namespace System
{
    /// <summary>
    /// 小数数字转换为整数数字格式
    /// </summary>
    public enum NumberToInt32Format
    {
        /// <summary>
        /// 四舍五入
        /// </summary>
        RoundAwayFromZero,

        /// <summary>
        /// 五舍六入
        /// </summary>
        Round,

        /// <summary>
        /// 仅取整数
        /// </summary>
        Floor,

        /// <summary>
        /// 进一法
        /// </summary>
        Ceiling,
    }

    /// <summary>
    /// Enum 扩展 <see cref="NumberToInt32Format"/>
    /// </summary>
    public static partial class NumberToInt32FormatEnumExtensions
    {
        public static int ToInt32(this float value, NumberToInt32Format format = NumberToInt32Format.Floor) => format switch
        {
            NumberToInt32Format.RoundAwayFromZero => (int)MathF.Round(value, MidpointRounding.AwayFromZero),
            NumberToInt32Format.Round => (int)MathF.Round(value),
            NumberToInt32Format.Floor => (int)MathF.Floor(value),
            NumberToInt32Format.Ceiling => (int)MathF.Ceiling(value),
            _ => throw new ArgumentOutOfRangeException(nameof(format), format, null),
        };

        public static int ToInt32(this double value, NumberToInt32Format format = NumberToInt32Format.Floor) => format switch
        {
            NumberToInt32Format.RoundAwayFromZero => (int)Math.Round(value, MidpointRounding.AwayFromZero),
            NumberToInt32Format.Round => (int)Math.Round(value),
            NumberToInt32Format.Floor => (int)Math.Floor(value),
            NumberToInt32Format.Ceiling => (int)Math.Ceiling(value),
            _ => throw new ArgumentOutOfRangeException(nameof(format), format, null),
        };
    }
}