main.py

from fastapi import FastAPI,HTTPException,Depends,status
from pydantic import BaseModel
from typing import List,Annotated
import models
from database import engine,SessionLocal
from sqlalchemy.orm import Session

#our app 
app = FastAPI()
models.Base.metadata.create_all(bind=engine)

class PostBase(BaseModel): 
    title: str
    content: str
    user_id: int

#Validate and return the response corret !

class UserBase(BaseModel):
    username: str 

def get_db():
    db = SessionLocal()
    try:
        yield db 
    finally:
        db.close()

#for Dependecy Injection Creating IAnottation

db_dependency = Annotated[Session,Depends(get_db)]

#apiEndpoint
@app.post("/posts/",status_code=status.HTTP_201_CREATED)
async def create_post(post:PostBase, db: db_dependency):
    db_post = models.Post(**post.dict())
    db.add(db_post)
    db.commit()

@app.get("/posts/{post_id}",status_code=status.HTTP_200_OK)
async def read_post(post_id:int, db: db_dependency):
    post = db.query(models.Post).filter(models.Post.id == post_id).first()
    if post is None:
       raise HTTPException(status_code=404,detail='post was not found')
    return post


@app.delete("/posts/{post_id}",status_code=status.HTTP_200_OK)
async def delete_post(post_id:int, db:db_dependency):
    db_post = db.query(models.Post).filter(models.Post.id == post_id).first()
    if db_post is None:
        raise HTTPException(status_code= 404,detail='Post not found')
    db.delete(db_post)
    db.commit()

@app.post("/users/",status_code=status.HTTP_201_CREATED)
async def create_user(user: UserBase,db: db_dependency):
    db_user = models.User(**user.dict())
    db.add(db_user)
    db.commit()


@app.get("/users/{users_id}",status_code=status.HTTP_200_OK)
async def read_user(user_id:int,db: db_dependency):
    user = db.query(models.User).filter(models.User.id == user_id).first()
    if user is None:
        raise HTTPException(status_code=404,detail='User not found')
    return  user

@app.delete("/users/{user_id}", status_code=status.HTTP_200_OK)
async def delete_user(user_id: int, db: db_dependency):
    db_user = db.query(models.User).filter(models.User.id == user_id).first()
    if db_user is None:
        raise HTTPException(status_code=404, detail='User not found')
    db.delete(db_user)
    db.commit()