HSEARCH-5300 Adjust the processor configuration properties

Author: marko-bekhta

metamodel/metamodel-processor/src/main/java/org/hibernate/search/metamodel/processor/HibernateSearchMetamodelProcessor.java

@@ -28,7 +28,8 @@
 @SupportedAnnotationTypes("*")
 // Currently this is more of a placeholder for future config options:
 @SupportedOptions({
-		HibernateSearchMetamodelProcessorSettings.ADD_GENERATED_ANNOTATION,
+		HibernateSearchMetamodelProcessorSettings.GENERATED_ANNOTATION_ADD,
+		HibernateSearchMetamodelProcessorSettings.GENERATED_ANNOTATION_TIMESTAMP,
 		HibernateSearchMetamodelProcessorSettings.BACKEND_VERSION })
 @org.hibernate.search.util.common.annotation.impl.SuppressJQAssistant(
 		reason = "JQAssistant has issue with detecting that getSupportedSourceVersion is an overridden method.")

metamodel/metamodel-processor/src/main/java/org/hibernate/search/metamodel/processor/HibernateSearchMetamodelProcessorSettings.java

@@ -6,6 +6,11 @@
 
 
 import java.io.Serializable;
+import java.time.Clock;
+import java.time.LocalDateTime;
+import java.time.ZoneOffset;
+import java.time.format.DateTimeFormatter;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
 
@@ -18,15 +23,17 @@ private HibernateSearchMetamodelProcessorSettings() {
 
 	private static final String PREFIX = "org.hibernate.search.metamodel.processor.";
 
-	public static final String ADD_GENERATED_ANNOTATION = PREFIX + Radicals.ADD_GENERATED_ANNOTATION;
+	public static final String GENERATED_ANNOTATION_ADD = PREFIX + Radicals.GENERATED_ANNOTATION_ADD;
+	public static final String GENERATED_ANNOTATION_TIMESTAMP = PREFIX + Radicals.GENERATED_ANNOTATION_TIMESTAMP;
 	public static final String BACKEND_VERSION = PREFIX + Radicals.BACKEND_VERSION;
 
 	public static class Radicals {
 
 		private Radicals() {
 		}
 
-		public static final String ADD_GENERATED_ANNOTATION = "add_generated_annotation";
+		public static final String GENERATED_ANNOTATION_ADD = "generated_annotation.add";
+		public static final String GENERATED_ANNOTATION_TIMESTAMP = "generated_annotation.timestamp";
 		public static final String BACKEND_VERSION = "backend.version";
 	}
 
@@ -35,20 +42,43 @@ private Radicals() {
 	 */
 	public static final class Defaults {
 
-		public static final String ADD_GENERATED_ANNOTATION = Boolean.TRUE.toString();
+		public static final String GENERATED_ANNOTATION_ADD = Boolean.TRUE.toString();
+		public static final String GENERATED_ANNOTATION_TIMESTAMP = Boolean.FALSE.toString();
 
 		private Defaults() {
 		}
 	}
 
-	public record Configuration(boolean addGeneratedAnnotation, String version) implements Serializable {
+	public record Configuration(boolean generatedAnnotationAdd, boolean generatedAnnotationTimestamp, String version)
+			implements Serializable {
 		public Configuration(Map<String, String> options) {
 			this(
-					Boolean.parseBoolean( options.getOrDefault( ADD_GENERATED_ANNOTATION, Defaults.ADD_GENERATED_ANNOTATION ) ),
+					Boolean.parseBoolean( options.getOrDefault( GENERATED_ANNOTATION_ADD, Defaults.GENERATED_ANNOTATION_ADD ) ),
+					Boolean.parseBoolean(
+							options.getOrDefault( GENERATED_ANNOTATION_TIMESTAMP, Defaults.GENERATED_ANNOTATION_TIMESTAMP ) ),
 					Objects.toString( options.get( BACKEND_VERSION ), null )
 			);
 		}
 
+		public String formattedGeneratedAnnotation() {
+			if ( !generatedAnnotationAdd ) {
+				return "";
+			}
+			if ( generatedAnnotationTimestamp ) {
+				return String.format(
+						Locale.ROOT, "@javax.annotation.processing.Generated(value = \"%s\", date = \"%s\")",
+						HibernateSearchMetamodelProcessor.class.getName(),
+						LocalDateTime.now( Clock.systemUTC() ).atOffset( ZoneOffset.UTC )
+								.format( DateTimeFormatter.ISO_OFFSET_DATE_TIME )
+				);
+			}
+			else {
+				return String.format( Locale.ROOT, "@javax.annotation.processing.Generated(value = \"%s\")",
+						HibernateSearchMetamodelProcessor.class.getName()
+				);
+			}
+		}
+
 		public String elasticsearchVersion() {
 			return version == null ? "9.0.0" : version;
 		}

metamodel/metamodel-processor/src/main/java/org/hibernate/search/metamodel/processor/writer/impl/MetamodelClassWriter.java

@@ -147,7 +147,7 @@ public String formatted() {
 				Locale.ROOT,
 				"""
 						%s
-						@javax.annotation.processing.Generated(value = "org.hibernate.search.metamodel.processor.HibernateSearchMetamodelProcessor")
+						%s
 						public final class %s implements
 							%s<%s, %s> {
 
@@ -174,6 +174,7 @@ public final class %s implements
 						}
 						""",
 				packageName.isEmpty() ? "" : "package " + packageName + ";\n",
+				configuration.formattedGeneratedAnnotation(),
 				metamodelClassName,
 				scopeInterfaceType(),
 				metamodelClassName,