using System;
using System.Collections.Generic;
using System.Data;
using System.Drawing;
using System.Globalization;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Input;
using System.Windows.Media;
using Comal.Classes;
using InABox.Clients;
using InABox.Configuration;
using InABox.Core;
using InABox.DynamicGrid;
using InABox.WPF;
using NPOI.SS.Formula.Functions;
using PRSDesktop.WidgetGroups;
using Syncfusion.UI.Xaml.Grid;
using Syncfusion.Windows.Tools.Controls;
using SelectionChangedEventArgs = System.Windows.Controls.SelectionChangedEventArgs;

namespace PRSDesktop
{

    public class JobResourcePlannerProperties : IUserConfigurationSettings, IDashboardProperties
    {
        public JobSelectorSettings JobSettings { get; set; }
        public JobSelectorData JobSelection { get; set; }
        
        public Guid ActivityType { get; set; }
        
        public int MonthsToView { get; set; }

        public TeamSelectorSettings TeamSettings { get; set; }
        public TeamSelectorData TeamSelection { get; set; }
        public double SplitterPosition { get; set; }
        public double HoursPerDay { get; set; }
        public double EmployeeSplitterPosition { get; set; }
        public bool IncludeUnApprovedLeave { get; set; }

        public JobResourcePlannerProperties()
        {
            JobSettings = new JobSelectorSettings();
            JobSelection = new JobSelectorData();
            TeamSettings = new TeamSelectorSettings();
            TeamSelection = new TeamSelectorData();
            MonthsToView = 1;
            SplitterPosition = 0F;
            EmployeeSplitterPosition = 0F;
            HoursPerDay = 8.5;
            ActivityType = Guid.Empty;
            IncludeUnApprovedLeave = false;
        }
    }

    public partial class JobResourcePlanner : UserControl
    {
    
    
        private enum Suppress
        {
            This
        }

        private ActivityModel[] _activities = new ActivityModel[] { };
        private LeaveRequestModel[] _leaverequests = new LeaveRequestModel[] { };
        private StandardLeaveModel[] _standardleaves = new StandardLeaveModel[] { };

        private JobModel[] _jobs = new JobModel[] { };

        private EmployeeResourceModel[] _emps = new EmployeeResourceModel[] { };

        private List<AssignmentModel> _assignments = new List<AssignmentModel>();
        
        public JobResourcePlannerProperties Properties { get; set; }
        public event LoadSettings<JobResourcePlannerProperties>? LoadSettings;
        public event SaveSettings<JobResourcePlannerProperties>? SaveSettings;

        private void DoLoadSettings()
        {
            Properties = LoadSettings?.Invoke(this);
        }      
        
        private void DoSaveSettings()
        {
            SaveSettings?.Invoke(this, Properties);
        }

        public JobResourcePlanner()
        {
            using (new EventSuppressor(Suppress.This))
                InitializeComponent();
        }
        
        public void Setup()
        {
            using (new EventSuppressor(Suppress.This))
            {
                DoLoadSettings();
                
                JobSelector.Setup();
                JobSelector.Settings = Properties.JobSettings;
                JobSelector.Selection = Properties.JobSelection;
                _jobs = JobSelector.GetJobData<JobModel>(r => new JobModel(r));

                TeamSelector.Setup();
                TeamSelector.Settings = Properties.TeamSettings;
                TeamSelector.Selection = Properties.TeamSelection;
                _emps = TeamSelector.GetEmployeeData<EmployeeResourceModel>(r => new EmployeeResourceModel(r));
                
                ViewWindow.ItemsSource = new Dictionary<int, String>()
                {
                    { 1, "1 Month" },
                    { 3, "3 Months" },
                    { 6, "6 Months" },
                    { 12, "12 months" }
                };
                ViewWindow.SelectedValue = Properties.MonthsToView;
                
                if (Properties.SplitterPosition != 0F)
                    TeamSelectorRow.Height = new GridLength(Properties.SplitterPosition, GridUnitType.Pixel);

                if (Properties.EmployeeSplitterPosition != 0F)
                    AvailableEmployeesRow.Height = new GridLength(Properties.SplitterPosition, GridUnitType.Pixel);

                HoursSelector.Text = $"{Properties.HoursPerDay:F2}";
                
                LeaveType.SelectedIndex = Properties.IncludeUnApprovedLeave ? 1 : 0;
                
                AvailableEmployees.Refresh(true, false);
                AssignedEmployees.Refresh(true, false);
                
                MultiQuery query = new MultiQuery();
                
                query.Add<StandardLeave>(
                    LookupFactory.DefineFilter<StandardLeave>(),
                    StandardLeaveModel.Columns
                );
                
                query.Add<LeaveRequest>(
                    new Filter<LeaveRequest>(x => x.Status).IsNotEqualTo(LeaveRequestStatus.Rejected),
                    LeaveRequestModel.Columns
                );

                query.Add<Activity>(
                    LookupFactory.DefineFilter<Activity>(),
                    new Columns<Activity>(x => x.ID).Add(x => x.Code).Add(x => x.Description),
                    new SortOrder<Activity>(x => x.Code)
                );

                query.Query();

                _standardleaves = query.Get<StandardLeave>().Rows.Select(r=>new StandardLeaveModel(r)).ToArray();
                _leaverequests = query.Get<LeaveRequest>().Rows.Select(r => new LeaveRequestModel(r)).ToArray();
                
                _activities = query.Get<Activity>().Rows.Select(r => new ActivityModel(r)).ToArray();
                ActivityType.ItemsSource = _activities;
                ActivityType.SelectedValue = Properties.ActivityType;
                
            }
        }

        public void Shutdown()
        {
        }
        
        private bool GetStandardLeaveTimes(DateTime date, out TimeSpan start, out TimeSpan finish)
        {
            bool result = false;
            start = TimeSpan.Zero;
            finish = TimeSpan.FromDays(1);
            var requests = _standardleaves.Where(x => 
                (x.From <= date) 
                && (x.To.Add(x.ToTime) > date)
            );
            if (requests.Any())
            {
                result = true;
                start = TimeSpan.FromDays(1);
                finish = TimeSpan.Zero;
                foreach (var leave in requests)
                {
                    var curstart = leave.From == date ? leave.FromTime : TimeSpan.Zero;
                    start = start > curstart ? curstart : start;
                    var curfinish = leave.To == date ? leave.ToTime : TimeSpan.FromDays(1);
                    finish = finish < curfinish ? curfinish : finish;

                }
            }

            return result;            
        }
        
        private void AdjustStandardLeave(DateTime date, ref TimeSpan time)
        {
            TimeSpan result = TimeSpan.Zero;
            var leaves = _standardleaves.Where(x => 
                (x.From <= date)
                && (x.To.Add(x.ToTime) > date)
            );
            foreach (var leave in leaves)
            {
                result += (leave.To == date ? leave.ToTime : TimeSpan.FromDays(1)) -
                             (leave.From == date ? leave.FromTime : TimeSpan.Zero);
            }
            time = time >= result ? time - result : TimeSpan.Zero;
        }

        private bool GetLeaveRequestTimes(DateTime date, EmployeeResourceModel emp, out TimeSpan start, out TimeSpan finish)
        {
            bool result = false;
            start = TimeSpan.Zero;
            finish = TimeSpan.FromDays(1);
            var requests = _leaverequests.Where(x => 
                (x.From <= date) 
                && (x.To.Add(x.ToTime) > date)
                && (x.EmployeeID == emp.ID)
                && (Properties.IncludeUnApprovedLeave ? true : x.Status == LeaveRequestStatus.Approved)
            );
            if (requests.Any())
            {
                result = true;
                start = TimeSpan.FromDays(1);
                finish = TimeSpan.Zero;
                foreach (var leave in requests)
                {
                    var curstart = leave.From == date ? leave.FromTime : TimeSpan.Zero;
                    start = start > curstart ? curstart : start;
                    var curfinish = leave.To == date ? leave.ToTime : TimeSpan.FromDays(1);
                    finish = finish < curfinish ? curfinish : finish;

                }
            }

            return result;            
        }
        
        private void AdjustLeaveRequests(DateTime date, EmployeeResourceModel emp, ref TimeSpan time)
        {
            TimeSpan result = TimeSpan.Zero;
            var requests = _leaverequests.Where(x => 
                (x.From <= date) 
                && (x.To.Add(x.ToTime) > date)
                && (x.EmployeeID == emp.ID)
                && (Properties.IncludeUnApprovedLeave ? true : x.Status == LeaveRequestStatus.Approved)
            );
            foreach (var leave in requests)
            {
                result += (leave.To == date ? leave.ToTime : TimeSpan.FromDays(1)) -
                             (leave.From == date ? leave.FromTime : TimeSpan.Zero);
            }

            time = time >= result ? time - result : TimeSpan.Zero;
        }

        public void Refresh()
        {
            using (new WaitCursor())
            {
                
                var jobids = _jobs.Select(x => x.ID).ToArray();
                var empids = _emps.Select(x => x.ID).ToArray();
                var actids = _activities.Select(x => x.ID).ToArray();

                DateTime todate = DateTime.Today.AddMonths(Properties.MonthsToView);
                
                MultiQuery query = new MultiQuery();

                query.Add<Assignment>(
                    new Filter<Assignment>(x=>x.EmployeeLink.ID).InList(empids)
                        .And(x=>x.Date).IsGreaterThanOrEqualTo(DateTime.Today)
                        .And(x=>x.Date).IsLessThanOrEqualTo(DateTime.Today.AddMonths(Properties.MonthsToView)),
                    AssignmentModel.Columns
                );
                query.Query();
                _assignments = query.Get<Assignment>().Rows.Select(r => new AssignmentModel(r)).ToList();

                var data = new DataTable();
                data.Columns.Add("Date", typeof(DateTime));
                data.PrimaryKey = new System.Data.DataColumn[] { data.Columns[0] };
                
                data.Columns.Add("Total", typeof(object));
                data.Columns.Add("Available", typeof(object));
                
                foreach (var job in _jobs)
                    data.Columns.Add(job.ID.ToString(), typeof(object));
                
                DateTime date = DateTime.Today;
                while (date <= DateTime.Today.AddMonths(Properties.MonthsToView))
                {
                    double avail = 0.0F;

                    foreach (var emp in _emps)
                    {
                        var roster = RosterUtils.GetRoster(emp.Roster, emp.Start, date);

                        var hours = roster.GetBlocks(date, TimeSpan.MinValue, TimeSpan.MaxValue)
                            .Aggregate<RosterBlock, TimeSpan>(TimeSpan.Zero, (value, block) => value + block.Duration);
                        
                        AdjustStandardLeave(date, ref hours);
                        
                        AdjustLeaveRequests(date, emp, ref hours);
                        
                        avail += hours.TotalHours;

                    }
                    
                    double total = avail;
                    
                    var values = new List<object> { date };
                    
                    var anyjobstoday = _assignments.Where(x => (x.Date.Date == date.Date)); 
                    avail -= anyjobstoday.Aggregate<AssignmentModel, double>(0F, (value, model) => value + model.BookedDuration.TotalHours);

                    foreach (var job in _jobs)
                    {
                        var thisjobtoday = _assignments.Where(x => (x.Date.Date == date.Date) && (x.JobID == job.ID));
                        if (thisjobtoday.Any())
                        {
                            var assigned = thisjobtoday.Aggregate<AssignmentModel, double>(0F,
                                (value, model) => value + model.BookedDuration.TotalHours);
                            values.Add(assigned / Properties.HoursPerDay);
                        }
                        else
                            values.Add(null);
                    }

                    values.Insert(1,avail / Properties.HoursPerDay);
                    values.Insert(1,total / Properties.HoursPerDay);

                    data.Rows.Add(values.ToArray());
                    date = date.AddDays(1);
                }

                dataGrid.ItemsSource = data;
            }
        }
        
        private abstract class LeaveConverter : IMultiValueConverter
        {

            protected System.Windows.Media.Color GetColor(object[] value)
            {
                if ((value[0] != DBNull.Value) && (value[0] != DependencyProperty.UnsetValue))
                    return Colors.DarkSeaGreen;
                if (value[1] is GridCell cell)
                {
                    if (cell.DataContext is DataRowView rowview)
                    {
                        var total = rowview.Row["Total"];
                        if ((total == DBNull.Value) || ((double)total == 0.0F))
                            return Colors.LightGray;

                        var avail = rowview.Row["Available"];
                        if ((avail == DBNull.Value) || ((double)avail == 0.0F))
                            return Colors.LightSalmon;
                        return Colors.LightYellow;
                    }
                }

                return Colors.WhiteSmoke;
            }

            public abstract object Convert(object[] value, Type targetType, object parameter, CultureInfo culture);

            public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
            {
                throw new NotImplementedException();
            }
        }
        
        private class LeaveBackgroundConverter : LeaveConverter
        {
            public override object Convert(object[] value, Type targetType, object parameter, CultureInfo culture)
            {
                return new SolidColorBrush(base.GetColor(value)) { Opacity = 0.8 };
            }
        }

        private class LeaveForegroundConverter : LeaveConverter
        {
            public override object Convert(object[] value, Type targetType, object parameter, CultureInfo culture)
            {
                return new SolidColorBrush(ImageUtils.GetForegroundColor(base.GetColor(value)));
            }
        }
        
       private void DataGrid_AutoGeneratingColumn(object sender, AutoGeneratingColumnArgs e)
        {
            MultiBinding CreateBinding<TConverter>(String path) where TConverter : IMultiValueConverter, new()
            {
                var binding = new MultiBinding();
                binding.Bindings.Add(new Binding(path));
                binding.Bindings.Add(new Binding() { RelativeSource = new RelativeSource(RelativeSourceMode.Self) });
                binding.Converter = new TConverter();
                return binding;
            }


            var value = (e.Column.ValueBinding as Binding)!;
            if (value.Path.Path.Equals("Date"))
            {
                e.Column.Width = 80;
                e.Column.HeaderStyle = Resources["DateHeaderStyle"] as Style;
                e.Column.AllowFocus = false;
            }
            else if (value.Path.Path.Equals("Total"))
            {
                e.Cancel = true;
            }
            else if (value.Path.Path.Equals("Available"))
            {
                e.Column = new GridNumericColumn() { NumberDecimalDigits = 2, MappingName = e.Column.MappingName};
                e.Column.Width = 50;
                e.Column.HeaderStyle = e.Column.HeaderStyle = Resources["ContentHeaderStyle"] as Style;
                e.Column.AllowFocus = false;
                e.Column.HeaderText = "Available";
            }
            else
            {

                e.Column = new GridNumericColumn() { NumberDecimalDigits = 2, MappingName = e.Column.MappingName};
                e.Column.Width = 40;
                e.Column.HeaderStyle = Resources["ContentHeaderStyle"] as Style;
                var jobid = Guid.Parse(value.Path.Path);
                e.Column.HeaderText = _jobs.FirstOrDefault(x=>x.ID == jobid)?.Name ?? jobid.ToString();

                e.Column.DisplayBinding = new Binding { Path = new PropertyPath(e.Column.MappingName) };
                e.Column.AllowFocus = true;
                var style = new Style(typeof(GridCell));
                style.Setters.Add(new Setter(BackgroundProperty, CreateBinding<LeaveBackgroundConverter>(value.Path.Path)));
                style.Setters.Add(new Setter(ForegroundProperty, CreateBinding<LeaveForegroundConverter>(value.Path.Path)));
                e.Column.CellStyle = style;
                

            }
            e.Column.TextAlignment = TextAlignment.Center;
            e.Column.HorizontalHeaderContentAlignment = HorizontalAlignment.Center;
            e.Column.ColumnSizer = GridLengthUnitType.None;
            e.Column.ShowHeaderToolTip = false;
            e.Column.ShowToolTip = false;
        }
       
        private void DataGrid_ContextMenuOpening(object sender, ContextMenuEventArgs e)
        {
            var emps = TeamSelector.GetEmployeeData<EmployeeResourceModel>(r => new EmployeeResourceModel(r));
        }
        
        private void DataGrid_OnSelectionChanging(object? sender, GridSelectionChangingEventArgs e)
        {
             
        }
        
        private bool bResettingSelection = false;
        
        private void DataGrid_OnPreviewMouseDown(object sender, MouseButtonEventArgs e)
        {
            bResettingSelection = true;
            dataGrid.SelectionController.ClearSelections(false);
        }
        
        private void DataGrid_OnCurrentCellActivating(object? sender, CurrentCellActivatingEventArgs e)
        {
            if (bResettingSelection)
            {
                bResettingSelection = false;
                return;
            }
            var thiscol = dataGrid.Columns[e.CurrentRowColumnIndex.ColumnIndex];
            var selected = dataGrid.SelectionController.SelectedCells;
            if (selected.Any(x => x.Column != thiscol))
                e.Cancel = true;
            else
                e.Cancel = false;
        }
        
        private void DataGrid_OnPreviewMouseUp(object sender, MouseButtonEventArgs e)
        {

        }

        private bool ExtractSelection(out Guid jobid, out DateTime[] dates)
        {
            var selected = dataGrid.SelectionController.SelectedCells;
            var colname = selected.Select(x => x.Column.MappingName).Distinct().FirstOrDefault();
            if (Guid.TryParse(colname, out Guid job))
            {
                jobid = job;
                dates = selected.Select(x => ((DataRowView)x.RowData).Row["Date"]).Cast<DateTime>().ToArray();
                return true;
            }
            else
            {
                jobid = Guid.Empty;
                dates = new DateTime[] { };
                return false;
            }
        }
        
        private void DataGrid_OnMouseUp(object sender, MouseButtonEventArgs e)
        {
            if (ExtractSelection(out Guid jobid, out DateTime[] dates))
            {
                LoadAssignedEmployees(jobid, dates);
                LoadAvailableEmployees(dates);
            }            
        }
        
        private JobPlannerEmployee GetEmployee(Guid id, List<JobPlannerEmployee> list)
        {
            var result = list.FirstOrDefault(x => x.ID == id);
            if (result == null)
            {
                result = new JobPlannerEmployee()
                {
                    ID = id,
                    Name = _emps.FirstOrDefault(x=>x.ID == id)?.Name ?? id.ToString(),
                    Time = TimeSpan.Zero
                };
                list.Add(result);
            }

            return result;
        }

        private void LoadAvailableEmployees(DateTime[] dates)
        {
            List<JobPlannerEmployee> availableemployees = new List<JobPlannerEmployee>();
            foreach (var emp in _emps)
            {
                foreach (var date in dates)
                {
                    var roster = RosterUtils.GetRoster(emp.Roster, emp.Start, date);
                    var blocks = roster?.GetBlocks(date, TimeSpan.MinValue, TimeSpan.MaxValue) ?? new RosterBlock[] { };
                    var rostered = blocks.Aggregate(TimeSpan.Zero, (time, block) => time += block.Duration);

                    AdjustStandardLeave(date, ref rostered);
                    AdjustLeaveRequests(date, emp, ref rostered);

                    var assignments = _assignments.Where(x => (x.Date == date) && (x.EmployeeID == emp.ID));
                    var assigned = assignments.Aggregate(TimeSpan.Zero, (time, assign) => time += assign.BookedDuration);

                    if (rostered > assigned)
                        GetEmployee(emp.ID, availableemployees).Time += rostered.Subtract(assigned);
                    AvailableEmployees.Items = availableemployees.OrderBy(x=>x.Name).ToList();
                    AvailableEmployees.Refresh(false, true);
                }
            }
        }
        
        private void LoadAssignedEmployees(Guid jobid, DateTime[] dates)
        {
            List<JobPlannerEmployee> assignedemployees = new List<JobPlannerEmployee>();
            foreach (var assignment in _assignments.Where(x => dates.Contains(x.Date) && (x.JobID == jobid)))
                GetEmployee(assignment.EmployeeID,assignedemployees).Time += assignment.BookedDuration;
            AssignedEmployees.Items = assignedemployees.OrderBy(x=>x.Name).ToList();;
            AssignedEmployees.Refresh(false, true);
        }

        private void JobSelector_OnSettingsChanged(object sender, JobSelectorSettingsChangedArgs args)
        {
            if (EventSuppressor.IsSet(Suppress.This))
                return;
            Properties.JobSettings = args.Settings;
            DoSaveSettings();
        }

        private void JobSelector_OnSelectionChanged(object sender, JobSelectorSelectionChangedArgs args)
        {
            if (EventSuppressor.IsSet(Suppress.This))
                return;
            Properties.JobSelection = args.Selection;
            _jobs = JobSelector.GetJobData<JobModel>(x => new JobModel(x));
            DoSaveSettings();
            Refresh();
        }

        private void TeamSelector_OnSettingsChanged(object sender, TeamSelectorSettingsChangedArgs args)
        {
            if (EventSuppressor.IsSet(Suppress.This))
                return;
            Properties.TeamSettings = args.Settings;
            DoSaveSettings();
        }

        private void TeamSelector_OnSelectionChanged(object sender, TeamSelectorSelectionChangedArgs args)
        {
            if (EventSuppressor.IsSet(Suppress.This))
                return;
            Properties.TeamSelection = args.Selection;
            _emps = TeamSelector.GetEmployeeData<EmployeeResourceModel>(x => new EmployeeResourceModel(x));
            DoSaveSettings();
            Refresh();
        }

        private void JobSelector_OnSizeChanged(object sender, SizeChangedEventArgs e)
        {
            if (EventSuppressor.IsSet(Suppress.This))
                return;
            Properties.SplitterPosition = TeamSelectorRow.Height.Value;
            DoSaveSettings();
        }

        private void ViewWindow_OnSelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            if (EventSuppressor.IsSet(Suppress.This))
                return; 
            Properties.MonthsToView = (int)ViewWindow.SelectedValue;
            DoSaveSettings();
            Refresh();
        }

        private void HoursSelector_Down_Click(object sender, RoutedEventArgs e)
        {
            Properties.HoursPerDay = Math.Max(0.25F, Properties.HoursPerDay - 0.25);
            HoursSelector.Text = $"{Properties.HoursPerDay:F2}";
            DoSaveSettings();
            Refresh();
        }

        private void HoursSelector_Up_Click(object sender, RoutedEventArgs e)
        {
            Properties.HoursPerDay = Math.Min(24F, Properties.HoursPerDay + 0.25);
            HoursSelector.Text = $"{Properties.HoursPerDay:F2}";
            DoSaveSettings();
            Refresh();
        }
        
        
        private void ActivityType_OnSelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            if (EventSuppressor.IsSet(Suppress.This))
                return;
            Properties.ActivityType = (Guid)(ActivityType.SelectedValue ?? Guid.Empty);
            DoSaveSettings();
        }
        
        private void AvailableEmployees_OnSizeChanged(object sender, SizeChangedEventArgs e)
        {
            if (EventSuppressor.IsSet(Suppress.This))
                return;
            Properties.EmployeeSplitterPosition = AvailableEmployeesRow.Height.Value;
            DoSaveSettings();
        }

        private void AvailableEmployees_OnOnAction(object sender, JobPlannerEmployee[] availables)
        {

            List<TimeSpan> edges = new List<TimeSpan>();
            void CheckEdges(params TimeSpan[] times)
            {
                foreach (var time in times)
                {
                    if (!edges.Contains(time))
                        edges.Add(time);
                }
            }

            bool IsRostered(RosterBlock[] blocks, TimeSpan start, TimeSpan finish)
            {
                foreach (var block in blocks)
                {
                    if ((block.Start <= start) && (block.Finish >= finish))
                        return true;
                }
                return false;
            }

            bool IsStandardLeave(DateTime date, TimeSpan start, TimeSpan finish)
            {
                return _standardleaves.Any(x =>
                    (x.From.Add(x.FromTime) <= date.Add(start))
                    && (x.To.Add(x.ToTime) >= date.Add(finish))
                );
            }
            
            bool IsLeaveRequest(DateTime date, EmployeeResourceModel emp, TimeSpan start, TimeSpan finish)
            {
                return _leaverequests.Any(x =>
                    (x.EmployeeID == emp.ID)
                    && (x.From.Add(x.FromTime) <= date.Add(start))
                    && (x.To.Add(x.ToTime) >= date.Add(finish))
                );
            }

            bool IsAssigned(AssignmentModel[] assignments, TimeSpan start, TimeSpan finish)
            {
                foreach (var assignment in assignments)
                {
                    if ((assignment.BookedStart <= start) && (assignment.BookedFinish >= finish))
                        return true;
                }
                return false;                
            }
            
            if (ExtractSelection(out Guid jobid, out DateTime[] dates))
            {

                if (dataGrid.ItemsSource is DataTable table)
                {

                    List<Assignment> updates = new List<Assignment>();
                    foreach (var available in availables)
                    {
                        foreach (var date in dates)
                        {
                            var emp = _emps.FirstOrDefault(x => x.ID == available.ID);
                            if (emp != null)
                            {
                                var roster = RosterUtils.GetRoster(emp.Roster, emp.Start, date);
                                var blocks = roster?.GetBlocks(date, TimeSpan.MinValue, TimeSpan.MaxValue) ?? new RosterBlock[] { };
                                foreach (var block in blocks)
                                    CheckEdges(block.Start, block.Finish);

                                if (GetStandardLeaveTimes(date, out TimeSpan stdleavestart, out TimeSpan stdleavefinish))
                                    CheckEdges(stdleavestart, stdleavefinish);

                                if (GetLeaveRequestTimes(date, emp, out TimeSpan leaverequeststart, out TimeSpan leaverequestfinish))
                                    CheckEdges(leaverequeststart, leaverequestfinish);
                                
                                var assignments = _assignments.Where(x => (x.Date == date) && (x.EmployeeID == emp.ID)).ToArray();
                                foreach (var assignment in assignments)
                                    CheckEdges(assignment.BookedStart, assignment.BookedFinish);
                                edges.Sort();
                                
                                double adjustment = 0.0F;
                                for (int i = 0; i < edges.Count - 1; i++)
                                {
                                    var start = edges[i];
                                    var finish = edges[i + 1];

                                    if (IsRostered(blocks, start, finish) 
                                        && (!IsStandardLeave(date,start,finish))
                                        && (!IsLeaveRequest(date,emp,start,finish))
                                        && !IsAssigned(assignments, start, finish))
                                    {
                                        Assignment assignment = new Assignment();
                                        assignment.ActivityLink.ID = Properties.ActivityType;
                                        assignment.EmployeeLink.ID = emp.ID;
                                        assignment.Date = date;
                                        assignment.JobLink.ID = jobid;
                                        assignment.Booked.Start = start;
                                        assignment.Booked.Finish = finish;
                                        assignment.Booked.Duration = finish - start;
                                        updates.Add(assignment);
                                        adjustment += assignment.Booked.Duration.TotalHours;
                                    }
                                }
                                System.Data.DataRow row = table.Rows.Find(date);
                                row.BeginEdit();
                                double jobvalue = (row[jobid.ToString()] == DBNull.Value)
                                    ? adjustment / Properties.HoursPerDay
                                    : (double)row[jobid.ToString()] + (adjustment / Properties.HoursPerDay);
                                row[jobid.ToString()] = jobvalue <= 0F ? null : jobvalue;
                                row["Available"] = Math.Max(0F, (double)row["Available"] - (adjustment / Properties.HoursPerDay));
                                row.EndEdit();
                            }
                        }

                        var entry = AvailableEmployees.Items.FirstOrDefault(x => x.ID == available.ID);
                        if (entry != null)
                        {
                            AvailableEmployees.Items.Remove(entry);
                            GetEmployee(entry.ID, AssignedEmployees.Items).Time += entry.Time;
                        }
                    }

                    if (updates.Any())
                    {
                        using (new WaitCursor())
                        {
                            new Client<Assignment>().Save(updates, "Assigned by Job Planner");
                            
                            CoreTable temp = new CoreTable();
                            temp.LoadColumns(typeof(Assignment));
                            temp.LoadRows(updates);
                            _assignments.AddRange(temp.Rows.Select(r => new AssignmentModel(r)));

                            AssignedEmployees.Items = AssignedEmployees.Items.OrderBy(x => x.Name).ToList();
                            AssignedEmployees.Refresh(false, true);
                            AvailableEmployees.Refresh(false, true);
                        }
                    }
                }
            }
        }

        private void AssignedEmployees_OnOnAction(object sender, JobPlannerEmployee[] employees)
        {
            if (ExtractSelection(out Guid jobid, out DateTime[] dates))
            {
                if (dataGrid.ItemsSource is DataTable table)
                {
                    foreach (var date in dates)
                    {
                        var emptimes = _assignments.Where(x =>
                            (x.JobID == jobid)
                            && (x.Date == date)
                            && employees.Any(e => e.ID == x.EmployeeID)
                        ).ToArray();
                        var emptime = emptimes.Aggregate(TimeSpan.Zero, (time, ass) => time += ass.BookedDuration);
                        System.Data.DataRow row = table.Rows.Find(date);
                        row.BeginEdit();
                        double value = (row[jobid.ToString()] == DBNull.Value)
                            ? 0.0F
                            : (double)row[jobid.ToString()] - (emptime.TotalHours / Properties.HoursPerDay);
                        row[jobid.ToString()] = value <= 0F ? null : value;
                        row["Available"] = (double)row["Available"] + (emptime.TotalHours/Properties.HoursPerDay);
                        row.EndEdit();
                    }
                }
                
                var assignments = _assignments.Where(x =>
                    (x.JobID == jobid)
                    && dates.Contains(x.Date)
                    && employees.Any(e => e.ID == x.EmployeeID)
                ).ToArray();
                if (assignments.Any())
                {
                    using (new WaitCursor())
                    {
                        var deletes = assignments.Select(x => new Assignment() { ID = x.ID }).ToArray();
                        new Client<Assignment>().Delete(deletes, "Deleted from Job Planner");
                        var removes = AssignedEmployees.Items.Where(x => employees.Any(e => e.ID == x.ID)).ToArray();
                        foreach (var remove in removes)
                        {
                            AssignedEmployees.Items.Remove(remove);
                            GetEmployee(remove.ID, AssignedEmployees.Items).Time += remove.Time;

                        }

                        AssignedEmployees.Refresh(false, true);
                        AvailableEmployees.Items = AvailableEmployees.Items.OrderBy(x => x.Name).ToList();
                        AvailableEmployees.Refresh(false, true);

                        foreach (var assignment in assignments)
                            _assignments.Remove(assignment);
                    }
                }
                

            }
        }

        private void LeaveType_OnSelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            if (EventSuppressor.IsSet(Suppress.This))
                return;
            Properties.IncludeUnApprovedLeave = LeaveType.SelectedIndex > 0;
            DoSaveSettings();
            Refresh();
        }
    }
}