using System;
using System.Windows;
using System.Windows.Data;

namespace DTS.Common.Converters
{
    /// <summary>
    /// Represents the converter that converts Boolean values to and from <see cref="Visibility">Visibility</see>  enumeration values.
    /// </summary>
    /// 
    /// <remarks>
    /// Use the BooleanToVisibilityConverter class to convert a Boolean to and from a <see cref="Visibility">Visibility</see> value. 
    /// The Convert method returns <see cref="Visibility.Visible">Visibility.Visible</see> when <b>true</b> is passed in 
    /// or <see cref="Visibility.Collapsed">Visibility.Collapsed</see> when <b>false</b> is passed in. 
    /// Note that the <see cref="Visibility.Collapsed">Visibility.Collapsed</see> value hides the control and does not reserve space for it in a layout. 
    /// When you call the ConvertBack method and specify a reference to an object, it returns <b>true</b> 
    /// if the object is <see cref="Visibility.Visible">Visible</see>; otherwise, it returns <b>false</b>.
    /// </remarks>
    /// 
    public class InverseBooleanToVisibilityConverter : IValueConverter
    {
        /// <summary>
        /// Converts a Boolean value to a Visibility enumeration value.
        /// </summary>
        /// <param name="value">The Boolean value to convert. This value can be a standard Boolean value or a nullable Boolean value.</param>
        /// <param name="targetType">This parameter is not used.</param>
        /// <param name="parameter">The converter parameter to use.</param>
        /// <param name="culture">This parameter is not used.</param>
        /// <returns>The value to be passed to the target dependency property.</returns>
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            var useFalseAsVisible = parameter != null && parameter.ToString().ToUpper() == "FALSE";
            var hideNotCollapse = parameter != null && parameter.ToString().ToUpper() == "HIDE";

            if (!useFalseAsVisible)
            {
                if (value != null && (bool)value)
                    return hideNotCollapse ? Visibility.Hidden : Visibility.Collapsed;
                return Visibility.Visible;
            }
            if (value != null && (bool)value)
                return Visibility.Visible;
            return hideNotCollapse ? Visibility.Hidden : Visibility.Collapsed;
        }

        /// <summary>
        /// Converts a Visibility enumeration value to a Boolean value.
        /// </summary>
        /// <param name="value">A Visibility enumeration value.</param>
        /// <param name="targetType">This parameter is not used.</param>
        /// <param name="parameter">This parameter is not used.</param>
        /// <param name="culture">This parameter is not used.</param>
        /// <returns>The value to be passed to the source object.</returns>
        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            return null;
        }
    }
}