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

namespace AxiOmron.PcbCheck.Converters;

/// <summary>
/// 将布尔值转换为 <see cref="Visibility"/>，支持通过 ConverterParameter 反转判定。
/// </summary>
/// <remarks>
/// 当 ConverterParameter 为 "Invert"、"Inverse" 或 "!" 时，布尔值的真假意义取反。
/// </remarks>
public sealed class BooleanToVisibilityConverter : IValueConverter
{
    /// <summary>
    /// 将布尔值转换为可见性。
    /// </summary>
    /// <param name="value">源布尔值。</param>
    /// <param name="targetType">目标类型。</param>
    /// <param name="parameter">若为 "Invert"/"!" 则反转判定。</param>
    /// <param name="culture">当前区域信息。</param>
    /// <returns><see cref="Visibility.Visible"/> 或 <see cref="Visibility.Collapsed"/>。</returns>
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        bool flag = value is bool b && b;
        if (IsInvert(parameter))
        {
            flag = !flag;
        }
        return flag ? Visibility.Visible : Visibility.Collapsed;
    }

    /// <summary>
    /// 将可见性反向转换为布尔值。
    /// </summary>
    /// <param name="value">目标可见性。</param>
    /// <param name="targetType">目标类型。</param>
    /// <param name="parameter">若为 "Invert"/"!" 则反转判定。</param>
    /// <param name="culture">当前区域信息。</param>
    /// <returns>布尔值。</returns>
    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        bool flag = value is Visibility v && v == Visibility.Visible;
        if (IsInvert(parameter))
        {
            flag = !flag;
        }
        return flag;
    }

    /// <summary>
    /// 判断参数是否要求反转判定。
    /// </summary>
    /// <param name="parameter">参数值。</param>
    /// <returns>是否反转。</returns>
    private static bool IsInvert(object? parameter)
    {
        if (parameter is null)
        {
            return false;
        }
        string token = parameter.ToString() ?? string.Empty;
        return token.Equals("Invert", StringComparison.OrdinalIgnoreCase)
               || token.Equals("Inverse", StringComparison.OrdinalIgnoreCase)
               || token.Equals("!", StringComparison.Ordinal);
    }
}