New: Newznab/Torznab categories dropdown with indexer provided category names

src/Lidarr.Api.V1/ProviderModuleBase.cs

@@ -27,7 +27,7 @@ namespace Lidarr.Api.V1
             Get("schema", x => GetTemplates());
             Post("test", x => Test(ReadResourceFromRequest(true)));
             Post("testall", x => TestAll());
-            Post("action/{action}", x => RequestAction(x.action, ReadResourceFromRequest(true)));
+            Post("action/{action}", x => RequestAction(x.action, ReadResourceFromRequest(true, true)));
 
             GetResourceAll = GetAll;
             GetResourceById = GetProviderById;

src/Lidarr.Http/ClientSchema/Field.cs

@@ -14,6 +14,7 @@ namespace Lidarr.Http.ClientSchema
         public string Type { get; set; }
         public bool Advanced { get; set; }
         public List<SelectOption> SelectOptions { get; set; }
+        public string SelectOptionsProviderAction { get; set; }
         public string Section { get; set; }
         public string Hidden { get; set; }
 

src/Lidarr.Http/ClientSchema/SchemaBuilder.cs

@@ -104,7 +104,14 @@ namespace Lidarr.Http.ClientSchema
 
                     if (fieldAttribute.Type == FieldType.Select)
                     {
-                        field.SelectOptions = GetSelectOptions(fieldAttribute.SelectOptions);
+                        if (fieldAttribute.SelectOptionsProviderAction.IsNotNullOrWhiteSpace())
+                        {
+                            field.SelectOptionsProviderAction = fieldAttribute.SelectOptionsProviderAction;
+                        }
+                        else
+                        {
+                            field.SelectOptions = GetSelectOptions(fieldAttribute.SelectOptions);
+                        }
                     }
 
                     if (fieldAttribute.Hidden != HiddenType.Visible)

src/Lidarr.Http/REST/RestModule.cs

@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using FluentValidation;
+using FluentValidation.Results;
 using Lidarr.Http.Extensions;
 using Nancy;
 using Nancy.Responses.Negotiation;
@@ -224,7 +225,7 @@ namespace Lidarr.Http.REST
             return Negotiate.WithModel(model).WithStatusCode(statusCode);
         }
 
-        protected TResource ReadResourceFromRequest(bool skipValidate = false)
+        protected TResource ReadResourceFromRequest(bool skipValidate = false, bool skipSharedValidate = false)
         {
             var resource = new TResource();
 
@@ -242,7 +243,12 @@ namespace Lidarr.Http.REST
                 throw new BadRequestException("Request body can't be empty");
             }
 
-            var errors = SharedValidator.Validate(resource).Errors.ToList();
+            var errors = new List<ValidationFailure>();
+
+            if (!skipSharedValidate)
+            {
+                errors.AddRange(SharedValidator.Validate(resource).Errors);
+            }
 
             if (Request.Method.Equals("POST", StringComparison.InvariantCultureIgnoreCase) && !skipValidate && !Request.Url.Path.EndsWith("/test", StringComparison.InvariantCultureIgnoreCase))
             {

src/NzbDrone.Core/Annotations/FieldDefinitionAttribute.cs

@@ -19,6 +19,7 @@ namespace NzbDrone.Core.Annotations
         public FieldType Type { get; set; }
         public bool Advanced { get; set; }
         public Type SelectOptions { get; set; }
+        public string SelectOptionsProviderAction { get; set; }
         public string Section { get; set; }
         public HiddenType Hidden { get; set; }
         public PrivacyLevel Privacy { get; set; }
@@ -38,6 +39,15 @@ namespace NzbDrone.Core.Annotations
         public string Hint { get; set; }
     }
 
+    public class FieldSelectOption
+    {
+        public int Value { get; set; }
+        public string Name { get; set; }
+        public int Order { get; set; }
+        public string Hint { get; set; }
+        public int? ParentValue { get; set; }
+    }
+
     public enum FieldType
     {
         Textbox,

src/NzbDrone.Core/Indexers/HttpIndexerBase.cs

@@ -294,7 +294,14 @@ namespace NzbDrone.Core.Indexers
             {
                 var parser = GetParser();
                 var generator = GetRequestGenerator();
-                var releases = FetchPage(generator.GetRecentRequests().GetAllTiers().First().First(), parser);
+                var firstRequest = generator.GetRecentRequests().GetAllTiers().FirstOrDefault()?.FirstOrDefault();
+
+                if (firstRequest == null)
+                {
+                    return new ValidationFailure(string.Empty, "No rss feed query available. This may be an issue with the indexer or your indexer category settings.");
+                }
+
+                var releases = FetchPage(firstRequest, parser);
 
                 if (releases.Empty())
                 {

src/NzbDrone.Core/Indexers/Newznab/Newznab.cs

@@ -138,5 +138,31 @@ namespace NzbDrone.Core.Indexers.Newznab
                 return new ValidationFailure(string.Empty, "Unable to connect to indexer, check the log for more details");
             }
         }
+
+        public override object RequestAction(string action, IDictionary<string, string> query)
+        {
+            if (action == "newznabCategories")
+            {
+                List<NewznabCategory> categories = null;
+                try
+                {
+                    if (Settings.BaseUrl.IsNotNullOrWhiteSpace() && Settings.ApiPath.IsNotNullOrWhiteSpace())
+                    {
+                        categories = _capabilitiesProvider.GetCapabilities(Settings).Categories;
+                    }
+                }
+                catch
+                {
+                    // Use default categories
+                }
+
+                return new
+                {
+                    options = NewznabCategoryFieldOptionsConverter.GetFieldSelectOptions(categories)
+                };
+            }
+
+            return base.RequestAction(action, query);
+        }
     }
 }

src/NzbDrone.Core/Indexers/Newznab/NewznabCapabilitiesProvider.cs

@@ -48,6 +48,7 @@ namespace NzbDrone.Core.Indexers.Newznab
             }
 
             var request = new HttpRequest(url, HttpAccept.Rss);
+            request.AllowAutoRedirect = true;
 
             HttpResponse response;
 

src/NzbDrone.Core/Indexers/Newznab/NewznabCategoryFieldOptionsConverter.cs

@@ -0,0 +1,69 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using NzbDrone.Core.Annotations;
+
+namespace NzbDrone.Core.Indexers.Newznab
+{
+    public static class NewznabCategoryFieldOptionsConverter
+    {
+        public static List<FieldSelectOption> GetFieldSelectOptions(List<NewznabCategory> categories)
+        {
+            // Ignore categories not relevant for Lidarr
+            var ignoreCategories = new[] { 0, 1000, 2000, 4000, 5000, 6000, 7000 };
+
+            var result = new List<FieldSelectOption>();
+
+            if (categories == null)
+            {
+                // Fetching categories failed, use default Newznab categories
+                categories = new List<NewznabCategory>();
+                categories.Add(new NewznabCategory
+                {
+                    Id = 3000,
+                    Name = "Music",
+                    Subcategories = new List<NewznabCategory>
+                    {
+                        new NewznabCategory { Id = 3040, Name = "Loseless" },
+                        new NewznabCategory { Id = 3010, Name = "MP3" },
+                        new NewznabCategory { Id = 3050, Name = "Other" },
+                        new NewznabCategory { Id = 3030, Name = "Audiobook" }
+                    }
+                });
+            }
+
+            foreach (var category in categories)
+            {
+                if (ignoreCategories.Contains(category.Id))
+                {
+                    continue;
+                }
+
+                result.Add(new FieldSelectOption
+                {
+                    Value = category.Id,
+                    Name = category.Name,
+                    Hint = $"({category.Id})"
+                });
+
+                if (category.Subcategories != null)
+                {
+                    foreach (var subcat in category.Subcategories)
+                    {
+                        result.Add(new FieldSelectOption
+                        {
+                            Value = subcat.Id,
+                            Name = subcat.Name,
+                            Hint = $"({subcat.Id})",
+                            ParentValue = category.Id
+                        });
+                    }
+                }
+            }
+
+            result.Sort((l, r) => l.Value.CompareTo(r.Value));
+
+            return result;
+        }
+    }
+}

src/NzbDrone.Core/Indexers/Newznab/NewznabSettings.cs

@@ -58,7 +58,7 @@ namespace NzbDrone.Core.Indexers.Newznab
         public NewznabSettings()
         {
             ApiPath = "/api";
-            Categories = new[] { 3000, 3010, 3020, 3030, 3040 };
+            Categories = new[] { 3000, 3010, 3030, 3040 };
         }
 
         [FieldDefinition(0, Label = "URL")]
@@ -70,7 +70,7 @@ namespace NzbDrone.Core.Indexers.Newznab
         [FieldDefinition(2, Label = "API Key", Privacy = PrivacyLevel.ApiKey)]
         public string ApiKey { get; set; }
 
-        [FieldDefinition(3, Label = "Categories", HelpText = "Comma Separated list, leave blank to disable standard/daily shows", Advanced = true)]
+        [FieldDefinition(3, Label = "Categories", Type = FieldType.Select, SelectOptionsProviderAction = "newznabCategories", HelpText = "Comma Separated list")]
         public IEnumerable<int> Categories { get; set; }
 
         [FieldDefinition(4, Type = FieldType.Number, Label = "Early Download Limit", HelpText = "Time before release date Lidarr will download from this indexer, empty is no limit", Unit = "days", Advanced = true)]

src/NzbDrone.Core/Indexers/Torznab/Torznab.cs

@@ -106,5 +106,28 @@ namespace NzbDrone.Core.Indexers.Torznab
                 return new ValidationFailure(string.Empty, "Unable to connect to indexer, check the log for more details");
             }
         }
+
+        public override object RequestAction(string action, IDictionary<string, string> query)
+        {
+            if (action == "newznabCategories")
+            {
+                List<NewznabCategory> categories = null;
+                try
+                {
+                    categories = _capabilitiesProvider.GetCapabilities(Settings).Categories;
+                }
+                catch
+                {
+                    // Use default categories
+                }
+
+                return new
+                {
+                    options = NewznabCategoryFieldOptionsConverter.GetFieldSelectOptions(categories)
+                };
+            }
+
+            return base.RequestAction(action, query);
+        }
     }
 }