Source code for eveuniverse.helpers

"""Helper functions and classes for Eve Universe."""

import hashlib
import json
from typing import Any, Dict, Optional

# CCP uses a non-standard factor to calculate light years
# See also: https://gitlab.com/ErikKalkoken/django-eveuniverse/-/issues/16
METERS_PER_LY = 9_460_000_000_000_000




def meters_to_ly(value: float) -> Optional[float]:
    """Convert meters into lightyears."""
    return float(value) / METERS_PER_LY if value is not None else None





def meters_to_au(value: float) -> Optional[float]:
    """Convert meters into AU."""
    return float(value) / 149_597_870_691 if value is not None else None





class EveEntityNameResolver:
    """Container with a mapping between entity Ids and entity names
    and a performant API
    """



    def __init__(self, names_map: Dict[int, str]) -> None:
        self._names_map = names_map




    def to_name(self, id: int) -> str:
        """Resolved an entity ID to a name

        Args:
            id: ID of the Eve entity to resolve

        Returns:
            name for corresponding entity ID if known else an empty string
        """
        try:
            name = self._names_map[id]
        except KeyError:
            name = ""

        return name




def dict_hash(dictionary: Dict[str, Any]) -> str:
    """SHA256 hash of a dictionary.

    :meta private:
    """
    my_hash = hashlib.sha256()
    encoded = json.dumps(dictionary, sort_keys=True).encode(encoding="utf8")
    my_hash.update(encoded)
    return my_hash.hexdigest()