//===============================================================================
// Microsoft patterns & practices Enterprise Library
// Core
//===============================================================================
// Copyright © Microsoft Corporation.  All rights reserved.
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY
// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT
// LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
// FITNESS FOR A PARTICULAR PURPOSE.
//===============================================================================

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

namespace Microsoft.Practices.EnterpriseLibrary.Configuration.Design.Converters
{
    /// <summary>
    /// The <see cref="EnumerableToBooleanConverter"/> converts an <see cref="IEnumerable"/> to <see langword="bool"/> based on
    /// the presence of enumerable items. 
    /// </summary>
    public class EnumerableToBooleanConverter : IValueConverter
    {
        /// <summary>
        /// Converts a <see cref="IEnumerable"/> to a <see cref="bool" /> based on the presence of enumerable items.
        /// </summary>
        /// <returns>
        /// Returns <see langword="true" /> if there is at least one item in the <see cref="IEnumerable"/>, <see langword="false" /> otherwise.
        /// </returns>
        /// <param name="value">The value produced by the binding source.
        ///                 </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>
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            var enumerable = value as IEnumerable;
            if (enumerable == null) return false;
            return enumerable.GetEnumerator().MoveNext();
        }


        /// <summary>
        /// Converts a value (not implemented).
        /// </summary>
        /// <returns>
        /// A converted value. If the method returns null, the valid null value is used.
        /// </returns>
        /// <param name="value">The value that is produced by the binding target.
        ///                 </param><param name="targetType">The type to convert to.
        ///                 </param><param name="parameter">The converter parameter to use.
        ///                 </param><param name="culture">The culture to use in the converter.
        ///                 </param>
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
}
