from datetime import datetime, timedelta, timezone
from typing import Annotated
from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from jose import jwt, JWTError
from passlib.context import CryptContext
from sqlalchemy.orm import Session
from app.core.config import settings
from app.core.database import get_db
from app.models.admin_user import AdminUser

pwd_ctx = CryptContext(schemes=["bcrypt"], deprecated="auto")
oauth2_scheme_admin = OAuth2PasswordBearer(tokenUrl=f"{settings.admin_api_prefix}/auth/login")

def verify_password(plain, hashed): return pwd_ctx.verify(plain, hashed)
def hash_password(pw): return pwd_ctx.hash(pw)

def create_admin_access_token(sub: str, minutes: int = 60):
    exp = datetime.now(timezone.utc) + timedelta(minutes=minutes)
    payload = {"sub": sub, "role": "admin", "exp": exp}
    return jwt.encode(payload, settings.secret_key, algorithm=settings.algorithm)

def get_current_admin(
    token: Annotated[str, Depends(oauth2_scheme_admin)],
    db: Annotated[Session, Depends(get_db)],
) -> AdminUser:
    cred_exc = HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid admin token")
    try:
        payload = jwt.decode(token, settings.secret_key, algorithms=[settings.algorithm])
        if payload.get("role") != "admin":
            raise cred_exc
        username = payload.get("sub")
    except JWTError:
        raise cred_exc
    user = db.query(AdminUser).filter(AdminUser.username == username, AdminUser.is_active == True).first()
    if not user:
        raise cred_exc
    return user