[KAN-101] chat gpt 기반 음식점 추천 (오늘의픽 API)

src/main/kotlin/com/restaurant/be/common/redis/RedisRepository.kt

@@ -11,10 +11,29 @@ class RedisRepository(
     companion object {
         private const val SEARCH_PREFIX = "SR:" // 검색어를 저장할 때 사용할 키 접두사
         private const val MAX_HISTORY = 5 // 저장할 최대 검색어 수
+        private const val RECOMMENDATION_PREFIX = "RECOMMENDATION:"
     }
 
     val REFRESH_PREFIX: String = "RT:"
 
+    // 사용자별 추천 식당을 조회하는 메서드
+    fun getRecommendation(userId: Long): List<Long> {
+        val values = redisTemplate.opsForValue()
+        val key = "$RECOMMENDATION_PREFIX$userId"
+        val recommendations = values.get(key)
+        if (recommendations != null) {
+            return recommendations.split(",").map { it.toLong() }
+        }
+
+        val defaultKey = RECOMMENDATION_PREFIX + "0"
+        val defaultRecommendations = values.get(defaultKey)
+        if (defaultRecommendations != null) {
+            return defaultRecommendations.split(",").map { it.toLong() }
+        }
+
+        return emptyList()
+    }
+
     // 사용자별 검색어를 추가하는 메서드
     fun addSearchQuery(userId: Long, query: String) {
         val key = "$SEARCH_PREFIX$userId" // 사용자별 고유 키 생성

src/main/kotlin/com/restaurant/be/restaurant/domain/service/RecommendRestaurantService.kt

@@ -0,0 +1,36 @@
+package com.restaurant.be.restaurant.domain.service
+
+import com.restaurant.be.common.exception.NotFoundUserException
+import com.restaurant.be.common.redis.RedisRepository
+import com.restaurant.be.restaurant.presentation.controller.dto.RecommendRestaurantResponse
+import com.restaurant.be.restaurant.repository.RestaurantRepository
+import com.restaurant.be.user.repository.UserRepository
+import org.springframework.stereotype.Service
+import org.springframework.transaction.annotation.Transactional
+
+@Service
+class RecommendRestaurantService(
+    private val redisRepository: RedisRepository,
+    private val restaurantRepository: RestaurantRepository,
+    private val userRepository: UserRepository
+) {
+
+    @Transactional(readOnly = true)
+    fun recommendRestaurants(email: String): RecommendRestaurantResponse {
+        val userId = userRepository.findByEmail(email)?.id ?: throw NotFoundUserException()
+
+        val restaurantIds = redisRepository.getRecommendation(userId)
+
+        val restaurantDtos = restaurantRepository.findDtoByIds(restaurantIds, userId)
+
+        val randomRestaurantDtos = if (restaurantDtos.size > 5) {
+            restaurantDtos.shuffled().take(5)
+        } else {
+            restaurantDtos
+        }
+
+        return RecommendRestaurantResponse(
+            restaurants = randomRestaurantDtos.map { it.toDto() }
+        )
+    }
+}

src/main/kotlin/com/restaurant/be/restaurant/presentation/controller/RecommendRestaurantController.kt

@@ -1,6 +1,7 @@
 package com.restaurant.be.restaurant.presentation.controller
 
 import com.restaurant.be.common.response.CommonResponse
+import com.restaurant.be.restaurant.domain.service.RecommendRestaurantService
 import com.restaurant.be.restaurant.presentation.controller.dto.RecommendRestaurantResponse
 import io.swagger.annotations.Api
 import io.swagger.annotations.ApiOperation
@@ -16,7 +17,9 @@ import java.security.Principal
 @Api(tags = ["02. Restaurant Info"], description = "음식점 서비스")
 @RestController
 @RequestMapping("/v1/restaurants")
-class RecommendRestaurantController {
+class RecommendRestaurantController(
+    private val recommendRestaurantService: RecommendRestaurantService
+) {
 
     @GetMapping("recommend")
     @PreAuthorize("hasRole('USER')")
@@ -29,6 +32,7 @@ class RecommendRestaurantController {
     fun getRecommendRestaurants(
         principal: Principal
     ): CommonResponse<RecommendRestaurantResponse> {
-        return CommonResponse.success()
+        val response = recommendRestaurantService.recommendRestaurants(principal.name)
+        return CommonResponse.success(response)
     }
 }