pip install "python-jose[cryptography]" "passlib[bcrypt]" python-multipart

# app/core/security.py
from datetime import datetime, timedelta, timezone
from passlib.context import CryptContext
from jose import jwt, JWTError

pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")

SECRET_KEY = "change-me-en-production"  # à charger depuis les settings, jamais en dur
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


def hash_password(password: str) -> str:
    return pwd_context.hash(password)


def verify_password(plain: str, hashed: str) -> bool:
    return pwd_context.verify(plain, hashed)


def create_access_token(data: dict, expires_delta: timedelta | None = None) -> str:
    to_encode = data.copy()
    expire = datetime.now(timezone.utc) + (expires_delta or timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES))
    to_encode.update({"exp": expire})
    return jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)


def decode_access_token(token: str) -> dict:
    try:
        return jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
    except JWTError:
        raise ValueError("Token invalide ou expiré")

# app/routers/auth.py — endpoint de login compatible OAuth2PasswordRequestForm
from fastapi import APIRouter, Depends, HTTPException, status
from fastapi.security import OAuth2PasswordRequestForm
from typing import Annotated
from sqlalchemy.orm import Session

router = APIRouter(prefix="/auth", tags=["auth"])


@router.post("/login")
def login(
    form_data: Annotated[OAuth2PasswordRequestForm, Depends()],
    db: Annotated[Session, Depends(get_db)],
):
    user = db.query(User).filter(User.email == form_data.username).first()

    if not user or not verify_password(form_data.password, user.hashed_password):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Email ou mot de passe incorrect",
            headers={"WWW-Authenticate": "Bearer"},
        )

    access_token = create_access_token(data={"sub": str(user.id), "role": user.role})
    return {"access_token": access_token, "token_type": "bearer"}

# app/dependencies.py — dépendance pour extraire l'utilisateur courant depuis le token
from fastapi.security import OAuth2PasswordBearer
from fastapi import Depends, HTTPException, status
from typing import Annotated

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="auth/login")  # utilisé par Swagger UI pour le bouton "Authorize"


def get_current_user(
    token: Annotated[str, Depends(oauth2_scheme)],
    db: Annotated[Session, Depends(get_db)],
) -> User:
    try:
        payload = decode_access_token(token)
        user_id = int(payload.get("sub"))
    except (ValueError, TypeError):
        raise HTTPException(status_code=401, detail="Token invalide")

    user = db.get(User, user_id)
    if not user:
        raise HTTPException(status_code=401, detail="Utilisateur introuvable")
    return user

# Utilisation dans un endpoint protégé
@router.get("/me")
def read_current_user(current_user: Annotated[User, Depends(get_current_user)]):
    return {"id": current_user.id, "email": current_user.email}

# Refresh token — renouveler l'access token sans redemander les identifiants
REFRESH_SECRET_KEY = "autre-secret-pour-le-refresh"


def create_refresh_token(user_id: int) -> str:
    expire = datetime.now(timezone.utc) + timedelta(days=7)
    return jwt.encode({"sub": str(user_id), "exp": expire}, REFRESH_SECRET_KEY, algorithm=ALGORITHM)


@router.post("/refresh")
def refresh_token(refresh_token: str, db: Annotated[Session, Depends(get_db)]):
    try:
        payload = jwt.decode(refresh_token, REFRESH_SECRET_KEY, algorithms=[ALGORITHM])
    except JWTError:
        raise HTTPException(status_code=401, detail="Refresh token invalide")

    user = db.get(User, int(payload["sub"]))
    new_access_token = create_access_token(data={"sub": str(user.id), "role": user.role})
    return {"access_token": new_access_token, "token_type": "bearer"}