using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Windows;
using System.Windows.Input;
using System.Windows.Media;
using AIStudio.Wpf.DiagramDesigner.Controls;
using AIStudio.Wpf.DiagramDesigner.Geometrys;
using AIStudio.Wpf.DiagramDesigner.Helpers;
using SvgPathProperties;

namespace AIStudio.Wpf.DiagramDesigner
{
    public class ConnectionViewModel : SelectableDesignerItemViewModelBase
    {
        public ConnectionViewModel(IDiagramViewModel root, FullyCreatedConnectorInfo sourceConnectorInfo, ConnectorInfoBase sinkConnectorInfo, DrawMode drawMode, RouterMode routerMode)
        {
            Root = root;
            PathMode = drawMode.ToString();
            RouterMode = routerMode.ToString();
            Init(sourceConnectorInfo, sinkConnectorInfo);
        }

        public ConnectionViewModel(IDiagramViewModel root, FullyCreatedConnectorInfo sourceConnectorInfo, FullyCreatedConnectorInfo sinkConnectorInfo, ConnectionItem designer) : base(root, designer)
        {
            PathMode = designer.PathMode;
            RouterMode = designer.RouterMode;

            Init(sourceConnectorInfo, sinkConnectorInfo);
        }

        public ConnectionViewModel(FullyCreatedConnectorInfo sourceConnectorInfo, ConnectorInfoBase sinkConnectorInfo, DrawMode drawMode, RouterMode routerMode) : this(null, sourceConnectorInfo, sinkConnectorInfo, drawMode, routerMode)
        {

        }

        public override SelectableItemBase GetSerializableObject()
        {
            if (IsFullConnection)
            {
                ConnectionItem connection = new ConnectionItem(this);

                return connection;
            }
            else
            {
                return null;
            }
        }

        protected virtual void Init(FullyCreatedConnectorInfo sourceConnectorInfo, ConnectorInfoBase sinkConnectorInfo)
        {
            this.Root = sourceConnectorInfo.DataItem.Root;

            if (Root != null && Root.ColorViewModel != null)
            {
                this.ColorViewModel = CopyHelper.Mapper(Root.ColorViewModel);
            }
            if (sinkConnectorInfo is FullyCreatedConnectorInfo sink && sink.DataItem.ShowArrow == false)
            {
                this.ColorViewModel.RightArrowPathStyle = ArrowPathStyle.None;
            }
            ColorViewModel.PropertyChanged += ConnectorViewModel_PropertyChanged;
            this.PropertyChanged += ConnectorViewModel_PropertyChanged;

            var routetype = GlobalType.AllTypes.Where(p => typeof(IRouter).IsAssignableFrom(p)).FirstOrDefault(p => p.Name == RouterMode);
            Router = routetype != null ? (System.Activator.CreateInstance(routetype) as IRouter) : new RouterNormal();

            var pathGeneratortype = GlobalType.AllTypes.Where(p => typeof(IPathGenerator).IsAssignableFrom(p)).FirstOrDefault(p => p.Name == PathMode);
            PathGenerator = pathGeneratortype != null ? (System.Activator.CreateInstance(pathGeneratortype) as IPathGenerator) : new ConnectingLineSmooth();

            this.SourceConnectorInfo = sourceConnectorInfo;
            this.SinkConnectorInfo = sinkConnectorInfo;
            DeleteConnectionCommand = new SimpleCommand(DeleteConnection);
            AddVertexCommand = new SimpleCommand(AddVertex);
            AddLabelCommand = new SimpleCommand(AddLabel);
        }

        protected override void LoadDesignerItemViewModel(IDiagramViewModel root, SelectableItemBase designerbase)
        {
            base.LoadDesignerItemViewModel(root, designerbase);

            if (designerbase is ConnectionItem designer)
            {
                Vertices = new ObservableCollection<ConnectorVertexModel>(designer.Vertices.Select(p => new ConnectorVertexModel(this.Root, this, designer)));
                Labels = new ObservableCollection<ConnectorLabelModel>(designer.Labels.Select(p => new ConnectorLabelModel(this.Root, this, designer)));
            }
        }    

        #region 属性
        private string _text;
        [Browsable(true)]
        [CanDo]
        public override string Text
        {
            get
            {
                var text = _text;
                if (Labels?.Count > 0)
                {
                    text = Labels[0].Text;
                }

                if (FontViewModel.FontCase == FontCase.Upper)
                {
                    return text?.ToUpper();
                }
                else if (FontViewModel.FontCase == FontCase.Lower)
                {
                    return text?.ToLower();
                }
                else
                {
                    return text;
                }
            }
            set
            {
                if (SetProperty(ref _text, value))
                {
                    if (!string.IsNullOrEmpty(_text))
                    {
                        if (Labels?.Count > 0)
                        {
                            Labels[0].Text = _text;
                        }
                        else
                        {
                            AddLabel(_text);
                        }
                    }
                }
            }
        }

        private PointBase _sourceA;
        public PointBase SourceA
        {
            get
            {
                return _sourceA;
            }
            set
            {
                SetProperty(ref _sourceA, value);
            }
        }

        private PointBase _sourceB;
        public PointBase SourceB
        {
            get
            {
                return _sourceB;
            }
            set
            {
                SetProperty(ref _sourceB, value);
            }
        }

        private PointBase _startPoint;
        public PointBase StartPoint
        {
            get
            {
                return _startPoint;
            }
            private set
            {
                SetProperty(ref _startPoint, value);
            }
        }

        private PointBase _endPoint;
        public PointBase EndPoint
        {
            get
            {
                return _endPoint;
            }
            private set
            {
                SetProperty(ref _endPoint, value);
            }
        }

        private double _startAngle;
        public double StartAngle
        {
            get
            {
                return _startAngle;
            }
            private set
            {
                SetProperty(ref _startAngle, value);
            }
        }

        private double _endAngle;
        public double EndAngle
        {
            get
            {
                return _endAngle;
            }
            private set
            {
                SetProperty(ref _endAngle, value);
            }
        }

        private RectangleBase _area;
        public RectangleBase Area
        {
            get
            {
                return _area;
            }
            private set
            {
                SetProperty(ref _area, value);
            }
        }

        public string PathMode
        {
            get; set;
        }

        public string RouterMode
        {
            get; set;
        }

        public IRouter Router
        {
            get; set;
        }

        public IPathGenerator PathGenerator
        {
            get; set;
        }

        private PathGeneratorResult _pathGeneratorResult;
        public PathGeneratorResult PathGeneratorResult
        {
            get
            {
                return _pathGeneratorResult;
            }
            private set
            {
                SetProperty(ref _pathGeneratorResult, value);
            }
        }

        private bool _shouldInsertAnchor;
        public bool ShouldInsertAnchor
        {
            get
            {
                return _shouldInsertAnchor;
            }
            set
            {
                SetProperty(ref _shouldInsertAnchor, value);
            }
        }

        //待完善这两处
        private ObservableCollection<ConnectorVertexModel> _vertices = new ObservableCollection<ConnectorVertexModel>();
        public ObservableCollection<ConnectorVertexModel> Vertices
        {
            get
            {
                return _vertices;
            }
            private set
            {
                SetProperty(ref _vertices, value);
            }
        }

        private ObservableCollection<ConnectorLabelModel> _labels = new ObservableCollection<ConnectorLabelModel>();
        public ObservableCollection<ConnectorLabelModel> Labels
        {
            get
            {
                return _labels;
            }
            private set
            {
                SetProperty(ref _labels, value);
            }
        }

    
        private LineAnimation _lineAnimation = LineAnimation.PathAnimation;
        [Browsable(true)]
        [CanDo]
        [StyleName("LineAnimationStyle")]
        public LineAnimation LineAnimation
        {
            get
            {
                return _lineAnimation;
            }
            set
            {
                SetProperty(ref _lineAnimation, value);
            }
        }

        public virtual Dictionary<string, string> PropertiesSetting
        {
            get
            {
                return new Dictionary<string, string>()
                {
                    { "Text","文本" },
                };
            }
        }

        private FullyCreatedConnectorInfo _sourceConnectorInfo;
        public FullyCreatedConnectorInfo SourceConnectorInfo
        {
            get
            {
                return _sourceConnectorInfo;
            }
            set
            {
                SetProperty(ref _sourceConnectorInfo, value);
            }
        }

        private ConnectorInfoBase _sinkConnectorInfo;
        public ConnectorInfoBase SinkConnectorInfo
        {
            get
            {
                return _sinkConnectorInfo;
            }
            set
            {
                SetProperty(ref _sinkConnectorInfo, value);

            }
        }

        public FullyCreatedConnectorInfo SinkConnectorInfoFully
        {
            get
            {
                return SinkConnectorInfo as FullyCreatedConnectorInfo;
            }
        }

        public PartCreatedConnectorInfo SinkConnectorInfoPart
        {
            get
            {
                return SinkConnectorInfo as PartCreatedConnectorInfo;
            }
        }

        public PointBase OnGoingPosition
        {
            get
            {
                return SinkConnectorInfoPart?.MiddlePosition ?? PointBase.Zero;
            }
        }

        public bool IsFullConnection
        {
            get
            {
                return SinkConnectorInfoFully != null;
            }
        }

        public bool IsPortless => SourceConnectorInfo?.DataItem?.Connectors?.Count() == 0;
        #endregion

        #region 方法
        public SimpleCommand DeleteConnectionCommand
        {
            get; set;
        }

        public SimpleCommand AddVertexCommand
        {
            get; set;
        }

        public SimpleCommand AddLabelCommand
        {
            get; set;
        }
        #endregion

        private void ConnectorViewModel_PropertyChanged(object sender, PropertyChangedEventArgs e)
        {
            if (sender is ConnectionViewModel)
            {
                switch (e.PropertyName)
                {
                    case nameof(SourceA):
                    case nameof(SourceB):
                        UpdateArea();
                        break;
                    case nameof(Area):
                        UpdatePathGeneratorResult();
                        break;
                    case nameof(Vertices):
                        foreach (var vertice in Vertices)
                        {
                            vertice.PropertyChanged += new WeakINPCEventHandler(ConnectorViewModel_PropertyChanged).Handler;
                        }
                        break;
                    case nameof(Labels):
                        foreach (var label in Labels)
                        {
                            label.PropertyChanged += new WeakINPCEventHandler(ConnectorViewModel_PropertyChanged).Handler;
                        }
                        break;
                    case nameof(SourceConnectorInfo):
                        SourceA = PointHelper.GetPointForConnector(SourceConnectorInfo);
                        (SourceConnectorInfo.DataItem as INotifyPropertyChanged).PropertyChanged += new WeakINPCEventHandler(ConnectorViewModel_PropertyChanged).Handler;
                        break;
                    case nameof(SinkConnectorInfo):
                        SourceB = SinkConnectorInfo.Position;
                        if (SinkConnectorInfo is FullyCreatedConnectorInfo)
                        {
                            (((FullyCreatedConnectorInfo)SinkConnectorInfo).DataItem as INotifyPropertyChanged).PropertyChanged += new WeakINPCEventHandler(ConnectorViewModel_PropertyChanged).Handler;
                        }
                        break;
                    case nameof(IsSelected):
                        if (IsSelected == false)
                        {
                            Labels.FirstOrDefault()?.AddToSelection(false);
                        }
                        break;

                }
            }
            else if (sender is ColorViewModel)
            {
                if (e.PropertyName == nameof(ColorViewModel.LeftArrowPathStyle) ||
                   e.PropertyName == nameof(ColorViewModel.LeftArrowSizeStyle) ||
                   e.PropertyName == nameof(ColorViewModel.RightArrowPathStyle) ||
                   e.PropertyName == nameof(ColorViewModel.RightArrowSizeStyle))
                {
                    UpdatePathGeneratorResult();
                }
            }
            else if (sender is DesignerItemViewModelBase)
            {
                switch (e.PropertyName)
                {
                    case nameof(DesignerItemViewModelBase.ItemHeight):
                    case nameof(DesignerItemViewModelBase.ItemWidth):
                    case nameof(DesignerItemViewModelBase.Left):
                    case nameof(DesignerItemViewModelBase.Top):
                        SourceA = PointHelper.GetPointForConnector(this.SourceConnectorInfo);
                        if (IsFullConnection)
                        {
                            SourceB = PointHelper.GetPointForConnector(this.SinkConnectorInfoFully);
                        }
                        break;
                }
            }
            else if (sender is ConnectorVertexModel)
            {
                switch (e.PropertyName)
                {
                    case nameof(ConnectorPointModel.X):
                    case nameof(ConnectorPointModel.Y):
                        UpdatePathGeneratorResult();
                        break;

                }
            }
            else if (sender is ConnectorLabelModel linkLabelModel)
            {
                switch (e.PropertyName)
                {
                    case nameof(ConnectorPointModel.X):
                        {
                            if (e is ValuePropertyChangedEventArgs valuePropertyChangedEventArgs)
                            {
                                linkLabelModel.UpdateOffsetX((double)valuePropertyChangedEventArgs.OldValue, (double)valuePropertyChangedEventArgs.NewValue);
                            }
                            break;
                        }
                    case nameof(ConnectorPointModel.Y):
                        {
                            if (e is ValuePropertyChangedEventArgs valuePropertyChangedEventArgs)
                            {
                                linkLabelModel.UpdateOffsetY((double)valuePropertyChangedEventArgs.OldValue, (double)valuePropertyChangedEventArgs.NewValue);
                            }
                            break;
                        }
                }
            }
        }

        private void UpdateArea()
        {
            Area = new RectangleBase(SourceA, SourceB);
        }

        private void UpdatePathGeneratorResult()
        {
            if (SourceConnectorInfo == null || SinkConnectorInfo == null)
                return;

            var route = Router.Get(Root, this);

            (var source, var target) = FindConnectionPoints(route);
            if (source == null || target == null)
                return;

            PathGeneratorResult = PathGenerator.Get(Root, this, route, source.Value, target.Value);

            //修正旋转
            switch (SourceConnectorInfo.Orientation)
            {
                case ConnectorOrientation.Left:
                    {
                        StartPoint = new PointBase(PathGeneratorResult.SourceMarkerPosition.X, PathGeneratorResult.SourceMarkerPosition.Y - ColorViewModel.LeftArrowSize / 2);
                        break;
                    }
                case ConnectorOrientation.Top:
                    {
                        StartPoint = new PointBase(PathGeneratorResult.SourceMarkerPosition.X - ColorViewModel.LeftArrowSize / 2, PathGeneratorResult.SourceMarkerPosition.Y);
                        break;
                    }
                case ConnectorOrientation.Right:
                    {
                        StartPoint = new PointBase(PathGeneratorResult.SourceMarkerPosition.X - ColorViewModel.LeftArrowSize, PathGeneratorResult.SourceMarkerPosition.Y - ColorViewModel.LeftArrowSize / 2);
                        break;
                    }
                case ConnectorOrientation.Bottom:
                    {
                        StartPoint = new PointBase(PathGeneratorResult.SourceMarkerPosition.X - ColorViewModel.LeftArrowSize / 2, PathGeneratorResult.SourceMarkerPosition.Y - ColorViewModel.LeftArrowSize);
                        break;
                    }
                default:
                    {
                        StartPoint = PathGeneratorResult.SourceMarkerPosition;
                        break;
                    }
            }

            //修正旋转
            switch (SinkConnectorInfo.Orientation)
            {
                case ConnectorOrientation.Left:
                    {
                        EndPoint = new PointBase(PathGeneratorResult.TargetMarkerPosition.X, PathGeneratorResult.TargetMarkerPosition.Y - ColorViewModel.RightArrowSize / 2);
                        break;
                    }

                case ConnectorOrientation.Top:
                    {
                        EndPoint = new PointBase(PathGeneratorResult.TargetMarkerPosition.X - ColorViewModel.RightArrowSize / 2, PathGeneratorResult.TargetMarkerPosition.Y);
                        break;
                    }
                case ConnectorOrientation.Right:
                    {
                        EndPoint = new PointBase(PathGeneratorResult.TargetMarkerPosition.X - ColorViewModel.RightArrowSize, PathGeneratorResult.TargetMarkerPosition.Y - ColorViewModel.RightArrowSize / 2);
                        break;
                    }
                case ConnectorOrientation.Bottom:
                    {
                        EndPoint = new PointBase(PathGeneratorResult.TargetMarkerPosition.X - ColorViewModel.RightArrowSize / 2, PathGeneratorResult.TargetMarkerPosition.Y - ColorViewModel.RightArrowSize);
                        break;
                    }
                default:
                    {
                        EndPoint = PathGeneratorResult.TargetMarkerPosition;
                        break;
                    }
            }

            StartAngle = PathGeneratorResult.SourceMarkerAngle;
            EndAngle = PathGeneratorResult.TargetMarkerAngle;

            var paths = Labels.Count > 0 ? PathGeneratorResult.Paths.Select(p => new SvgPath(p)).ToArray() : Array.Empty<SvgPath>();
            foreach (var label in Labels)
            {
                label.UpdatePosition(paths);
            }
        }

        private void DeleteConnection(object args)
        {
            if (this.Root is IDiagramViewModel)
            {
                var diagramVM = this.Root as IDiagramViewModel;
                diagramVM.RemoveItemCommand.Execute(this);
            }
        }

        private (PointBase? source, PointBase? target) FindConnectionPoints(PointBase[] route)
        {
            if (IsPortless) // Portless
            {
                if (SourceConnectorInfo.DataItem == null || (IsFullConnection && SinkConnectorInfoFully.DataItem == null))
                    return (null, null);

                var sourceCenter = SourceConnectorInfo.DataItem.GetBounds().Center;
                var targetCenter = SinkConnectorInfoFully?.DataItem?.GetBounds().Center ?? OnGoingPosition;
                var firstPt = route.Length > 0 ? route[0] : targetCenter;
                var secondPt = route.Length > 0 ? route[0] : sourceCenter;
                var sourceLine = new LineBase(firstPt, sourceCenter);
                var targetLine = new LineBase(secondPt, targetCenter);
                var sourceIntersections = SourceConnectorInfo.DataItem.GetShape().GetIntersectionsWithLine(sourceLine);
                var targetIntersections = SinkConnectorInfoFully.DataItem.GetShape()?.GetIntersectionsWithLine(targetLine) ?? new PointBase[] { OnGoingPosition };
                var sourceIntersection = GetClosestPointTo(sourceIntersections, firstPt);
                var targetIntersection = GetClosestPointTo(targetIntersections, secondPt);
                return (sourceIntersection ?? sourceCenter, targetIntersection ?? targetCenter);
            }
            else
            {
                var source = SourceConnectorInfo.MiddlePosition;//GetPortPositionBasedOnAlignment(SourceConnectorInfo, ColorViewModel.LeftArrowSizeStyle);
                var target = SinkConnectorInfo.MiddlePosition;// GetPortPositionBasedOnAlignment(SinkConnectorInfoFully, ColorViewModel.RightArrowSizeStyle);
                return (source, target);
            }
        }

        private PointBase? GetPortPositionBasedOnAlignment(ConnectorInfoBase port, ArrowSizeStyle marker)
        {
            if (port == null)
                return null;

            if (marker == 0)
                return port.MiddlePosition;

            var pt = port.Position;
            switch (port.Orientation)
            {
                case ConnectorOrientation.Top:
                    return new PointBase(pt.X + port.ConnectorWidth / 2, pt.Y);
                case ConnectorOrientation.TopRight:
                    return new PointBase(pt.X + port.ConnectorWidth, pt.Y);
                case ConnectorOrientation.Right:
                    return new PointBase(pt.X + port.ConnectorWidth, pt.Y + port.ConnectorHeight / 2);
                case ConnectorOrientation.BottomRight:
                    return new PointBase(pt.X + port.ConnectorWidth, pt.Y + port.ConnectorHeight);
                case ConnectorOrientation.Bottom:
                    return new PointBase(pt.X + port.ConnectorWidth / 2, pt.Y + port.ConnectorHeight);
                case ConnectorOrientation.BottomLeft:
                    return new PointBase(pt.X, pt.Y + port.ConnectorHeight);
                case ConnectorOrientation.Left:
                    return new PointBase(pt.X, pt.Y + port.ConnectorHeight / 2);
                default:
                    return pt;
            }
        }

        private PointBase? GetClosestPointTo(IEnumerable<PointBase> points, PointBase point)
        {
            var minDist = double.MaxValue;
            PointBase? minPoint = null;

            foreach (var pt in points)
            {
                var dist = pt.DistanceTo(point);
                if (dist < minDist)
                {
                    minDist = dist;
                    minPoint = pt;
                }
            }

            return minPoint;
        }

        #region 双击添加
        private void AddVertex(object parameter)
        {
            MouseButtonEventArgs mosueArg = ((EventToCommandArgs)parameter).EventArgs as MouseButtonEventArgs;
            var position = mosueArg.GetPosition(((EventToCommandArgs)parameter).Sender as IInputElement);

            var vertice = new ConnectorVertexModel(this, new PointBase(position.X, position.Y));
            vertice.PropertyChanged += new WeakINPCEventHandler(ConnectorViewModel_PropertyChanged).Handler;
            Vertices.Add(vertice);
            UpdatePathGeneratorResult();

            if (!((Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control))
            {
                ShouldInsertAnchor = false;
            }
        }

        protected override void ExecuteEditCommand(object param)
        {
            AddLabel();
        }

        public void AddLabel(object text = null)
        {
            var label = new ConnectorLabelModel(this, text?.ToString());
            label.PropertyChanged += new WeakINPCEventHandler(ConnectorViewModel_PropertyChanged).Handler;
            label.IsSelected = true;
            Labels.Add(label);

            var paths = Labels.Count > 0 ? PathGeneratorResult.Paths.Select(p => new SvgPath(p)).ToArray() : Array.Empty<SvgPath>();
            label.UpdatePosition(paths);
        }


        #endregion
    }
}