using System.ComponentModel;
using System.ComponentModel.Composition;
using System.Threading.Tasks;
using DTS.Common.Events;
using GroupList.Model;
using DTS.Common.Interface.Groups.GroupTemplateList;
using DTS.Common.Enums.Groups.GroupList;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System;
using System.Collections.Specialized;
using System.Linq;
using DTS.Common.Events.Groups.GroupList;
using DTS.Common.Interface.Groups.GroupList;
using System.Windows;
using DTS.Common.Storage;
using DTS.Common.Interface.Groups;
using Prism.Events;
using Prism.Regions;
using Unity;
using DTS.Common.Interactivity;

// ReSharper disable CheckNamespace
// ReSharper disable MemberCanBePrivate.Global
// ReSharper disable InconsistentNaming

namespace GroupList
{
    /// <summary>
    /// this class handles GroupList functionality
    /// </summary>
    [PartCreationPolicy(CreationPolicy.Shared)]
    public class GroupListViewModel : IGroupListViewModel
    {
        /// <summary>
        /// The GroupList view
        /// </summary>
        public IGroupListView View { get; set; }
        private IEventAggregator _eventAggregator { get; }
        private IRegionManager _regionManager;
        private IUnityContainer UnityContainer { get; }

        public InteractionRequest<Notification> NotificationRequest { get; }
        public InteractionRequest<Confirmation> ConfirmationRequest { get; }

        /// <inheritdoc />
        /// <summary>
        /// Occurs when a property value changes.
        /// </summary>
        public event PropertyChangedEventHandler PropertyChanged;
        public void OnPropertyChanged(string propertyName)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }

        #region constructors and initializers
        /// <summary>
        /// Creates a new instance of the GroupListViewModel
        /// </summary>
        /// <param name="view"></param>
        /// <param name="regionManager">The logical placeholder defined within the application's UI (in the shell or within views) into which views are displayed.</param>
        /// <param name="eventAggregator">The EventAggregator which allows different components to publish/subscribe to events without being coupled to each other.</param>
        /// <param name="unityContainer">The unityContainer.</param>
        public GroupListViewModel(IGroupListView view, IRegionManager regionManager,
            IEventAggregator eventAggregator, IUnityContainer unityContainer)
        {
            View = view;
            View.DataContext = this;

            NotificationRequest = new InteractionRequest<Notification>();
            ConfirmationRequest = new InteractionRequest<Confirmation>();

            _eventAggregator = eventAggregator;
            UnityContainer = unityContainer;
            _regionManager = regionManager;
            _eventAggregator.GetEvent<RaiseNotification>().Subscribe(OnRaiseNotification);
            _eventAggregator.GetEvent<BusyIndicatorChangeNotification>()
                .Subscribe(OnBusyIndicatorNotification, ThreadOption.PublisherThread, true);
            SelectedGroupItems = new ObservableCollection<IGroup>();
        }
        #endregion

        #region Methods

        public void ClearAllFilters()
        {
            _filterByField.Clear();
        }
        public void MouseDoubleClick(int index)
        {
            if (index >= 0 && index < Groups.Length && SelectedGroupItems.Count == 1)
            {
                _eventAggregator.GetEvent<GroupListEditGroupEvent>().Publish(Groups[index].Id);
            }
        }

        public void Filter(string term)
        {
            CurrentSearchTerm = term;
            Sort(_sortField.ToString(), false);
        }

        public IGroup GetGroup(int? id, bool updateTags = true)
        {
            if (id >= 0)
            {
                if (updateTags)
                {
                    //Update the Tags in case they were modified by a different user
                    DTS.Common.Classes.Tags.TagsInstance.GetTagsInstance(DbOperations.TagsGet).UpdateList(DbOperations.TagsGet);
                }
                var groups = Group.GetAllGroups(id);
                if (groups.Any())
                {
                    return groups[0];
                }
            }
            return new Group();
        }

        public IGroup GetGroup(string displayName)
        {
            //Get all of the groups with this DisplayName.  This consists of both embedded and non-embedded
            //if it was a pre-2.0 static Group or just the embedded, if it was a pre-2.0 Added Group.
            //If the Group was first created in 2.0, it may have both embedded and non-embedded or just embedded.
            var groups = Group.GetAllGroups(displayName);
            foreach (var group in groups)
            {
                if (!group.Embedded)
                {
                    //Return the corresponding non-embedded Group
                    return group;
                }
            }
            return null;
        }

        public IGroup[] GetGroups(int[] ids)
        {
            var allGroups = Group.GetAllGroups().ToList();
            for (var i = allGroups.Count - 1; i >= 0; i--)
            {
                if (ids.Contains(allGroups[i].Id)) { continue; }
                allGroups.RemoveAt(i);
            }
            return allGroups.ToArray();
        }
        public IGroup[] GetAllGroups()
        {
            var allGroups = Group.GetAllGroups();
            return allGroups;
        }
        public void DeleteGroups(int[] ids)
        {
            try
            {
                foreach (var id in ids)
                {
                    //Set any embedded Groups' that have the to-be-deleted 
                    //Group's Id as their StaticGroupId to null.
                    var relatedEmbeddedGroups = Group.GetAllRelatedEmbeddedGroups(id);
                    foreach (var embeddedGroup in relatedEmbeddedGroups)
                    {
                        Group.SetNullStaticGroupId(embeddedGroup);
                    }

                    Group.Delete(id);
                }

                var list = AllGroups.ToList();
                for (var i = AllGroups.Length - 1; i >= 0; i--)
                {
                    if (ids.Contains(AllGroups[i].Id))
                    {
                        list.RemoveAt(i);
                    }
                }

                AllGroups = list.ToArray();
                Filter(CurrentSearchTerm);
            }
            catch (Exception ex)
            {
                _eventAggregator.GetEvent<PageErrorEvent>().Publish(new PageErrorArg(new[] { ex.Message }, Page));
            }

        }

        public IGroup CreateGroup()
        {
            return new Group(true);
        }
        public IGroup CreateGroup(System.Data.SqlClient.SqlDataReader reader, List<string> includedHardwareStringList, List<int> dasIdList)
        {
            return new Group(reader, includedHardwareStringList, dasIdList);
        }

        public IGroup CreateGroup(IGroupDbRecord groupRecord, List<string> includedHardwareStringList, List<int> dasIdList)
        {
            return new Group(groupRecord, includedHardwareStringList, dasIdList);
        }

        public IGroup CreateGroup(List<string> includedHardwareStringList)
        {
            return new Group(includedHardwareStringList);
        }

        public void Filter(object tag, string term)
        {
            if (!Enum.TryParse((string)tag, out GroupFields field)) return;
            _filterByField[field] = term;
            _sortField = field;
            Filter(term);
        }

        public void OnSetActive(object page, bool groupTile, object o)
        {
            try
            {
                var currentUser = (DTS.Slice.Users.User)o;
                Page = page;
                var groups = Group.GetAllGroups().Where(@group => currentUser.Role == DTS.Slice.Users.User.DefaultRoles.Administrator || currentUser.TagCompatible(@group.TagIDs)).ToList();
                if (groupTile)
                {
                    AllGroups = groups.ToArray();
                    Task.Run(() => GetTestSetupListsAsync());
                }
                else
                {
                    AllGroups = groups.ToArray();
                    Sort(_sortField.ToString(), false);
                }
            }
            catch (Exception ex)
            {
                _eventAggregator.GetEvent<PageErrorEvent>().Publish(new PageErrorArg(new[] { ex.Message }, Page));
            }
        }

        private void GetTestSetupListsAsync()
        {
            _eventAggregator.GetEvent<AppStatusEvent>().Publish(AppStatusArg.Busy);
            var groups = AllGroups.ToArray();


            _eventAggregator.GetEvent<ProgressBarEvent>().Publish(new ProgressBarEventArg()
            { ProgressBarText = $"Getting groups", SetText = true });

            groups.AsParallel().ForAll(g =>
            {
                _eventAggregator.GetEvent<ProgressBarEvent>().Publish(new ProgressBarEventArg()
                { ProgressBarText = $"Getting group {g.DisplayName}", SetText = true });
                g.SetTestSetupLists();
            });

            Application.Current.Dispatcher.Invoke(new Action(() =>
            {
                Sort(_sortField.ToString(), false);
            }));

            _eventAggregator.GetEvent<ProgressBarEvent>().Publish(new ProgressBarEventArg()
            { ProgressBarText = $"Waiting for user input", SetText = true });
            _eventAggregator.GetEvent<AppStatusEvent>().Publish(AppStatusArg.Available);
        }
        public void Unset()
        {
            AllGroups = new IGroup[0];
            Groups = new IGroup[0];
            ClearAllFilters();
            _eventAggregator.GetEvent<ListViewStatusEvent>()
                .Publish(new ListViewStatusArg(ListViewStatusArg.ListViewStatus.Unloaded, ListViewId));
        }
        public void Sort(object o, bool bColumnClick)
        {
            if (!(o is string s)) { return; }
            if (!Enum.TryParse(s, out GroupFields tag)) { return; }

            if (bColumnClick)
            {
                if (tag != _sortField)
                {
                    _sortField = tag;
                    _sortAscending = true;
                }
                else
                {
                    _sortAscending = !_sortAscending;
                }
            }

            _comparer.SortAscending = _sortAscending;
            _comparer.SortField = _sortField;
            var list = new List<IGroup>();
            foreach (var group in AllGroups)
            {
                if (group.Filter(CurrentSearchTerm))
                {
                    if (GroupFilter(group))
                    {
                        list.Add(group);
                    }
                }
            }
            var originalList = list.ToList();
            list.Sort(_comparer);
            //this doesn't seem right, should just use the _sortField and sort ascending
            //logic already present
            //if (originalList.SequenceEqual(list) && originalList.Count > 1 &&
            //    !(_comparer.SortAscending && _comparer.SortField == GroupFields.LastModified))//AllGroups already ordered by lastmodified, ascending
            //{
            //    //list was already in order. flip it for the user
            //    _sortAscending = !_sortAscending;
            //    _comparer.SortAscending = _sortAscending;
            //    list.Sort(_comparer);
            //}
            Groups = list.ToArray();
            OnPropertyChanged("Groups");
        }

        private bool GroupFilter(IGroup group)
        {
            var fields = Enum.GetValues(typeof(GroupFields)).Cast<GroupFields>().ToArray();
            foreach (var field in fields)
            {
                if (!_filterByField.ContainsKey(field)) { continue; }
                var term = _filterByField[field];
                if (string.IsNullOrWhiteSpace(term)) { continue; }
                switch (field)
                {
                    case GroupFields.DisplayName:
                        if (!(System.Globalization.CultureInfo.CurrentCulture.CompareInfo.IndexOf(group.DisplayName, term,
                                  System.Globalization.CompareOptions.OrdinalIgnoreCase) >= 0))
                        {
                            return false;
                        }
                        break;
                    case GroupFields.Description:
                        if (!(System.Globalization.CultureInfo.CurrentCulture.CompareInfo.IndexOf(group.Description, term,
                                  System.Globalization.CompareOptions.OrdinalIgnoreCase) >= 0))
                        {
                            return false;
                        }
                        break;
                    case GroupFields.ChannelCount:
                        if (!(System.Globalization.CultureInfo.CurrentCulture.CompareInfo.IndexOf(group.ChannelCount.ToString(), term,
                                  System.Globalization.CompareOptions.OrdinalIgnoreCase) >= 0))
                        {
                            return false;
                        }
                        break;
                    case GroupFields.LastModified:
                        if (!(System.Globalization.CultureInfo.CurrentCulture.CompareInfo.IndexOf(group.LastModified.ToString(), term,
                                  System.Globalization.CompareOptions.OrdinalIgnoreCase) >= 0))
                        {
                            return false;
                        }
                        break;
                    case GroupFields.LastModifiedBy:
                        if (!(System.Globalization.CultureInfo.CurrentCulture.CompareInfo.IndexOf(group.LastModifiedBy, term,
                                  System.Globalization.CompareOptions.OrdinalIgnoreCase) >= 0))
                        {
                            return false;
                        }
                        break;
                    case GroupFields.AssociatedTestSetups:
                        {
                            var testSetups = new List<string>();
                            foreach (var assoc in group.AssociatedTestSetups) { testSetups.Add(assoc.Name); }
                            var s = string.Join(", ", testSetups.ToArray());
                            if (!(System.Globalization.CultureInfo.CurrentCulture.CompareInfo.IndexOf(s, term,
                                  System.Globalization.CompareOptions.OrdinalIgnoreCase) >= 0))
                            {
                                return false;
                            }
                        }
                        break;
                    default:
                        throw new ArgumentOutOfRangeException();
                }
            }
            return true;
        }
        public void Cleanup()
        {
        }

        public Task CleanupAsync()
        {
            return Task.CompletedTask;
        }

        public void Initialize()
        {
        }

        public void Initialize(object parameter)
        {
        }

        public void Initialize(object parameter, object model)
        {
        }

        public Task InitializeAsync()
        {
            return Task.CompletedTask;
        }

        public Task InitializeAsync(object parameter)
        {
            return Task.CompletedTask;
        }

        public void Activated()
        {
        }
        /// <summary>
        /// Private Event handler for RaiseNotification event.
        /// </summary>
        private void OnBusyIndicatorNotification(bool eventArg)
        {
            IsBusy = eventArg;
        }

        private void FireSelectionChanged()
        {
            _eventAggregator.GetEvent<GroupListGroupSelectedEvent>().Publish(_selectedGroupItems.Select(grp => grp.Id).ToArray());
        }
        /// <summary>
        /// Private Event handler for RaiseNotification event.
        /// </summary>
        private void OnRaiseNotification(NotificationContentEventArgs eventArgsWithTitle)
        {
            // The NotificationRequest.Raise triggers the Invoke() method of the PopupWindowAction object to show the NotificationWindow window
            // Notification object expects a NotificationContentEventArgsWithoutTitle object and a Title string.
            var eventArgsWithoutTitle = new NotificationContentEventArgs(eventArgsWithTitle.Message, "",
                eventArgsWithTitle.Image, string.Empty);

            NotificationRequest.Raise(new Notification
            {
                Content = eventArgsWithoutTitle,
                Title = eventArgsWithTitle.Title
            });
        }

        #endregion

        #region Properties  

        private readonly Dictionary<GroupFields, string> _filterByField = new Dictionary<GroupFields, string>();
        private string CurrentSearchTerm = "";
        public int SelectedGroupIndex { get; set; } = -1;

        public ObservableCollection<IGroup> _selectedGroupItems;
        public ObservableCollection<IGroup> SelectedGroupItems
        {
            get => _selectedGroupItems;
            set
            {
                if (_selectedGroupItems != null)
                {
                    _selectedGroupItems.CollectionChanged -= SelectedGroupItemsOnCollectionChanged;
                }
                _selectedGroupItems = value;
                if (_selectedGroupItems != null)
                {
                    _selectedGroupItems.CollectionChanged += SelectedGroupItemsOnCollectionChanged;
                }
                FireSelectionChanged();
            }
        }

        private void SelectedGroupItemsOnCollectionChanged(object sender, NotifyCollectionChangedEventArgs notifyCollectionChangedEventArgs)
        {
            if (DTS.Common.Enums.SelectedItemsStatus.GetUpdating(SelectedGroupItems)) { return; }
            FireSelectionChanged();
        }
        private IGroup[] AllGroups { get; set; }
        //sort by last modified descending by default
        private bool _sortAscending = false;
        private GroupFields _sortField = GroupFields.LastModified;
        private readonly GroupComparer _comparer = new GroupComparer();
        public IGroup[] Groups { get; set; }
        public bool IsDirty { get; private set; }
        private bool _isBusy;

        public bool IsBusy
        {
            get => _isBusy;
            set
            {
                _isBusy = value;
                OnPropertyChanged("IsBusy");
            }
        }

        private bool _isMenuIncluded;

        public bool IsMenuIncluded
        {
            get => _isMenuIncluded;
            set
            {
                _isMenuIncluded = value;
                OnPropertyChanged("IsMenuIncluded");
            }
        }

        private bool _isNavigationIncluded;

        public bool IsNavigationIncluded
        {
            get => _isNavigationIncluded;
            set
            {
                _isNavigationIncluded = value;
                OnPropertyChanged("IsNavigationIncluded");
            }
        }

        public string ListViewId => "GroupListView";
        private object Page { get; set; }
        #endregion Properties

        #region Commands

        #endregion
    }
}