From f29756e5f8ee56a0c359344f2b4bce0b8f0398d6 Mon Sep 17 00:00:00 2001
From: Jens Schauder <jschauder@pivotal.io>
Date: Mon, 1 Jul 2019 14:48:12 +0200
Subject: [PATCH] DATACMNS-1550 - Added RevisionType to RevisionMetadata.

---
 .../history/AnnotationRevisionMetadata.java   | 30 ++++++++++++++++++-
 .../data/history/RevisionMetadata.java        | 28 +++++++++++++++++
 2 files changed, 57 insertions(+), 1 deletion(-)

diff --git a/src/main/java/org/springframework/data/history/AnnotationRevisionMetadata.java b/src/main/java/org/springframework/data/history/AnnotationRevisionMetadata.java
index aea4a5a86..d8cdb1fe2 100755
--- a/src/main/java/org/springframework/data/history/AnnotationRevisionMetadata.java
+++ b/src/main/java/org/springframework/data/history/AnnotationRevisionMetadata.java
@@ -40,10 +40,12 @@ public class AnnotationRevisionMetadata<N extends Number & Comparable<N>> implem
 	private final Object entity;
 	private final Lazy<Optional<N>> revisionNumber;
 	private final Lazy<Optional<Object>> revisionDate;
+	private final RevisionType revisionType;
 
 	/**
 	 * Creates a new {@link AnnotationRevisionMetadata} inspecting the given entity for the given annotations. If no
-	 * annotations will be provided these values will not be looked up from the entity and return {@literal null}.
+	 * annotations will be provided these values will not be looked up from the entity and return {@literal null}. The
+	 * revisionType will be set to {@literal unknown}
 	 *
 	 * @param entity must not be {@literal null}.
 	 * @param revisionNumberAnnotation must not be {@literal null}.
@@ -52,13 +54,31 @@ public class AnnotationRevisionMetadata<N extends Number & Comparable<N>> implem
 	public AnnotationRevisionMetadata(Object entity, Class<? extends Annotation> revisionNumberAnnotation,
 			Class<? extends Annotation> revisionTimeStampAnnotation) {
 
+		this(entity, revisionNumberAnnotation, revisionTimeStampAnnotation, RevisionType.UNKNOWN);
+	}
+
+	/**
+	 * Creates a new {@link AnnotationRevisionMetadata} inspecting the given entity for the given annotations. If no
+	 * annotations will be provided these values will not be looked up from the entity and return {@literal null}.
+	 *
+	 * @param entity must not be {@literal null}.
+	 * @param revisionNumberAnnotation must not be {@literal null}.
+	 * @param revisionTimeStampAnnotation must not be {@literal null}.
+	 * @param revisionType Must not be {@literal null}.
+	 * @since 2.2.0
+	 */
+	public AnnotationRevisionMetadata(Object entity, Class<? extends Annotation> revisionNumberAnnotation,
+			Class<? extends Annotation> revisionTimeStampAnnotation, RevisionType revisionType) {
+
 		Assert.notNull(entity, "Entity must not be null!");
 		Assert.notNull(revisionNumberAnnotation, "Revision number annotation must not be null!");
 		Assert.notNull(revisionTimeStampAnnotation, "Revision time stamp annotation must not be null!");
+		Assert.notNull(revisionType, "Revision Type must not be null!");
 
 		this.entity = entity;
 		this.revisionNumber = detectAnnotation(entity, revisionNumberAnnotation);
 		this.revisionDate = detectAnnotation(entity, revisionTimeStampAnnotation);
+		this.revisionType = revisionType;
 	}
 
 	/*
@@ -77,6 +97,14 @@ public class AnnotationRevisionMetadata<N extends Number & Comparable<N>> implem
 		return revisionDate.get().map(AnnotationRevisionMetadata::convertToInstant);
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.history.RevisionMetadata#getRevisionDate()
+	 */
+	public RevisionType getRevisionType() {
+		return revisionType;
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.repository.history.RevisionMetadata#getDelegate()
diff --git a/src/main/java/org/springframework/data/history/RevisionMetadata.java b/src/main/java/org/springframework/data/history/RevisionMetadata.java
index b9332e772..ce5392c7d 100755
--- a/src/main/java/org/springframework/data/history/RevisionMetadata.java
+++ b/src/main/java/org/springframework/data/history/RevisionMetadata.java
@@ -71,4 +71,32 @@ public interface RevisionMetadata<N extends Number & Comparable<N>> {
 	 * @return
 	 */
 	<T> T getDelegate();
+
+	/**
+	 * Returns the {@link RevisionType} of this change. If the {@link RevisionType} cannot be determined this method
+	 * returns {@link RevisionType#UNKNOWN}.
+	 * 
+	 * @return Guaranteed to be not {@literal null}.
+	 * @since 2.2.0
+	 */
+	default RevisionType getRevisionType() {
+		return RevisionType.UNKNOWN;
+	}
+
+	/**
+	 * The type of a {@link Revision}.
+	 * 
+	 * @author Jens Schauder
+	 * @since 2.2.0
+	 */
+	enum RevisionType {
+		/** Fallback when the type of a revision cannot be determined. */
+		UNKNOWN,
+		/** Creation of an instance */
+		INSERT,
+		/** Change of an instance */
+		UPDATE,
+		/** Deletion of an instance */
+		DELETE
+	}
 }