app/api/auth.py

from fastapi import APIRouter, Depends, HTTPException, status, Form, Body
from fastapi.security import OAuth2PasswordBearer, OAuth2PasswordRequestForm
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select
from sqlalchemy.orm import selectinload
from ..core.security import create_access_token, verify_password, get_password_hash
from ..db.database import get_db
from ..db.models import User
from ..db.schemas import UserCreate, UserInDB, LoginData
from datetime import timedelta
from typing import Any

router = APIRouter()
oauth2_scheme = OAuth2PasswordBearer(tokenUrl="token")

@router.post("/login/form")
async def login_form(
    form_data: OAuth2PasswordRequestForm = Depends(),
    db: AsyncSession = Depends(get_db)
) -> Any:
    return await authenticate_user(db, form_data.username, form_data.password)

@router.post("/login")
async def login_json(
    login_data: LoginData,
    db: AsyncSession = Depends(get_db)
) -> Any:
    return await authenticate_user(db, login_data.email, login_data.password)

async def authenticate_user(db: AsyncSession, email: str, password: str) -> dict:
    stmt = select(User).where(User.email == email)
    result = await db.execute(stmt)
    user = result.scalar_one_or_none()
    
    if not user:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Incorrect email or password",
        )
    
    if not verify_password(password, user.hashed_password):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Incorrect email or password",
        )
    
    access_token = create_access_token(user.id)
    return {"access_token": access_token, "token_type": "bearer"}

@router.post("/register", response_model=UserInDB)
async def register(
    user_data: UserCreate,
    db: AsyncSession = Depends(get_db)
) -> Any:
    # Check if user exists by email
    stmt = select(User).where(User.email == user_data.email)
    result = await db.execute(stmt)
    if result.scalar_one_or_none():
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Email already registered",
        )

    # Extract username from email if not provided
    username = user_data.username or user_data.email.split('@')[0]

    # Create new user
    user = User(
        email=user_data.email,
        username=username,
        full_name=user_data.full_name,
        hashed_password=get_password_hash(user_data.password),
        is_active=user_data.is_active,
        is_superuser=user_data.is_superuser,
        branch_id=user_data.branch_id
    )

    db.add(user)
    await db.commit()
    
    # Refresh user with roles relationship loaded
    stmt = select(User).options(selectinload(User.roles)).where(User.id == user.id)
    result = await db.execute(stmt)
    user = result.scalar_one()

    return user