New: Validate that naming formats don't contain illegal characters

Fixes #620

(cherry picked from commit 145c644c9d8f1636027da8a782a7e74f3182c678)

src/NzbDrone.Core/Organizer/FileNameValidation.cs

@@ -1,6 +1,10 @@
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
 using System.Text.RegularExpressions;
 using FluentValidation;
 using FluentValidation.Validators;
+using NzbDrone.Common.Extensions;
 
 namespace NzbDrone.Core.Organizer
 {
@@ -12,12 +16,16 @@ namespace NzbDrone.Core.Organizer
         public static IRuleBuilderOptions<T, string> ValidBookFormat<T>(this IRuleBuilder<T, string> ruleBuilder)
         {
             ruleBuilder.SetValidator(new NotEmptyValidator(null));
+            ruleBuilder.SetValidator(new IllegalCharactersValidator());
+
             return ruleBuilder.SetValidator(new ValidStandardTrackFormatValidator());
         }
 
         public static IRuleBuilderOptions<T, string> ValidAuthorFolderFormat<T>(this IRuleBuilder<T, string> ruleBuilder)
         {
             ruleBuilder.SetValidator(new NotEmptyValidator(null));
+            ruleBuilder.SetValidator(new IllegalCharactersValidator());
+            
             return ruleBuilder.SetValidator(new RegularExpressionValidator(FileNameBuilder.AuthorNameRegex)).WithMessage("Must contain Author name");
         }
     }
@@ -42,4 +50,42 @@ namespace NzbDrone.Core.Organizer
             return true;
         }
     }
+
+    public class IllegalCharactersValidator : PropertyValidator
+    {
+        private readonly char[] _invalidPathChars = Path.GetInvalidPathChars();
+
+        public IllegalCharactersValidator()
+            : base("Contains illegal characters: {InvalidCharacters}")
+        {
+
+        }
+
+        protected override bool IsValid(PropertyValidatorContext context)
+        {
+            var value = context.PropertyValue as string;
+            var invalidCharacters = new List<char>();
+
+            if (value.IsNullOrWhiteSpace())
+            {
+                return true;
+            }
+
+            foreach (var i in _invalidPathChars)
+            {
+                if (value.IndexOf(i) >= 0)
+                {
+                    invalidCharacters.Add(i);
+                }
+            }
+
+            if (invalidCharacters.Any())
+            {
+                context.MessageFormatter.AppendArgument("InvalidCharacters", string.Join("", invalidCharacters));
+                return false;
+            }
+
+            return true;
+        }
+    }
 }