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.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace Tango.Visuals
{
    /// <summary>
    /// Interaction logic for Fader.xaml
    /// </summary>
    public partial class Fader : UserControl
    {
        public Fader()
        {
            InitializeComponent();
            this.Loaded += Fader_Loaded;
            this.SizeChanged += Fader_SizeChanged;
        }

        private void Fader_SizeChanged(object sender, SizeChangedEventArgs e)
        {
            SetSize();
        }

        private void SetSize()
        {
            border.Margin = new Thickness(0, gridThumb.ActualHeight / 2, 0, gridThumb.ActualHeight / 2);
        }

        private void Fader_Loaded(object sender, RoutedEventArgs e)
        {
            SetSize();
            OnValueChanged();
        }

        public Brush TrackBrush
        {
            get { return (Brush)GetValue(TrackBrushProperty); }
            set { SetValue(TrackBrushProperty, value); }
        }
        public static readonly DependencyProperty TrackBrushProperty =
            DependencyProperty.Register("TrackBrush", typeof(Brush), typeof(Fader), new PropertyMetadata(null));

        public Brush TrackHighlighBrush
        {
            get { return (Brush)GetValue(TrackHighlighBrushProperty); }
            set { SetValue(TrackHighlighBrushProperty, value); }
        }
        public static readonly DependencyProperty TrackHighlighBrushProperty =
            DependencyProperty.Register("TrackHighlighBrush", typeof(Brush), typeof(Fader), new PropertyMetadata(null));

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

        public double Minimum
        {
            get { return (double)GetValue(MinimumProperty); }
            set { SetValue(MinimumProperty, value); }
        }
        public static readonly DependencyProperty MinimumProperty =
            DependencyProperty.Register("Minimum", typeof(double), typeof(Fader), new PropertyMetadata(0.0, (d, e) => (d as Fader).OnValueChanged()));

        public double Maximum
        {
            get { return (double)GetValue(MaximumProperty); }
            set { SetValue(MaximumProperty, value); }
        }
        public static readonly DependencyProperty MaximumProperty =
            DependencyProperty.Register("Maximum", typeof(double), typeof(Fader), new PropertyMetadata(100.0, (d, e) => (d as Fader).OnValueChanged()));

        public double Value
        {
            get { return (double)GetValue(ValueProperty); }
            set { SetValue(ValueProperty, value); }
        }
        public static readonly DependencyProperty ValueProperty =
            DependencyProperty.Register("Value", typeof(double), typeof(Fader), new FrameworkPropertyMetadata(0.0, (d, e) => (d as Fader).OnValueChanged(), (d, baseValue) => (d as Fader).OnCoerceValue((double)baseValue)) { BindsTwoWayByDefault = true });

        public bool SnapToValues
        {
            get { return (bool)GetValue(SnapToValuesProperty); }
            set { SetValue(SnapToValuesProperty, value); }
        }
        public static readonly DependencyProperty SnapToValuesProperty =
            DependencyProperty.Register("SnapToValues", typeof(bool), typeof(Fader), 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(Fader), new PropertyMetadata(1));

        public int Ticks
        {
            get { return (int)GetValue(TicksProperty); }
            set { SetValue(TicksProperty, value); }
        }
        public static readonly DependencyProperty TicksProperty =
            DependencyProperty.Register("Ticks", typeof(int), typeof(Fader), new PropertyMetadata(50));

        public int? BigTicksInterval
        {
            get { return (int?)GetValue(BigTicksIntervalProperty); }
            set { SetValue(BigTicksIntervalProperty, value); }
        }
        public static readonly DependencyProperty BigTicksIntervalProperty =
            DependencyProperty.Register("BigTicksInterval", typeof(int?), typeof(Fader), new PropertyMetadata(5));

        public Brush TicksBrush
        {
            get { return (Brush)GetValue(TicksBrushProperty); }
            set { SetValue(TicksBrushProperty, value); }
        }
        public static readonly DependencyProperty TicksBrushProperty =
            DependencyProperty.Register("TicksBrush", typeof(Brush), typeof(Fader), new PropertyMetadata(null));

        public Brush BigTicksBrush
        {
            get { return (Brush)GetValue(BigTicksBrushProperty); }
            set { SetValue(BigTicksBrushProperty, value); }
        }
        public static readonly DependencyProperty BigTicksBrushProperty =
            DependencyProperty.Register("BigTicksBrush", typeof(Brush), typeof(Fader), new PropertyMetadata(null));

        public double FaderWidth
        {
            get { return (double)GetValue(FaderWidthProperty); }
            set { SetValue(FaderWidthProperty, value); }
        }
        public static readonly DependencyProperty FaderWidthProperty =
            DependencyProperty.Register("FaderWidth", typeof(double), typeof(Fader), new PropertyMetadata(40.0));

        public double TrackWidth
        {
            get { return (double)GetValue(TrackWidthProperty); }
            set { SetValue(TrackWidthProperty, value); }
        }
        public static readonly DependencyProperty TrackWidthProperty =
            DependencyProperty.Register("TrackWidth", typeof(double), typeof(Fader), new PropertyMetadata(10.0));

        public bool ShowTicks
        {
            get { return (bool)GetValue(ShowTicksProperty); }
            set { SetValue(ShowTicksProperty, value); }
        }
        public static readonly DependencyProperty ShowTicksProperty =
            DependencyProperty.Register("ShowTicks", typeof(bool), typeof(Fader), new PropertyMetadata(true));

        public Color? FaderColor
        {
            get { return (Color?)GetValue(FaderColorProperty); }
            set { SetValue(FaderColorProperty, value); }
        }
        public static readonly DependencyProperty FaderColorProperty =
            DependencyProperty.Register("FaderColor", typeof(Color?), typeof(Fader), new PropertyMetadata(null));

        public double TicksWidth
        {
            get { return (double)GetValue(TicksWidthProperty); }
            set { SetValue(TicksWidthProperty, value); }
        }
        public static readonly DependencyProperty TicksWidthProperty =
            DependencyProperty.Register("TicksWidth", typeof(double), typeof(Fader), new PropertyMetadata(8.0));

        public double BigTicksWidth
        {
            get { return (double)GetValue(BigTicksWidthProperty); }
            set { SetValue(BigTicksWidthProperty, value); }
        }
        public static readonly DependencyProperty BigTicksWidthProperty =
            DependencyProperty.Register("BigTicksWidth", typeof(double), typeof(Fader), new PropertyMetadata(20.0));

        public Brush FaderLightBrush
        {
            get { return (Brush)GetValue(FaderLightBrushProperty); }
            set { SetValue(FaderLightBrushProperty, value); }
        }
        public static readonly DependencyProperty FaderLightBrushProperty =
            DependencyProperty.Register("FaderLightBrush", typeof(Brush), typeof(Fader), new PropertyMetadata(null));

        public double Change
        {
            get { return (double)GetValue(ChangeProperty); }
            set { SetValue(ChangeProperty, value); }
        }
        public static readonly DependencyProperty ChangeProperty =
            DependencyProperty.Register("Change", typeof(double), typeof(Fader), new PropertyMetadata(0.01));

        internal bool IsKeyDown
        {
            get { return (bool)GetValue(IsKeyDownProperty); }
            set { SetValue(IsKeyDownProperty, value); }
        }
        internal static readonly DependencyProperty IsKeyDownProperty =
            DependencyProperty.Register("IsKeyDown", typeof(bool), typeof(Fader), new PropertyMetadata(false));


        private object OnCoerceValue(double value)
        {
            if (value > Maximum) return Maximum;
            if (value < Minimum) return Minimum;
            return SnapToValues ? Math.Round(value, SnapPercision) : value;
        }

        private void OnValueChanged()
        {
            double percentage = (Value - Minimum) / (Maximum - Minimum);
            double faderHeight = gridThumb.ActualHeight;
            faderTranslate.Y = -((this.ActualHeight - faderHeight) * percentage);
            borderHighLight.Height = Math.Abs(faderTranslate.Y);
        }

        private void OnThumbDrag(object sender, System.Windows.Controls.Primitives.DragDeltaEventArgs e)
        {
            double value = (faderTranslate.Y + e.VerticalChange);
            double faderHeight = gridThumb.ActualHeight;

            if (value > 0) value = 0;
            if (value < -(this.ActualHeight - faderHeight))
            {
                value = -(this.ActualHeight - faderHeight);
            }

            faderTranslate.Y = value;
            borderHighLight.Height = Math.Abs(faderTranslate.Y);

            double percentage = Math.Abs(value / (this.ActualHeight - faderHeight));
            Value = (Minimum + (Maximum - Minimum) * percentage);
        }

        private void OnKeyDown(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.Down)
            {
                Value -= Change;
            }
            else if (e.Key == Key.Up)
            {
                Value += Change;
            }

            Focus();

            IsKeyDown = true;

            e.Handled = true;
        }

        private void OnPreviewMouseDown(object sender, MouseButtonEventArgs e)
        {
            Focus();
        }

        private void OnKeyUp(object sender, KeyEventArgs e)
        {
            IsKeyDown = false;
        }
    }
}