using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media.Imaging;
using Comal.Classes;
using InABox.Clients;
using InABox.Core;
using InABox.DynamicGrid;
using InABox.WPF;
using Syncfusion.Linq;

namespace PRSDesktop
{
    public class LeaveRequestGrid : DynamicDataGrid<LeaveRequest>
    {
        //public bool FutureOnly = true;
        //private bool InProgressOnly = true;

        protected override void Init()
        {
            base.Init();
            
            HiddenColumns.Add(x=>x.OpenForms);
            HiddenColumns.Add(x=>x.FormCount);
            HiddenColumns.Add(x=>x.ApprovalSet.ID);
            HiddenColumns.Add(x=>x.OutstandingApprovals);
            ActionColumns.Add(new DynamicImageColumn(FormImage, FormAction) { Position = DynamicActionColumnPosition.End, ToolTip = FormToolTip});
            ActionColumns.Add(new DynamicMenuColumn(BuildMenu));
        }

        private Guid[]? availableApprovalSets = null;
        
        private void BuildMenu(DynamicMenuColumn column, CoreRow? row)
        {
            if (row is null) return;

            var menu = column.GetMenu();
            
            availableApprovalSets ??= Client.Query(
                new Filter<LeaveRequestApprovalSetEmployee>(x=>x.Employee.ID).IsEqualTo(App.EmployeeID),
                Columns.None<LeaveRequestApprovalSetEmployee>().Add(x=>x.ApprovalSet.ID)
            ).Rows
                .Select(r =>r.Get<LeaveRequestApprovalSetEmployee,Guid>(c=>c.ApprovalSet.ID))
                .Distinct()
                .ToArray();

            if (availableApprovalSets.Contains(row.Get<LeaveRequest, Guid>(x => x.ApprovalSet.ID)))
            {
                var approvals = row.Get<LeaveRequest, string>(x => x.OutstandingApprovals).Split(',');
                if (approvals.Contains(App.EmployeeCode))
                {
                    menu.AddItem("Approve", null, () => UpdateLeaveRequest(row,LeaveRequestApprovalStatus.Approved));
                    menu.AddItem("Reject", null, () => UpdateLeaveRequest(row,LeaveRequestApprovalStatus.Rejected, true));
                }
                else
                    menu.AddItem("Reset", null, () => UpdateLeaveRequest(row,LeaveRequestApprovalStatus.NotYetApproved));
            }
            
            if (Security.IsAllowed<ManageLeaveRequestApprovals>())
            {
                if (menu.Items.Count > 0)
                    menu.AddSeparator();
                
                var approvalSetItem = menu.AddItem("Approval Set", null, null);
                approvalSetItem.AddItem("Loading...", null, null, enabled: false);
                
                menu.AddItem("Manage Approvals", null, row, ManageApprovals_Click);
                
                var id = row.Get<LeaveRequest, Guid>(x => x.ID);
                var selectedApproval = row.Get<LeaveRequest, Guid>(x => x.ApprovalSet.ID);
                Task.Run(() =>
                {
                    return Client.Query<LeaveRequestApprovalSet>(
                            null,
                            Columns.None<LeaveRequestApprovalSet>().Add(x => x.ID).Add(x => x.Code).Add(x => x.Description))
                        .ToArray<LeaveRequestApprovalSet>();
                }).ContinueWith(approvals =>
                {
                    approvalSetItem.Items.Clear();
                    foreach(var approval in approvals.Result)
                    {
                        var item = approvalSetItem.AddItem($"{approval.Code}: {approval.Description}", null, (row, approval), ApprovalSet_Click);
                        item.IsChecked = approval.ID == selectedApproval;
                    }

                    if (row.Get<LeaveRequest, Guid>(x => x.ApprovalSet.ID) != Guid.Empty)
                    {
                        if (approvalSetItem.Items.Count > 0)
                            approvalSetItem.AddSeparator();
                        approvalSetItem.AddItem("Clear Approval Set", null, row, ApprovalSetClear_Click);
                    }
                }, TaskScheduler.FromCurrentSynchronizationContext());
            }
        }

        private void UpdateLeaveRequest(CoreRow row, LeaveRequestApprovalStatus status, bool requireNotes = false)
        {
            var note = "";
            if (requireNotes)
            {
                if (!TextBoxDialog.Execute("Reason for Rejection", ref note, false))
                    return;
            }
            
            var requestid = row.Get<LeaveRequest, Guid>(x => x.ID);
            var approval = Client.Query(
                new Filter<LeaveRequestApproval>(x => x.LeaveRequest.ID).IsEqualTo(requestid)
                    .And(x => x.Employee.ID).IsEqualTo(App.EmployeeID),
                Columns.None<LeaveRequestApproval>().Add(x=>x.ID).Add(x=>x.Status)
            ).Rows
                .FirstOrDefault()?
                .ToObject<LeaveRequestApproval>();
            if ((approval != null) && (approval.Status != status))
            {
                approval.Status = status;
                approval.Notes = note;
                Client.Save(approval,$"Status Updated to {status}");
                Refresh(false, true);
            }
        }

        private void ApprovalSetClear_Click(CoreRow row)
        {
            var bill = row.ToObject<LeaveRequest>();
            bill.ApprovalSet.ID = Guid.Empty;
            SaveItem(bill);
            Refresh(false, true);
        }

        private void ManageApprovals_Click(CoreRow row)
        {
            var request = row.ToObject<LeaveRequest>();

            var grid = new LeaveRequestApprovalGrid(request);
            var dlg = new DynamicContentDialog(grid, buttonsVisible: false)
            {
                Title = "Manage Approvals"
            };
            grid.Refresh(true, true);
            dlg.ShowDialog();

            request = LoadItem(row);
            UpdateRow(row, request);

            DoChanged();
        }

        private void ApprovalSet_Click((CoreRow row, LeaveRequestApprovalSet approvalSet) item)
        {
            var request = item.row.ToObject<LeaveRequest>();
            if (request.ApprovalSet.ID == item.approvalSet.ID) return;
            request.ApprovalSet.CopyFrom(item.approvalSet);
            SaveItem(request);
            Refresh(false, true);
        }
        
        private readonly BitmapImage _openforms = PRSDesktop.Resources.warning.AsBitmapImage();
        private readonly BitmapImage _completedforms = PRSDesktop.Resources.contract.AsBitmapImage();
        
        private BitmapImage? FormImage(CoreRow? row)
        {
            return row == null
                ? _completedforms
                : row?.Get<LeaveRequest, int>(x => x.OpenForms) != 0
                    ? _openforms
                    : row?.Get<LeaveRequest, int>(x => x.FormCount) != 0
                        ? _completedforms
                        : null;
        }
        
        private bool FormAction(CoreRow? row)
        {
            if (row is null)
                return false;

            var leaveRequestID = row.Get<LeaveRequest, Guid>(x => x.ID);

            var menu = new ContextMenu();

            DynamicGridUtils.PopulateFormMenu<LeaveRequestForm, LeaveRequest, LeaveRequestLink>(menu, leaveRequestID, () => row.ToObject<LeaveRequest>());

            menu.IsOpen = true;

            return false;
        }
        
        private FrameworkElement? FormToolTip(DynamicActionColumn column, CoreRow? row)
        {
            if (row == null)
                return column.TextToolTip("Leave Request Form Status?");
            int open = row.Get<LeaveRequest, int>(x => x.OpenForms);
            int total = row.Get<LeaveRequest, int>(x => x.FormCount);
            if (open != 0)
                return column.TextToolTip($"{open} incomplete forms");
            if (total != 0)
                return column.TextToolTip($"{total} forms");
            return null;
        }
        
        protected override void DoReconfigure(DynamicGridOptions options)
        {
            base.DoReconfigure(options);
            options.RecordCount = true;
            options.FilterRows = true;
            options.SelectColumns = true;
        }
        
        protected override Dictionary<string, object?> EditorValueChanged(IDynamicEditorForm editor, LeaveRequest[] items, string name, object value)
        {
            var result = base.EditorValueChanged(editor, items, name, value);

            if (name == "LeaveType.ID")
            {
                ReloadForms<LeaveRequest, LeaveRequestForm, ActivityForm>(editor, items.FirstOrDefault(), x => x.Activity.ID,
                    value != null ? (Guid)value : Guid.Empty);
            }
            else if (name.Equals("EmployeeLink.ID"))
            {
                var activity = editor.FindEditor("LeaveType.ID") as ILookupEditorControl;
                if (activity != null)
                    DefineLookups(activity, items);
            }

            return result;
        }

        protected override void AfterLoad(IDynamicEditorForm editor, LeaveRequest[] items)
        {
            base.AfterLoad(editor, items);
            if (items.First().ID == Guid.Empty)
                ReloadForms<LeaveRequest, LeaveRequestForm, ActivityForm>(editor, items.First(), x => x.Activity.ID,
                    items.First().LeaveType.ID);
        }

        protected override BaseEditor? GetEditor(object item, DynamicGridColumn column)
        {
            var result = base.GetEditor(item, column);
            if (result == null)
                return null;

            if (!Security.IsAllowed<CanApproveLeaveRequests>() && (column.ColumnName.Equals("Approved") || column.ColumnName.Equals("Status")))
            {
                result = result.CloneEditor();
                result.Editable = Editable.Disabled;
            }
            return result;
        }
    }
}