Support struct field with dynamic disabled (opensearch-project#3829)

* Support struct field with dynamic disabled

Signed-off-by: Heng Qian <qianheng@amazon.com>

* Fix UT

Signed-off-by: Heng Qian <qianheng@amazon.com>

* Address comments

Signed-off-by: Heng Qian <qianheng@amazon.com>

* Revert change in GSON

Signed-off-by: Heng Qian <qianheng@amazon.com>

* Revert change in GSON

Signed-off-by: Heng Qian <qianheng@amazon.com>

---------

Signed-off-by: Heng Qian <qianheng@amazon.com>

Author: qianheng-aws

integ-test/src/yamlRestTest/resources/rest-api-spec/test/issues/3343.yml

@@ -0,0 +1,55 @@
+setup:
+  - do:
+      indices.create:
+        index: test
+        body:
+          settings:
+            number_of_shards: 1
+            number_of_replicas: 0
+          mappings:
+            properties:
+              profile:
+                type: object
+                dynamic: false
+  - do:
+      query.settings:
+        body:
+          transient:
+            plugins.calcite.enabled : true
+            plugins.calcite.fallback.allowed : false
+
+---
+teardown:
+  - do:
+      query.settings:
+        body:
+          transient:
+            plugins.calcite.enabled : false
+            plugins.calcite.fallback.allowed : true
+
+---
+"Handle struct field with dynamic mapping disabled":
+  - skip:
+      features:
+        - headers
+        - allowed_warnings
+  - do:
+      bulk:
+        index: test
+        refresh: true
+        body:
+          - '{ "index": { "_index": "test" } }'
+          - '{ "profile": { "age": 1 } }'
+          - '{ "index": { "_index": "test" } }'
+          - '{ "profile": { "address": "a" } }'
+  - do:
+      allowed_warnings:
+        - 'Loading the fielddata on the _id field is deprecated and will be removed in future versions. If you require sorting or aggregating on this field you should also include the id in the body of your documents, and map this field as a keyword field that has [doc_values] enabled'
+      headers:
+        Content-Type: 'application/json'
+      ppl:
+        body:
+          query: 'source=test'
+  - match: {"total": 2}
+  - match: {"schema": [{"name": "profile", "type": "struct"}]}
+  - match: {"datarows": [[{"age": 1}], [{"address": "a"}]]}

opensearch/src/main/java/org/opensearch/sql/opensearch/data/utils/Content.java

@@ -32,6 +32,9 @@ public interface Content {
   /** Is double value. */
   boolean isDouble();
 
+  /** Is int value. */
+  boolean isInt();
+
   /** Is long value. */
   boolean isLong();
 

opensearch/src/main/java/org/opensearch/sql/opensearch/data/utils/ObjectContent.java

@@ -104,6 +104,11 @@ public boolean isNumber() {
     return value instanceof Number;
   }
 
+  @Override
+  public boolean isInt() {
+    return value instanceof Integer;
+  }
+
   @Override
   public boolean isFloat() {
     return value instanceof Float;

opensearch/src/main/java/org/opensearch/sql/opensearch/data/utils/OpenSearchJsonContent.java

@@ -92,6 +92,11 @@ public boolean isNumber() {
     return value().isNumber();
   }
 
+  @Override
+  public boolean isInt() {
+    return value.isInt();
+  }
+
   @Override
   public boolean isLong() {
     return value().isLong();

opensearch/src/main/java/org/opensearch/sql/opensearch/data/value/OpenSearchExprValueFactory.java

@@ -187,10 +187,16 @@ public ExprValue construct(String field, Object value, boolean supportArrays) {
 
   private ExprValue parse(
       Content content, String field, Optional<ExprType> fieldType, boolean supportArrays) {
-    if (content.isNull() || !fieldType.isPresent()) {
+    if (content.isNull()) {
       return ExprNullValue.of();
     }
 
+    // Field type may be not defined in mapping if users have disabled dynamic mapping.
+    // Then try to parse content directly based on the value itself
+    if (fieldType.isEmpty()) {
+      return parseContent(content);
+    }
+
     final ExprType type = fieldType.get();
 
     if (type.equals(OpenSearchDataType.of(OpenSearchDataType.MappingType.GeoPoint))) {
@@ -210,6 +216,31 @@ private ExprValue parse(
     }
   }
 
+  private ExprValue parseContent(Content content) {
+    if (content.isNumber()) {
+      if (content.isInt()) {
+        return new ExprIntegerValue(content.intValue());
+      } else if (content.isLong()) {
+        return new ExprLongValue(content.longValue());
+      } else if (content.isFloat()) {
+        return new ExprFloatValue(content.floatValue());
+      } else if (content.isDouble()) {
+        return new ExprDoubleValue(content.doubleValue());
+      } else {
+        // Default case for number, treat as double
+        return new ExprDoubleValue(content.doubleValue());
+      }
+    } else if (content.isString()) {
+      return new ExprStringValue(content.stringValue());
+    } else if (content.isBoolean()) {
+      return ExprBooleanValue.of(content.booleanValue());
+    } else if (content.isNull()) {
+      return ExprNullValue.of();
+    }
+    // Default case, treat as a string value
+    return new ExprStringValue(content.objectValue().toString());
+  }
+
   /**
    * In OpenSearch, it is possible field doesn't have type definition in mapping. but has empty
    * value. For example, {"empty_field": []}.

opensearch/src/test/java/org/opensearch/sql/opensearch/data/value/OpenSearchExprValueFactoryTest.java

@@ -952,7 +952,7 @@ public void constructFromInvalidJsonThrowException() {
   public void noTypeFoundForMapping() {
     assertEquals(nullValue(), tupleValue("{\"not_exist\":[]}").get("not_exist"));
     // Only for test coverage, It is impossible in OpenSearch.
-    assertEquals(nullValue(), tupleValue("{\"not_exist\":1}").get("not_exist"));
+    assertEquals(ExprValueUtils.integerValue(1), tupleValue("{\"not_exist\":1}").get("not_exist"));
   }
 
   @Test