using System;
using System.Collections.Generic;
using System.Linq;
using System.Reactive.Disposables;
using System.Reactive.Linq;
using System.Windows;
using System.Windows.Controls;
using Intromat.ViewModels;
using NodeNetwork.ViewModels;
using NodeNetwork.Views;
using ReactiveUI;

namespace Intromat.Views
{
    /// <summary>
    /// Interaction logic for CodeGenNetworkView.xaml
    /// </summary>
    public partial class CodeGenNetworkView : IViewFor<CodeGenNetworkViewModel>
    {
        private readonly MenuItem _groupNodesButton;
        private readonly MenuItem _openGroupButton;
        private readonly MenuItem _ungroupNodesButton;

        public CodeGenNetworkView()
        {
            InitializeComponent();
            
            var nodeMenu = ((ContextMenu)Resources["nodeMenu"]).Items.OfType<MenuItem>().ToList();
            _groupNodesButton = nodeMenu.First(c => c.Name == nameof(_groupNodesButton));
            _ungroupNodesButton = nodeMenu.First(c => c.Name == nameof(_ungroupNodesButton));
            _openGroupButton = nodeMenu.First(c => c.Name == nameof(_openGroupButton));

            this.WhenActivated(d =>
            {
                Observable.FromEventPattern<NetworkView.NodeMoveStartDelegate, NetworkView.NodeMoveStartEventArgs>(handler => _network.NodeMoveStart += handler, handler => _network.NodeMoveStart -= handler)
                    .Select(e => e.EventArgs.Nodes.ToDictionary(node => node, node => node.Position))
                    .Zip(Observable.FromEventPattern<NetworkView.NodeMoveEndDelegate, NetworkView.NodeMoveEndEventArgs>(handler => _network.NodeMoveEnd += handler, handler => _network.NodeMoveEnd -= handler))
                    .Select(pair => pair.Second.EventArgs.Nodes.ToDictionary(node => node, node => (pair.First[node], node.Position)))
                    .Subscribe(RecordNodeDragAction)
                    .DisposeWith(d);

                var networkViewModel = ViewModel!;
                _network.ViewModel = networkViewModel;
                this.BindCommand(networkViewModel, vm => vm.GroupNodes, v => v._groupNodesButton).DisposeWith(d);
                this.BindCommand(networkViewModel, vm => vm.UngroupNodes, v => v._ungroupNodesButton).DisposeWith(d);
                this.BindCommand(networkViewModel, vm => vm.OpenGroup, v => v._openGroupButton).DisposeWith(d);
            });
        }

        private void RecordNodeDragAction(IDictionary<NodeViewModel, (Point, Point)> nodePositions)
        {
            var undoRedo = ViewModel!.Document.MainViewModel.UndoRedo;
            undoRedo.PushGroup(ViewModel.Document);
            foreach (var (node, (before, after)) in nodePositions)
                undoRedo.Record(new UndoItem<NodeViewModel, Point>(ViewModel.Document, node, v => v.Position, before, after));
            undoRedo.PopGroup();
        }

        object? IViewFor.ViewModel
        {
            get => ViewModel;
            set => ViewModel = (CodeGenNetworkViewModel?)value;
        }

        public CodeGenNetworkViewModel? ViewModel { get; set; }
    }
}