using System;
using System.ComponentModel;
using System.Windows;
using System.Windows.Controls;

namespace CustomControls
{
    [DesignTimeVisible(false)]
    public partial class NumericUpDown : UserControl, INotifyPropertyChanged
    {
        public NumericUpDown()
        {
            InitializeComponent();
        }

        public event PropertyChangedEventHandler PropertyChanged;

        public decimal Maximum
        {
            get { return (decimal)GetValue(MaximumProperty); }
            set { SetValue(MaximumProperty, value); }
        }
        public readonly static DependencyProperty MaximumProperty = DependencyProperty.Register(
            "Maximum", typeof(decimal), typeof(NumericUpDown), new UIPropertyMetadata(100m));

        public decimal Minimum
        {
            get { return (decimal)GetValue(MinimumProperty); }
            set { SetValue(MinimumProperty, value); }
        }
        public readonly static DependencyProperty MinimumProperty = DependencyProperty.Register(
            "Minimum", typeof(decimal), typeof(NumericUpDown), new UIPropertyMetadata(0m));

        public decimal Value
        {
            get { return (decimal)GetValue(ValueProperty); }
            set { SetCurrentValue(ValueProperty, value); }
        }
        public readonly static DependencyProperty ValueProperty = DependencyProperty.Register(
            "Value", typeof(decimal), typeof(NumericUpDown), new UIPropertyMetadata(0m, (o, e) =>
            {
                NumericUpDown tb = (NumericUpDown)o;
                tb.RaiseValueChangedEvent(e);
            }));

        public event EventHandler<DependencyPropertyChangedEventArgs> ValueChanged;
        private void RaiseValueChangedEvent(DependencyPropertyChangedEventArgs e)
        {
            ValueChanged?.Invoke(this, e);
        }

        public decimal Increment
        {
            get { return (decimal)GetValue(IncrementProperty); }
            set { SetValue(IncrementProperty, value); }
        }
        public readonly static DependencyProperty IncrementProperty = DependencyProperty.Register(
            "Increment", typeof(decimal), typeof(NumericUpDown), new UIPropertyMetadata(1m));

        public int DecimalPlaces
        {
            get { return (int)GetValue(DecimalPlacesProperty); }
            set { SetValue(DecimalPlacesProperty, value); }
        }
        public static readonly DependencyProperty DecimalPlacesProperty = DependencyProperty.Register(
            "DecimalPlaces", typeof(int), typeof(NumericUpDown), new PropertyMetadata(0));


        public string FormattedValue
        {
            get => Value.ToString("N" + DecimalPlaces.ToString());
            set
            {
                if (decimal.TryParse(value, out decimal d))
                    Value = d;
            }
        }

        protected override void OnPropertyChanged(DependencyPropertyChangedEventArgs e)
        {
            base.OnPropertyChanged(e);
            if (e.Property.Name == "Value" || e.Property.Name == "DecimalPlaces")
            {
                PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("FormattedValue"));
            }
        }

        private void btnUp_Click(object sender, RoutedEventArgs e)
        {
            if (Value < Maximum)
            {
                Value += Increment;
                if (Value > Maximum)
                    Value = Maximum;
            }
        }

        private void btnDown_Click(object sender, RoutedEventArgs e)
        {
            if (Value > Minimum)
            {
                Value -= Increment;
                if (Value < Minimum)
                    Value = Minimum;
            }
        }

        private void tbmain_KeyDown(object sender, System.Windows.Input.KeyEventArgs e)
        {
            if (e.Key == System.Windows.Input.Key.Enter)
            {
                ((TextBox)sender).GetBindingExpression(TextBox.TextProperty).UpdateSource();
            }
        }
    }
}