refactor the crud & paginate

backend/app/core/common.py

@@ -1,10 +1,43 @@
 
+import math
+from fastapi import Query
+from fastapi_pagination.bases import  AbstractPage,AbstractParams,RawParams
 from pydantic import BaseModel
-from typing import Generic,TypeVar,Optional
+from typing import Generic, List,TypeVar,Generic,Sequence
+from fastapi_pagination import  Page,utils
 
 T = TypeVar('T')
 
 class ApiReturnModel(BaseModel,Generic[T]):
     code:int = 0
     msg:str ="OK"
-    data:T
+    data:T
+
+class Params(BaseModel, AbstractParams):
+    page:int = Query(1,get=1, description="Page number")
+    size:int = Query(20,get=0, le=100,description="Page size")
+
+    def to_raw_params(self) -> RawParams:
+        return RawParams(
+            limit=self.size,
+            offset=self.size*(self.page-1)
+            )
+    
+class ApiReturnPage(AbstractPage[T],Generic[T]):
+    code:int =0
+    msg:str ="OK"
+    data:Sequence[T]
+    total:int
+    page:int
+    size:int
+    # next:str
+    # previous:str
+    total_pages:int
+
+    __params_type__ =Params
+
+    @classmethod
+    def create(cls,items:Sequence[T],total:int,params:Params) -> Page[T]:
+        total_pages = math.ceil(total/params.size)
+    
+        return utils.create_pydantic_model(cls,data=items,total=total,page=params.page,size=params.size,total_pages=total_pages)