using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Threading;
using RealTimeGraphEx.Models;
using RealTimeGraphEx.DataSeries;
using RealTimeGraphEx.Controllers;
using System.Runtime.ExceptionServices;

namespace RealTimeGraphEx.FastGraphs
{
    /// <summary>
    /// Represents a real-time graph with a single scrollable line.
    /// </summary>
    public class RealTimeGraphExLineScroll : RealTimeGraphExBase
    {
        #region Protected Fields

        protected ConcurrentpointsList graphPolygon;
        protected int updateCounter;

        #endregion

        #region Cross Thread Fields

        protected GraphController _graphController;
        protected int _maxPoints;
        protected double _scaleFactor;
        protected Color _stroke;
        protected Color _fill;
        protected bool _fillGraph;
        protected List<double> _markers;

        #endregion

        #region Properties

        /// <summary>
        /// Gets or sets the graph fill color.
        /// </summary>
        public Color Stroke
        {
            get { return (Color)GetValue(StrokeProperty); }
            set { SetValue(StrokeProperty, value); }
        }
        public static readonly DependencyProperty StrokeProperty =
            DependencyProperty.Register("Stroke", typeof(Color), typeof(RealTimeGraphExLineScroll), new PropertyMetadata(Colors.Black, new PropertyChangedCallback(CrossModelChanged)));

        /// <summary>
        /// Gets or sets the graph fill color.
        /// </summary>
        public Color Fill
        {
            get { return (Color)GetValue(FillProperty); }
            set { SetValue(FillProperty, value); }
        }
        public static readonly DependencyProperty FillProperty =
            DependencyProperty.Register("Fill", typeof(Color), typeof(RealTimeGraphExLineScroll), new PropertyMetadata(Colors.Gray, new PropertyChangedCallback(CrossModelChanged)));

        /// <summary>
        /// Gets or sets whether the graph will be rendered using the Fill color property.
        /// </summary>
        public bool FillGraph
        {
            get { return (bool)GetValue(FillGraphProperty); }
            set { SetValue(FillGraphProperty, value); }
        }
        public static readonly DependencyProperty FillGraphProperty =
            DependencyProperty.Register("FillGraph", typeof(bool), typeof(RealTimeGraphExLineScroll), new PropertyMetadata(false, new PropertyChangedCallback(CrossModelChanged)));


        /// <summary>
        /// Gets or sets the IDataSeries used to push data vectorsCollection to the graph.
        /// </summary>
        public GraphController Controller
        {
            get { return (GraphController)GetValue(ControllerProperty); }
            set { SetValue(ControllerProperty, value); }
        }
        public static readonly DependencyProperty ControllerProperty =
            DependencyProperty.Register("Controller", typeof(GraphController), typeof(RealTimeGraphExLineScroll), new PropertyMetadata(null, new PropertyChangedCallback(GraphControllerChanged)));
        private static void GraphControllerChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var control = d as RealTimeGraphExLineScroll;

            if (control.Controller != null)
            {
                control.Controller.RegisterMethods(control.ClearGraph, control.StartPushThread, control.SetPaused, control.ChangeRenderMode, control.OnPushMarker);
                control._graphController = control.Controller;
            }
        }

        #endregion

        #region Constructors

        public RealTimeGraphExLineScroll()
            : base()
        {
            graphPolygon = new ConcurrentpointsList();
            _markers = new List<double>();
        }

        #endregion

        #region Override Methods

        protected override void OnSizeChanged(object sender, SizeChangedEventArgs e)
        {
            OnSetCrossThreadFields();
        }

        protected override void OnSetCrossThreadFields()
        {
            base.OnSetCrossThreadFields();

            this.Dispatcher.Invoke(() =>
            {
                _maxPoints = MaxPoints;
                _scaleFactor = _width / _maxPoints;
                _graphController = Controller;
                _stroke = Stroke;
                _fillGraph = FillGraph;
                _fill = Fill;

            }, DispatcherPriority.Send);
        }

        protected override void OnClearGraph()
        {
            base.OnClearGraph();
            _graphController.dataSeries.ClearPoints();
            graphPolygon.Clear();
        }

        protected internal override void OnRenderGraph()
        {
            if (_graphController != null && _graphController.dataSeries.Points != null && _graphController.dataSeries.Points.Count > 0 && _width > 1 && _height > 1)
            {
                var points = _graphController.dataSeries.Points.GetAndClearAllPoints();

                if (!_isPaused)
                {

                    for (int i = 0; i < points.Count; i++)
                    {
                        double value = points[i];
                        NormalizeValue(ref value);

                        graphPolygon.Add(value);

                        xValueCounter += _scaleFactor;
                    }

                    if (graphPolygon.Count > _maxPoints + 1)
                    {
                        xValueCounter -= (_scaleFactor * (graphPolygon.Count - (_maxPoints + 1)));
                        graphPolygon.RemoveFromStart(graphPolygon.Count - (_maxPoints + 1));
                    }
                }

                updateCounter++;

                if (updateCounter >= 1)
                {
                    updateCounter = 0;

                    if (!_disableRendering)
                    {
                        WriteableBitmap bmp = BitmapFactory.New((int)_mainWidth, (int)_mainHeight);
                        bmp.Clear(Colors.Transparent);

                        OnDrawVisuals(bmp);

                        bmp.Freeze();

                        img.Dispatcher.BeginInvoke(new Action(() =>
                        {
                            img.Source = bmp;
                        }), System.Windows.Threading.DispatcherPriority.Send);
                    }
                }
            }
        }

        protected override void OnZoomingComplete(Point transformOrigin, double scaleX, double scaleY)
        {
            base.OnZoomingComplete(transformOrigin, scaleX, scaleY);
        }

        #endregion

        #region Virtual Methods

        protected virtual void OnPushMarker()
        {
            
        }

        /// <summary>
        /// Calculate the scaling factor for the current graph width.
        /// </summary>
        /// <returns></returns>
        protected virtual double GetPolygonScaleFactor()
        {
            return _width / (graphPolygon.Count - 1);
        }

        /// <summary>
        /// Draw the actual polygon on the image.
        /// </summary>
        /// <param name="bmp"></param>
        [HandleProcessCorruptedStateExceptions]
        protected virtual void OnDrawVisuals(WriteableBitmap bmp)
        {
            Color stroke = _graphController.dataSeries.GetStrokeColor() != null ? _graphController.dataSeries.GetStrokeColor().Value : _stroke;
            Color fill = _graphController.dataSeries.GetFillColor() != null ? _graphController.dataSeries.GetFillColor().Value : _fill;

            double scale = GetPolygonScaleFactor();

            OnBeforeRenderingVisuals(bmp, scale);

            if (_fillGraph) //Fill Graph
            {
                bmp.FillPolygon(graphPolygon.ToPolygonPointsFill(_offSetX, _offSetY, _mainWidth, _mainHeight, scale, ConvertYToImageYFliped), fill);
            }

            DrawPolyline(bmp, graphPolygon.ToPolygonPoints(_offSetX, _offSetY, scale, ConvertYToImageYFliped), stroke);

            OnAfterRenderingVisuals(bmp, scale);
        }
        #endregion
    }
}