from pydantic import BaseModel
from datetime import datetime
from typing import Optional

class MembershipBase(BaseModel):
    company_code: str
    level: int
    start_date: datetime
    end_date: datetime

class MembershipCreate(MembershipBase):
    pass

class MembershipUpdate(BaseModel):
    level: Optional[int] = None
    start_date: Optional[datetime] = None
    end_date: Optional[datetime] = None

class MembershipResponse(MembershipBase):
    id: int
    created_at: datetime
    updated_at: Optional[datetime] = None
    
    class Config:
        from_attributes = True