using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Media.Effects;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using Tango.Visuals;

namespace Tango.Visuals
{
    /// <summary>
    /// <para><img class="classImage" src="../Media/VolumeKnob.png" /></para>
    /// Represents a knob control.
    /// </summary>
    public partial class Knob : UserControl
    {
        private List<Line> lines;
        private Line markLine;
        private Brush oldTicksHighlightBrush;
        private double initialAngle;
        private bool _showSmallMarkers;

        #region Events

        /// <summary>
        /// Occurs when the knob's value has changed.
        /// </summary>
        public event EventHandler<DoubleValueChangedEventArgs> ValueChanged;

        #endregion

        #region Private Methods

        private void SetValueFromMouse(double angle)
        {
            if (angle < -140)
            {
                angle = -140;
            }
            if (angle > 140)
            {
                angle = 140;
            }

            double value = angle + 140;
            value = ((value) * 100) / 280;
            value = (value * (Maximum - Minimum)) / 100;
            value += Minimum;

            if (value < Minimum)
            {
                Value = Minimum;
            }
            else if (value > Maximum)
            {
                Value = Maximum;
            }
            else
            {
                Value = value;
            }
        }

        private void SetAngle(double angle)
        {
            if (ellipseGrid != null)
            {
                ellipseGrid.RenderTransformOrigin = new Point(0.5, 0.5);
                ellipseGrid.RenderTransform = new RotateTransform(angle);
                ellipseGrid.InvalidateMeasure();
            }
        }

        private void LightMarkers()
        {
            if (ellipseGrid != null)
            {
                RotateTransform rotate = ellipseGrid.RenderTransform as RotateTransform;
                double currentAngle = rotate.Angle;

                if (lines != null)
                {
                    foreach (Line m in lines)
                    {
                        RotateTransform t = m.RenderTransform as RotateTransform;
                        if (currentAngle >= t.Angle)
                        {
                            m.Stroke = TicksHighlightBrush;
                        }
                        else
                        {
                            m.Stroke = TicksBrush;
                        }
                    }
                }
            }
        }

        private void RenderMarkers()
        {
            lines = new List<Line>();

            double angleChange = 280 / 20;
            double markChange = 5;
            double counter = 0;
            int marksCounter = 0;

            mainGrid.Children.OfType<Line>().ToList().ForEach(x => mainGrid.Children.Remove(x));
            ellipseGrid.Children.OfType<Line>().ToList().ForEach(x => mainGrid.Children.Remove(x));

            if (_showSmallMarkers)
            {
                for (int i = 0; i < 21; i++)
                {
                    Line line = new Line();
                    line.StrokeThickness = TicksWidth;
                    line.Stroke = TicksBrush;
                    line.X1 = this.ActualWidth / 2;
                    if ((marksCounter == markChange || marksCounter == 0))
                    {
                        line.Y1 = 0;
                        marksCounter = 0;
                    }
                    else
                    {
                        line.Y1 = 3;
                    }
                    line.X2 = this.ActualWidth / 2;
                    line.Y2 = TicksHeight;
                    mainGrid.Children.Add(line);
                    line.RenderTransform = new RotateTransform(counter - 140, this.ActualWidth / 2, this.ActualHeight / 2);
                    counter += angleChange;
                    marksCounter++;
                    lines.Add(line);
                }
            }

            ellipseGrid.Children.Remove(markLine);
            markLine = new Line();
            markLine.StrokeThickness = 2;
            markLine.Stroke = TicksHighlightBrush;
            markLine.X1 = ellipseGrid.ActualWidth / 2;
            markLine.Y1 = 5;
            markLine.X2 = markLine.X1;
            markLine.Y2 = (ellipseGrid.ActualWidth / 2) * 0.8;
            ellipseGrid.Children.Add(markLine);
        }

        private static BitmapSource GetImageFromApplicationResource(String resourcePath)
        {
            String callingAssembly = Assembly.GetCallingAssembly().GetName().Name;
            Uri uri = new Uri("/" + callingAssembly + ";component/" + resourcePath, UriKind.Relative);
            System.Windows.Resources.StreamResourceInfo info = Application.GetResourceStream(uri);

            var bitmapImage = new BitmapImage();
            bitmapImage.BeginInit();
            bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
            bitmapImage.StreamSource = info.Stream;
            bitmapImage.EndInit();
            return bitmapImage;
        }

        #endregion

        #region Virtual Methods

        /// <summary>
        /// Called when the value changed.
        /// </summary>
        protected virtual void OnValueChanged()
        {
            try
            {
                if (Value < Minimum)
                {
                    Value = Minimum;
                }

                if (Value > Maximum)
                {
                    Value = Maximum;
                }

                double angle = ((Value - Minimum) * 100) / (Maximum - Minimum);
                angle = ((angle * 280) / 100) - 140;

                SetAngle(angle);
                LightMarkers();
            }
            catch { }

            if (ValueChanged != null) ValueChanged(this, new DoubleValueChangedEventArgs(Value));
        }

        /// <summary>
        /// Invoked before the value has changed.
        /// </summary>
        /// <param name="value">The value.</param>
        /// <returns></returns>
        protected virtual object OnCoerceValue(double value)
        {
            var v = SnapToValues ? Math.Round(value, SnapPercision) : value;
            return v;
        }

        /// <summary>
        /// Draws the knob.
        /// </summary>
        protected virtual void OnDrawKnob()
        {
            try
            {
                RenderMarkers();
                LightMarkers();

                if (KnobType == KnobType.MetroDark)
                {
                    img.Source = GetImageFromApplicationResource("Knob/volumeKnobMetroDark.png");
                }
                else if (KnobType == KnobType.MetroLight)
                {
                    img.Source = GetImageFromApplicationResource("Knob/volumeKnobMetroLight.png");
                }
                else if (KnobType == KnobType.Dark)
                {
                    img.Source = GetImageFromApplicationResource("Knob/volumeKnobDark.png");
                }
                else if (KnobType == KnobType.Light)
                {
                    img.Source = GetImageFromApplicationResource("Knob/volumeKnobLight.png");
                }
                else if (KnobType == KnobType.Complex)
                {
                    img.Source = GetImageFromApplicationResource("Knob/volumeKnobComplex.png");
                }


            }
            catch { }
        }

        #endregion

        #region Properties

        /// <summary>
        /// Gets or sets the ticks highlight brush.
        /// </summary>
        public Brush TicksHighlightBrush
        {
            get { return (Brush)GetValue(TicksHighlightBrushProperty); }
            set { SetValue(TicksHighlightBrushProperty, value); }
        }
        public static readonly DependencyProperty TicksHighlightBrushProperty =
            DependencyProperty.Register("TicksHighlightBrush", typeof(Brush), typeof(Knob), new PropertyMetadata(Brushes.Red, OnPropertiesChanged));

        /// <summary>
        /// Gets or sets the ticks brush.
        /// </summary>
        public Brush TicksBrush
        {
            get { return (Brush)GetValue(TicksBrushProperty); }
            set { SetValue(TicksBrushProperty, value); }
        }
        public static readonly DependencyProperty TicksBrushProperty =
            DependencyProperty.Register("TicksBrush", typeof(Brush), typeof(Knob), new PropertyMetadata(Brushes.DimGray, OnPropertiesChanged));

        /// <summary>
        /// Gets or sets the type of the knob.
        /// </summary>
        public KnobType KnobType
        {
            get { return (KnobType)GetValue(KnobTypeProperty); }
            set { SetValue(KnobTypeProperty, value); }
        }
        public static readonly DependencyProperty KnobTypeProperty =
            DependencyProperty.Register("KnobType", typeof(KnobType), typeof(Knob), new PropertyMetadata(KnobType.Dark, OnPropertiesChanged));

        /// <summary>
        /// Gets or sets amount of change when using keyboard arrows.
        /// </summary>
        public double Change
        {
            get { return (double)GetValue(ChangeProperty); }
            set { SetValue(ChangeProperty, value); }
        }
        public static readonly DependencyProperty ChangeProperty =
            DependencyProperty.Register("Change", typeof(double), typeof(Knob), new PropertyMetadata(1.0));

        /// <summary>
        /// Gets or sets the width of the ticks.
        /// </summary>
        public double TicksWidth
        {
            get { return (double)GetValue(TicksWidthProperty); }
            set { SetValue(TicksWidthProperty, value); }
        }
        public static readonly DependencyProperty TicksWidthProperty =
            DependencyProperty.Register("TicksWidth", typeof(double), typeof(Knob), new PropertyMetadata(3.0, OnPropertiesChanged));

        /// <summary>
        /// Gets or sets the height of the ticks.
        /// </summary>
        public double TicksHeight
        {
            get { return (double)GetValue(TicksHeightProperty); }
            set { SetValue(TicksHeightProperty, value); }
        }
        public static readonly DependencyProperty TicksHeightProperty =
            DependencyProperty.Register("TicksHeight", typeof(double), typeof(Knob), new PropertyMetadata(10.0, OnPropertiesChanged));

        /// <summary>
        /// Gets or sets the value.
        /// </summary>
        public double Value
        {
            get { return (double)GetValue(ValueProperty); }
            set { SetValue(ValueProperty, SnapToValues ? Math.Round(value, SnapPercision) : value); }
        }
        public static readonly DependencyProperty ValueProperty =
            DependencyProperty.Register("Value", typeof(double), typeof(Knob), new FrameworkPropertyMetadata(0.0, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault, (d, e) => (d as Knob).OnValueChanged(), (d, value) => (d as Knob).OnCoerceValue((double)value)));

        /// <summary>
        /// Gets or sets the minimum value.
        /// </summary>
        public double Minimum
        {
            get { return (double)GetValue(MinimumProperty); }
            set { SetValue(MinimumProperty, value); }
        }
        public static readonly DependencyProperty MinimumProperty =
            DependencyProperty.Register("Minimum", typeof(double), typeof(Knob), new PropertyMetadata(0.0, OnPropertiesChanged));

        public bool SnapToValues
        {
            get { return (bool)GetValue(SnapToValuesProperty); }
            set { SetValue(SnapToValuesProperty, value); }
        }
        public static readonly DependencyProperty SnapToValuesProperty =
            DependencyProperty.Register("SnapToValues", typeof(bool), typeof(Knob), new PropertyMetadata(false));

        public int SnapPercision
        {
            get { return (int)GetValue(SnapPercisionProperty); }
            set { SetValue(SnapPercisionProperty, value); }
        }
        public static readonly DependencyProperty SnapPercisionProperty =
            DependencyProperty.Register("SnapPercision", typeof(int), typeof(Knob), new PropertyMetadata(1));

        /// <summary>
        /// Gets or sets the maximum value.
        /// </summary>
        public double Maximum
        {
            get { return (double)GetValue(MaximumProperty); }
            set { SetValue(MaximumProperty, value); }
        }
        public static readonly DependencyProperty MaximumProperty =
            DependencyProperty.Register("Maximum", typeof(double), typeof(Knob), new PropertyMetadata(1.0, OnPropertiesChanged));
        private static void OnPropertiesChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            (d as Knob).OnDrawKnob();
            (d as Knob).OnValueChanged();
        }

        #endregion

        #region Constructors

        public Knob()
        {
            _showSmallMarkers = true;
            InitializeComponent();
            this.Loaded += Knob_Loaded;
            moveThumb.AddHandler(Thumb.MouseEnterEvent, new MouseEventHandler(ellipseGrid_MouseEnter), true);
            moveThumb.AddHandler(Thumb.MouseLeaveEvent, new MouseEventHandler(ellipseGrid_MouseLeave), true);
            this.AddHandler(UserControl.PreviewKeyDownEvent, new KeyEventHandler(Knob_PreviewKeyDown), true);
            this.PreviewMouseDown += Knob_PreviewMouseDown;
            this.Focusable = true;

            KnobType = KnobType.MetroLight;

            this.IsEnabledChanged += Knob_IsEnabledChanged;

            moveThumb.DragStarted += moveThumb_DragStarted;
            moveThumb.DragDelta += moveThumb_DragDelta;

            this.SizeChanged += VolumeKnob_SizeChanged;
        }

        #endregion

        #region Event Handlers

        /// <summary>
        /// Handles the SizeChanged event of the VolumeKnob control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="SizeChangedEventArgs"/> instance containing the event data.</param>
        private void VolumeKnob_SizeChanged(object sender, SizeChangedEventArgs e)
        {
            OnDrawKnob();
        }

        /// <summary>
        /// Handles the DragDelta event of the moveThumb control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="DragDeltaEventArgs"/> instance containing the event data.</param>
        private void moveThumb_DragDelta(object sender, DragDeltaEventArgs e)
        {
            double angle = 0;

            angle = e.VerticalChange * -1;

            angle = this.initialAngle + angle;

            this.SetValueFromMouse(angle);
        }

        /// <summary>
        /// Handles the DragStarted event of the moveThumb control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="DragStartedEventArgs"/> instance containing the event data.</param>
        private void moveThumb_DragStarted(object sender, DragStartedEventArgs e)
        {
            Point startPoint = Mouse.GetPosition(ellipseGrid);

            RotateTransform t = ellipseGrid.RenderTransform as RotateTransform;
            if (t != null)
            {
                this.initialAngle = t.Angle;
            }
        }

        /// <summary>
        /// Handles the IsEnabledChanged event of the Knob control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="DependencyPropertyChangedEventArgs"/> instance containing the event data.</param>
        private void Knob_IsEnabledChanged(object sender, DependencyPropertyChangedEventArgs e)
        {
            if (e.NewValue == e.OldValue) return;

            if (IsEnabled)
            {
                TicksHighlightBrush = oldTicksHighlightBrush;
                RenderMarkers();
            }
            else
            {
                oldTicksHighlightBrush = TicksHighlightBrush;
                TicksHighlightBrush = Brushes.Gray;
                RenderMarkers();
            }
        }

        /// <summary>
        /// Handles the PreviewMouseDown event of the Knob control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="MouseButtonEventArgs"/> instance containing the event data.</param>
        private void Knob_PreviewMouseDown(object sender, MouseButtonEventArgs e)
        {
            this.FocusVisualStyle = null;
            this.Focusable = true;
            this.Focus();
        }

        /// <summary>
        /// Handles the PreviewKeyDown event of the Knob control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="KeyEventArgs"/> instance containing the event data.</param>
        private void Knob_PreviewKeyDown(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.Up && Value < Maximum)
            {
                Value += Change;
            }
            else if (e.Key == Key.Down && Value > Minimum)
            {
                Value -= Change;
            }

            this.Focusable = true;
            this.Focus();
            e.Handled = true;
        }

        /// <summary>
        /// Handles the Loaded event of the Knob control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="RoutedEventArgs"/> instance containing the event data.</param>
        private void Knob_Loaded(object sender, RoutedEventArgs e)
        {
            OnDrawKnob();
        }

        /// <summary>
        /// Handles the MouseLeave event of the ellipseGrid control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="MouseEventArgs"/> instance containing the event data.</param>
        private void ellipseGrid_MouseLeave(object sender, MouseEventArgs e)
        {
            DoubleAnimation maskAni = new DoubleAnimation(0, new Duration(TimeSpan.FromMilliseconds(200)));

            maskEllipse.Fill.BeginAnimation(RadialGradientBrush.OpacityProperty, maskAni);

            DoubleAnimation glowAni = new DoubleAnimation(0, new Duration(TimeSpan.FromMilliseconds(200)));
            glowEllipse.BeginAnimation(OpacityProperty, glowAni);

            //DoubleAnimation efxAni = new DoubleAnimation(0, new Duration(TimeSpan.FromMilliseconds(200)));
            //glowEffect.BeginAnimation(OpacityProperty, efxAni);

            DoubleAnimation glow = new DoubleAnimation(0, new Duration(TimeSpan.FromMilliseconds(200)));
            imgGlow.BeginAnimation(RadialGradientBrush.OpacityProperty, glow);
        }

        /// <summary>
        /// Handles the MouseEnter event of the ellipseGrid control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="MouseEventArgs"/> instance containing the event data.</param>
        private void ellipseGrid_MouseEnter(object sender, MouseEventArgs e)
        {
            DoubleAnimation maskAni = new DoubleAnimation(0.5, new Duration(TimeSpan.FromMilliseconds(200)));

            maskEllipse.Fill.BeginAnimation(RadialGradientBrush.OpacityProperty, maskAni);

            DoubleAnimation glowAni = new DoubleAnimation(1, new Duration(TimeSpan.FromMilliseconds(200)));
            glowEllipse.BeginAnimation(OpacityProperty, glowAni);

            //DoubleAnimation efxAni = new DoubleAnimation(1, new Duration(TimeSpan.FromMilliseconds(200)));
            //glowEffect.BeginAnimation(OpacityProperty, efxAni);

            DoubleAnimation glow = new DoubleAnimation(0.5, new Duration(TimeSpan.FromMilliseconds(200)));
            imgGlow.BeginAnimation(RadialGradientBrush.OpacityProperty, glow);

        }

        #endregion
    }
}