SQL: Add Verification for HAVING on TopHits with subquery (#72967)

Previously, when a TopHits aggregation function was used (FIRST/LAST,
or MIN/MAX on keyword field) in a subquery and on an outer query this
aggregation was filtered (with WHERE/HAVING) the Verification was passed
successfully and the query was planned and translated resulting into an
unsupported query DSL - since bucket selector on a TopHits agg is not
currently supported, and the user received a weird error msg.

Verify this case of subselects with TopHits aggs and throw an
appropriate error message to the user.

Closes: #71441

x-pack/plugin/sql/src/main/java/org/elasticsearch/xpack/sql/analysis/analyzer/Verifier.java

@@ -686,6 +686,20 @@ public final class Verifier {
                         }
                     }
                 });
+            } else {
+                Set<Expression> unsupported = new LinkedHashSet<>();
+                filter.condition().forEachDown(Expression.class, e -> {
+                    Expression f = attributeRefs.resolve(e, e);
+                    if (f instanceof TopHits) {
+                        unsupported.add(f);
+                    }
+                });
+                if (unsupported.isEmpty() == false) {
+                    String plural = unsupported.size() > 1 ? "s" : StringUtils.EMPTY;
+                    localFailures.add(
+                            fail(filter.condition(), "filtering is unsupported for function" + plural + " {}",
+                                    Expressions.names(unsupported)));
+                }
             }
         }
     }

x-pack/plugin/sql/src/test/java/org/elasticsearch/xpack/sql/analysis/analyzer/VerifierErrorMessagesTests.java

@@ -13,6 +13,8 @@ import org.elasticsearch.xpack.ql.plan.logical.LogicalPlan;
 import org.elasticsearch.xpack.ql.type.EsField;
 import org.elasticsearch.xpack.sql.analysis.index.IndexResolverTests;
 import org.elasticsearch.xpack.sql.expression.function.SqlFunctionRegistry;
+import org.elasticsearch.xpack.sql.expression.function.aggregate.First;
+import org.elasticsearch.xpack.sql.expression.function.aggregate.Last;
 import org.elasticsearch.xpack.sql.expression.function.scalar.math.Round;
 import org.elasticsearch.xpack.sql.expression.function.scalar.math.Truncate;
 import org.elasticsearch.xpack.sql.expression.function.scalar.string.Char;
@@ -24,7 +26,6 @@ import org.elasticsearch.xpack.sql.expression.predicate.conditional.Least;
 import org.elasticsearch.xpack.sql.expression.predicate.conditional.NullIf;
 import org.elasticsearch.xpack.sql.parser.SqlParser;
 import org.elasticsearch.xpack.sql.stats.Metrics;
-
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
@@ -1073,30 +1074,59 @@ public class VerifierErrorMessagesTests extends ESTestCase {
     }
 
     public void testTopHitsFirstArgConstant() {
-        assertEquals("1:8: first argument of [FIRST('foo', int)] must be a table column, found constant ['foo']",
-            error("SELECT FIRST('foo', int) FROM test"));
+        String topHitsFunction = randomTopHitsFunction();
+        assertEquals("1:8: first argument of [" + topHitsFunction + "('foo', int)] must be a table column, found constant ['foo']",
+            error("SELECT " + topHitsFunction + "('foo', int) FROM test"));
     }
 
     public void testTopHitsSecondArgConstant() {
-        assertEquals("1:8: second argument of [LAST(int, 10)] must be a table column, found constant [10]",
-            error("SELECT LAST(int, 10) FROM test"));
+        String topHitsFunction = randomTopHitsFunction();
+        assertEquals("1:8: second argument of [" + topHitsFunction + "(int, 10)] must be a table column, found constant [10]",
+            error("SELECT " + topHitsFunction + "(int, 10) FROM test"));
     }
 
     public void testTopHitsFirstArgTextWithNoKeyword() {
-        assertEquals("1:8: [FIRST(text)] cannot operate on first argument field of data type [text]: " +
+        String topHitsFunction = randomTopHitsFunction();
+        assertEquals("1:8: [" + topHitsFunction + "(text)] cannot operate on first argument field of data type [text]: " +
                 "No keyword/multi-field defined exact matches for [text]; define one or use MATCH/QUERY instead",
-            error("SELECT FIRST(text) FROM test"));
+            error("SELECT " + topHitsFunction + "(text) FROM test"));
     }
 
     public void testTopHitsSecondArgTextWithNoKeyword() {
-        assertEquals("1:8: [LAST(keyword, text)] cannot operate on second argument field of data type [text]: " +
+        String topHitsFunction = randomTopHitsFunction();
+        assertEquals("1:8: [" + topHitsFunction + "(keyword, text)] cannot operate on second argument field of data type [text]: " +
                 "No keyword/multi-field defined exact matches for [text]; define one or use MATCH/QUERY instead",
-            error("SELECT LAST(keyword, text) FROM test"));
+            error("SELECT " + topHitsFunction + "(keyword, text) FROM test"));
+    }
+
+    public void testTopHitsByHavingUnsupported() {
+        String topHitsFunction = randomTopHitsFunction();
+        int column = 31 + topHitsFunction.length();
+        assertEquals("1:" + column + ": filtering is unsupported for function [" + topHitsFunction + "(int)]",
+                error("SELECT " + topHitsFunction + "(int) FROM test HAVING " + topHitsFunction + "(int) > 10"));
     }
 
     public void testTopHitsGroupByHavingUnsupported() {
-        assertEquals("1:50: HAVING filter is unsupported for function [FIRST(int)]",
-            error("SELECT FIRST(int) FROM test GROUP BY text HAVING FIRST(int) > 10"));
+        String topHitsFunction = randomTopHitsFunction();
+        int column = 45 + topHitsFunction.length();
+        assertEquals("1:" + column + ": filtering is unsupported for function [" + topHitsFunction + "(int)]",
+            error("SELECT " + topHitsFunction + "(int) FROM test GROUP BY text HAVING " + topHitsFunction + "(int) > 10"));
+    }
+
+    public void testTopHitsHavingWithSubqueryUnsupported() {
+        String filter = randomFrom("WHERE", "HAVING");
+        int column = 99 + filter.length();
+        assertEquals("1:" + column + ": filtering is unsupported for functions [FIRST(int), LAST(int)]",
+                error("SELECT * FROM (SELECT * FROM (SELECT * FROM (SELECT FIRST(int) AS f, LAST(int) AS l FROM test))) " +
+                        filter + " f > 10 or l < 10"));
+    }
+
+    public void testTopHitsGroupByHavingWithSubqueryUnsupported() {
+        String filter = randomFrom("WHERE", "HAVING");
+        int column = 113 + filter.length();
+        assertEquals("1:" + column + ": filtering is unsupported for functions [FIRST(int), LAST(int)]",
+                error("SELECT * FROM (SELECT * FROM (SELECT * FROM (SELECT FIRST(int) AS f, LAST(int) AS l FROM test GROUP BY bool))) " +
+                        filter + " f > 10 or l < 10"));
     }
 
     public void testMinOnInexactUnsupported() {
@@ -1329,4 +1359,8 @@ public class VerifierErrorMessagesTests extends ESTestCase {
     public void testSubselectWithOrderWhereOnAggregate() {
         accept("SELECT * FROM (SELECT bool as b, AVG(int) as a FROM test GROUP BY bool ORDER BY bool) WHERE a > 10");
     }
+
+    private String randomTopHitsFunction() {
+        return randomFrom(Arrays.asList(First.class, Last.class)).getSimpleName().toUpperCase(Locale.ROOT);
+    }
 }