using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Data;

namespace Microsoft.Research.DynamicDataDisplay.Converters
{
	public abstract class ThreeValuesMultiConverter<T1, T2, T3> : IMultiValueConverter
	{
		#region IMultiValueConverter Members

		public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
		{
			if (values != null && values.Length == 3)
			{
				if (values[0] is T1 && values[1] is T2 && values[2] is T3)
				{
					T1 param1 = (T1)values[0];
					T2 param2 = (T2)values[1];
					T3 param3 = (T3)values[2];

					var result = ConvertCore(param1, param2, param3, targetType, parameter, culture);
					return result;
				}
			}
			return null;
		}

		protected abstract object ConvertCore(T1 value1, T2 value2, T3 value3, Type targetType, object parameter, System.Globalization.CultureInfo culture);

		public virtual object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
		{
			throw new NotSupportedException();
		}

		#endregion
	}
}