using System.Runtime.InteropServices;

namespace FluidExplorer.Services.Shell;

/// <summary>
/// 资源管理器"名称"列用的排序：调用系统 shlwapi 的 StrCmpLogicalW（自然排序，数字按数值比较）。
/// 这样 "文件2" 会排在 "文件10" 前面，和原版体验一致。
/// </summary>
public sealed class NaturalStringComparer : IComparer<string>
{
    public static NaturalStringComparer Instance { get; } = new();

    public int Compare(string? x, string? y)
    {
        if (ReferenceEquals(x, y)) return 0;
        if (x is null) return -1;
        if (y is null) return 1;
        try
        {
            return StrCmpLogicalW(x, y);
        }
        catch
        {
            return string.Compare(x, y, StringComparison.CurrentCultureIgnoreCase);
        }
    }

    [DllImport("shlwapi.dll", CharSet = CharSet.Unicode, ExactSpelling = true)]
    private static extern int StrCmpLogicalW(string psz1, string psz2);
}