from typing import Optional, Union
from fastapi import FastAPI, Depends, HTTPException
from sqlmodel import Field, Session, SQLModel, create_engine, select


class ActiveRecord(SQLModel):
    @classmethod
    def by_id(cls, id: int, session):
        obj = session.get(cls, id)
        if obj is None:
            raise HTTPException(status_code=404, detail=f"{cls.__name__} with id {id} not found")
        return obj

    @classmethod
    def all(cls, session):
        return session.exec(select(cls)).all()

    @classmethod
    def create(cls, source: Union[dict, SQLModel], session):
        if isinstance(source, SQLModel):
            obj = cls.from_orm(source)
        elif isinstance(source, dict):
            obj = cls.parse_obj(source)
        session.add(obj)
        session.commit()
        session.refresh(obj)
        return obj

    def save(self, session):
        session.add(self)
        session.commit()
        session.refresh(self)

    def update(self, source: Union[dict, SQLModel], session):
        if isinstance(source, SQLModel):
            source = source.dict(exclude_unset=True)

        for key, value in source.items():
            setattr(self, key, value)
        self.save(session)

    def delete(self, session):
        session.delete(self)
        session.commit()


class HeroBase(SQLModel):
    name: str = Field(index=True)
    secret_name: str
    age: Optional[int] = Field(default=None, index=True)

class HeroCreate(HeroBase):
    pass

class HeroRead(HeroBase):
    id: int

class HeroUpdate(SQLModel):
    name: Optional[str] = None
    secret_name: Optional[str] = None
    age: Optional[int] = None

class Hero(HeroBase, ActiveRecord, table=True):
    id: Optional[int] = Field(default=None, primary_key=True)


sqlite_file_name = "database.db"
sqlite_url = f"sqlite:///{sqlite_file_name}"

connect_args = {"check_same_thread": False}
engine = create_engine(sqlite_url, echo=True, connect_args=connect_args)


def create_db_and_tables():
    SQLModel.metadata.create_all(engine)

def get_session():
    with Session(engine) as session:
        yield session


app = FastAPI()

@app.on_event("startup")
def on_startup():
    create_db_and_tables()

@app.post("/heroes/", response_model=HeroRead)
def create_hero(hero: HeroCreate, session: Session = Depends(get_session)):
    return Hero.create(hero, session)

@app.get("/heroes/", response_model=list[HeroRead])
def read_heroes(session: Session = Depends(get_session)):
    return Hero.all(session)

@app.get("/heroes/{id}", response_model=HeroRead)
def read_heroes(id: int, session: Session = Depends(get_session)):
    return Hero.by_id(id, session)

@app.patch("/heroes/{id}", response_model=HeroRead)
def read_heroes(id: int, hero: HeroUpdate, session: Session = Depends(get_session)):
    db_hero = Hero.by_id(id, session)
    db_hero.update(hero, session)
    return db_hero