made folder paths cross platform, introduced file handler for abstracting the serving of files, enabled url mapping for broken file links, resolved public folder deletion issue

Oqtane.Server/Pages/Files.cshtml.cs

@@ -0,0 +1,98 @@
+using System;
+using System.IO;
+using System.Net;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.Http.Extensions;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.RazorPages;
+using Oqtane.Enums;
+using Oqtane.Extensions;
+using Oqtane.Infrastructure;
+using Oqtane.Models;
+using Oqtane.Repository;
+using Oqtane.Security;
+using Oqtane.Shared;
+
+namespace Oqtane.Pages
+{
+    [AllowAnonymous]
+    public class FilesModel : PageModel
+    {
+        private readonly IWebHostEnvironment _environment;
+        private readonly IFileRepository _files;
+        private readonly IUserPermissions _userPermissions;
+        private readonly IUrlMappingRepository _urlMappings;
+        private readonly ILogManager _logger;
+        private readonly Alias _alias;
+
+        public FilesModel(IWebHostEnvironment environment, IFileRepository files, IUserPermissions userPermissions, IUrlMappingRepository urlMappings, ILogManager logger, ITenantManager tenantManager)
+        {
+            _environment = environment;
+            _files = files;
+            _userPermissions = userPermissions;
+            _urlMappings = urlMappings;
+            _logger = logger;
+            _alias = tenantManager.GetAlias();
+        }
+
+        public IActionResult OnGet(string path)
+        {
+            path = path.Replace("\\", "/");
+            var folderpath = "";
+            var filename = "";
+
+            var segments = path.Split('/');
+            if (segments.Length > 0)
+            {
+                filename = segments[segments.Length - 1].ToLower();
+                if (segments.Length > 1)
+                {
+                    folderpath = string.Join("/", segments, 0, segments.Length - 1).ToLower() + "/";
+                }
+            }
+
+            var file = _files.GetFile(_alias.SiteId, folderpath, filename);
+            if (file != null)
+            {
+                if (_userPermissions.IsAuthorized(User, PermissionNames.View, file.Folder.Permissions))
+                {
+                    var filepath = _files.GetFilePath(file);
+                    if (System.IO.File.Exists(filepath))
+                    {
+                        return PhysicalFile(filepath, file.GetMimeType());
+                    }
+                    else
+                    {
+                        _logger.Log(LogLevel.Error, this, LogFunction.Read, "File Does Not Exist {FilePath}", filepath);
+                        HttpContext.Response.StatusCode = (int)HttpStatusCode.NotFound;
+                    }
+                }
+                else
+                {
+                    _logger.Log(LogLevel.Error, this, LogFunction.Security, "Unauthorized File Access Attempt {SiteId} {Path}", _alias.SiteId, path);
+                    HttpContext.Response.StatusCode = (int)HttpStatusCode.Forbidden;
+                }
+            }
+            else
+            {
+                // look for url mapping
+                var urlMapping = _urlMappings.GetUrlMapping(_alias.SiteId, "files/" + folderpath + filename);
+                if (urlMapping != null && !string.IsNullOrEmpty(urlMapping.MappedUrl))
+                {
+                    var url = urlMapping.MappedUrl;
+                    if (!url.StartsWith("http"))
+                    {
+                        var uri = new Uri(HttpContext.Request.GetEncodedUrl());
+                        url = uri.Scheme + "://" + uri.Authority + ((!string.IsNullOrEmpty(_alias.Path)) ? "/" + _alias.Path : "") + "/" + url;
+                    }
+                    return RedirectPermanent(url);
+                }
+            }
+
+            // broken link
+            string errorPath = Path.Combine(Utilities.PathCombine(_environment.ContentRootPath, "wwwroot\\images"), "error.png");
+            return PhysicalFile(errorPath, MimeUtilities.GetMimeType(errorPath));
+        }
+    }
+}