feat(content-ranking): 랭킹 공개 시각 정책을 추가한다

src/main/kotlin/kr/co/vividnext/sodalive/v2/content/ranking/domain/AudioRankingSchedulePolicy.kt

@@ -0,0 +1,25 @@
+package kr.co.vividnext.sodalive.v2.content.ranking.domain
+
+import java.time.LocalDateTime
+import java.time.LocalTime
+import java.time.ZoneId
+
+class AudioRankingSchedulePolicy {
+    fun resolveVisibleFromAt(aggregationEndAtKst: LocalDateTime): LocalDateTime {
+        return aggregationEndAtKst.toLocalDate()
+            .atTime(VISIBLE_FROM_TIME)
+            .atZone(KST_ZONE)
+            .withZoneSameInstant(UTC_ZONE)
+            .toLocalDateTime()
+    }
+
+    fun isVisible(visibleFromAtUtc: LocalDateTime, nowUtc: LocalDateTime): Boolean {
+        return !nowUtc.isBefore(visibleFromAtUtc)
+    }
+
+    companion object {
+        private val KST_ZONE: ZoneId = ZoneId.of("Asia/Seoul")
+        private val UTC_ZONE: ZoneId = ZoneId.of("UTC")
+        private val VISIBLE_FROM_TIME: LocalTime = LocalTime.of(9, 0)
+    }
+}