New: Author folder hint when selecting a root folder while adding a new author

(cherry picked from commit dd09f31abb4dd3f699bcff0a47577075300c70ee)

Fix AuthorFolderAsRootFolderValidator

(cherry picked from commit 0ce81e1ab69d43fde382cc4ae22cd46fe626dea7)

src/Readarr.Api.V1/Author/AuthorController.cs

@@ -59,7 +59,8 @@ namespace Readarr.Api.V1.Author
                             AuthorAncestorValidator authorAncestorValidator,
                             SystemFolderValidator systemFolderValidator,
                             QualityProfileExistsValidator qualityProfileExistsValidator,
-                            MetadataProfileExistsValidator metadataProfileExistsValidator)
+                            MetadataProfileExistsValidator metadataProfileExistsValidator,
+                            AuthorFolderAsRootFolderValidator authorFolderAsRootFolderValidator)
             : base(signalRBroadcaster)
         {
             _authorService = authorService;
@@ -89,7 +90,10 @@ namespace Readarr.Api.V1.Author
             SharedValidator.RuleFor(s => s.MetadataProfileId).SetValidator(metadataProfileExistsValidator);
 
             PostValidator.RuleFor(s => s.Path).IsValidPath().When(s => s.RootFolderPath.IsNullOrWhiteSpace());
-            PostValidator.RuleFor(s => s.RootFolderPath).IsValidPath().When(s => s.Path.IsNullOrWhiteSpace());
+            PostValidator.RuleFor(s => s.RootFolderPath)
+                         .IsValidPath()
+                         .SetValidator(authorFolderAsRootFolderValidator)
+                         .When(s => s.Path.IsNullOrWhiteSpace());
             PostValidator.RuleFor(s => s.AuthorName).NotEmpty();
             PostValidator.RuleFor(s => s.ForeignAuthorId).NotEmpty().SetValidator(authorExistsValidator);
 

src/Readarr.Api.V1/Author/AuthorFolderAsRootFolderValidator.cs

@@ -0,0 +1,49 @@
+using System;
+using System.IO;
+using FluentValidation.Validators;
+using NzbDrone.Common.Extensions;
+using NzbDrone.Core.Organizer;
+
+namespace Readarr.Api.V1.Author
+{
+    public class AuthorFolderAsRootFolderValidator : PropertyValidator
+    {
+        private readonly IBuildFileNames _fileNameBuilder;
+
+        public AuthorFolderAsRootFolderValidator(IBuildFileNames fileNameBuilder)
+        {
+            _fileNameBuilder = fileNameBuilder;
+        }
+
+        protected override string GetDefaultMessageTemplate() => "Root folder path contains author folder";
+
+        protected override bool IsValid(PropertyValidatorContext context)
+        {
+            if (context.PropertyValue == null)
+            {
+                return true;
+            }
+
+            var authorResource = context.ParentContext.InstanceToValidate as AuthorResource;
+
+            if (authorResource == null)
+            {
+                return true;
+            }
+
+            var rootFolderPath = context.PropertyValue.ToString();
+            var rootFolder = new DirectoryInfo(rootFolderPath).Name;
+            var author = authorResource.ToModel();
+            var authorFolder = _fileNameBuilder.GetAuthorFolder(author);
+
+            if (authorFolder == rootFolder)
+            {
+                return false;
+            }
+
+            var distance = authorFolder.LevenshteinDistance(rootFolder);
+
+            return distance >= Math.Max(1, authorFolder.Length * 0.2);
+        }
+    }
+}

src/Readarr.Api.V1/Author/AuthorLookupController.cs

@@ -3,6 +3,7 @@ using System.Linq;
 using Microsoft.AspNetCore.Mvc;
 using NzbDrone.Core.MediaCover;
 using NzbDrone.Core.MetadataSource;
+using NzbDrone.Core.Organizer;
 using Readarr.Http;
 
 namespace Readarr.Api.V1.Author
@@ -11,11 +12,13 @@ namespace Readarr.Api.V1.Author
     public class AuthorLookupController : Controller
     {
         private readonly ISearchForNewAuthor _searchProxy;
+        private readonly IBuildFileNames _fileNameBuilder;
         private readonly IMapCoversToLocal _coverMapper;
 
-        public AuthorLookupController(ISearchForNewAuthor searchProxy, IMapCoversToLocal coverMapper)
+        public AuthorLookupController(ISearchForNewAuthor searchProxy, IBuildFileNames fileNameBuilder, IMapCoversToLocal coverMapper)
         {
             _searchProxy = searchProxy;
+            _fileNameBuilder = fileNameBuilder;
             _coverMapper = coverMapper;
         }
 
@@ -41,6 +44,8 @@ namespace Readarr.Api.V1.Author
                     resource.RemotePoster = poster.Url;
                 }
 
+                resource.Folder = _fileNameBuilder.GetAuthorFolder(currentAuthor);
+
                 yield return resource;
             }
         }

src/Readarr.Api.V1/Author/AuthorResource.cs

@@ -45,6 +45,7 @@ namespace Readarr.Api.V1.Author
         public NewItemMonitorTypes MonitorNewItems { get; set; }
 
         public string RootFolderPath { get; set; }
+        public string Folder { get; set; }
         public List<string> Genres { get; set; }
         public string CleanName { get; set; }
         public string SortName { get; set; }