using System.Collections.ObjectModel;
using System.Windows.Threading;
using JD.WPF.Models;
using JD.WPF.Models.Menus;

namespace JD.SceneExplorer.ViewModels
{
    public class ObjectWithRefHierarchy : DataModelBase
    {
        private ObjectWithRef m_currentObject;
        private readonly ObservableCollection<HierarchyItem> m_objectHierarchy;
        private readonly ObjectWithRef m_separator;
        private readonly SceneExplorerPlugin m_mainModel;

        public ObjectWithRefHierarchy(SceneExplorerPlugin mainModel)
        {
            m_currentObject = ObjectWithRef.InvalidObject;
            m_objectHierarchy = new ObservableCollection<HierarchyItem>();
            m_objectHierarchy.Add(new HierarchyItem(m_separator));
            m_separator = new ObjectWithRef(0, null, null);
            m_separator.FriendlyName = " > ";
            m_mainModel = mainModel;
        }

        public ObservableCollection<HierarchyItem> Hierarchy
        {
            get { return m_objectHierarchy; }
        }

        public ObjectWithRef Separator
        {
            get { return m_separator; }
        }

        public void FillHierarchy(Dispatcher maintThreadDispatcher, ObjectWithRef currentObject)
        {
            maintThreadDispatcher.Invoke(() => {
                m_objectHierarchy.Clear();
                m_currentObject = currentObject;
                if (m_currentObject != null && m_currentObject.IsSelected)
                    FillHierarchyInternal(m_currentObject);

                RaisePropertyChanged("HierarchyText");
            });
        }

        private void FillHierarchyInternal(ObjectWithRef currentObject)
        {
            if (m_objectHierarchy.Count != 0)
                m_objectHierarchy.Insert(0, new HierarchyItem(m_separator));
            m_objectHierarchy.Insert(0, new HierarchyItem(currentObject, m_mainModel));
            if (currentObject.Parent != null)
                FillHierarchyInternal(currentObject.Parent as ObjectWithRef);
        }

        public struct HierarchyItem
        {
            private readonly ObjectWithRef m_item;
            public MenuItemDataCollection m_contextMenu;

            public HierarchyItem(ObjectWithRef item)
            {
                m_item = item;
                m_contextMenu = null;
            }

            public HierarchyItem(ObjectWithRef item, SceneExplorerPlugin mainModel)
            {
                m_item = item;
                m_contextMenu = new MenuItemDataCollection();
                //BuildContextMenu(mainModel); // Unsafe : need better multithread checks. 
            }

            public ObjectWithRef Item { get { return m_item; } }
            public MenuItemDataCollection ContextMenu { get { return m_contextMenu; } }

            /*private void BuildContextMenu(SceneExplorerModel mainModel)
            {
                if (m_item.Parent != null)
                {
                    foreach (ObjectWithRef child in m_item.Parent.Children)
                    {
                        m_contextMenu.Add(new MenuItemData(child.FriendlyName, null, command: new SelectItemCommand(mainModel), data: child));
                    }
                }
            }*/
        }
    }
}