Fixed: Indexers that do not support movie search should give better error messages. Radarr now also complains if an indexer does not support certain categories.

src/.idea/.idea.NzbDrone/.idea/vcs.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$/.." vcs="Git" />
+    <mapping directory="$PROJECT_DIR$/ExternalModules/CurlSharp" vcs="Git" />
+  </component>
+</project>

src/NzbDrone.Core/Indexers/HttpIndexerBase.cs

@@ -298,7 +298,8 @@ namespace NzbDrone.Core.Indexers
 
                 if (releases.Empty())
                 {
-                    return new ValidationFailure(string.Empty, "No results were returned from your indexer, please check your settings.");
+                    return new ValidationFailure(string.Empty,
+                        "No results were returned from your indexer, please check your settings.");
                 }
             }
             catch (ApiKeyException)
@@ -319,7 +320,8 @@ namespace NzbDrone.Core.Indexers
                 }
                 else
                 {
-                    return new ValidationFailure("CaptchaToken", "Site protected by CloudFlare CAPTCHA. Valid CAPTCHA token required.");
+                    return new ValidationFailure("CaptchaToken",
+                        "Site protected by CloudFlare CAPTCHA. Valid CAPTCHA token required.");
                 }
             }
             catch (UnsupportedFeedException ex)
@@ -334,6 +336,21 @@ namespace NzbDrone.Core.Indexers
 
                 return new ValidationFailure(string.Empty, "Unable to connect to indexer. " + ex.Message);
             }
+            catch (HttpException ex)
+            {
+                if (ex.Response.StatusCode == HttpStatusCode.BadRequest &&
+                    ex.Response.Content.Contains("not support the requested query"))
+                {
+                    _logger.Warn(ex, "Indexer does not support the query");
+                    return new ValidationFailure(string.Empty, "Indexer does not support the current query. Check if the categories and or searching for movies are supported. Check the log for more details.");
+                }
+                else
+                {
+                    _logger.Warn(ex, "Unable to connect to indexer");
+
+                    return new ValidationFailure(string.Empty, "Unable to connect to indexer, check the log for more details");
+                }
+            }
             catch (Exception ex)
             {
                 _logger.Warn(ex, "Unable to connect to indexer");

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

@@ -93,25 +93,44 @@ namespace NzbDrone.Core.Indexers.Newznab
             failures.AddIfNotNull(TestCapabilities());
         }
 
+        protected static List<int> CategoryIds(List<NewznabCategory> categories)
+        {
+            var l = categories.Select(c => c.Id).ToList();
+
+            foreach (var category in categories)
+            {
+                l.AddRange(CategoryIds(category.Subcategories));
+            }
+            
+            return l;
+        }
+
         protected virtual ValidationFailure TestCapabilities()
         {
             try
             {
                 var capabilities = _capabilitiesProvider.GetCapabilities(Settings);
 
+                var notSupported = Settings.Categories.Except(CategoryIds(capabilities.Categories));
+                
+                if (notSupported.Any())
+                {
+                    return new ValidationFailure(string.Empty, $"This indexer does not support the following categories: {string.Join(", ", notSupported)}");
+                }
+
                 if (capabilities.SupportedSearchParameters != null && capabilities.SupportedSearchParameters.Contains("q"))
                 {
                     return null;
                 }
 
-                if (capabilities.SupportedTvSearchParameters != null &&
+                if (capabilities.SupportedMovieSearchParameters != null &&
                     new[] { "q", "imdbid" }.Any(v => capabilities.SupportedMovieSearchParameters.Contains(v)) &&
                     new[] { "imdbtitle", "imdbyear" }.All(v => capabilities.SupportedMovieSearchParameters.Contains(v)))
                 {
                     return null;
                 }
 
-                return new ValidationFailure(string.Empty, "Indexer does not support required search parameters");
+                return new ValidationFailure(string.Empty, "This indexer does not support searching for movies :(. Tell your indexer staff to enable this or force add the indexer by disabling search, adding the indexer and then enabling it again.");
             }
             catch (Exception ex)
             {

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

@@ -40,10 +40,15 @@ namespace NzbDrone.Core.Indexers.Newznab
 
             var capabilities = _capabilitiesProvider.GetCapabilities(Settings);
 
+            // Some indexers might forget to enable movie search, but normal search still works fine. Thus we force a normal search.
             if (capabilities.SupportedMovieSearchParameters != null)
             {
                 pageableRequests.Add(GetPagedRequests(MaxPages, Settings.Categories.Concat(Settings.AnimeCategories), "movie", ""));
             }
+            else if (capabilities.SupportedSearchParameters != null)
+            {
+                pageableRequests.Add(GetPagedRequests(MaxPages, Settings.Categories.Concat(Settings.AnimeCategories), "search", ""));
+            }
 
             return pageableRequests;
         }

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

@@ -83,24 +83,47 @@ namespace NzbDrone.Core.Indexers.Torznab
             failures.AddIfNotNull(TestCapabilities());
         }
 
+        protected static List<int> CategoryIds(List<NewznabCategory> categories)
+        {
+            var l = categories.Select(c => c.Id).ToList();
+
+            foreach (var category in categories)
+            {
+                if (category.Subcategories != null)
+                    l.AddRange(CategoryIds(category.Subcategories));
+            }
+            
+            return l;
+        }
+
         protected virtual ValidationFailure TestCapabilities()
         {
             try
             {
                 var capabilities = _capabilitiesProvider.GetCapabilities(Settings);
 
+                var notSupported = Settings.Categories.Except(CategoryIds(capabilities.Categories));
+                
+                if (notSupported.Any())
+                {
+                    _logger.Warn($"{Definition.Name} does not support the following categories: {string.Join(", ", notSupported)}");
+                    if (notSupported.Count() == Settings.Categories.Count())
+                        return new ValidationFailure(string.Empty, $"This indexer does not support any of the selected categories! (You may need to turn on advanced settings to see them)");
+                }
+
                 if (capabilities.SupportedSearchParameters != null && capabilities.SupportedSearchParameters.Contains("q"))
                 {
                     return null;
                 }
 
                 if (capabilities.SupportedMovieSearchParameters != null &&
-                    new[] { "q", "imdbid" }.Any(v => capabilities.SupportedMovieSearchParameters.Contains(v)))
+                    new[] { "q", "imdbid" }.Any(v => capabilities.SupportedMovieSearchParameters.Contains(v)) &&
+                    new[] { "imdbtitle", "imdbyear" }.All(v => capabilities.SupportedMovieSearchParameters.Contains(v)))
                 {
                     return null;
                 }
 
-                return new ValidationFailure(string.Empty, "Indexer does not support required search parameters");
+                return new ValidationFailure(string.Empty, "This indexer does not support searching for movies :(. Tell your indexer staff to enable this or force add the indexer by disabling search, adding the indexer and then enabling it again.");
             }
             catch (Exception ex)
             {