from typing import Optional, List
from sqlmodel import Session
from sqlmodel import SQLModel, select
from pydantic import RootModel
from sqlmodel import Field, Relationship
from datetime import datetime


class PostBase(SQLModel):
    content: str
    timestamp: datetime

    # model_config = ConfigDict(from_attributes=True)


class UserBase(SQLModel):
    username: str
    display_name: str

    # model_config = ConfigDict(from_attributes=True)


class Post(PostBase, table=True):
    id: Optional[int] = Field(default=None, primary_key=True)
    user_id: int = Field(foreign_key="user.id")
    user: Optional["User"] = Relationship(back_populates="posts")


class User(UserBase, table=True):
    id: Optional[int] = Field(default=None, primary_key=True)
    posts: List[Post] = Relationship(back_populates="user")

    @classmethod
    def get_all(cls, session: Session) -> List["User"]:
        statement = select(cls)  # .options(selectinload(cls.posts))
        users = session.exec(statement).all()
        return users


# Pydantic response models
class PostRead(PostBase):
    id: int
    user_id: int


class PostReadWithUser(PostRead):
    user: "UserRead"


class PostsRead(RootModel[List[PostRead]]): ...


class UserRead(UserBase):
    id: int


class UserWithRecentPosts(UserRead):
    recent_posts: List[PostRead]


class UserReadWithPosts(UserRead):
    posts: List[PostRead] = []


# PostRead.update_forward_refs()
# UserRead.update_forward_refs()