/*************************************************************************************

   Extended WPF Toolkit

   Copyright (C) 2007-2013 Xceed Software Inc.

   This program is provided to you under the terms of the Microsoft Public
   License (Ms-PL) as published at http://wpftoolkit.codeplex.com/license 

   For more features, controls, and fast professional support,
   pick up the Plus Edition at http://xceed.com/wpf_toolkit

   Stay informed: follow @datagrid on Twitter or Like http://facebook.com/datagrids

  ***********************************************************************************/

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Runtime.InteropServices;
using System.Windows.Interop;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Media;
using System.Windows.Input;
using Xceed.Wpf.AvalonDock.Layout;
using Xceed.Wpf.AvalonDock.Converters;
using System.Diagnostics;
using System.Windows.Controls.Primitives;
using Xceed.Wpf.AvalonDock.Commands;
using Microsoft.Windows.Shell;

namespace Xceed.Wpf.AvalonDock.Controls
{
    public class LayoutAnchorableFloatingWindowControl : LayoutFloatingWindowControl, IOverlayWindowHost
    {
        static LayoutAnchorableFloatingWindowControl()
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(LayoutAnchorableFloatingWindowControl), new FrameworkPropertyMetadata(typeof(LayoutAnchorableFloatingWindowControl)));
        } 


        internal LayoutAnchorableFloatingWindowControl(LayoutAnchorableFloatingWindow model)
            :base(model)
        {
            _model = model;
            HideWindowCommand = new RelayCommand((p) => OnExecuteHideWindowCommand(p), (p) => CanExecuteHideWindowCommand(p));
        }

        internal override void UpdateThemeResources( Xceed.Wpf.AvalonDock.Themes.Theme oldTheme = null )
        {
            base.UpdateThemeResources(oldTheme);

            if (_overlayWindow != null)
                _overlayWindow.UpdateThemeResources(oldTheme);
        }

        LayoutAnchorableFloatingWindow _model;

        public override ILayoutElement Model
        {
            get { return _model; }
        }

        #region SingleContentLayoutItem

        /// <summary>
        /// SingleContentLayoutItem Dependency Property
        /// </summary>
        public static readonly DependencyProperty SingleContentLayoutItemProperty =
            DependencyProperty.Register("SingleContentLayoutItem", typeof(LayoutItem), typeof(LayoutAnchorableFloatingWindowControl),
                new FrameworkPropertyMetadata((LayoutItem)null,
                    new PropertyChangedCallback(OnSingleContentLayoutItemChanged)));

        /// <summary>
        /// Gets or sets the SingleContentLayoutItem property.  This dependency property 
        /// indicates the layout item of the selected content when is shown a single anchorable pane.
        /// </summary>
        public LayoutItem SingleContentLayoutItem
        {
            get { return (LayoutItem)GetValue(SingleContentLayoutItemProperty); }
            set { SetValue(SingleContentLayoutItemProperty, value); }
        }

        /// <summary>
        /// Handles changes to the SingleContentLayoutItem property.
        /// </summary>
        private static void OnSingleContentLayoutItemChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            ((LayoutAnchorableFloatingWindowControl)d).OnSingleContentLayoutItemChanged(e);
        }

        /// <summary>
        /// Provides derived classes an opportunity to handle changes to the SingleContentLayoutItem property.
        /// </summary>
        protected virtual void OnSingleContentLayoutItemChanged(DependencyPropertyChangedEventArgs e)
        {
        }

        #endregion



        protected override void OnInitialized(EventArgs e)
        {
            base.OnInitialized(e);

            var manager = _model.Root.Manager;

            Content = manager.CreateUIElementForModel(_model.RootPanel);

            //SetBinding(VisibilityProperty, new Binding("IsVisible") { Source = _model, Converter = new BoolToVisibilityConverter(), Mode = BindingMode.OneWay, ConverterParameter = Visibility.Hidden });

            //Issue: http://avalondock.codeplex.com/workitem/15036
            IsVisibleChanged += (s, args) =>
            {
                var visibilityBinding = GetBindingExpression(VisibilityProperty);
                if (IsVisible && (visibilityBinding == null))
                {
                    SetBinding(VisibilityProperty, new Binding("IsVisible") { Source = _model, Converter = new BoolToVisibilityConverter(), Mode = BindingMode.OneWay, ConverterParameter = Visibility.Hidden });
                }
            };

            SetBinding(SingleContentLayoutItemProperty, new Binding("Model.SinglePane.SelectedContent") { Source = this, Converter = new LayoutItemFromLayoutModelConverter() });

            _model.PropertyChanged += new System.ComponentModel.PropertyChangedEventHandler(_model_PropertyChanged);
        }


        void _model_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
        {
            if (e.PropertyName == "RootPanel" &&
                _model.RootPanel == null)
            {
                InternalClose();
            }
        }


        bool IOverlayWindowHost.HitTest(Point dragPoint)
        {
            Rect detectionRect = new Rect(this.PointToScreenDPIWithoutFlowDirection(new Point()), this.TransformActualSizeToAncestor());
            return detectionRect.Contains(dragPoint);
        }

        DockingManager IOverlayWindowHost.Manager
        {
            get { return _model.Root.Manager; }
        }

        OverlayWindow _overlayWindow = null;
        void CreateOverlayWindow()
        {
            if (_overlayWindow == null)
                _overlayWindow = new OverlayWindow(this);
            Rect rectWindow = new Rect(this.PointToScreenDPIWithoutFlowDirection(new Point()), this.TransformActualSizeToAncestor());
            _overlayWindow.Left = rectWindow.Left;
            _overlayWindow.Top = rectWindow.Top;
            _overlayWindow.Width = rectWindow.Width;
            _overlayWindow.Height = rectWindow.Height;
        }

        IOverlayWindow IOverlayWindowHost.ShowOverlayWindow(LayoutFloatingWindowControl draggingWindow)
        {
            CreateOverlayWindow();
            _overlayWindow.Owner = draggingWindow;
            _overlayWindow.EnableDropTargets();
            _overlayWindow.Show();

            return _overlayWindow;
        }

        void IOverlayWindowHost.HideOverlayWindow()
        {
            _dropAreas = null;
            _overlayWindow.Owner = null;
            _overlayWindow.HideDropTargets();
        }

        List<IDropArea> _dropAreas = null;
        IEnumerable<IDropArea> IOverlayWindowHost.GetDropAreas(LayoutFloatingWindowControl draggingWindow)
        {
            if (_dropAreas != null)
                return _dropAreas;

            _dropAreas = new List<IDropArea>();

            if (draggingWindow.Model is LayoutDocumentFloatingWindow)
                return _dropAreas;

            var rootVisual = (Content as FloatingWindowContentHost).RootVisual;

            foreach (var areaHost in rootVisual.FindVisualChildren<LayoutAnchorablePaneControl>())
            {
                _dropAreas.Add(new DropArea<LayoutAnchorablePaneControl>(
                    areaHost,
                    DropAreaType.AnchorablePane));
            }
            foreach (var areaHost in rootVisual.FindVisualChildren<LayoutDocumentPaneControl>())
            {
                _dropAreas.Add(new DropArea<LayoutDocumentPaneControl>(
                    areaHost,
                    DropAreaType.DocumentPane));
            }

            return _dropAreas;
        }

        protected override void OnClosed(EventArgs e)
        {
            var root = Model.Root;
            root.Manager.RemoveFloatingWindow(this);
            root.CollectGarbage();
            if (_overlayWindow != null)
            {
                _overlayWindow.Close();
                _overlayWindow = null;
            }

            base.OnClosed(e);

            if (!CloseInitiatedByUser)
            {
                root.FloatingWindows.Remove(_model);
            }

            _model.PropertyChanged -= new System.ComponentModel.PropertyChangedEventHandler(_model_PropertyChanged);
        }

        protected override void OnClosing(System.ComponentModel.CancelEventArgs e)
        {
            if (CloseInitiatedByUser && !KeepContentVisibleOnClose)
            {
                e.Cancel = true;
                _model.Descendents().OfType<LayoutAnchorable>().ToArray().ForEach<LayoutAnchorable>((a) => a.Hide());
            }

            base.OnClosing(e);
        }

        protected override IntPtr FilterMessage(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
        {
            switch (msg)
            {
                case Win32Helper.WM_NCLBUTTONDOWN: //Left button down on title -> start dragging over docking manager
                    if (wParam.ToInt32() == Win32Helper.HT_CAPTION)
                    {
                        _model.Descendents().OfType<LayoutAnchorablePane>().First(p => p.ChildrenCount > 0 && p.SelectedContent != null).SelectedContent.IsActive = true;
                        handled = true;
                    }
                    break;
                case Win32Helper.WM_NCRBUTTONUP:
                    if (wParam.ToInt32() == Win32Helper.HT_CAPTION)
                    {
                        if (OpenContextMenu())
                            handled = true;

                        if (_model.Root.Manager.ShowSystemMenu)
                            WindowChrome.GetWindowChrome(this).ShowSystemMenu = !handled;
                        else
                            WindowChrome.GetWindowChrome(this).ShowSystemMenu = false;
                    }
                    break;

            }

            return base.FilterMessage(hwnd, msg, wParam, lParam, ref handled);
        }

        bool OpenContextMenu()
        {
            var ctxMenu = _model.Root.Manager.AnchorableContextMenu;
            if (ctxMenu != null && SingleContentLayoutItem != null)
            {
                ctxMenu.PlacementTarget = null;
                ctxMenu.Placement = PlacementMode.MousePoint;
                ctxMenu.DataContext = SingleContentLayoutItem;
                ctxMenu.IsOpen = true;
                return true;
            }

            return false;
        }

        bool IsContextMenuOpen()
        {
            var ctxMenu = _model.Root.Manager.AnchorableContextMenu;
            if (ctxMenu != null && SingleContentLayoutItem != null)
            {
                return ctxMenu.IsOpen;
            }

            return false;
        }

        #region HideWindowCommand
        public ICommand HideWindowCommand
        {
            get;
            private set;
        }

        private bool CanExecuteHideWindowCommand(object parameter)
        {
            if (Model == null)
                return false;

            var root = Model.Root;
            if (root == null)
                return false;

            var manager = root.Manager;
            if (manager == null)
                return false;

            bool canExecute = false;
            foreach (var anchorable in this.Model.Descendents().OfType<LayoutAnchorable>().ToArray())
            {
                if (!anchorable.CanHide)
                {
                    canExecute = false;
                    break;
                }

                var anchorableLayoutItem = manager.GetLayoutItemFromModel(anchorable) as LayoutAnchorableItem;
                if (anchorableLayoutItem == null ||
                    anchorableLayoutItem.HideCommand == null ||
                    !anchorableLayoutItem.HideCommand.CanExecute(parameter))
                {
                    canExecute = false;
                    break;
                }

                canExecute = true;
            }

            return canExecute;
        }

        private void OnExecuteHideWindowCommand(object parameter)
        {
            var manager = Model.Root.Manager;
            foreach (var anchorable in this.Model.Descendents().OfType<LayoutAnchorable>().ToArray())
            {
                var anchorableLayoutItem = manager.GetLayoutItemFromModel(anchorable) as LayoutAnchorableItem;
                anchorableLayoutItem.HideCommand.Execute(parameter);
            }
        }
        #endregion
    }
}