Ship Secure Code, Fast

from fastapi import FastAPI, Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from sqlalchemy.orm import Session
from . import models, schemas, security
from .database import engine, get_db
from typing import Optional

# Create database tables
models.Base.metadata.create_all(bind=engine)

app = FastAPI(title="User Management API")

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="token")

@app.post("/signup", response_model=schemas.UserResponse, status_code=status.HTTP_201_CREATED)
async def signup(user: schemas.UserCreate, db: Session = Depends(get_db)):
    # Validate password match
    if user.password != user.confirm_password:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Passwords do not match"
        )
    
    # Check if email already exists
    if db.query(models.User).filter(models.User.email == user.email).first():
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Email already registered"
        )
    
    # Check if username already exists
    if db.query(models.User).filter(models.User.username == user.username).first():
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Username already taken"
        )
    
    # Create new user
    hashed_password = security.get_password_hash(user.password)
    db_user = models.User(
        email=user.email,
        username=user.username,
        hashed_password=hashed_password
    )
    
    try:
        db.add(db_user)
        db.commit()
        db.refresh(db_user)
        return db_user
    except Exception as e:
        db.rollback()
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="An error occurred while creating the user"
        )

@app.get("/")
async def root():
    return {"message": "Welcome to User Management API"}