webmusic/Pages/Index.cshtml.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
using System.Web;
using Microsoft.AspNetCore.Mvc.RazorPages;


namespace webmusic.Pages
{
    public class IndexModel : PageModel
    {
        public static string root = "music";
        public string path = "";
        public string displaypath = "";
        public string path_oneup = "";
        public string fullpath = "";
        public List<string> dirs = new List<string>();
        public List<string> files = new List<string>();
        public void OnGet()
        {
            if (Request.QueryString.HasValue)
                path = HttpUtility.UrlDecode(Request.QueryString.Value.Remove(0,1));
            if (path.Contains(".."))
            {
                Response.Redirect("/Error");
                return;
            }
            path_oneup = Regex.Match(path, @".*(?=\/)").Value;
            fullpath = root + path;
            displaypath = string.IsNullOrWhiteSpace(path) ? "/" : path;
            dirs = Directory.GetDirectories(fullpath).Select(Path.GetFileName).ToList();
            dirs.Sort();
            files = Directory.GetFiles(fullpath).Select(Path.GetFileName).ToList();
            files.RemoveAll(p => p.EndsWith(".m3u"));
            files.Sort(new NumericComparer());
        }

        public string Encode(string str)
        {
            return str.Replace("\"", "%22").Replace("'", "%27")
                .Replace("?", "%3F").Replace("&", "%26")
                .Replace(" ", "%20");
        }
        
        public class NumericComparer : IComparer<string>
        {
            public int Compare(string x, string y)
            {
                var regex = new Regex(@"^\d+");

                // run the regex on both strings
                var xRegexResult = regex.Match(x);
                var yRegexResult = regex.Match(y);

                // check if they are both numbers
                if (xRegexResult.Success && yRegexResult.Success)
                {
                    return int.Parse(xRegexResult.Value).CompareTo(int.Parse(yRegexResult.Value));
                }

                // otherwise return as string comparison
                return string.Compare(x, y, StringComparison.Ordinal);
            }
        }
    }
}