New: Custom Format Spec Validation

Fixes #7405

src/NzbDrone.Core/CustomFormats/Specifications/LanguageSpecification.cs

@@ -1,11 +1,31 @@
+using System.Linq;
+using FluentValidation;
 using NzbDrone.Core.Annotations;
 using NzbDrone.Core.Languages;
 using NzbDrone.Core.Parser.Model;
+using NzbDrone.Core.Validation;
 
 namespace NzbDrone.Core.CustomFormats
 {
+    public class LanguageSpecificationValidator : AbstractValidator<LanguageSpecification>
+    {
+        public LanguageSpecificationValidator()
+        {
+            RuleFor(c => c.Value).NotEmpty();
+            RuleFor(c => c.Value).Custom((value, context) =>
+            {
+                if (!Language.All.Any(o => o.Id == value))
+                {
+                    context.AddFailure(string.Format("Invalid Language condition value: {0}", value));
+                }
+            });
+        }
+    }
+
     public class LanguageSpecification : CustomFormatSpecificationBase
     {
+        private static readonly LanguageSpecificationValidator Validator = new LanguageSpecificationValidator();
+
         public override int Order => 3;
         public override string ImplementationName => "Language";
 
@@ -19,5 +39,10 @@ namespace NzbDrone.Core.CustomFormats
                 : (Language)Value;
             return movieInfo?.Languages?.Contains(comparedLanguage) ?? false;
         }
+
+        public override NzbDroneValidationResult Validate()
+        {
+            return new NzbDroneValidationResult(Validator.Validate(this));
+        }
     }
 }