using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Data;

namespace RealTimeGraphX.WPF.Converters
{
    /// <summary>
    /// Converts an instance of <see cref="IGraphDataPoint"/> and a string format expression to a formated string representation of the data point.
    /// </summary>
    /// <seealso cref="System.Windows.Data.IMultiValueConverter" />
    public class IGraphDataPointToStringConverter : IMultiValueConverter
    {
        /// <summary>
        /// Converts source values to a value for the binding target. The data binding engine calls this method when it propagates the values from source bindings to the binding target.
        /// </summary>
        /// <param name="values">The array of values that the source bindings in the <see cref="T:System.Windows.Data.MultiBinding" /> produces. The value <see cref="F:System.Windows.DependencyProperty.UnsetValue" /> indicates that the source binding has no value to provide for conversion.</param>
        /// <param name="targetType">The type of the binding target property.</param>
        /// <param name="parameter">The converter parameter to use.</param>
        /// <param name="culture">The culture to use in the converter.</param>
        /// <returns>
        /// A converted value.If the method returns <see langword="null" />, the valid <see langword="null" /> value is used.A return value of <see cref="T:System.Windows.DependencyProperty" />.<see cref="F:System.Windows.DependencyProperty.UnsetValue" /> indicates that the converter did not produce a value, and that the binding will use the <see cref="P:System.Windows.Data.BindingBase.FallbackValue" /> if it is available, or else will use the default value.A return value of <see cref="T:System.Windows.Data.Binding" />.<see cref="F:System.Windows.Data.Binding.DoNothing" /> indicates that the binding does not transfer the value or use the <see cref="P:System.Windows.Data.BindingBase.FallbackValue" /> or the default value.
        /// </returns>
        public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
        {
            if (values.Length == 2 && values[0] != null)
            {
                if (values[1] != null)
                {
                    return (values[0] as IGraphDataPoint).ToString(values[1].ToString());
                }
                else
                {
                    return (values[0] as IGraphDataPoint).ToString();
                }
            }
            else
            {
                return null;
            }
        }

        /// <summary>
        /// Converts a binding target value to the source binding values.
        /// </summary>
        /// <param name="value">The value that the binding target produces.</param>