From f53c12317c659d7f8b389a4c6a5a3c0437776398 Mon Sep 17 00:00:00 2001
From: ihun-il <hunil9978@gmail.com>
Date: Wed, 4 Dec 2024 21:42:02 +0900
Subject: [PATCH] =?UTF-8?q?feat:=20No=20offset=20=EB=B0=A9=EC=8B=9D?=
 =?UTF-8?q?=EC=9D=98=20=EC=B1=84=ED=8C=85=20=EC=A1=B0=ED=9A=8C?=
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---
 .../chat/repository/ChatCustomRepository.java |  9 ++++
 .../repository/ChatCustomRepositoryImpl.java  | 52 +++++++++++++++++++
 2 files changed, 61 insertions(+)
 create mode 100644 src/main/java/com/palettee/chat/repository/ChatCustomRepository.java
 create mode 100644 src/main/java/com/palettee/chat/repository/ChatCustomRepositoryImpl.java

diff --git a/src/main/java/com/palettee/chat/repository/ChatCustomRepository.java b/src/main/java/com/palettee/chat/repository/ChatCustomRepository.java
new file mode 100644
index 0000000..425fa9f
--- /dev/null
+++ b/src/main/java/com/palettee/chat/repository/ChatCustomRepository.java
@@ -0,0 +1,9 @@
+package com.palettee.chat.repository;
+
+import com.palettee.chat.controller.dto.response.ChatCustomResponse;
+
+import java.time.LocalDateTime;
+
+public interface ChatCustomRepository {
+    ChatCustomResponse findChatNoOffset(Long chatRoomId, int size, LocalDateTime lastTimeStamp);
+}
diff --git a/src/main/java/com/palettee/chat/repository/ChatCustomRepositoryImpl.java b/src/main/java/com/palettee/chat/repository/ChatCustomRepositoryImpl.java
new file mode 100644
index 0000000..1226f86
--- /dev/null
+++ b/src/main/java/com/palettee/chat/repository/ChatCustomRepositoryImpl.java
@@ -0,0 +1,52 @@
+package com.palettee.chat.repository;
+
+import com.palettee.chat.controller.dto.response.ChatCustomResponse;
+import com.palettee.chat.domain.Chat;
+import com.querydsl.jpa.impl.JPAQueryFactory;
+import org.springframework.stereotype.Repository;
+
+import java.time.LocalDateTime;
+import java.util.List;
+
+import static com.palettee.chat.domain.QChat.*;
+import static com.palettee.chat.domain.QChatImage.*;
+import static com.palettee.chat_room.domain.QChatRoom.*;
+import static com.palettee.user.domain.QUser.*;
+
+@Repository
+public class ChatCustomRepositoryImpl implements ChatCustomRepository{
+    private final JPAQueryFactory queryFactory;
+
+    public ChatCustomRepositoryImpl(JPAQueryFactory queryFactory) {
+        this.queryFactory = queryFactory;
+    }
+
+    @Override
+    public ChatCustomResponse findChatNoOffset(Long chatRoomId, int size, LocalDateTime sendAt) {
+        List<Chat> chats = queryFactory
+                .selectFrom(chat)
+                .where(
+                        chat.chatRoom.id.eq(chatRoomId),
+                        sendAt != null ?
+                                chat.sendAt.lt(sendAt) : null
+                )
+                .leftJoin(chat.chatImages, chatImage).fetchJoin()
+                .leftJoin(chat.user, user).fetchJoin()
+                .leftJoin(chat.chatRoom, chatRoom).fetchJoin()
+                .orderBy(chat.sendAt.desc())
+                .limit(size + 1)
+                .fetch();
+
+        boolean hasNext = chats.size() > size;
+
+        LocalDateTime lastSendAt = null;
+        if(hasNext) {
+            if(size != 0) {
+                lastSendAt = chats.get(size-1).getSendAt();
+            }
+            chats = chats.subList(0, size);
+        }
+
+        return ChatCustomResponse.toResponseFromEntity(chats, hasNext, lastSendAt);
+    }
+}