feat(ranking): 크리에이터 랭킹 점수 정책을 추가한다

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

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+package kr.co.vividnext.sodalive.v2.ranking.domain
+
+class CreatorRankingScorePolicy {
+    fun calculateContentLiveScore(
+        liveCanAmount: Long,
+        contentPurchaseCanAmount: Long
+    ): Double {
+        return (liveCanAmount * CreatorRankingScoreSpec.CONTENT_LIVE_CAN_WEIGHT) +
+            (contentPurchaseCanAmount * CreatorRankingScoreSpec.CONTENT_PURCHASE_CAN_WEIGHT)
+    }
+
+    fun calculateEngagementScore(
+        contentLikeCount: Long,
+        contentCommentCount: Long
+    ): Double {
+        return (contentLikeCount * CreatorRankingScoreSpec.CONTENT_LIKE_COUNT_WEIGHT) +
+            (contentCommentCount * CreatorRankingScoreSpec.CONTENT_COMMENT_COUNT_WEIGHT)
+    }
+
+    fun calculateSupportScore(
+        channelDonationCanAmount: Long,
+        channelDonationCount: Long,
+        fanTalkCount: Long
+    ): Double {
+        return (channelDonationCanAmount * CreatorRankingScoreSpec.CHANNEL_DONATION_CAN_WEIGHT) +
+            (channelDonationCount * CreatorRankingScoreSpec.CHANNEL_DONATION_COUNT_WEIGHT) +
+            (fanTalkCount * CreatorRankingScoreSpec.FAN_TALK_COUNT_WEIGHT)
+    }
+
+    fun calculateFanLoyaltyScore(
+        finalFollowerCount: Long,
+        followIncrease: Long
+    ): Double {
+        return (finalFollowerCount * CreatorRankingScoreSpec.FINAL_FOLLOWER_COUNT_WEIGHT) +
+            (followIncrease * CreatorRankingScoreSpec.FOLLOW_INCREASE_WEIGHT)
+    }
+
+    fun calculateFinalScore(
+        contentLiveScore: Double,
+        engagementScore: Double,
+        supportScore: Double,
+        fanLoyaltyScore: Double
+    ): Double {
+        return (contentLiveScore * CreatorRankingScoreSpec.CONTENT_LIVE_SCORE_WEIGHT) +
+            (engagementScore * CreatorRankingScoreSpec.ENGAGEMENT_SCORE_WEIGHT) +
+            (supportScore * CreatorRankingScoreSpec.SUPPORT_SCORE_WEIGHT) +
+            (fanLoyaltyScore * CreatorRankingScoreSpec.FAN_LOYALTY_SCORE_WEIGHT)
+    }
+}

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

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+package kr.co.vividnext.sodalive.v2.ranking.domain
+
+object CreatorRankingScoreSpec {
+    const val CONTENT_LIVE_CAN_WEIGHT = 0.7
+    const val CONTENT_PURCHASE_CAN_WEIGHT = 0.3
+
+    const val CONTENT_LIKE_COUNT_WEIGHT = 0.5
+    const val CONTENT_COMMENT_COUNT_WEIGHT = 0.5
+
+    const val CHANNEL_DONATION_CAN_WEIGHT = 0.6
+    const val CHANNEL_DONATION_COUNT_WEIGHT = 0.2
+    const val FAN_TALK_COUNT_WEIGHT = 0.2
+
+    const val FINAL_FOLLOWER_COUNT_WEIGHT = 0.7
+    const val FOLLOW_INCREASE_WEIGHT = 0.3
+
+    const val CONTENT_LIVE_SCORE_WEIGHT = 0.35
+    const val ENGAGEMENT_SCORE_WEIGHT = 0.3
+    const val SUPPORT_SCORE_WEIGHT = 0.25
+    const val FAN_LOYALTY_SCORE_WEIGHT = 0.1
+}

src/test/kotlin/kr/co/vividnext/sodalive/v2/ranking/domain/CreatorRankingScorePolicyTest.kt

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+package kr.co.vividnext.sodalive.v2.ranking.domain
+
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.DisplayName
+import org.junit.jupiter.api.Test
+
+class CreatorRankingScorePolicyTest {
+    private val policy = CreatorRankingScorePolicy()
+
+    @Test
+    @DisplayName("콘텐츠/라이브 점수는 라이브 계열 캔 70%와 콘텐츠 구매 캔 30%를 raw value로 계산한다")
+    fun shouldCalculateContentLiveScore() {
+        assertEquals(0.7, CreatorRankingScoreSpec.CONTENT_LIVE_CAN_WEIGHT, 0.0001)
+        assertEquals(0.3, CreatorRankingScoreSpec.CONTENT_PURCHASE_CAN_WEIGHT, 0.0001)
+
+        val score = policy.calculateContentLiveScore(liveCanAmount = 1000, contentPurchaseCanAmount = 200)
+
+        assertEquals(760.0, score, 0.0001)
+    }
+
+    @Test
+    @DisplayName("참여 반응 점수는 좋아요 수와 댓글 수를 각각 50% raw value로 계산한다")
+    fun shouldCalculateEngagementScore() {
+        assertEquals(0.5, CreatorRankingScoreSpec.CONTENT_LIKE_COUNT_WEIGHT, 0.0001)
+        assertEquals(0.5, CreatorRankingScoreSpec.CONTENT_COMMENT_COUNT_WEIGHT, 0.0001)
+
+        val score = policy.calculateEngagementScore(contentLikeCount = 40, contentCommentCount = 20)
+
+        assertEquals(30.0, score, 0.0001)
+    }
+
+    @Test
+    @DisplayName("응원 점수는 채널 후원 캔/건수와 팬 Talk 수를 raw value로 계산한다")
+    fun shouldCalculateSupportScore() {
+        assertEquals(0.6, CreatorRankingScoreSpec.CHANNEL_DONATION_CAN_WEIGHT, 0.0001)
+        assertEquals(0.2, CreatorRankingScoreSpec.CHANNEL_DONATION_COUNT_WEIGHT, 0.0001)
+        assertEquals(0.2, CreatorRankingScoreSpec.FAN_TALK_COUNT_WEIGHT, 0.0001)
+
+        val score = policy.calculateSupportScore(
+            channelDonationCanAmount = 1000,
+            channelDonationCount = 10,
+            fanTalkCount = 20
+        )
+
+        assertEquals(606.0, score, 0.0001)
+    }
+
+    @Test
+    @DisplayName("팬 충성도 점수는 음수 팔로우 증가 수를 최종 점수에 그대로 반영한다")
+    fun shouldCalculateFanLoyaltyScoreWithNegativeFollowIncrease() {
+        assertEquals(0.7, CreatorRankingScoreSpec.FINAL_FOLLOWER_COUNT_WEIGHT, 0.0001)
+        assertEquals(0.3, CreatorRankingScoreSpec.FOLLOW_INCREASE_WEIGHT, 0.0001)
+
+        val score = policy.calculateFanLoyaltyScore(finalFollowerCount = 100, followIncrease = -10)
+
+        assertEquals(67.0, score, 0.0001)
+    }
+
+    @Test
+    @DisplayName("최종 점수는 카테고리별 점수에 PRD 가중치를 적용하고 0~100 정규화하지 않는다")
+    fun shouldCalculateFinalScoreWithoutNormalization() {
+        assertEquals(0.35, CreatorRankingScoreSpec.CONTENT_LIVE_SCORE_WEIGHT, 0.0001)
+        assertEquals(0.3, CreatorRankingScoreSpec.ENGAGEMENT_SCORE_WEIGHT, 0.0001)
+        assertEquals(0.25, CreatorRankingScoreSpec.SUPPORT_SCORE_WEIGHT, 0.0001)
+        assertEquals(0.1, CreatorRankingScoreSpec.FAN_LOYALTY_SCORE_WEIGHT, 0.0001)
+
+        val score = policy.calculateFinalScore(
+            contentLiveScore = 760.0,
+            engagementScore = 30.0,
+            supportScore = 606.0,
+            fanLoyaltyScore = 67.0
+        )
+
+        assertEquals(433.2, score, 0.0001)
+    }
+}