from datetime import date
from typing import Any, Generator, TypeVar

from django.apps import apps
from django.db.models import Model


def safe_division(numerator: int | float, denominator: int | float) -> int | float:
    """
    Divides without triggering division by zero exception.
    Returns 0 if denominator is 0.
    """
    try:
        return numerator / denominator
    except ZeroDivisionError:
        return 0


def safe_getattr(obj: object, attr_chain: str, default: Any | None = None) -> object:
    """
    Safely get the nested attribute from an object.

    Parameters:
    obj (object): The object from which to retrieve the attribute.
    attr_chain (str): The chain of attributes, separated by dots.
    default: The default value to return if any attribute in the chain does not exist.

    Returns:
    The value of the nested attribute if it exists, otherwise the default value.
    """
    attrs = attr_chain.split(".")
    for attr in attrs:
        try:
            obj = getattr(obj, attr)
        except AttributeError:
            return default
    return obj


def truncate(input_string: str, length: int = 30, ellipsis: str = "…") -> str:
    return (
        (f"{input_string[:length-len(ellipsis)]}{ellipsis}")
        if len(input_string) > 30
        else input_string
    )


T = TypeVar("T", str, int, date)


def generate_split_ranges(
    value_list: list[T], split_points: list[T]
) -> Generator[tuple[T, T], None, None]:
    for x in range(0, len(split_points) + 1):
        if x == 0:
            start = 0
        elif x >= len(split_points):
            start = value_list.index(split_points[x - 1]) + 1
        else:
            start = value_list.index(split_points[x - 1]) + 1
        try:
            end = value_list.index(split_points[x])
        except IndexError:
            end = len(value_list)
        yield (value_list[start], value_list[end - 1])


def format_float_or_int(number: int | float):
    return int(number) if float(number).is_integer() else f"{number:03.2f}"


def get_model_by_string(app_label: str, model_name: str):
    return apps.get_model(app_label, model_name)


def get_field(model: Model, field_name: str):
    field = model._meta.get_field(field_name)
    return field


def get_field_type(model: Model, field_name: str):
    field = model._meta.get_field(field_name)
    return type(field)