backend/app/api/api_v1/endpoints/auth.py

from typing import Any
from fastapi import APIRouter, Depends, HTTPException, status
from fastapi.security import OAuth2PasswordRequestForm
from sqlalchemy.orm import Session
from ... import deps
from ....core import security
from ....core.config import settings
from ....db.session import get_db
from ....models.user import User
from ....schemas.user import UserCreate, User as UserSchema
from ....schemas.token import Token

router = APIRouter()

@router.post("/register", response_model=dict)
def register(user_in: UserCreate, db: Session = Depends(get_db)):
    # Check if username exists
    user = db.query(User).filter(User.username == user_in.username).first()
    if user:
        raise HTTPException(
            status_code=400,
            detail="The user with this username already exists in the system.",
        )
    # Check if email exists
    user = db.query(User).filter(User.email == user_in.email).first()
    if user:
        raise HTTPException(
            status_code=400,
            detail="The user with this email already exists in the system.",
        )
    
    hashed_password = security.get_password_hash(user_in.password)
    new_user = User(
        username=user_in.username, 
        email=user_in.email,
        hashed_password=hashed_password
    )
    db.add(new_user)
    db.commit()
    return {"message": "User registered successfully"}

@router.post("/token", response_model=Token)
def login_access_token(
    db: Session = Depends(get_db), form_data: OAuth2PasswordRequestForm = Depends()
) -> Any:
    # Treat the username field from the form as email
    user = db.query(User).filter(User.email == form_data.username).first()
    if not user or not security.verify_password(form_data.password, user.hashed_password):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Incorrect email or password",
            headers={"WWW-Authenticate": "Bearer"},
        )
    elif not user.is_active:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Inactive user")
    
    access_token = security.create_access_token(subject=user.email)
    return {"access_token": access_token, "token_type": "bearer"}