dev -> prd

layer-admin/src/main/java/org/layer/admin/retrospect/controller/dto/RetrospectOverviewResponse.java

@@ -4,6 +4,7 @@ public record RetrospectOverviewResponse(
 	long createdRetrospectCount,
 	long completedRetrospectCount,
 	double averageCompletionRate,
-	double averageRetrospectLength
+	double averageRetrospectLength,
+	double averageWritingTimeMinutes
 ) {
 }

layer-admin/src/main/java/org/layer/admin/retrospect/repository/AdminRetrospectAnswerRepository.java

@@ -59,6 +59,9 @@ SELECT COALESCE(AVG(LENGTH(a.answerContent)), 0)
 	List<AdminRetrospectAnswerHistory> findAllByEventTimeBetweenAndAnswerEndTimeIsNotNull(
 		LocalDateTime startTime, LocalDateTime endTime);
 
+	List<AdminRetrospectAnswerHistory> findAllByAnswerEndTimeBetweenAndAnswerStartTimeIsNotNullAndAnswerEndTimeIsNotNull(
+		LocalDateTime startTime, LocalDateTime endTime);
+
 	void deleteByMemberIdAndSpaceIdAndRetrospectId(
 		Long memberId, Long spaceId, Long retrospectId
 	);

layer-admin/src/main/java/org/layer/admin/retrospect/service/AdminRetrospectService.java

@@ -76,12 +76,20 @@ public RetrospectOverviewResponse getRetrospectOverview(LocalDateTime startDate,
 
 		double averageRetrospectLength = adminRetrospectAnswerRepository.findAverageRetrospectLengthBetween(
 			startDate, endDate);
+		List<AdminRetrospectAnswerHistory> completedAnswerHistories =
+			adminRetrospectAnswerRepository.findAllByAnswerEndTimeBetweenAndAnswerStartTimeIsNotNullAndAnswerEndTimeIsNotNull(
+				startDate, endDate);
+		double averageWritingTimeMinutes = completedAnswerHistories.stream()
+			.mapToLong(AdminRetrospectAnswerHistory::getAnswerTime)
+			.average()
+			.orElse(0.0);
 
 		return new RetrospectOverviewResponse(
 			createdRetrospectCount,
 			completedRetrospectCount,
 			averageCompletionRate,
-			averageRetrospectLength
+			averageRetrospectLength,
+			averageWritingTimeMinutes
 		);
 	}