Entity into_inner method

Signed-off-by: John Brain <jnbrain@amazon.com>

Author: jtbrain

CedarJava/src/main/java/com/cedarpolicy/model/entity/Entity.java

@@ -66,6 +66,37 @@ public Entity(EntityUID uid, Map<String, Value> attributes, Set<EntityUID> paren
         this.tags = new HashMap<>(tags);
     }
 
+    /**
+     * An InnerEntity is a data wrapper for an Entity that holds its entity uid, attributes, and ancestors
+     */
+    public static class InnerEntity {
+        public final EntityUID euid;
+        public final Map<String, Value> attrs;
+        public final Set<EntityUID> ancestors;
+
+        protected InnerEntity(Entity entity) {
+            this.euid = entity.getEUID();
+            this.attrs = entity.attrs;
+            this.ancestors = entity.getParents();
+        }
+
+        public EntityUID getEntityUid() {
+            return this.euid;
+        }
+
+        public Map<String, Value> getAttributes() {
+            return attrs;
+        }
+
+        public Set<EntityUID> getAncestors() {
+            return ancestors;
+        }
+    }
+
+    public InnerEntity intoInner() {
+        return new InnerEntity(this);
+    }
+
     /**
      * Get the value for the given attribute, or null if not present.
      * 

CedarJava/src/test/java/com/cedarpolicy/EntityTests.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
- package com.cedarpolicy;
+package com.cedarpolicy;
 
 import org.junit.jupiter.api.Test;
 import static org.junit.jupiter.api.Assertions.assertThrows;
@@ -26,7 +26,7 @@
 
 import com.cedarpolicy.value.*;
 import com.cedarpolicy.model.entity.Entity;
-
+import com.cedarpolicy.model.entity.Entity.InnerEntity;
 
 public class EntityTests {
 
@@ -49,4 +49,27 @@ public void getAttrTests() {
         // Test key not found
         assertEquals(principal.getAttr("decimalAttr"), null);
     }
+
+    @Test
+    public void intoInnerTests() {
+        PrimString stringAttr = new PrimString("stringAttrValue");
+        HashMap<String, Value> attrs = new HashMap<>();
+        attrs.put("stringAttr", stringAttr);
+
+        EntityTypeName principalType = EntityTypeName.parse("User").get();
+
+        HashSet<EntityUID> parents = new HashSet<EntityUID>();
+        parents.add(principalType.of("Bob"));
+
+        PrimString longTag = new PrimString("longTagValue");
+        HashMap<String, Value> tags = new HashMap<>();
+        tags.put("tag", longTag);
+
+        Entity principal = new Entity(principalType.of("Alice"), attrs, parents, tags);
+        InnerEntity innerPrincipal = principal.intoInner();
+
+        assertEquals(innerPrincipal.getEntityUid(), principalType.of("Alice"));
+        assertEquals(innerPrincipal.getAttributes(), attrs);
+        assertEquals(innerPrincipal.getAncestors(), parents);
+    }
 }