新增点赞收藏功能：cloud_favorites 模型、查询/设置点赞状态及收藏列表接口

app/routers/favorites.py

@@ -0,0 +1,178 @@
+import math
+import uuid
+
+from fastapi import APIRouter, HTTPException, Query, status
+from sqlalchemy import delete, func, select
+from sqlalchemy.dialects.postgresql import insert as pg_insert
+from sqlalchemy.dialects.sqlite import insert as sqlite_insert
+from sqlalchemy.orm import joinedload
+
+from app.deps import CurrentUser, DbSession
+from app.models import Cloud, CloudFavorite, User
+from app.schemas import CloudOut, FavoriteIn, FavoriteOut, PageOut
+from app.serializers import cloud_out
+
+
+router = APIRouter(tags=["点赞收藏"])
+
+
+def _cloud_options():
+    return (
+        joinedload(Cloud.user).joinedload(User.profile),
+        joinedload(Cloud.cloud_type),
+    )
+
+
+async def _get_visible_cloud(
+    db: DbSession,
+    cloud_id: uuid.UUID,
+    user: CurrentUser,
+) -> Cloud:
+    result = await db.execute(
+        select(Cloud).options(*_cloud_options()).where(Cloud.id == cloud_id)
+    )
+    cloud = result.scalar_one_or_none()
+    if not cloud:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="图片不存在")
+
+    can_manage = cloud.user_id == user.id or user.profile.role == "admin"
+    if not can_manage and (cloud.status != "approved" or cloud.is_hidden):
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="图片不存在")
+    return cloud
+
+
+async def _favorite_count(db: DbSession, cloud_id: uuid.UUID) -> int:
+    return (
+        await db.scalar(
+            select(func.count())
+            .select_from(CloudFavorite)
+            .where(CloudFavorite.cloud_id == cloud_id)
+        )
+        or 0
+    )
+
+
+async def _is_favorited(db: DbSession, user_id: uuid.UUID, cloud_id: uuid.UUID) -> bool:
+    favorite_id = await db.scalar(
+        select(CloudFavorite.id).where(
+            CloudFavorite.user_id == user_id,
+            CloudFavorite.cloud_id == cloud_id,
+        )
+    )
+    return favorite_id is not None
+
+
+async def _favorite_out(
+    db: DbSession,
+    *,
+    cloud_id: uuid.UUID,
+    user_id: uuid.UUID,
+    favorited: bool | None = None,
+) -> FavoriteOut:
+    if favorited is None:
+        favorited = await _is_favorited(db, user_id, cloud_id)
+    return FavoriteOut(
+        cloud_id=cloud_id,
+        user_id=user_id,
+        favorited=favorited,
+        favorite_count=await _favorite_count(db, cloud_id),
+    )
+
+
+@router.get("/clouds/{cloud_id}/favorite", response_model=FavoriteOut)
+async def get_cloud_favorite(
+    cloud_id: uuid.UUID,
+    user: CurrentUser,
+    db: DbSession,
+    user_id: uuid.UUID | None = Query(
+        None,
+        description="要查询的用户 ID；默认当前登录用户。仅本人或管理员可查他人。",
+    ),
+) -> FavoriteOut:
+    """查询某用户对某张照片的点赞/收藏状态。"""
+    await _get_visible_cloud(db, cloud_id, user)
+
+    target_user_id = user_id or user.id
+    if target_user_id != user.id and user.profile.role != "admin":
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="只能查询自己的喜欢状态",
+        )
+
+    return await _favorite_out(db, cloud_id=cloud_id, user_id=target_user_id)
+
+
+@router.put("/clouds/{cloud_id}/favorite", response_model=FavoriteOut)
+async def set_cloud_favorite(
+    cloud_id: uuid.UUID,
+    payload: FavoriteIn,
+    user: CurrentUser,
+    db: DbSession,
+) -> FavoriteOut:
+    """点赞/收藏照片，或取消。"""
+    await _get_visible_cloud(db, cloud_id, user)
+
+    if payload.favorited:
+        insert_factory = (
+            pg_insert if db.bind and db.bind.dialect.name == "postgresql" else sqlite_insert
+        )
+        await db.execute(
+            insert_factory(CloudFavorite)
+            .values(user_id=user.id, cloud_id=cloud_id)
+            .on_conflict_do_nothing(
+                index_elements=[CloudFavorite.user_id, CloudFavorite.cloud_id]
+            )
+        )
+    else:
+        await db.execute(
+            delete(CloudFavorite).where(
+                CloudFavorite.user_id == user.id,
+                CloudFavorite.cloud_id == cloud_id,
+            )
+        )
+
+    await db.commit()
+    return await _favorite_out(
+        db,
+        cloud_id=cloud_id,
+        user_id=user.id,
+        favorited=payload.favorited,
+    )
+
+
+@router.get("/favorites/me", response_model=PageOut[CloudOut])
+async def list_my_favorites(
+    user: CurrentUser,
+    db: DbSession,
+    page: int = Query(1, ge=1),
+    page_size: int = Query(50, ge=1, le=100),
+) -> PageOut[CloudOut]:
+    """当前用户点赞收藏的照片列表（按收藏时间倒序）。"""
+    total = (
+        await db.scalar(
+            select(func.count())
+            .select_from(CloudFavorite)
+            .where(CloudFavorite.user_id == user.id)
+        )
+        or 0
+    )
+    result = await db.execute(
+        select(Cloud)
+        .join(CloudFavorite, CloudFavorite.cloud_id == Cloud.id)
+        .options(*_cloud_options())
+        .where(CloudFavorite.user_id == user.id)
+        .order_by(CloudFavorite.created_at.desc(), CloudFavorite.id.desc())
+        .offset((page - 1) * page_size)
+        .limit(page_size)
+    )
+    items = [
+        cloud_out(item, include_private=item.user_id == user.id or user.profile.role == "admin")
+        for item in result.scalars().unique().all()
+    ]
+    return PageOut(
+        items=items,
+        page=page,
+        page_size=page_size,
+        total=total,
+        total_pages=max(1, math.ceil(total / page_size)) if total else 1,
+    )