Add getAspectRatio method to collection config

fapi-client/src/main/scala/com/gu/facia/api/models/collectionconfig.scala

@@ -1,5 +1,6 @@
 package com.gu.facia.api.models
 
+import com.gu.facia.api.models.CollectionConfig.AspectRatio.{Landscape53, Landscape54, Landscape54Collections, Portrait45, PortraitCollections, Square}
 import com.gu.facia.client.models.{AnyPlatform, Backfill, CollectionConfigJson, CollectionPlatform, DisplayHintsJson, FrontsToolSettings, Metadata, TargetedTerritory}
 
 case class Groups(groups: List[String])
@@ -88,4 +89,48 @@ object CollectionConfig {
       collectionJson.platform.getOrElse(AnyPlatform),
       collectionJson.frontsToolSettings,
       collectionJson.suppressImages.exists(identity))
+
+  sealed trait AspectRatio {
+    def label: String
+  }
+
+  object AspectRatio {
+    case object Portrait45 extends AspectRatio {
+      val label = "4:5"
+    }
+
+    case object Landscape53 extends AspectRatio {
+      val label = "5:3"
+    }
+
+    case object Landscape54 extends AspectRatio {
+      val label = "5:4"
+    }
+
+    case object Square extends AspectRatio {
+      val label = "1:1"
+    }
+
+    val Landscape54Collections = List(
+      "flexible/special",
+      "flexible/general",
+      "scrollable/small",
+      "scrollable/medium",
+      "static/medium/4",
+    )
+
+    val PortraitCollections = List(
+      "scrollable/feature",
+      "static/feature/2",
+    )
+  }
+
+  def getAspectRatio(collectionConfig: CollectionConfig): AspectRatio = {
+    collectionConfig.collectionType match {
+      case _ if PortraitCollections.contains(collectionConfig.collectionType) => Portrait45
+      case _ if Landscape54Collections.contains(collectionConfig.collectionType) => Landscape54
+      case "scrollable/highlights" => Square
+      case _ => Landscape53
+    }
+  }
 }

fapi-client/src/test/scala/com/gu/facia/api/models/CollectionTest.scala

@@ -3,6 +3,7 @@ package com.gu.facia.api.models
 import com.gu.contentapi.client.model.v1.{Content, ContentFields, ContentType}
 import com.gu.facia.api.utils.ContentApiUtils._
 import com.gu.facia.api.utils._
+import com.gu.facia.client.models.CollectionConfigJson.emptyConfig.collectionType
 import com.gu.facia.client.models.{Branded, CollectionConfigJson, CollectionJson, Trail, TrailMetaData}
 import org.joda.time.DateTime
 import org.mockito.Mockito._
@@ -473,5 +474,17 @@ class CollectionTest extends AnyFreeSpec with Matchers with MockitoSugar with On
       )
       FaciaContentUtils.headline(FaciaContentUtils.supporting(result.head).head) should be ("straight banana")
     }
+    "AspectRatio.getAspectRatio" in {
+      val defaultCollectionType = collectionConfig.collectionType
+      val defaultCollectionConfig = CollectionConfig.empty.copy(collectionType = defaultCollectionType)
+      val scrollableFeatureConfig = CollectionConfig.empty.copy(collectionType ="scrollable/feature")
+      val scrollableSmallConfig = CollectionConfig.empty.copy(collectionType ="scrollable/small")
+      val scrollableHighlightsConfig = CollectionConfig.empty.copy(collectionType ="scrollable/highlights")
+
+      CollectionConfig.getAspectRatio(defaultCollectionConfig) should be (CollectionConfig.AspectRatio.Landscape53)
+      CollectionConfig.getAspectRatio(scrollableFeatureConfig) should be (CollectionConfig.AspectRatio.Portrait45)
+      CollectionConfig.getAspectRatio(scrollableSmallConfig) should be (CollectionConfig.AspectRatio.Landscape54)
+      CollectionConfig.getAspectRatio(scrollableHighlightsConfig) should be (CollectionConfig.AspectRatio.Square)
+    }
   }
 }