from datetime import datetime, timedelta, timezone
from typing import Iterable
from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from jose import jwt, JWTError
from passlib.context import CryptContext
from sqlmodel import Session, select
from .config import settings
from .db import get_session
from .models import User, Role

pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/api/auth/login")

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

def verify_password(password: str, password_hash: str) -> bool:
    return pwd_context.verify(password, password_hash)

def create_access_token(user: User) -> str:
    exp = datetime.now(timezone.utc) + timedelta(minutes=settings.access_token_expire_minutes)
    return jwt.encode({"sub": str(user.id), "tenant_id": user.tenant_id, "role": user.role.value, "exp": exp}, settings.secret_key, algorithm="HS256")

def get_current_user(token: str = Depends(oauth2_scheme), session: Session = Depends(get_session)) -> User:
    try:
        payload = jwt.decode(token, settings.secret_key, algorithms=["HS256"])
        user_id = int(payload["sub"])
    except (JWTError, KeyError, ValueError):
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid token")
    user = session.get(User, user_id)
    if not user or not user.is_active:
        raise HTTPException(status_code=401, detail="Inactive or missing user")
    return user

def require_roles(*roles: Role):
    def dep(user: User = Depends(get_current_user)) -> User:
        if roles and user.role not in roles:
            raise HTTPException(status_code=403, detail="Insufficient role")
        return user
    return dep

WRITE_ROLES = (Role.owner, Role.compliance_manager, Role.it_manager)
ADMIN_ROLES = (Role.owner,)