using Comal.Classes;
using InABox.Clients;
using InABox.Core;
using InABox.DynamicGrid;
using InABox.WPF;
using PRS.Shared.Events;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Imaging;

namespace PRS.Shared;

public class EventGrid : DynamicDataGrid<Event>
{
    private readonly BitmapImage _email = InABox.Wpf.Resources.email.AsBitmapImage();
    private readonly BitmapImage _notification = InABox.Wpf.Resources.notification.AsBitmapImage();
    private readonly BitmapImage _edit = InABox.Wpf.Resources.pencil.AsBitmapImage();

    private Button? EnableButton = null;

    private Dictionary<Guid, EventSubscriberType> _subscribedSet = new();

    public Guid EmployeeID { get; set; }

    protected override void Init()
    {
        base.Init();

        HiddenColumns.Add(x => x.Data);
        HiddenColumns.Add(x => x.Enabled);
        HiddenColumns.Add(x => x.Visible);

        ActionColumns.Add(new DynamicMenuColumn(BuildMenu, getImage: Menu_GetImage) { ToolTip = Subscribed_ToolTip });

        if (Security.IsAllowed<CanManageEvents>())
        {
            ActionColumns.Add(new DynamicImageColumn(_edit, Edit_Click));

            EnableButton = AddButton("Disable", null, Enable_Click);
            EnableButton.Visibility = Visibility.Collapsed;
        }
    }

    protected override void SelectItems(CoreRow[]? rows)
    {
        base.SelectItems(rows);
        if(EnableButton is not null)
        {
            if(rows is not null && rows.Length > 0)
            {
                EnableButton.Visibility = Visibility.Visible;
                EnableButton.Content = rows.Any(x => !x.Get<Event, bool>(x => x.Enabled))
                    ? "Enable" : "Disable";
            }
            else
            {
                EnableButton.Visibility = Visibility.Collapsed;
            }
        }
    }

    private bool Enable_Click(Button button, CoreRow[] rows)
    {
        var items = LoadItems(rows);
        if(items.Any(x => !x.Enabled))
        {
            foreach(var item in items)
            {
                item.Enabled = true;
            }
            Client.Save(items, "Event enabled.");
            return true;
        }
        else
        {
            foreach(var item in items)
            {
                item.Enabled = false;
            }
            Client.Save(items, "Event disabled.");
            return true;
        }
    }

    #region UIComponent

    private class UIComponent : DynamicGridGridUIComponent<Event>
    {
        protected override Brush? GetCellBackground(CoreRow row, DynamicColumnBase column)
        {
            if(row.Get<Event, bool>(x => x.Enabled))
            {
                return null;
            }
            else
            {
                return Colors.Gainsboro.ToBrush(0.5);
            }
        }
    }

    protected override IDynamicGridUIComponent CreateUIComponent()
    {
        return new UIComponent { Parent = this };
    }

    #endregion

    protected override void DoReconfigure(DynamicGridOptions options)
    {
        base.DoReconfigure(options);

        if (Security.IsAllowed<CanManageEvents>())
        {
            options.AddRows = true;
            options.EditRows = true;
            options.DeleteRows = true;
        }
        else
        {
            options.AddRows = false;
            options.EditRows = false;
            options.DeleteRows = false;
        }
    }

    #region Action Columns

    private FrameworkElement? Subscribed_ToolTip(DynamicActionColumn column, CoreRow? row)
    {
        if(row is null)
        {
            return column.TextToolTip("Are you subscribed to this event?");
        }
        else
        {
            return _subscribedSet.TryGetValue(row.Get<Event, Guid>(x => x.ID), out var type)
                ? (type == EventSubscriberType.Notification
                    ? column.TextToolTip("You are subscribed to this event by notification.")
                    : column.TextToolTip("You are subscribed to this event by email."))
                : null;
        }
    }

    private void BuildMenu(DynamicMenuColumn column, CoreRow? row)
    {
        if (row is null) return;

        var menu = column.GetMenu();

        var eventID = row.Get<Event, Guid>(x => x.ID);

        if (_subscribedSet.TryGetValue(eventID, out var type))
        {
            menu.AddItem("Unsubscribe", null, row, Unsubscribe);
            if(type == EventSubscriberType.Notification)
            {
                menu.AddItem("Subscribe by Email", null, (row, EventSubscriberType.Email), ChangeSubscription);
            }
            else
            {
                menu.AddItem("Subscribe by Notification", null, (row, EventSubscriberType.Notification), ChangeSubscription);
            }
        }
        else
        {
            menu.AddItem("Subscribe by Notification", null, (row, EventSubscriberType.Notification), Subscribe);
            menu.AddItem("Subscribe by Email", null, (row, EventSubscriberType.Email), Subscribe);
        }
    }

    private BitmapImage? Menu_GetImage(CoreRow? row)
    {
        if (row is null) return _notification;

        return _subscribedSet.TryGetValue(row.Get<Event, Guid>(x => x.ID), out var type)
            ? (type == EventSubscriberType.Notification ? _notification : _email)
            : null;
    }

    private void ChangeSubscription((CoreRow row, EventSubscriberType Notification) tuple)
    {
        Unsubscribe(tuple.row, false);
        Subscribe(tuple);
    }

    private void Subscribe((CoreRow row, EventSubscriberType type) tuple)
    {
        var ev = tuple.row.ToObject<Event>();
        var subscriber = new EventSubscriber();
        subscriber.Event.CopyFrom(ev);
        subscriber.Employee.ID = EmployeeID;
        subscriber.SubscriberType = tuple.type;
        Client.Save(subscriber, "");
        _subscribedSet.Add(ev.ID, subscriber.SubscriberType);

        Refresh(false, true);
    }

    private void Unsubscribe(CoreRow row)
    {
        Unsubscribe(row, true);
    }
    private void Unsubscribe(CoreRow row, bool refresh)
    {
        var eventID = row.Get<Event, Guid>(x => x.ID);

        var subscriber = Client.Query(
            new Filter<EventSubscriber>(x => x.Employee.ID).IsEqualTo(EmployeeID)
                .And(x => x.Event.ID).IsEqualTo(eventID),
            Columns.None<EventSubscriber>().Add(x => x.ID))
            .ToObjects<EventSubscriber>().FirstOrDefault();
        if(subscriber is not null)
        {
            Client.Delete(subscriber, "");
        }

        _subscribedSet.Remove(eventID);

        if (refresh)
        {
            Refresh(false, true);
        }
    }

    private bool Edit_Click(CoreRow? row)
    {
        if (row is null) return false;

        var ev = row.ToObject<Event>();

        IEventData? data = null;
        if(ev.Data is not null && ev.Data.Length != 0)
        {
            data = EventUtils.Deserialize(ev.Data);
        }

        var type = ev.EventType;
        if(EventEditor.Run(ref type, ref data))
        {
            ev.EventType = type;
            if(data is not null)
            {
                ev.Data = EventUtils.Serialize(data);
            }
            else
            {
                ev.Data = "";
            }
            SaveItem(ev);
            return true;
        }
        else
        {
            return false;
        }
    }

    #endregion

    private readonly Column<Event> EventTypeColumn = new(x => x.EventType);
    private readonly Column<Event> NotificationExpressionColumn = new(x => x.NotificationExpression);

    private IEventData? EventData;

    protected override void BeforeLoad(IDynamicEditorForm form, Event[] items)
    {
        base.BeforeLoad(form, items);

        form.ReadOnly = !Security.IsAllowed<CanManageEvents>();

        var ev = items.First();

        IEventData? data = null;
        if(ev.Data is not null && ev.Data.Length != 0)
        {
            data = EventUtils.Deserialize(ev.Data);
        }
        EventData = data;
    }

    protected override void CustomiseEditor(IDynamicEditorForm form, Event[] items, DynamicGridColumn column, BaseEditor editor)
    {
        base.CustomiseEditor(form, items, column, editor);

        if(EventTypeColumn.IsEqualTo(column.ColumnName) && editor is EnumLookupEditor enumEditor)
        {
            var ev = items.First();

            var editButton = new EditorButton(ev, "Edit Event", 100, (e, i) => EditEvent_Click(form, e, i), false);
            enumEditor.Buttons = [editButton];
        }
        else if(NotificationExpressionColumn.IsEqualTo(column.ColumnName) && editor is ExpressionEditor exprEditor)
        {
            exprEditor.OnGetVariables += ExprEditor_OnGetVariables;
        }
    }

    private IEnumerable<string> ExprEditor_OnGetVariables()
    {
        return EventData?.Event.DataModelDefinition().GetVariables().Select(x => x.Name) ?? [];
    }

    private void EditEvent_Click(IDynamicEditorForm form, object editor, object? item)
    {
        if (item is not Event ev) return;

        var type = ev.EventType;

        var data = EventData;
        if(EventEditor.Run(ref type, ref data))
        {
            EventData = data;
            ev.EventType = type;
            form.SetEditorValue(nameof(Event.EventType), type);
            if(data is not null)
            {
                ev.Data = EventUtils.Serialize(data);
            }
            else
            {
                ev.Data = "";
            }
        }
        else
        {
            // We have to 'cancel' by just re-deserialising.
            if(ev.Data is not null && ev.Data.Length != 0)
            {
                EventData = EventUtils.Deserialize(ev.Data);
            }
        }
    }

    protected override void Reload(Filters<Event> criteria, Columns<Event> columns, ref SortOrder<Event>? sort, CancellationToken token, Action<CoreTable?, Exception?> action)
    {
        if (!Security.IsAllowed<CanManageEvents>())
        {
            criteria.Add(new Filter<Event>(x => x.Visible).IsEqualTo(true));
        }
        base.Reload(criteria, columns, ref sort, token, (data, error) =>
        {
            if(data is not null)
            {
                var ids = data.ExtractValues<Event, Guid>(x => x.ID);
                _subscribedSet = Client.Query(
                    new Filter<EventSubscriber>(x => x.Employee.ID).IsEqualTo(EmployeeID)
                        .And(x => x.Event.ID).InList(ids),
                    Columns.None<EventSubscriber>().Add(x => x.Event.ID).Add(x => x.SubscriberType))
                    .ToObjects<EventSubscriber>().ToDictionary(x => x.Event.ID, x => x.SubscriberType);
            }
            action(data, error);
        });
    }
}