from datetime import datetime, timedelta, timezone
from fastapi import Depends, HTTPException, status
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
from jose import jwt, JWTError
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select
from app.config import settings
from app.database import get_db
from app.models import Usuario, Rol

security = HTTPBearer()


async def get_current_user(
    credentials: HTTPAuthorizationCredentials = Depends(security),
    db: AsyncSession = Depends(get_db),
) -> Usuario:
    token = credentials.credentials
    try:
        payload = jwt.decode(token, settings.SECRET_KEY, algorithms=[settings.ALGORITHM])
        user_id: str = payload.get("sub")
        if user_id is None:
            raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Token invalido")
    except JWTError:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Token invalido o expirado")

    result = await db.execute(select(Usuario).where(Usuario.id == user_id))
    user = result.scalar_one_or_none()
    if user is None:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Usuario no encontrado")
    if not user.activo:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Usuario inactivo")
    return user


def create_access_token(user_id: str, rol_id: int, pais_id: int | None = None) -> str:
    expire = datetime.now(timezone.utc) + timedelta(minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES)
    payload = {
        "sub": user_id,
        "rol": rol_id,
        "pais_id": pais_id,
        "exp": expire,
    }
    return jwt.encode(payload, settings.SECRET_KEY, algorithm=settings.ALGORITHM)


async def get_user_permissions(user: Usuario, db: AsyncSession) -> list[int]:
    result = await db.execute(
        select(Rol.id, Rol.nombre).where(Rol.id == user.rol)
    )
    return result.scalar_one_or_none()