Merge pull request #29 from wafflestudio/pagnation

페이지네이션 구현

snuvote/app/vote/dto/responses.py

@@ -55,7 +55,7 @@ def from_vote_user(vote: Vote, user: User) -> "VotesListInfoResponse":
 class OnGoingVotesListResponse(BaseModel):
     votes_list: List[VotesListInfoResponse]
     has_next: bool
-    next_cursor: str|None = None
+    next_cursor: datetime|None = None
 
 class ChoiceDetailResponse(BaseModel):
     choice_id: int

snuvote/app/vote/service.py

@@ -43,8 +43,8 @@ def add_vote(self,
                                         choices=choices)
 
     # 진행 중인 투표 리스트 조회
-    def get_ongoing_list(self) -> List[Vote]:
-        return self.vote_store.get_ongoing_list()
+    def get_ongoing_list(self, start_cursor: datetime|None) -> tuple[List[Vote], bool, datetime|None]:
+        return self.vote_store.get_ongoing_list(start_cursor)
 
     # 투표글 상세 내용 조회
     def get_vote_by_vote_id(self, vote_id: int) -> Vote:

snuvote/app/vote/store.py

@@ -56,8 +56,30 @@ def add_vote(self,
         return vote
 
     # 진행 중인 투표 리스트 조회
-    def get_ongoing_list(self) -> List[Vote]:
-        return self.session.execute(select(Vote).where(Vote.end_datetime > datetime.now(timezone.utc))).scalars().all()
+    def get_ongoing_list(self, start_cursor: datetime|None) -> tuple[List[Vote], bool, datetime|None]:
+
+        #커서가 none이면 가장 최신 것부터 40개
+        if start_cursor is None:
+            start_cursor = datetime.now(timezone.utc)
+
+        #생성 시간이 커서보다 최신인 것부터 오름차순(최신순)으로 40개 리턴
+        query = (
+            select(Vote)
+            .where(Vote.create_datetime < start_cursor)
+            .where(Vote.end_datetime > datetime.now(timezone.utc))
+            .order_by(Vote.create_datetime.desc())
+            .limit(40)
+        )
+
+        results = self.session.execute(query).scalars().all()
+
+        #만약 40개를 꽉 채웠다면 추가 내용이 있을 가능성 있음
+        has_next = len(results) == 40
+
+        #다음 커서는 40개 중 가장 과거에 생성된 것
+        next_cursor = results[-1].create_datetime if has_next else None
+
+        return results, has_next, next_cursor
 
     # 투표글 상세 내용 조회
     def get_vote_by_vote_id(self, vote_id: int) -> Vote:

snuvote/app/vote/views.py

@@ -8,6 +8,7 @@
 from snuvote.app.vote.dto.requests import CreateVoteRequest, ParticipateVoteRequest, CommentRequest
 from snuvote.app.vote.dto.responses import OnGoingVotesListResponse, VotesListInfoResponse, VoteDetailResponse, ChoiceDetailResponse, CommentDetailResponse
 from snuvote.app.vote.errors import VoteNotFoundError, MultipleChoicesError, ChoiceNotFoundError, CommentNotFoundError
+from datetime import datetime, timedelta, timezone
 
 from snuvote.database.models import User
 from snuvote.app.vote.service import VoteService
@@ -45,13 +46,14 @@ def create_vote(
 @vote_router.get("/ongoing_list", status_code=HTTP_200_OK)
 def get_ongoing_list(
     user: Annotated[User, Depends(login_with_access_token)],
-    vote_service: Annotated[VoteService, Depends()]
+    vote_service: Annotated[VoteService, Depends()],
+    start_cursor: datetime|None = None
 ):
-    votes = vote_service.get_ongoing_list()
+    votes, has_next, next_cursor = vote_service.get_ongoing_list(start_cursor)
     return OnGoingVotesListResponse(
-        votes_list = list(reversed([ VotesListInfoResponse.from_vote_user(vote, user) for vote in votes])),
-        has_next = True,
-        next_cursor = 'next_cursor'
+        votes_list = list([ VotesListInfoResponse.from_vote_user(vote, user) for vote in votes]),
+        has_next = has_next,
+        next_cursor = next_cursor
     )