From 862bacea2ac26f3995f978f25ec814354f42d6db Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yoann=20Rodi=C3=A8re?= <yoann@hibernate.org>
Date: Tue, 8 Nov 2016 15:10:18 +0100
Subject: [PATCH] HSEARCH-2451 Added the "source" field to FacetMetadata

Preliminary work for HSEARCH-2451.
---
 .../impl/AnnotationMetadataProvider.java         |  4 +++-
 .../engine/metadata/impl/FacetMetadata.java      | 16 +++++++++++++++-
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/engine/src/main/java/org/hibernate/search/engine/metadata/impl/AnnotationMetadataProvider.java b/engine/src/main/java/org/hibernate/search/engine/metadata/impl/AnnotationMetadataProvider.java
index 2889b38e228..a9eca76c7fd 100644
--- a/engine/src/main/java/org/hibernate/search/engine/metadata/impl/AnnotationMetadataProvider.java
+++ b/engine/src/main/java/org/hibernate/search/engine/metadata/impl/AnnotationMetadataProvider.java
@@ -1327,7 +1327,9 @@ private void bindFieldAnnotation(
 				relativeFacetFieldName = relativeFieldName; // if not explicitly set the facet name is the same as the field name
 			}
 			DocumentFieldPath facetFieldPath = new DocumentFieldPath( prefix, relativeFacetFieldName );
-			FacetMetadata.Builder facetMetadataBuilder = new FacetMetadata.Builder( facetFieldPath );
+			FacetMetadata.Builder facetMetadataBuilder = new FacetMetadata.Builder(
+					fieldMetadataBuilder.getResultReference(), facetFieldPath
+					);
 			FacetEncodingType facetEncodingType = determineFacetEncodingType( member, facetAnnotation );
 			facetMetadataBuilder.setFacetEncoding( facetEncodingType );
 			fieldMetadataBuilder.addFacetMetadata( facetMetadataBuilder.build() );
diff --git a/engine/src/main/java/org/hibernate/search/engine/metadata/impl/FacetMetadata.java b/engine/src/main/java/org/hibernate/search/engine/metadata/impl/FacetMetadata.java
index 8c0738c3ba6..4b3d504c6ab 100644
--- a/engine/src/main/java/org/hibernate/search/engine/metadata/impl/FacetMetadata.java
+++ b/engine/src/main/java/org/hibernate/search/engine/metadata/impl/FacetMetadata.java
@@ -15,15 +15,25 @@
  */
 public class FacetMetadata {
 
+	private final BackReference<DocumentFieldMetadata> sourceField;
+
 	private final DocumentFieldPath path;
 
 	private final FacetEncodingType encoding;
 
 	private FacetMetadata(Builder builder) {
+		this.sourceField = builder.sourceField;
 		this.path = builder.path;
 		this.encoding = builder.encoding;
 	}
 
+	/**
+	 * @return The {@link DocumentFieldMetadata} to which the facet applies.
+	 */
+	public DocumentFieldMetadata getSourceField() {
+		return sourceField.get();
+	}
+
 	/**
 	 * @return The full name of the facet field, including any indexed-embedded prefix. Equivalent to {@code #getPath().getAbsoluteName()}.
 	 */
@@ -44,12 +54,15 @@ public FacetEncodingType getEncoding() {
 
 	public static class Builder {
 		// required parameters
+		private final BackReference<DocumentFieldMetadata> sourceField;
 		private final DocumentFieldPath path;
 
 		// optional parameters
 		private FacetEncodingType encoding = FacetEncodingType.AUTO;
 
-		public Builder(DocumentFieldPath path) {
+		public Builder(BackReference<DocumentFieldMetadata> sourceField,
+				DocumentFieldPath path) {
+			this.sourceField = sourceField;
 			this.path = path;
 		}
 
@@ -65,6 +78,7 @@ public FacetMetadata build() {
 	@Override
 	public String toString() {
 		return "FacetMetadata{" +
+				"sourceField='" + sourceField + '\'' +
 				"path='" + path + '\'' +
 				", encoding=" + encoding +
 				'}';