Supoprt and'ing two not's

4 files changed, 56 insertions, 20 deletions

diff --git a/container-search/abi-spec.json b/container-search/abi-spec.json
index 6c68260df32..164794243ec 100644
--- a/container-search/abi-spec.json
+++ b/container-search/abi-spec.json
@@ -872,6 +872,7 @@
       "public java.lang.String getName()",
       "public void addItem(com.yahoo.prelude.query.Item)",
       "public void addNegativeItem(com.yahoo.prelude.query.Item)",
+      "public java.util.List negativeItems()",
       "public com.yahoo.prelude.query.Item getPositiveItem()",
       "public com.yahoo.prelude.query.Item setPositiveItem(com.yahoo.prelude.query.Item)",
       "public void addPositiveItem(com.yahoo.prelude.query.Item)",
diff --git a/container-search/src/main/java/com/yahoo/prelude/query/NotItem.java b/container-search/src/main/java/com/yahoo/prelude/query/NotItem.java
index 702d90bec94..ab1e1b4bd33 100644
--- a/container-search/src/main/java/com/yahoo/prelude/query/NotItem.java
+++ b/container-search/src/main/java/com/yahoo/prelude/query/NotItem.java
@@ -3,14 +3,15 @@ package com.yahoo.prelude.query;
 
 import com.yahoo.protect.Validator;
 
+import java.util.Collections;
 import java.util.Iterator;
-
+import java.util.List;
 
 /**
- * <p>A composite item where the first item is positive and the following
+ * A composite item where the first item is positive and the following
  * items are negative items which should be excluded from the result.
  *
- * @author  bratseth
+ * @author bratseth
  */
 // TODO: Handle nulls by creating nullItem or checking in encode/toString
 public class NotItem extends CompositeItem {
@@ -42,6 +43,9 @@ public class NotItem extends CompositeItem {
         addItem(negative);
     }
 
+    /** Returns the negative items of this: All child items except the first */
+    public List<Item> negativeItems() { return items().subList(1, getItemCount()); }
+
     /**
      * Returns the positive item (the first subitem),
      * or null if no positive items has been added
diff --git a/container-search/src/main/java/com/yahoo/search/query/QueryTree.java b/container-search/src/main/java/com/yahoo/search/query/QueryTree.java
index 6eba6ae4837..1bf176e2131 100644
--- a/container-search/src/main/java/com/yahoo/search/query/QueryTree.java
+++ b/container-search/src/main/java/com/yahoo/search/query/QueryTree.java
@@ -114,31 +114,44 @@ public class QueryTree extends CompositeItem {
      * @return the resulting root item in this
      */
     public Item and(Item item) {
-        if (isEmpty()) {
-            setRoot(item);
+        Item result = and(getRoot(), item);
+        setRoot(result);
+        return result;
+    }
+
+    private Item and(Item a, Item b) {
+        if (a == null || a instanceof NullItem) {
+            return b;
         }
-        else if (getRoot() instanceof NotItem && item instanceof NotItem) {
-            throw new IllegalArgumentException("Can't AND two NOTs"); // TODO: Complete
+        else if (a instanceof NotItem && b instanceof NotItem) {
+            NotItem notItemA = (NotItem)a;
+            NotItem notItemB = (NotItem)b;
+            NotItem combined = new NotItem();
+            combined.addPositiveItem(and(notItemA.getPositiveItem(), notItemB.getPositiveItem()));
+            notItemA.negativeItems().forEach(item -> combined.addNegativeItem(item));
+            notItemB.negativeItems().forEach(item -> combined.addNegativeItem(item));
+            return combined;
         }
-        else if (getRoot() instanceof NotItem){
-            NotItem notItem = (NotItem)getRoot();
-            notItem.addPositiveItem(item);
+        else if (a instanceof NotItem){
+            NotItem notItem = (NotItem)a;
+            notItem.addPositiveItem(b);
+            return a;
         }
-        else if (item instanceof NotItem){
-            NotItem notItem = (NotItem)item;
-            notItem.addPositiveItem(getRoot());
-            setRoot(notItem);
+        else if (b instanceof NotItem){
+            NotItem notItem = (NotItem)b;
+            notItem.addPositiveItem(a);
+            return notItem;
         }
-        else if (getRoot() instanceof AndItem) {
-            ((AndItem) getRoot()).addItem(item);
+        else if (a instanceof AndItem) {
+            ((AndItem)a).addItem(b);
+            return a;
         }
         else {
             AndItem andItem = new AndItem();
-            andItem.addItem(getRoot());
-            andItem.addItem(item);
-            setRoot(andItem);
+            andItem.addItem(a);
+            andItem.addItem(b);
+            return andItem;
         }
-        return getRoot();
     }
 
     /** Returns a flattened list of all positive query terms under the given item */
diff --git a/container-search/src/test/java/com/yahoo/search/query/QueryTreeTest.java b/container-search/src/test/java/com/yahoo/search/query/QueryTreeTest.java
index f929e54fd2d..c55c9531e49 100644
--- a/container-search/src/test/java/com/yahoo/search/query/QueryTreeTest.java
+++ b/container-search/src/test/java/com/yahoo/search/query/QueryTreeTest.java
@@ -23,4 +23,22 @@ public class QueryTreeTest {
                      new QueryTree(new WordItem("a")).and(not).toString());
      }
 
+     @Test
+     public void addNotToNot() {
+         NotItem not1 = new NotItem();
+         not1.addPositiveItem(new WordItem("p1"));
+         not1.addNegativeItem(new WordItem("n1.1"));
+         not1.addNegativeItem(new WordItem("n1.2"));
+
+         NotItem not2 = new NotItem();
+         not2.addPositiveItem(new WordItem("p2"));
+         not2.addNegativeItem(new WordItem("n2.1"));
+         not2.addNegativeItem(new WordItem("n2.2"));
+
+         QueryTree tree = new QueryTree(not1);
+         tree.and(not2);
+
+         assertEquals("+(AND p1 p2) -n1.1 -n1.2 -n2.1 -n2.2", tree.toString());
+     }
+
 }