1 files changed, 11 insertions, 0 deletions
diff --git a/src/main/scala/reading/models/Filter.scala b/src/main/scala/reading/models/Filter.scala
index c4836bb..5e96cf9 100644
--- a/src/main/scala/reading/models/Filter.scala
+++ b/src/main/scala/reading/models/Filter.scala
@@ -7,8 +7,10 @@ trait Filter {
 }
 
 sealed trait FilterKind
+case object PeriodKind extends FilterKind
 case object ThemeKind extends FilterKind
 case object GenreKind extends FilterKind
+case object DifficultyKind extends FilterKind
 
 object Filter {
   def apply[T](in: T)(implicit filterFactory: FilterFactory[T]): Filter =
@@ -26,6 +28,15 @@ trait FilterFactory[T] {
 }
 
 object FilterFactory {
+  implicit object PeriodFilter extends FilterFactory[Period] {
+    def create(period: Period): Filter =
+      new Filter {
+        def filter(book: Book): Boolean = book.period == period
+        val kind: FilterKind = PeriodKind
+        val name: String = period.toString()
+      }
+  }
+
   implicit object ThemeFilter extends FilterFactory[Theme] {
     def create(theme: Theme): Filter =
       new Filter {