feat: Redis에서 랭킹 가중치를 읽어오는 컴포넌트 추가

Author: rnqhstmd

apps/commerce-batch/src/main/java/com/loopers/batch/domain/RankingWeightReader.java

@@ -0,0 +1,57 @@
+package com.loopers.batch.domain;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.stereotype.Component;
+
+/**
+ * Redis에서 랭킹 가중치를 읽어오는 컴포넌트
+ * commerce-streamer의 RankingWeight와 동일한 Redis Key를 사용
+ */
+@Slf4j
+@Component
+@RequiredArgsConstructor
+public class RankingWeightReader {
+
+    private final RedisTemplate<String, String> redisTemplate;
+
+    // commerce-streamer의 RankingWeight와 동일한 Key
+    private static final String WEIGHT_KEY = "ranking:config:weights";
+
+    // 기본 가중치 (commerce-streamer와 동일)
+    private static final double DEFAULT_VIEW_WEIGHT = 0.1;
+    private static final double DEFAULT_LIKE_WEIGHT = 0.2;
+    private static final double DEFAULT_ORDER_WEIGHT = 0.7;
+
+    public double getViewWeight() {
+        return getWeight("view", DEFAULT_VIEW_WEIGHT);
+    }
+
+    public double getLikeWeight() {
+        return getWeight("like", DEFAULT_LIKE_WEIGHT);
+    }
+
+    public double getOrderWeight() {
+        return getWeight("order", DEFAULT_ORDER_WEIGHT);
+    }
+
+    /**
+     * 총점 계산
+     */
+    public double calculateTotalScore(int totalLikes, int totalSales, int totalViews) {
+        return (totalViews * getViewWeight()) + (totalLikes * getLikeWeight()) + (totalSales * getOrderWeight());
+    }
+
+    private double getWeight(String field, double defaultValue) {
+        try {
+            Object value = redisTemplate.opsForHash().get(WEIGHT_KEY, field);
+            if (value != null) {
+                return Double.parseDouble(value.toString());
+            }
+        } catch (Exception e) {
+            log.warn("가중치 조회 실패, 기본값 사용: field={}, default={}", field, defaultValue, e);
+        }
+        return defaultValue;
+    }
+}