feat(chat-character): 추천 캐릭터 조회 및 메인/새로고침 API 반영

src/main/kotlin/kr/co/vividnext/sodalive/chat/character/controller/ChatCharacterController.kt

@@ -74,6 +74,13 @@ class ChatCharacterController(
             size = 50
         ).content
 
+        // 추천 캐릭터 조회
+        // 최근 대화한 캐릭터를 제외한 랜덤 20개 조회
+        // Controller에서는 호출만
+        // 세부로직은 추후에 변경될 수 있으므로 Service에 별도로 생성
+        val excludeIds = recentCharacters.map { it.characterId }
+        val recommendCharacters = service.getRecommendCharacters(excludeIds, 20)
+
         // 큐레이션 섹션 (활성화된 큐레이션 + 캐릭터)
         val curationSections = curationQueryService.getActiveCurationsWithCharacters()
             .map { agg ->
@@ -98,6 +105,7 @@ class ChatCharacterController(
                 recentCharacters = recentCharacters,
                 popularCharacters = popularCharacters,
                 newCharacters = newCharacters,
+                recommendCharacters = recommendCharacters,
                 curationSections = curationSections
             )
         )
@@ -193,4 +201,23 @@ class ChatCharacterController(
             )
         )
     }
+
+    /**
+     * 추천 캐릭터 새로고침 API
+     * - 최근 대화한 캐릭터를 제외하고 랜덤 20개 반환
+     * - 비회원 또는 본인인증되지 않은 경우: 최근 대화 목록 없음 → 전체 활성 캐릭터 중 랜덤 20개
+     */
+    @GetMapping("/recommend")
+    fun getRecommendCharacters(
+        @AuthenticationPrincipal(expression = "#this == 'anonymousUser' ? null : member") member: Member?
+    ) = run {
+        val recent = if (member == null || member.auth == null) {
+            emptyList()
+        } else {
+            chatRoomService
+                .listMyChatRooms(member, 0, 50) // 최근 기록은 최대 50개까지만 제외 대상으로 고려
+                .map { it.characterId }
+        }
+        ApiResponse.ok(service.getRecommendCharacters(recent, 20))
+    }
 }

src/main/kotlin/kr/co/vividnext/sodalive/chat/character/dto/CharacterHomeResponse.kt

@@ -7,6 +7,7 @@ data class CharacterMainResponse(
     val recentCharacters: List<RecentCharacter>,
     val popularCharacters: List<Character>,
     val newCharacters: List<Character>,
+    val recommendCharacters: List<Character>,
     val curationSections: List<CurationSection>
 )
 

src/main/kotlin/kr/co/vividnext/sodalive/chat/character/repository/ChatCharacterRepository.kt

@@ -74,5 +74,29 @@ interface ChatCharacterRepository : JpaRepository<ChatCharacter, Long> {
         pageable: Pageable
     ): List<ChatCharacter>
 
+    /**
+     * 활성 캐릭터 무작위 조회
+     */
+    @Query(
+        """
+        SELECT c FROM ChatCharacter c
+        WHERE c.isActive = true
+        ORDER BY function('RAND')
+        """
+    )
+    fun findRandomActive(pageable: Pageable): List<ChatCharacter>
+
+    /**
+     * 제외할 캐릭터를 뺀 활성 캐릭터 무작위 조회
+     */
+    @Query(
+        """
+        SELECT c FROM ChatCharacter c
+        WHERE c.isActive = true AND c.id NOT IN :excludeIds
+        ORDER BY function('RAND')
+        """
+    )
+    fun findRandomActiveExcluding(@Param("excludeIds") excludeIds: List<Long>, pageable: Pageable): List<ChatCharacter>
+
     fun findByIdInAndIsActiveTrue(ids: List<Long>): List<ChatCharacter>
 }

src/main/kotlin/kr/co/vividnext/sodalive/chat/character/service/ChatCharacterService.kt

@@ -38,6 +38,24 @@ class ChatCharacterService(
     @Value("\${cloud.aws.cloud-front.host}")
     private val imageHost: String
 ) {
+    @Transactional(readOnly = true)
+    fun getRecommendCharacters(excludeCharacterIds: List<Long> = emptyList(), limit: Int = 20): List<Character> {
+        val safeLimit = if (limit <= 0) 20 else if (limit > 50) 50 else limit
+        val chars = if (excludeCharacterIds.isNotEmpty()) {
+            chatCharacterRepository.findRandomActiveExcluding(excludeCharacterIds, PageRequest.of(0, safeLimit))
+        } else {
+            chatCharacterRepository.findRandomActive(PageRequest.of(0, safeLimit))
+        }
+        return chars.map {
+            Character(
+                characterId = it.id!!,
+                name = it.name,
+                description = it.description,
+                imageUrl = "$imageHost/${it.imagePath ?: "profile/default-profile.png"}"
+            )
+        }
+    }
+
     /**
      * UTC 20:00 경계 기준 지난 윈도우의 메시지 수 상위 캐릭터 조회
      * Spring Cache(@Cacheable) + 동적 키 + 고정 TTL(24h) 사용