src/main/kotlin/kr/co/vividnext/sodalive/chat/character/comment/CharacterComment.kt

@@ -0,0 +1,39 @@
+package kr.co.vividnext.sodalive.chat.character.comment
+
+import kr.co.vividnext.sodalive.chat.character.ChatCharacter
+import kr.co.vividnext.sodalive.common.BaseEntity
+import kr.co.vividnext.sodalive.member.Member
+import javax.persistence.Column
+import javax.persistence.Entity
+import javax.persistence.FetchType
+import javax.persistence.JoinColumn
+import javax.persistence.ManyToOne
+import javax.persistence.OneToMany
+import javax.persistence.Table
+
+@Entity
+@Table(name = "character_comment")
+data class CharacterComment(
+    @Column(columnDefinition = "TEXT", nullable = false)
+    var comment: String,
+    var isActive: Boolean = true
+) : BaseEntity() {
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "parent_id", nullable = true)
+    var parent: CharacterComment? = null
+        set(value) {
+            value?.children?.add(this)
+            field = value
+        }
+
+    @OneToMany(mappedBy = "parent")
+    var children: MutableList<CharacterComment> = mutableListOf()
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "member_id", nullable = false)
+    var member: Member? = null
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "character_id", nullable = false)
+    var chatCharacter: ChatCharacter? = null
+}

src/main/kotlin/kr/co/vividnext/sodalive/chat/character/comment/CharacterCommentController.kt

@@ -0,0 +1,80 @@
+package kr.co.vividnext.sodalive.chat.character.comment
+
+import kr.co.vividnext.sodalive.common.ApiResponse
+import kr.co.vividnext.sodalive.common.SodaException
+import kr.co.vividnext.sodalive.member.Member
+import org.springframework.beans.factory.annotation.Value
+import org.springframework.security.core.annotation.AuthenticationPrincipal
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.PathVariable
+import org.springframework.web.bind.annotation.PostMapping
+import org.springframework.web.bind.annotation.RequestBody
+import org.springframework.web.bind.annotation.RequestMapping
+import org.springframework.web.bind.annotation.RequestParam
+import org.springframework.web.bind.annotation.RestController
+
+@RestController
+@RequestMapping("/api/chat/character")
+class CharacterCommentController(
+    private val service: CharacterCommentService,
+    @Value("\${cloud.aws.cloud-front.host}")
+    private val imageHost: String
+) {
+
+    @PostMapping("/{characterId}/comments")
+    fun createComment(
+        @PathVariable characterId: Long,
+        @RequestBody request: CreateCharacterCommentRequest,
+        @AuthenticationPrincipal(expression = "#this == 'anonymousUser' ? null : member") member: Member?
+    ) = run {
+        if (member == null) throw SodaException("로그인 정보를 확인해주세요.")
+        if (member.auth == null) throw SodaException("본인인증을 하셔야 합니다.")
+        if (request.comment.isBlank()) throw SodaException("댓글 내용을 입력해주세요.")
+
+        val id = service.addComment(characterId, member, request.comment)
+        ApiResponse.ok(id)
+    }
+
+    @PostMapping("/{characterId}/comments/{commentId}/replies")
+    fun createReply(
+        @PathVariable characterId: Long,
+        @PathVariable commentId: Long,
+        @RequestBody request: CreateCharacterCommentRequest,
+        @AuthenticationPrincipal(expression = "#this == 'anonymousUser' ? null : member") member: Member?
+    ) = run {
+        if (member == null) throw SodaException("로그인 정보를 확인해주세요.")
+        if (member.auth == null) throw SodaException("본인인증을 하셔야 합니다.")
+        if (request.comment.isBlank()) throw SodaException("댓글 내용을 입력해주세요.")
+
+        val id = service.addReply(characterId, commentId, member, request.comment)
+        ApiResponse.ok(id)
+    }
+
+    @GetMapping("/{characterId}/comments")
+    fun listComments(
+        @PathVariable characterId: Long,
+        @RequestParam(required = false, defaultValue = "20") limit: Int,
+        @AuthenticationPrincipal(expression = "#this == 'anonymousUser' ? null : member") member: Member?
+    ) = run {
+        if (member == null) throw SodaException("로그인 정보를 확인해주세요.")
+        if (member.auth == null) throw SodaException("본인인증을 하셔야 합니다.")
+
+        val data = service.listComments(imageHost, characterId, limit)
+        ApiResponse.ok(data)
+    }
+
+    @GetMapping("/{characterId}/comments/{commentId}/replies")
+    fun listReplies(
+        @PathVariable characterId: Long,
+        @PathVariable commentId: Long,
+        @RequestParam(required = false, defaultValue = "20") limit: Int,
+        @AuthenticationPrincipal(expression = "#this == 'anonymousUser' ? null : member") member: Member?
+    ) = run {
+        if (member == null) throw SodaException("로그인 정보를 확인해주세요.")
+        if (member.auth == null) throw SodaException("본인인증을 하셔야 합니다.")
+
+        // characterId는 서비스 내부 검증(원본 댓글과 캐릭터 일치)에서 검증됨
+        val data = service.getReplies(imageHost, commentId, limit)
+        ApiResponse.ok(data)
+    }
+}

src/main/kotlin/kr/co/vividnext/sodalive/chat/character/comment/CharacterCommentDto.kt

@@ -0,0 +1,45 @@
+package kr.co.vividnext.sodalive.chat.character.comment
+
+// Request DTOs
+data class CreateCharacterCommentRequest(
+    val comment: String
+)
+
+// Response DTOs
+// 댓글 Response
+// - 댓글 ID
+// - 댓글 쓴 Member 프로필 이미지
+// - 댓글 쓴 Member 닉네임
+// - 댓글 쓴 시간 timestamp(long)
+// - 답글 수
+
+data class CharacterCommentResponse(
+    val commentId: Long,
+    val memberProfileImage: String,
+    val memberNickname: String,
+    val createdAt: Long,
+    val replyCount: Int,
+    val comment: String
+)
+
+// 답글 Response 단건(목록 원소)
+// - 답글 ID
+// - 답글 쓴 Member 프로필 이미지
+// - 답글 쓴 Member 닉네임
+// - 답글 쓴 시간 timestamp(long)
+
+data class CharacterReplyResponse(
+    val replyId: Long,
+    val memberProfileImage: String,
+    val memberNickname: String,
+    val createdAt: Long
+)
+
+// 댓글의 답글 조회 Response 컨테이너
+// - 원본 댓글 Response
+// - 답글 목록(위 사양의 필드 포함)
+
+data class CharacterCommentRepliesResponse(
+    val original: CharacterCommentResponse,
+    val replies: List<CharacterReplyResponse>
+)

src/main/kotlin/kr/co/vividnext/sodalive/chat/character/comment/CharacterCommentRepository.kt

@@ -0,0 +1,18 @@
+package kr.co.vividnext.sodalive.chat.character.comment
+
+import org.springframework.data.domain.Pageable
+import org.springframework.data.jpa.repository.JpaRepository
+
+interface CharacterCommentRepository : JpaRepository<CharacterComment, Long> {
+    fun findByChatCharacter_IdAndIsActiveTrueAndParentIsNullOrderByCreatedAtDesc(
+        chatCharacterId: Long,
+        pageable: Pageable
+    ): List<CharacterComment>
+
+    fun countByParent_IdAndIsActiveTrue(parentId: Long): Int
+    fun findByParent_IdAndIsActiveTrueOrderByCreatedAtDesc(parentId: Long, pageable: Pageable): List<CharacterComment>
+    fun findFirstByChatCharacter_IdAndIsActiveTrueOrderByCreatedAtDesc(chatCharacterId: Long): CharacterComment?
+
+    // 전체(상위+답글) 활성 댓글 총 개수
+    fun countByChatCharacter_IdAndIsActiveTrue(chatCharacterId: Long): Int
+}

src/main/kotlin/kr/co/vividnext/sodalive/chat/character/comment/CharacterCommentService.kt

@@ -0,0 +1,119 @@
+package kr.co.vividnext.sodalive.chat.character.comment
+
+import kr.co.vividnext.sodalive.chat.character.repository.ChatCharacterRepository
+import kr.co.vividnext.sodalive.common.SodaException
+import kr.co.vividnext.sodalive.member.Member
+import org.springframework.data.domain.PageRequest
+import org.springframework.stereotype.Service
+import org.springframework.transaction.annotation.Transactional
+import java.time.ZoneId
+
+@Service
+class CharacterCommentService(
+    private val chatCharacterRepository: ChatCharacterRepository,
+    private val commentRepository: CharacterCommentRepository
+) {
+
+    private fun profileUrl(imageHost: String, profileImage: String?): String {
+        return if (profileImage.isNullOrBlank()) {
+            "$imageHost/profile/default-profile.png"
+        } else {
+            "$imageHost/$profileImage"
+        }
+    }
+
+    private fun toEpochMilli(created: java.time.LocalDateTime?): Long {
+        return created?.atZone(ZoneId.systemDefault())?.toInstant()?.toEpochMilli() ?: 0L
+    }
+
+    private fun toCommentResponse(
+        imageHost: String,
+        entity: CharacterComment,
+        replyCountOverride: Int? = null
+    ): CharacterCommentResponse {
+        val member = entity.member ?: throw SodaException("유효하지 않은 댓글입니다.")
+        return CharacterCommentResponse(
+            commentId = entity.id!!,
+            memberProfileImage = profileUrl(imageHost, member.profileImage),
+            memberNickname = member.nickname,
+            createdAt = toEpochMilli(entity.createdAt),
+            replyCount = replyCountOverride ?: commentRepository.countByParent_IdAndIsActiveTrue(entity.id!!),
+            comment = entity.comment
+        )
+    }
+
+    private fun toReplyResponse(imageHost: String, entity: CharacterComment): CharacterReplyResponse {
+        val member = entity.member ?: throw SodaException("유효하지 않은 댓글입니다.")
+        return CharacterReplyResponse(
+            replyId = entity.id!!,
+            memberProfileImage = profileUrl(imageHost, member.profileImage),
+            memberNickname = member.nickname,
+            createdAt = toEpochMilli(entity.createdAt)
+        )
+    }
+
+    @Transactional
+    fun addComment(characterId: Long, member: Member, text: String): Long {
+        val character = chatCharacterRepository.findById(characterId).orElseThrow { SodaException("캐릭터를 찾을 수 없습니다.") }
+        if (!character.isActive) throw SodaException("비활성화된 캐릭터입니다.")
+        if (text.isBlank()) throw SodaException("댓글 내용을 입력해주세요.")
+
+        val entity = CharacterComment(comment = text)
+        entity.chatCharacter = character
+        entity.member = member
+        commentRepository.save(entity)
+        return entity.id!!
+    }
+
+    @Transactional
+    fun addReply(characterId: Long, parentCommentId: Long, member: Member, text: String): Long {
+        val character = chatCharacterRepository.findById(characterId).orElseThrow { SodaException("캐릭터를 찾을 수 없습니다.") }
+        if (!character.isActive) throw SodaException("비활성화된 캐릭터입니다.")
+        val parent = commentRepository.findById(parentCommentId).orElseThrow { SodaException("댓글을 찾을 수 없습니다.") }
+        if (parent.chatCharacter?.id != characterId) throw SodaException("잘못된 요청입니다.")
+        if (!parent.isActive) throw SodaException("비활성화된 댓글입니다.")
+        if (text.isBlank()) throw SodaException("댓글 내용을 입력해주세요.")
+
+        val entity = CharacterComment(comment = text)
+        entity.chatCharacter = character
+        entity.member = member
+        entity.parent = parent
+        commentRepository.save(entity)
+        return entity.id!!
+    }
+
+    @Transactional(readOnly = true)
+    fun listComments(imageHost: String, characterId: Long, limit: Int = 20): List<CharacterCommentResponse> {
+        val pageable = PageRequest.of(0, limit)
+        val comments = commentRepository.findByChatCharacter_IdAndIsActiveTrueAndParentIsNullOrderByCreatedAtDesc(
+            characterId,
+            pageable
+        )
+        return comments.map { toCommentResponse(imageHost, it) }
+    }
+
+    @Transactional(readOnly = true)
+    fun getReplies(imageHost: String, commentId: Long, limit: Int = 20): CharacterCommentRepliesResponse {
+        val original = commentRepository.findById(commentId).orElseThrow { SodaException("댓글을 찾을 수 없습니다.") }
+        if (!original.isActive) throw SodaException("비활성화된 댓글입니다.")
+
+        val pageable = PageRequest.of(0, limit)
+        val replies = commentRepository.findByParent_IdAndIsActiveTrueOrderByCreatedAtDesc(commentId, pageable)
+
+        return CharacterCommentRepliesResponse(
+            original = toCommentResponse(imageHost, original, 0),
+            replies = replies.map { toReplyResponse(imageHost, it) }
+        )
+    }
+
+    @Transactional(readOnly = true)
+    fun getLatestComment(imageHost: String, characterId: Long): CharacterCommentResponse? {
+        val last = commentRepository.findFirstByChatCharacter_IdAndIsActiveTrueOrderByCreatedAtDesc(characterId)
+        return last?.let { toCommentResponse(imageHost, it) }
+    }
+
+    @Transactional(readOnly = true)
+    fun getTotalCommentCount(characterId: Long): Int {
+        return commentRepository.countByChatCharacter_IdAndIsActiveTrue(characterId)
+    }
+}

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

@@ -1,5 +1,6 @@
 package kr.co.vividnext.sodalive.chat.character.controller
 
+import kr.co.vividnext.sodalive.chat.character.comment.CharacterCommentService
 import kr.co.vividnext.sodalive.chat.character.dto.Character
 import kr.co.vividnext.sodalive.chat.character.dto.CharacterBackgroundResponse
 import kr.co.vividnext.sodalive.chat.character.dto.CharacterBannerResponse
@@ -29,6 +30,7 @@ class ChatCharacterController(
     private val service: ChatCharacterService,
     private val bannerService: ChatCharacterBannerService,
     private val chatRoomService: ChatRoomService,
+    private val characterCommentService: CharacterCommentService,
 
     @Value("\${cloud.aws.cloud-front.host}")
     private val imageHost: String
@@ -148,6 +150,9 @@ class ChatCharacterController(
                 )
             }
 
+        // 최신 댓글 1개 조회
+        val latestComment = characterCommentService.getLatestComment(imageHost, character.id!!)
+
         // 응답 생성
         ApiResponse.ok(
             CharacterDetailResponse(
@@ -162,7 +167,9 @@ class ChatCharacterController(
                 originalTitle = character.originalTitle,
                 originalLink = character.originalLink,
                 characterType = character.characterType,
-                others = others
+                others = others,
+                latestComment = latestComment,
+                totalComments = characterCommentService.getTotalCommentCount(character.id!!)
             )
         )
     }

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

@@ -1,6 +1,7 @@
 package kr.co.vividnext.sodalive.chat.character.dto
 
 import kr.co.vividnext.sodalive.chat.character.CharacterType
+import kr.co.vividnext.sodalive.chat.character.comment.CharacterCommentResponse
 
 data class CharacterDetailResponse(
     val characterId: Long,
@@ -14,7 +15,9 @@ data class CharacterDetailResponse(
     val originalTitle: String?,
     val originalLink: String?,
     val characterType: CharacterType,
-    val others: List<OtherCharacter>
+    val others: List<OtherCharacter>,
+    val latestComment: CharacterCommentResponse?,
+    val totalComments: Int
 )
 
 data class OtherCharacter(