using Comal.Classes;
using InABox.Clients;
using InABox.Core;
using InABox.WPF;
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Drawing;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using Color = System.Drawing.Color;
using InABox.DynamicGrid;
using InABox.Wpf;
using MailKit.Search;
using NPOI.SS.Formula.Functions;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using Syncfusion.UI.Xaml.Kanban;

namespace PRSDesktop;

public class TasksByStatusColumn : INotifyPropertyChanged
{
    public KanbanStatus Status { get; }

    public string Title { get; }

    public int NumTasks { get => Tasks.Count; }

    public double NumHours { get => Tasks.Sum(x => x.EstimatedTime.TotalHours); }

    public ObservableCollection<TaskModel> Tasks { get; } = new();

    public TasksByStatusColumn(KanbanStatus status, string title)
    {
        Status = status;
        Title = title;

        Tasks.CollectionChanged += Tasks_CollectionChanged;
    }

    private void Tasks_CollectionChanged(object? sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
    {
        OnPropertyChanged(nameof(Tasks));
    }

    public event PropertyChangedEventHandler? PropertyChanged;

    // Create the OnPropertyChanged method to raise the event
    // The calling member's name will be used as the parameter.
    protected void OnPropertyChanged([CallerMemberName] string? name = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));

        if(name == nameof(Tasks))
        {
            OnPropertyChanged(nameof(NumTasks));
            OnPropertyChanged(nameof(NumHours));
        }
    }
}

public class EmployeeModel
{
    public Guid ID { get; set; }

    public string Name { get; set; }

    public BitmapImage? Image { get; set; }

    public Guid ThumbnailID { get; set; }

    public EmployeeModel(Guid id, string name, Guid thumbnail, BitmapImage? image)
    {
        ID = id;
        Name = name;
        Image = image;
        ThumbnailID = thumbnail;
    }
}

public class SuspendableObservableCollection<T> : ObservableCollection<T>
{
    private bool _notificationSupressed = false;
    private bool _supressNotification = false;
    public bool SupressNotification
    {
        get
        {
            return _supressNotification;
        }
        set
        {
            _supressNotification = value;
            if (_supressNotification == false && _notificationSupressed)
            {
                this.OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
                _notificationSupressed = false;
            }
        }
    }

    protected override void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
    {
        if (SupressNotification)
        {
            _notificationSupressed = true;
            return;
        }
        base.OnCollectionChanged(e);
    }
}


/// <summary>
/// Interaction logic for TasksByStatusControl.xaml
/// </summary>
public partial class TasksByStatusControl : UserControl, ITaskControl, INotifyPropertyChanged
{
    private enum Suppress
    {
        This
    }

    public SuspendableObservableCollection<TasksByStatusColumn> Columns { get; private set; } = new();

    private List<EmployeeModel> Employees = new();

    public TasksByStatusControl()
    {
        InitializeComponent();
    }

    #region INotifyPropertyChanged

    public event PropertyChangedEventHandler? PropertyChanged;

    // Create the OnPropertyChanged method to raise the event
    // The calling member's name will be used as the parameter.
    protected void OnPropertyChanged([CallerMemberName] string? name = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
    }

    #endregion

    #region Setup

    public void Setup()
    {
        var employeesTask = Task.Run(() => LoadEmployees());
        var kanbanTypesTask = Task.Run(() => LoadKanbanTypes());

        SetupToolbar();

        SetupColumns();

        employeesTask.Wait();
        SetupEmployeeList();

        kanbanTypesTask.Wait();
        SetupKanbanTypesLookup(kanbanTypesTask.Result);

        Mode = Host.KanbanSettings.StatusSettings.CompactView ? KanbanViewMode.Compact : KanbanViewMode.Full;
        FilterButton.SetSettings(Host.KanbanSettings.Filters, false);
    }

    private void SetupToolbar()
    {
        IncludeCompleted.Visibility = Security.IsAllowed<CanHideTaskCompletedColumn>() ? Visibility.Visible : Visibility.Collapsed;
        IncludeCompleted.IsChecked = IncludeCompleted.Visibility == Visibility.Visible ? Host.KanbanSettings.StatusSettings.IncludeCompleted : true;
        IncludeObserved.IsChecked = Host.KanbanSettings.StatusSettings.IncludeObserved;
        ViewType.SelectedIndex = Host.KanbanSettings.StatusSettings.CompactView ? 1 : 0;
    }

    #endregion

    #region Columns

    private void SetupColumns()
    {
        Columns.SupressNotification = true;

        Columns.Clear();

        Columns.Add(new TasksByStatusColumn(KanbanStatus.Open, "To Do"));

        Columns.Add(new TasksByStatusColumn(KanbanStatus.InProgress, "In Progress"));

        Columns.Add(new TasksByStatusColumn(KanbanStatus.Waiting, "Waiting for Others"));

        if (Host.KanbanSettings.StatusSettings.IncludeCompleted)
            Columns.Add(new TasksByStatusColumn(KanbanStatus.Complete, "Completed"));

        Columns.SupressNotification = false;
    }

    private TasksByStatusColumn? GetColumn(KanbanStatus category)
    {
        return Columns.FirstOrDefault(x => x.Status.Equals(category));
    }

    private void Column_ContextMenuOpening(object sender, ContextMenuEventArgs e)
    {
        if (sender is not FrameworkElement element || element.Tag is not TasksByStatusColumn column) return;

        var menu = element.ContextMenu;

        menu.Items.Clear();

        menu.AddItem("New Task", null, CreateTask);
        menu.AddItem($"Select all {column.Title} tasks", null, column, SelectAll);
        menu.AddItem($"Deselect all {column.Title} tasks", null, column, DeselectAll);
    }

    private void SelectColumn(TasksByStatusColumn column, bool selected)
    {
        SelectedTasks.Clear();
        if (selected)
        {
            SelectedTasks.AddRange(column.Tasks);
            foreach (var task in Tasks)
                task.Checked = task.Status == column.Status ? selected : !selected;
        }

        FilterKanbans();
    }

    private void DeselectAll(TasksByStatusColumn column)
    {
        SelectColumn(column, false);
    }

    private void SelectAll(TasksByStatusColumn column)
    {
        SelectColumn(column, true);
    }

    #endregion

    #region Kanban Types

    private IEnumerable<KanbanType> LoadKanbanTypes()
    {
        return Client.Query(
            new Filter<KanbanType>(x => x.Hidden).IsEqualTo(false),
            InABox.Core.Columns.None<KanbanType>().Add(x => x.ID, x => x.Description),
            new SortOrder<KanbanType>(x => x.Description))
            .ToObjects<KanbanType>();
    }

    private void SetupKanbanTypesLookup(IEnumerable<KanbanType> kanbanTypes)
    {
        if (ClientFactory.IsSupported<KanbanType>())
        {
            var tasktypes = new Dictionary<Guid, string>
                {
                    { CoreUtils.FullGuid, "All Types" },
                    { Guid.Empty, "Unallocated Types" }
                };
            foreach(var type in kanbanTypes)
            {
                tasktypes.Add(type.ID, type.Description);
            }

            TaskTypes.ItemsSource = tasktypes;
            if (tasktypes.ContainsKey(Host.KanbanSettings.StatusSettings.SelectedType))
                TaskTypes.SelectedValue = Host.KanbanSettings.StatusSettings.SelectedType;
            else
                TaskTypes.SelectedValue = CoreUtils.FullGuid;

            TaskTypesLabel.Visibility = Visibility.Visible;
            TaskTypes.Visibility = Visibility.Visible;
        }
        else
        {
            TaskTypesLabel.Visibility = Visibility.Collapsed;
            TaskTypes.Visibility = Visibility.Collapsed;
        }
    }

    #endregion

    #region Employees

    private EmployeeModel SelectedEmployee;

    private void LoadEmployees()
    {
        Employees.Clear();

        var employeeFilter = Security.IsAllowed<CanViewOthersTasks>()
            ? new Filter<Employee>(x => x.CanAllocateTasks).IsEqualTo(true)
                .And(new Filter<Employee>(x => x.FinishDate).IsEqualTo(DateTime.MinValue)
                    .Or(x => x.FinishDate).IsGreaterThan(DateTime.Today))
            : new Filter<Employee>(x => x.ID).IsEqualTo(App.EmployeeID);

        var employees = Client.Query<Employee>(
            employeeFilter,
            InABox.Core.Columns.None<Employee>().Add(x => x.ID)
                .Add(x => x.Thumbnail.ID)
                .Add(x => x.Name));

        var anonymous = PRSDesktop.Resources.anonymous.AsBitmapImage();
        anonymous.Freeze();
        if (Security.IsAllowed<CanViewOthersTasks>())
        {
            var everyone = PRSDesktop.Resources.everyone.AsBitmapImage();
            everyone.Freeze();
            Employees.Add(new EmployeeModel(CoreUtils.FullGuid, "All Staff", Guid.Empty, everyone));
            Employees.Add(new EmployeeModel(Guid.Empty, "Unallocated", Guid.Empty, null));
        }

        foreach (var employee in employees.ToObjects<Employee>())
        {
            var name = employee.ID == App.EmployeeID ? "My Tasks" : employee.Name;

            var model = new EmployeeModel(employee.ID, name, employee.Thumbnail.ID, anonymous);

            if (employee.ID == App.EmployeeID)
            {
                Employees.Insert(0, model);
            }
            else
            {
                Employees.Add(model);
            }
        }
    }

    private void SetupEmployeeList()
    {
        if (Security.IsAllowed<CanViewOthersTasks>())
        {
            EmployeeListColumn.Width = new GridLength(1.0F, GridUnitType.Auto);
            var thumbnails = Employees
                .Select(e => e.ThumbnailID)
                .Where(x => x != Guid.Empty).ToArray();
            EmployeeList.ItemsSource = Employees;
            SelectedEmployee = Employees.FirstOrDefault(x => x.ID == Host.KanbanSettings.StatusSettings.SelectedEmployee) ?? Employees.First();
            EmployeeList.SelectedItem = SelectedEmployee;
            if (thumbnails.Any())
                new Client<Document>().Query(
                    new Filter<Document>(x => x.ID).InList(thumbnails),
                    InABox.Core.Columns.None<Document>().Add(x => x.ID, x => x.Data),
                    null,
                    CoreRange.All,
                    (data, error) =>
                    {
                        if (data != null)
                            ProcessThumbnails(data);
                    }
                );
        }
        else
        {
            EmployeeListColumn.Width = new GridLength(0.0F, GridUnitType.Pixel);
            EmployeeList.ItemsSource = Employees;
            SelectedEmployee = Employees.FirstOrDefault(x => x.ID == Host.KanbanSettings.StatusSettings.SelectedEmployee) ?? Employees.First();
            EmployeeList.SelectedItem = SelectedEmployee;
        }
    }

    private bool _updatingEmployees = false;
    private void ProcessThumbnails(CoreTable data)
    {
        Dispatcher.Invoke(() =>
        {
            foreach (var row in data.Rows)
            {
                var id = row.Get<Document, Guid>(x => x.ID);
                var model = Employees.FirstOrDefault(x => x.ThumbnailID.Equals(id));
                if (model != null)
                {
                    model.Image = ImageUtils.LoadImage(row.Get<Document, byte[]>(x => x.Data));
                }
            }

            _updatingEmployees = true;
            EmployeeList.ItemsSource = null;
            EmployeeList.ItemsSource = Employees;
            SelectedEmployee = Employees.FirstOrDefault(x => x.ID == Host.KanbanSettings.StatusSettings.SelectedEmployee) ?? Employees.First();
            EmployeeList.SelectedItem = SelectedEmployee;
            _updatingEmployees = false;
        });
    }

    private void Employees_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        if (_updatingEmployees || EventSuppressor.IsSet(Suppress.This))
            return;

        SelectedEmployee = (EmployeeList.SelectedItem as EmployeeModel)!;
        Host.KanbanSettings.StatusSettings.SelectedEmployee = SelectedEmployee.ID;
        Host.SaveSettings();

        SelectedTasks.Clear();
        if (IsReady)
            Refresh();
    }

    #endregion

    #region Kanbans

    private List<TaskModel> AllTasks { get; set; } = new();
    private IEnumerable<TaskModel> Tasks => Columns.SelectMany(x => x.Tasks);

    private readonly List<TaskModel> SelectedTasks = new();

    private void CreateTask()
    {
        var result = Host.CreateKanban(
            kanban =>
            {
                kanban.EmployeeLink.ID = SelectedEmployee.ID != CoreUtils.FullGuid ? SelectedEmployee.ID : App.EmployeeID;
                kanban.ManagerLink.ID = App.EmployeeID;
                kanban.ManagerLink.UserLink.ID = ClientFactory.UserGuid;
            });
        if (result != null)
            Refresh();
    }

    private void DoEdit(TaskModel task)
    {
        var result = Host.EditReferences(new[] { task });
        if (result)
        {
            Refresh();
        }
    }

    private void EditTask_Executed(object sender, ExecutedRoutedEventArgs e)
    {
        if (e.Parameter is not TaskModel model) return;

        DoEdit(model);
    }

    private void OpenTaskMenu_Executed(object sender, ExecutedRoutedEventArgs e)
    {
        if (e.Parameter is not KanbanResources.OpenTaskMenuCommandArgs args) return;

        Host.PopulateMenu(this, args.Model, args.Menu);
    }

    private void SelectTask_Executed(object sender, ExecutedRoutedEventArgs e)
    {
        if (e.Parameter is not TaskModel model) return;

        if (!SelectedTasks.Remove(model))
        {
            SelectedTasks.Add(model);
        }
    }

    private void CommandBinding_CanExecute(object sender, CanExecuteRoutedEventArgs e)
    {
        e.CanExecute = true;
    }

    private void ItemsControl_DragOver(object sender, DragEventArgs e)
    {
        if (sender is not FrameworkElement element || element.Tag is not TasksByStatusColumn column) return;

        e.Effects = DragDropEffects.None;
        if (e.Data.GetDataPresent(typeof(TaskModel)))
        {
            var model = e.Data.GetData(typeof(TaskModel)) as TaskModel;
            if(model is not null && model.Status != column.Status && !SelectedTasks.Any(x => x.Locked))
            {
                e.Effects = DragDropEffects.Move;
            }
        }
    }

    private void ChangeStatus(IEnumerable<TaskModel> tasks, KanbanStatus status)
    {
        var models = tasks
            .Where(x => !x.Status.Equals(status))
            .Where(x => !x.Locked)
            .ToList();
        if (!models.Any())
        {
            return;
        }
        if(status == KanbanStatus.Complete)
        {
            if (!MessageWindow.ShowYesNo($"Are you sure you want to complete the selected tasks?", "Confirm Completion"))
                return;
        }

        var completed = DateTime.Now;

        var kanbans = Host.LoadKanbans(tasks, InABox.Core.Columns.Required<Kanban>().Add(x => x.ID).Add(x => x.Status));
        foreach (var kanban in kanbans)
        {
            kanban.Status = status;
        }
        if (status == KanbanStatus.Complete)
        {
            foreach (var kanban in kanbans)
            {
                kanban.Completed = completed;
            }
        }
        Client.Save(kanbans, $"Task Status Updated to {status}", (o, err) =>
        {
            if (err is not null)
            {
                CoreUtils.LogException("", err);
            }
        });

        foreach (var model in models)
        {
            model.Checked = false;
            model.Status = status;
        }
        if (status == KanbanStatus.Complete)
        {
            foreach (var model in models)
            {
                model.CompletedDate = completed;
            }
        }
        FilterKanbans();
    }

    private void ItemsControl_Drop(object sender, DragEventArgs e)
    {
        if (sender is not FrameworkElement element || element.Tag is not TasksByStatusColumn column) return;

        if (e.Data.GetDataPresent(typeof(TaskModel)))
        {
            ChangeStatus(SelectedModels(e.Data.GetData(typeof(TaskModel)) as TaskModel), column.Status);
        }
    }

    #endregion

    #region Filters

    private Guid JobFilterID = Guid.Empty;
    private string SearchText = "";
    private Guid SelectedType = CoreUtils.FullGuid;

    private void FilterButton_OnFilterRefresh()
    {
        Refresh();
    }

    private void FilterButton_OnFiltersSelected(DynamicGridSelectedFilterSettings filters)
    {
        Host.KanbanSettings.Filters = filters;
        Host.SaveSettings();
    }

    private static Filter<T> GetSearchFilter<T>(Expression<Func<T, object?>> expression, string searchText) where T : Entity, new()
    {
        Filter<T>? result = null;
        var comps = searchText.Trim().Split(' ');
        foreach (var comp in comps)
            result = result == null ? new Filter<T>(expression).Contains(comp) : result.And(expression).Contains(comp);
        return result ?? new Filter<T>().All();
    }

    private Filter<KanbanSubscriber> GetKanbanSubscriberFilter()
    {
        var filter = new Filter<KanbanSubscriber>(x => x.Kanban.Closed).IsEqualTo(DateTime.MinValue);

        if (Host.Master != null)
            filter = filter.And(x => x.Kanban.JobLink.ID).IsEqualTo(Host.Master.ID);
        
        // All Tasks (EmployeeID.HasValue == false) or Unallocated (EmployeeID = Guid.Empty) are retrieved directly from the Kanban Table
        // so if we are here, we can assume that we are pulling subscriber data
        var empfilter = new Filter<KanbanSubscriber>(x => x.Employee.ID).IsEqualTo(SelectedEmployee.ID);
        filter.Ands.Add(empfilter);

        if (SelectedEmployee.ID != App.EmployeeID)
            filter = filter.And(x => x.Kanban.Private).IsEqualTo(false);

        return filter;
    }

    private Filter<Kanban>? GetKanbanFilter()
    {
        var filters = new Filters<Kanban>();

        filters.Add(new Filter<Kanban>(x => x.Closed).IsEqualTo(DateTime.MinValue));
        filters.Add(FilterButton.GetFilter());

        if (Host.Master != null)
                filters.Add(new Filter<Kanban>(x => x.JobLink.ID).IsEqualTo(Host.Master.ID));
        
        if (SelectedEmployee.ID != CoreUtils.FullGuid)
        {
            if (SelectedEmployee.ID != Guid.Empty)
            {
                var empfilter = new Filter<Kanban>(x => x.EmployeeLink.ID).IsEqualTo(SelectedEmployee.ID)
                    .Or(x => x.ManagerLink.ID).IsEqualTo(SelectedEmployee.ID);
                filters.Add(empfilter);
            }
            else
            {
                filters.Add(new Filter<Kanban>(x => x.EmployeeLink.ID).IsEqualTo(SelectedEmployee.ID));
            }
        }

        if (SelectedEmployee.ID != App.EmployeeID)
            filters.Add(new Filter<Kanban>(x => x.Private).IsEqualTo(false));

        return filters.Combine();
    }

    private void TaskTypesLabel_OnClick(object sender, RoutedEventArgs e)
    {
        var list = new MasterList(typeof(KanbanType));
        list.ShowDialog();
        SetupKanbanTypesLookup(LoadKanbanTypes());
    }

    private void TaskTypes_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        if (!IsReady || EventSuppressor.IsSet(Suppress.This))
            return;
        if (e.AddedItems.Count > 0)
        {
            var item = (KeyValuePair<Guid, string>)e.AddedItems[0];
            SelectedType = item.Key;
        }
        else
        {
            SelectedType = CoreUtils.FullGuid;
        }

        Host.KanbanSettings.StatusSettings.SelectedType = SelectedType;
        Host.SaveSettings();
        FilterKanbans();
    }

    private void JobFilterBtn_OnClick(object sender, RoutedEventArgs e)
    {
        if (JobFilterID != Guid.Empty)
        {
            JobFilterBtn.Content = "Filter Job";
            JobFilterID = Guid.Empty;
            FilterKanbans();
            return;
        }

        var window = new ThemableWindow();
        var grid = new ProjectsGrid();
        grid.Reconfigure(options =>
        {
            options.EditRows = false;
            options.DeleteRows = false;
            options.AddRows = false;
            options.MultiSelect = false;
            options.ExportData = false;
            options.ImportData = false;
        });
        grid.OnSelectItem += (object sender, DynamicGridSelectionEventArgs e) =>
        {
            if (grid.SelectedRows.Count() == 0)
                return;

            else
            {
                var item = grid.SelectedRows[0];
                AddJobFilter(item);
                window.Close();
            }
        };
        grid.Refresh(true, true);
        window.Content = grid;
        window.ShowDialog();
    }
    private void AddJobFilter(CoreRow item)
    {
        JobFilterID = item.Get<Job, Guid>(x => x.ID);
        JobFilterBtn.Content = item.Get<Job, string>(x => x.JobNumber) + " (click to cancel)";
        FilterKanbans();
    }

    private void IncludeCompleted_Checked(object sender, RoutedEventArgs e)
    {
        if (!IsReady)
            return;
        Host.KanbanSettings.StatusSettings.IncludeCompleted = IncludeCompleted.IsChecked ?? false;
        Host.SaveSettings();
        SetupColumns();
        FilterKanbans();
    }

    private void IncludeObserved_Checked(object sender, RoutedEventArgs e)
    {
        if (!IsReady)
            return;
        Host.KanbanSettings.StatusSettings.IncludeObserved = IncludeObserved.IsChecked ?? false;
        Host.SaveSettings();
        FilterKanbans();
    }

    private void IncludeLocked_Checked(object sender, RoutedEventArgs e)
    {
        if (!IsReady)
            return;
        Host.KanbanSettings.StatusSettings.IncludeLocked = IncludeLocked.IsChecked ?? false;
        Host.SaveSettings();
        FilterKanbans();
    }

    private void Search_KeyUp(object sender, KeyEventArgs e)
    {
        if (string.IsNullOrWhiteSpace(Search.Text) || e.Key == Key.Return)
        {
            SearchText = Search.Text;
            FilterKanbans();
        }
    }

    #endregion

    #region Refresh

    private static Columns<Kanban> GetKanbanColumns()
    {
        return InABox.Core.Columns.None<Kanban>().Add(
            x => x.ID,
            x => x.DueDate,
            x => x.Completed,
            x => x.Summary,
            x => x.Status,
            x => x.EmployeeLink.ID,
            x => x.ManagerLink.ID,
            x => x.Notes,
            x => x.Title,
            x => x.JobLink.ID,
            x => x.JobLink.JobNumber,
            x => x.JobLink.Name,
            x => x.Type.ID,
            x => x.Type.Code,
            x => x.Number,
            x => x.Attachments,
            x => x.EstimatedTime,
            x => x.Locked);
    }

    public void Refresh()
    {
        using var cursor = new WaitCursor();

        IEnumerable<Kanban> kanbans;
        if (SelectedEmployee.ID != CoreUtils.FullGuid && SelectedEmployee.ID != Guid.Empty)
        {
            var filter = new Filter<Kanban>(x => x.ID).InQuery(GetKanbanSubscriberFilter(), x => x.Kanban.ID);
            filter.And(FilterButton.GetFilter() ?? new Filter<Kanban>().All());

            kanbans = Client.Query(
                filter,
                GetKanbanColumns().Cast<Kanban>(),
                new SortOrder<Kanban>(x => x.DueDate) { Direction = SortDirection.Ascending }
            ).ToObjects<Kanban>();
        }
        else
        {
            kanbans = new Client<Kanban>().Query(
                GetKanbanFilter(),
                GetKanbanColumns().Cast<Kanban>(),
                new SortOrder<Kanban>(x => x.DueDate) { Direction = SortDirection.Ascending }
            ).ToObjects<Kanban>();
        }

        AllTasks = CreateModels(kanbans).ToList();
        FilterKanbans();
    }
    private IEnumerable<TaskModel> CreateModels(IEnumerable<Kanban> kanbans)
    {
        foreach(var kanban in kanbans)
        {
            TaskModel? model = null;
            try
            {
                model = new TaskModel();

                var employee = Employees.FirstOrDefault(x => x.ID == kanban.EmployeeLink.ID);
                var manager = Employees.FirstOrDefault(x => x.ID == kanban.ManagerLink.ID);

                model.Title = kanban.Title;
                model.ID = kanban.ID;
                model.Description = kanban.Summary ?? "";
                model.Status = kanban.Status;

                var colour = SelectedEmployee.ID == Guid.Empty
                    || SelectedEmployee.ID == CoreUtils.FullGuid
                    || kanban.EmployeeLink.ID == SelectedEmployee.ID
                    ? TaskModel.KanbanColor(kanban.DueDate, kanban.Completed)
                    : (kanban.ManagerLink.ID == SelectedEmployee.ID
                        ? Color.Silver
                        : Color.Plum);
                if (kanban.Locked)
                {
                    colour = colour.MixColors(0.5F, Color.White);
                }
                model.Color = System.Windows.Media.Color.FromArgb(colour.A, colour.R, colour.G, colour.B);
                model.Image = employee?.Image;
                model.Attachments = kanban.Attachments > 0;
                model.DueDate = kanban.DueDate;
                model.CompletedDate = kanban.Completed;
                model.Locked = kanban.Locked;
                model.EstimatedTime = kanban.EstimatedTime;

                if (kanban.Notes is not null)
                {
                    model.Notes = string.Join(
                        "\n===================================\n",
                        kanban.Notes.Reverse());
                }

                model.EmployeeID = kanban.EmployeeLink.ID;
                model.ManagerID = kanban.ManagerLink.ID;

                var employeeString = "";
                if (kanban.EmployeeLink.ID != SelectedEmployee.ID)
                {
                    if (kanban.EmployeeLink.ID == Guid.Empty)
                    {
                        employeeString = "Unallocated";
                    }
                    else
                    {
                        employeeString = employee is not null
                            ? (employee.ID == App.EmployeeID
                                ? App.EmployeeName
                                : employee.Name)
                            : "";
                    }
                }

                var managerString = "";
                if (kanban.ManagerLink.ID != SelectedEmployee.ID)
                {
                    if (kanban.ManagerLink.ID != Guid.Empty)
                    {
                        managerString = manager is not null
                            ? (manager.ID == App.EmployeeID
                                ? App.EmployeeName
                                : manager.Name)
                            : "";
                    }
                }
                model.Manager = managerString;

                if (!string.IsNullOrEmpty(employeeString))
                {
                    if (!managerString.IsNullOrWhiteSpace() && !managerString.Equals(employeeString))
                    {
                        model.AssignedTo = $"Assigned to {employeeString} by {managerString}";
                    }
                    else
                    {
                        model.AssignedTo = $"Assigned to {employeeString}";
                    }
                }
                else
                {
                    if (!managerString.IsNullOrWhiteSpace())
                    {
                        model.AssignedTo = $"Allocated by {managerString}";
                    }
                    else
                    {
                        model.AssignedTo = "";
                    }
                }

                model.JobID = kanban.JobLink.ID;
                model.JobNumber = kanban.JobLink.JobNumber.NotWhiteSpaceOr("");
                model.JobName = kanban.JobLink.Name;
                model.Checked = SelectedTasks.Any(x => x.ID == model.ID);
                model.Type = new KanbanType
                {
                    ID = kanban.Type.ID,
                    Code = kanban.Type.Code
                };
                model.Number = kanban.Number;
            }
            catch(Exception e)
            {
                CoreUtils.LogException("", e);
            }
            if(model is not null)
            {
                yield return model;
            }
        }
    }

    /// <summary>
    /// Take the full list of kanbans loaded from the database, and filter based on the search UI elements, filtering into the columns.
    /// </summary>
    private void FilterKanbans()
    {
        IEnumerable<TaskModel> filtered;
        if (JobFilterID == Guid.Empty)
        {
            filtered = AllTasks;
        }
        else
        {
            filtered = AllTasks.Where(x => x.JobSearch(JobFilterID));
        }
        if (!Host.KanbanSettings.StatusSettings.IncludeLocked)
        {
            filtered = filtered.Where(x => !x.Locked);
        }
        if (!Host.KanbanSettings.StatusSettings.IncludeObserved
            && SelectedEmployee.ID != CoreUtils.FullGuid)
        {
            filtered = filtered.Where(x => x.EmployeeID == SelectedEmployee.ID || x.ManagerID == SelectedEmployee.ID);
        }
        if (!Host.KanbanSettings.StatusSettings.IncludeCompleted)
        {
            filtered = filtered.Where(x => x.CompletedDate.IsEmpty());
        }
        if (SelectedType != CoreUtils.FullGuid)
        {
            filtered = filtered.Where(x => x.Type.ID == SelectedType);
        }
        filtered = filtered.Where(x => x.Search(SearchText.Split()))
            .OrderBy(x => x.EmployeeID == SelectedEmployee.ID ? 0 : 1)
            .ThenBy(x => x.DueDate);

        SelectedTasks.Clear();

        foreach (var column in Columns)
        {
            column.Tasks.Clear();
        }

        foreach (var task in filtered)
        {
            var column = GetColumn(task.Status);
            column?.Tasks.Add(task);
            if (task.Checked)
            {
                SelectedTasks.Add(task);
            }
        }
    }

    #endregion

    #region ITaskControl

    public ITaskHost Host { get; set; }

    public KanbanViewType KanbanViewType => KanbanViewType.Status;

    public bool IsReady { get; set; }

    public string SectionName => "Task List";

    public DataModel DataModel(Selection selection)
    {
        var ids = SelectedModels().Select(x => x.ID).ToArray();
        return new AutoDataModel<Kanban>(new Filter<Kanban>(x => x.ID).InList(ids));
    }

    public IEnumerable<TaskModel> SelectedModels(TaskModel? sender = null)
    {
        if(sender is null)
        {
            return SelectedTasks;
        }
        else
        {
            var result = SelectedTasks.ToList();
            if (!result.Contains(sender))
            {
                result.Add(sender);
            }
            return result;
        }
    }

    #endregion

    private void Export_Click(object sender, RoutedEventArgs e)
    {
        var form = new DynamicExportForm(typeof(Kanban), GetKanbanColumns().ColumnNames());
        if (form.ShowDialog() != true)
            return;
        var export = new Client<Kanban>().Query(
            GetKanbanFilter(),
            InABox.Core.Columns.None<Kanban>().Add(form.Fields),
            LookupFactory.DefineSort<Kanban>()
        );

        var employee = "Tasks for All Staff";
        if (SelectedEmployee.ID != CoreUtils.FullGuid)
        {
            if (SelectedEmployee.ID == Guid.Empty)
            {
                employee = "Unallocated Tasks";
            }
            else
            {
                var model = Employees.FirstOrDefault(x => x.ID == SelectedEmployee.ID);
                employee = model == null ? "Tasks for (Unknown)" : "Tasks for " + (model.ID == App.EmployeeID ? App.EmployeeName : model.Name);
            }
        }

        ExcelExporter.DoExport<Kanban>(
            export,
            string.Format(
                "{0} ({1:dd-MMM-yy})",
                employee,
                DateTime.Today
            )
        );
    }

    private KanbanViewMode _mode;
    public KanbanViewMode Mode
    {
        get => _mode;
        set
        {
            _mode = value;
            OnPropertyChanged();
        }
    }

    private void ViewType_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        if (!IsReady || EventSuppressor.IsSet(Suppress.This))
            return;
        Mode = ViewType.SelectedIndex switch
        {
            0 => KanbanViewMode.Full,
            1 => KanbanViewMode.Compact,
            _ => KanbanViewMode.Full
        };

        Host.KanbanSettings.StatusSettings.CompactView = Mode == KanbanViewMode.Compact;
        Host.SaveSettings();
    }
}