roles.GroupBy(x => x.RoleEnum).Any(x => x.Count() > 1))
                {
                    throw new InvalidOperationException("Cannot save user with duplicate roles.");
                }
            }
            catch (Exception ex)
            {
                _notification.ShowError(ex.Message);
                return;
            }

            using (_notification.PushTaskItem("Saving user details..."))
            {
                var userAfter = UserDTO.FromObservable(ManagedUser);
                await ManagedUser.SaveAsync(_userContext);
                _actionLogManager.InsertLog(ActionLogType.UserSaved, _authenticationProvider.CurrentUser, ManagedUser.Email, _userBeforeSave, userAfter, "User saved using Machine Studio.");
                _userBeforeSave = userAfter;
                LoadSelectedOrganization();
            }
        }

        private async void RestoreAndSaveManagedUser()
        {
            try
            {
                ManagedUser.Validate(_userContext);

                if (ManagedUser.Roles.GroupBy(x => x.RoleEnum).Any(x => x.Count() > 1))
                {
                    throw new InvalidOperationException("Cannot save user with duplicate roles.");
                }
            }
            catch (Exception ex)
            {
                _notification.ShowError(ex.Message);
                return;
            }
            if (_notification.ShowQuestion("Are you sure you wish to re-activate this account?"))
            {
                using (_notification.PushTaskItem("Saving user details..."))
                {
                    ManagedUser.Deleted = false;

                    var userAfter = UserDTO.FromObservable(ManagedUser);
                    await ManagedUser.SaveAsync(_userContext);
                    _actionLogManager.InsertLog(ActionLogType.UserRestored, _authenticationProvider.CurrentUser, ManagedUser.Email, _userBeforeSave, userAfter, "User restored using Machine Studio.");
                    _userBeforeSave = userAfter;
                    LoadSelectedOrganization();
                }
            }
        }

        private async void LoadSelectedOrganization()
        {
            using (_notification.PushTaskItem("Loading organization..."))
            {
                await Task.Factory.StartNew(() =>
                {
                    _manageContext = ObservablesContext.CreateDefault();

                    ManagedOrganization = new OrganizationBuilder(_manageContext).Set(SelectedOrganization.Guid).WithUsers(true).Build();

                    _organizationBeforeSave = OrganizationDTO.FromObservable(ManagedOrganization);
                });

                _navigation.NavigateTo(UsersAndRolesNavigationView.OrganizationManagementView);
            }
        }

        private Task LoadOrganizations()
        {
            return Task.Factory.StartNew(() =>
            {
                _organizationsContext = ObservablesContext.CreateDefault();

                Organizations = new OrganizationsCollectionBuilder(_organizationsContext).SetAll().WithUsers().WithMachines().Build();
            });
        }

        public void OnDropRole(Role role)
        {
            ManagedUser.UsersRoles.Add(new UsersRole()
            {
                Role = role,
                RoleGuid = role.Guid,
                User = ManagedUser,
                UserGuid = ManagedUser.Guid,
            });

            ManagedUserRoles.Add(role);
        }

        private async void RemoveSelectedUser()
        {
            if (_notification.ShowQuestion("Are you sure you want to remove the selected user?"))
            {
                using (_notification.PushTaskItem("Removing user..."))
                {
                    await SelectedUser.DeleteCascadeAsync(_manageContext);
                    _actionLogManager.InsertLog(ActionLogType.UserDeleted, _authenticationProvider.CurrentUser, SelectedUser.Email, SelectedUser, "User deleted using Machine Studio.");
                    LoadSelectedOrganization();
                }
            }
        }

        private void AddNewUser()
        {
            _notification.ShowModalDialog<UserCreationDialogVM>(async (vm) =>
            {
                User user = new User();
                user.Email = vm.Email;
                user.Password = User.GetPasswordHash(vm.Password);
                user.PasswordChangeRequired = true;
                user.Contact = new Contact()
                {
                    FirstName = vm.FirstName,
                    LastName = vm.LastName,
                    Email = vm.Email,
                };

                user.Address = new Address();

                user.UsersRoles.Add(new UsersRole()
                {
                    User = user,
                    Role = _manageContext.Roles.SingleOrDefault(x => x.Code == (int)BL.Enumerations.Roles.User)
                });

                user.UsersRoles.Add(new UsersRole()
                {
                    User = user,
                    Role = _manageContext.Roles.SingleOrDefault(x => x.Code == (int)BL.Enumerations.Roles.MachineStudioUser)
                });

                user.UsersRoles.Add(new UsersRole()
                {
                    User = user,
                    Role = _manageContext.Roles.SingleOrDefault(x => x.Code == (int)BL.Enumerations.Roles.PPCUser)
                });

                try
                {
                    if (!user.Validate(_manageContext))
                    {
                        _notification.ShowError(String.Join(Environment.NewLine, user.ValidationErrors));
                        return;
                    }
                }
                catch (Exception ex)
                {
                    _notification.ShowError(ex.Message);
                    return;
                }

                ManagedOrganization.Users.Add(user);

                using (_notification.PushTaskItem("Adding new user..."))
                {
                    await ManagedOrganization.SaveAsync(_manageContext);
                    _actionLogManager.InsertLog(ActionLogType.UserCreated, _authenticationProvider.CurrentUser, user.Email, user, "User created using Machine Studio.");
                    await LoadOrganizations();
                    SelectedOrganization = Organizations.SingleOrDefault(x => x.Guid == ManagedOrganization.Guid);
                    SelectedUser = user;
                    LoadSelectedUser();
                }
            });
        }

        private void SetUserPlace(Place place)
        {
            ManagedUser.Address.AddressString = place.Address.Road;
            ManagedUser.Address.City = place.Address.City;
            ManagedUser.Address.Country = place.Address.Country;
            ManagedUser.Address.CountryCode = place.Address.CountryCode;
            ManagedUser.Address.Locality = place.Address.CountryCode;
            ManagedUser.Address.PostalCode = place.Address.PostalCode;
            ManagedUser.Address.State = place.Address.State;
        }

        private void SetOrganizationPlace(Place place)
        {
            ManagedOrganization.Address.AddressString = place.Address.Road;
            ManagedOrganization.Address.City = place.Address.City;
            ManagedOrganization.Address.Country = place.Address.Country;
            ManagedOrganization.Address.CountryCode = place.Address.CountryCode;
            ManagedOrganization.Address.Locality = place.Address.CountryCode;
            ManagedOrganization.Address.PostalCode = place.Address.PostalCode;
            ManagedOrganization.Address.State = place.Address.State;
        }

        protected override void RaisePropertyChangedAuto([CallerMemberName] string caller = null)
        {
            base.RaisePropertyChangedAuto(caller);
            InvalidateRelayCommands();
        }
    }
}