commander/FileSystemService.cs

using System.IO;
using System.Linq;

namespace CommanderApp;

public class FileSystemService : IFileSystemService
{
    public string GetRootPath()
    {
#if ANDROID || IOS || MACCATALYST
        return FileSystem.AppDataDirectory;
#else
        var path = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile);
        return Path.GetFullPath(path);
#endif
    }

    public IEnumerable<FileSystemItem> GetDirectoryContents(string path)
    {
        path = Path.GetFullPath(path.TrimEnd(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar));

        if (!Directory.Exists(path))
        {
            System.Diagnostics.Debug.WriteLine($"Directory does not exist: {path}");
            return Enumerable.Empty<FileSystemItem>();
        }

        var items = new List<FileSystemItem>();

        var parent = Directory.GetParent(path);
        if (parent != null)
        {
            items.Add(new FileSystemItem
            {
                Name = "..",
                FullName = parent.FullName,
                IsDirectory = true
            });
        }

        try
        {
            var dirs = Directory.GetDirectories(path)
                .Select(d => new FileSystemItem
                {
                    Name = Path.GetFileName(d),
                    FullName = d,
                    IsDirectory = true
                });

            var files = Directory.GetFiles(path)
                .Select(f => new FileSystemItem
                {
                    Name = Path.GetFileName(f),
                    FullName = f,
                    IsDirectory = false
                });

            items.AddRange(dirs.OrderBy(d => d.Name));
            items.AddRange(files.OrderBy(f => f.Name));
        }
        catch (Exception ex)
        {
            System.Diagnostics.Debug.WriteLine($"Error reading directory {path}: {ex.Message}");
            if (items.Count == 0 && Directory.GetParent(path) != null)
            {
                items.Add(new FileSystemItem
                {
                    Name = "..",
                    FullName = Directory.GetParent(path)!.FullName,
                    IsDirectory = true
                });
            }
        }

        return items;
    }
}