using Microsoft.Kinect;
using System;
using System.Collections.Generic;
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;
using System.Windows.Shapes;

namespace KinectConnection
{
    public class BodyImageStream : KinectStream
    {
        private BodyFrameReader bodyFrameReader = null;
        private Body[] bodies = null;
        private DrawingGroup drawingGroup = new DrawingGroup();
        private List<Pen> bodyColors = new List<Pen>();
        private CoordinateMapper coordinateMapper = null;
        private List<Tuple<JointType, JointType>> bones = new List<Tuple<JointType, JointType>>();
        private readonly Brush trackedJointBrush = new SolidColorBrush(Color.FromArgb(255, 68, 192, 68));
        private readonly Brush inferredJointBrush = Brushes.Yellow;
        private const double HandSize = 30;
        private const double JointThickness = 3;
        private readonly Brush handClosedBrush = new SolidColorBrush(Color.FromArgb(128, 255, 0, 0));
        private readonly Brush handOpenBrush = new SolidColorBrush(Color.FromArgb(128, 0, 255, 0));
        private readonly Brush handLassoBrush = new SolidColorBrush(Color.FromArgb(128, 0, 0, 255));
        private readonly Pen inferredBonePen = new Pen(Brushes.Gray, 1);
        private const double ClipBoundsThickness = 10;
        private DrawingImage imageSource = new DrawingImage();
        private FrameDescription frameDescription;
        private int displayHeight;
        private int displayWidth;

        public override ImageSource Source
        {
            get { return this.imageSource; }
        }

        public BodyImageStream() : base()
        {
            this.coordinateMapper = this.KinectSensor.CoordinateMapper;
            frameDescription = this.KinectSensor.DepthFrameSource.FrameDescription;
            displayHeight = frameDescription.Height;
            displayWidth = frameDescription.Width;

            // Torso
            this.bones.Add(new Tuple<JointType, JointType>(JointType.Head, JointType.Neck));
            this.bones.Add(new Tuple<JointType, JointType>(JointType.Neck, JointType.SpineShoulder));
            this.bones.Add(new Tuple<JointType, JointType>(JointType.SpineShoulder, JointType.SpineMid));
            this.bones.Add(new Tuple<JointType, JointType>(JointType.SpineMid, JointType.SpineBase));
            this.bones.Add(new Tuple<JointType, JointType>(JointType.SpineShoulder, JointType.ShoulderRight));
            this.bones.Add(new Tuple<JointType, JointType>(JointType.SpineShoulder, JointType.ShoulderLeft));
            this.bones.Add(new Tuple<JointType, JointType>(JointType.SpineBase, JointType.HipRight));
            this.bones.Add(new Tuple<JointType, JointType>(JointType.SpineBase, JointType.HipLeft));

            // Right Arm
            this.bones.Add(new Tuple<JointType, JointType>(JointType.ShoulderRight, JointType.ElbowRight));
            this.bones.Add(new Tuple<JointType, JointType>(JointType.ElbowRight, JointType.WristRight));
            this.bones.Add(new Tuple<JointType, JointType>(JointType.WristRight, JointType.HandRight));
            this.bones.Add(new Tuple<JointType, JointType>(JointType.HandRight, JointType.HandTipRight));
            this.bones.Add(new Tuple<JointType, JointType>(JointType.WristRight, JointType.ThumbRight));

            // Left Arm
            this.bones.Add(new Tuple<JointType, JointType>(JointType.ShoulderLeft, JointType.ElbowLeft));
            this.bones.Add(new Tuple<JointType, JointType>(JointType.ElbowLeft, JointType.WristLeft));
            this.bones.Add(new Tuple<JointType, JointType>(JointType.WristLeft, JointType.HandLeft));
            this.bones.Add(new Tuple<JointType, JointType>(JointType.HandLeft, JointType.HandTipLeft));
            this.bones.Add(new Tuple<JointType, JointType>(JointType.WristLeft, JointType.ThumbLeft));

            // Right Leg
            this.bones.Add(new Tuple<JointType, JointType>(JointType.HipRight, JointType.KneeRight));
            this.bones.Add(new Tuple<JointType, JointType>(JointType.KneeRight, JointType.AnkleRight));
            this.bones.Add(new Tuple<JointType, JointType>(JointType.AnkleRight, JointType.FootRight));

            // Left Leg
            this.bones.Add(new Tuple<JointType, JointType>(JointType.HipLeft, JointType.KneeLeft));
            this.bones.Add(new Tuple<JointType, JointType>(JointType.KneeLeft, JointType.AnkleLeft));
            this.bones.Add(new Tuple<JointType, JointType>(JointType.AnkleLeft, JointType.FootLeft));

            this.bodyColors.Add(new Pen(Brushes.Red, 6));
            this.bodyColors.Add(new Pen(Brushes.Orange, 6));
            this.bodyColors.Add(new Pen(Brushes.Green, 6));
            this.bodyColors.Add(new Pen(Brushes.Blue, 6));
            this.bodyColors.Add(new Pen(Brushes.Indigo, 6));
            this.bodyColors.Add(new Pen(Brushes.Violet, 6));

            this.imageSource = new DrawingImage(this.drawingGroup);
        }

        public override void Start()
        {
            if (this.KinectSensor != null)
            {
                this.bodyFrameReader = this.KinectSensor.BodyFrameSource.OpenReader();

                if (this.bodyFrameReader != null)
                {
                    this.bodyFrameReader.FrameArrived += this.Reader_BodyFrameArrived;
                }
            }
        }

        public override void Stop()
        {
            if (this.bodyFrameReader != null)
            {
                this.bodyFrameReader.FrameArrived -= this.Reader_BodyFrameArrived;

                // Dispose the reader to free resources.
                // If we don't dispose manualy, the gc will do it for us, but we don't know when.
                this.bodyFrameReader.Dispose();
                this.bodyFrameReader = null;
            }
        }

        private void Reader_BodyFrameArrived(object sender, BodyFrameArrivedEventArgs e)
        {
            bool dataReceived = false;

            using (BodyFrame bodyFrame = e.FrameReference.AcquireFrame())
            {
                if (bodyFrame != null)
                {
                    if (this.bodies == null)
                    {
                        this.bodies = new Body[bodyFrame.BodyCount];
                    }

                    // The first time GetAndRefreshBodyData is called, Kinect will allocate each Body in the array.
                    // As long as those body objects are not disposed and not set to null in the array,
                    // those body objects will be re-used.
                    bodyFrame.GetAndRefreshBodyData(this.bodies);
                    dataReceived = true;
                }
            }

            if (dataReceived)
            {
                using (DrawingContext dc = this.drawingGroup.Open())
                {
                    // Draw a transparent background to set the render size
                    dc.DrawRectangle(Brushes.Black, null, new Rect(0.0, 0.0, displayWidth, displayHeight));

                    int penIndex = 0;
                    foreach (Body body in this.bodies)
                    {
                        Pen drawPen = this.bodyColors[penIndex++];

                        if (body.IsTracked)
                        {
                            this.DrawClippedEdges(body, dc);

                            IReadOnlyDictionary<JointType, Joint> joints = body.Joints;

                            // convert the joint points to depth (display) space
                            Dictionary<JointType, Point> jointPoints = new Dictionary<JointType, Point>();

                            foreach (JointType jointType in joints.Keys)
                            {
                                // sometimes the depth(Z) of an inferred joint may show as negative
                                // clamp down to 0.1f to prevent coordinatemapper from returning (-Infinity, -Infinity)
                                CameraSpacePoint position = joints[jointType].Position;
                                if (position.Z < 0)
                                {
                                    position.Z = 0.1f;
                                }

                                DepthSpacePoint depthSpacePoint = this.coordinateMapper.MapCameraPointToDepthSpace(position);
                                jointPoints[jointType] = new Point(depthSpacePoint.X, depthSpacePoint.Y);
                            }

                            this.DrawBody(joints, jointPoints, dc, drawPen);

                            this.DrawHand(body.HandLeftState, jointPoints[JointType.HandLeft], dc);
                            this.DrawHand(body.HandRightState, jointPoints[JointType.HandRight], dc);
                        }
                    }

                    // prevent drawing outside of our render area
                    this.drawingGroup.ClipGeometry = new RectangleGeometry(new Rect(0.0, 0.0, displayWidth, displayHeight));
                }
            }
        }

        private void DrawBody(IReadOnlyDictionary<JointType, Joint> joints, IDictionary<JointType, Point> jointPoints, DrawingContext drawingContext, Pen drawingPen)
        {
            // Draw the bones
            foreach (var bone in this.bones)
            {
                this.DrawBone(joints, jointPoints, bone.Item1, bone.Item2, drawingContext, drawingPen);
            }

            // Draw the joints
            foreach (JointType jointType in joints.Keys)
            {
                Brush drawBrush = null;

                TrackingState trackingState = joints[jointType].TrackingState;

                if (trackingState == TrackingState.Tracked)
                {
                    drawBrush = this.trackedJointBrush;
                }
                else if (trackingState == TrackingState.Inferred)
                {
                    drawBrush = this.inferredJointBrush;
                }

                if (drawBrush != null)
                {
                    drawingContext.DrawEllipse(drawBrush, null, jointPoints[jointType], JointThickness, JointThickness);
                }
            }
        }

        private void DrawHand(HandState handState, Point handPosition, DrawingContext drawingContext)
        {
            switch (handState)
            {
                case HandState.Closed:
                    drawingContext.DrawEllipse(this.handClosedBrush, null, handPosition, HandSize, HandSize);
                    break;

                case HandState.Open:
                    drawingContext.DrawEllipse(this.handOpenBrush, null, handPosition, HandSize, HandSize);
                    break;

                case HandState.Lasso:
                    drawingContext.DrawEllipse(this.handLassoBrush, null, handPosition, HandSize, HandSize);
                    break;
            }
        }

        private void DrawBone(IReadOnlyDictionary<JointType, Joint> joints, IDictionary<JointType, Point> jointPoints, JointType jointType0, JointType jointType1, DrawingContext drawingContext, Pen drawingPen)
        {
            Joint joint0 = joints[jointType0];
            Joint joint1 = joints[jointType1];

            // If we can't find either of these joints, exit
            if (joint0.TrackingState == TrackingState.NotTracked ||
            joint1.TrackingState == TrackingState.NotTracked)
            {
                return;
            }

            // We assume all drawn bones are inferred unless BOTH joints are tracked
            Pen drawPen = this.inferredBonePen;
            if ((joint0.TrackingState == TrackingState.Tracked) && (joint1.TrackingState == TrackingState.Tracked))
            {
                drawPen = drawingPen;
            }

            drawingContext.DrawLine(drawPen, jointPoints[jointType0], jointPoints[jointType1]);
        }

        private void DrawClippedEdges(Body body, DrawingContext drawingContext)
        {
            FrameEdges clippedEdges = body.ClippedEdges;

            if (clippedEdges.HasFlag(FrameEdges.Bottom))
            {
                drawingContext.DrawRectangle(
                    Brushes.Red,
                    null,
                    new Rect(0, displayHeight - ClipBoundsThickness, displayWidth, ClipBoundsThickness));
            }

            if (clippedEdges.HasFlag(FrameEdges.Top))
            {
                drawingContext.DrawRectangle(
                    Brushes.Red,
                    null,
                    new Rect(0, 0, displayWidth, ClipBoundsThickness));
            }

            if (clippedEdges.HasFlag(FrameEdges.Left))
            {
                drawingContext.DrawRectangle(
                    Brushes.Red,
                    null,
                    new Rect(0, 0, ClipBoundsThickness, displayHeight));
            }

            if (clippedEdges.HasFlag(FrameEdges.Right))
            {
                drawingContext.DrawRectangle(
                    Brushes.Red,
                    null,
                    new Rect(displayWidth - ClipBoundsThickness, 0, ClipBoundsThickness, displayHeight));
            }
        }
    }
}