feat(be): AiChatMessage + Session + Enum Class 생성 및 erd 수정

Author: Mrbaeksang

docs/erd-diagram.md

@@ -47,7 +47,6 @@ erDiagram
         bigint session_id FK "세션 ID"
         text content "메시지 내용"
         enum sender_type "USER, AI"
-        json metadata "AI 도구 사용 정보"
         datetime created_at "메시지 전송 시간"
     }
 
@@ -143,7 +142,6 @@ AI 채팅 메시지를 저장하는 테이블입니다.
 | session_id | BIGINT | FK, NOT NULL | 세션 ID |
 | content | TEXT | NOT NULL | 메시지 내용 |
 | sender_type | ENUM | NOT NULL | 발신자 유형 (USER, AI) |
-| metadata | JSON | NULL | AI 도구 사용 정보 (WeatherTool, TourTool) |
 | created_at | DATETIME | NOT NULL | 메시지 전송 시간 |
 
 **제약조건:**
@@ -243,7 +241,7 @@ Guest가 AI 채팅 세션과 채팅방을 평가하는 테이블입니다.
 1. User → AiChatSession 생성
 2. User → AiChatMessage 전송
 3. Spring AI → WeatherTool/TourTool 호출
-4. AI → AiChatMessage(sender_type=AI) 생성 + metadata 저장
+4. AI → AiChatMessage(sender_type=AI) 생성
 5. SSE로 실시간 응답 전송
 ```
 

src/main/kotlin/com/back/koreaTravelGuide/domain/ai/aiChat/entity/AiChatMessage.kt

@@ -0,0 +1,34 @@
+package com.back.koreaTravelGuide.domain.ai.aiChat.entity
+
+import jakarta.persistence.Column
+import jakarta.persistence.Entity
+import jakarta.persistence.EnumType
+import jakarta.persistence.Enumerated
+import jakarta.persistence.FetchType
+import jakarta.persistence.GeneratedValue
+import jakarta.persistence.GenerationType
+import jakarta.persistence.Id
+import jakarta.persistence.JoinColumn
+import jakarta.persistence.ManyToOne
+import jakarta.persistence.Table
+import java.time.ZoneId
+import java.time.ZonedDateTime
+
+@Entity
+@Table(name = "ai_chat_messages")
+class AiChatMessage(
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column(name = "id")
+    val id: Long? = null,
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "session_id", nullable = false)
+    val aiChatSession: AiChatSession,
+    @Column(name = "content", columnDefinition = "TEXT", nullable = false)
+    val content: String,
+    @Enumerated(EnumType.STRING)
+    @Column(name = "sender_type", nullable = false)
+    val senderType: SenderType,
+    @Column(name = "created_at", nullable = false)
+    val createdAt: ZonedDateTime = ZonedDateTime.now(ZoneId.of("Asia/Seoul")),
+)

src/main/kotlin/com/back/koreaTravelGuide/domain/ai/aiChat/entity/AiChatSession.kt

@@ -0,0 +1,25 @@
+package com.back.koreaTravelGuide.domain.ai.aiChat.entity
+
+import jakarta.persistence.Column
+import jakarta.persistence.Entity
+import jakarta.persistence.GeneratedValue
+import jakarta.persistence.GenerationType
+import jakarta.persistence.Id
+import jakarta.persistence.Table
+import java.time.ZoneId
+import java.time.ZonedDateTime
+
+@Entity
+@Table(name = "ai_chat_sessions")
+class AiChatSession(
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    @Column(name = "id")
+    val id: Long? = null,
+    @Column(name = "user_id", nullable = false)
+    val userId: Long,
+    @Column(name = "session_title", nullable = true, length = 100)
+    var sessionTitle: String? = null,
+    @Column(name = "created_at", nullable = false)
+    val createdAt: ZonedDateTime = ZonedDateTime.now(ZoneId.of("Asia/Seoul")),
+)

src/main/kotlin/com/back/koreaTravelGuide/domain/ai/aiChat/entity/ChatHistory.kt

@@ -0,0 +1,6 @@
+package com.back.koreaTravelGuide.domain.ai.aiChat.entity
+
+enum class SenderType {
+    USER,
+    AI,
+}