"""Utility functions for the database module."""

from enum import Enum
from typing import Any

import sqlalchemy

from spoolman.database import models


class SortOrder(Enum):
    ASC = 1
    DESC = 2


def parse_nested_field(base_obj: type[models.Base], field: str) -> sqlalchemy.Column[Any]:
    """Parse a nested field string into a sqlalchemy field object."""
    fields = field.split(".")
    if not hasattr(base_obj, fields[0]):
        raise ValueError(f"Invalid field name '{field}'")

    if fields[0] == "filament" and len(fields) == 1:
        raise ValueError("No field specified for filament")
    if fields[0] == "filament":
        return parse_nested_field(models.Filament, ".".join(fields[1:]))

    if fields[0] == "vendor" and len(fields) == 1:
        raise ValueError("No field specified for vendor")
    if fields[0] == "vendor":
        return parse_nested_field(models.Vendor, ".".join(fields[1:]))

    if len(fields) > 1:
        raise ValueError(f"Field '{fields[0]}' does not have any nested fields")

    return getattr(base_obj, fields[0])