Di Formatting

1"""Shared rendering primitives used by every ``*_rendering.py`` module.
2
3These convert raw AWS API values into the human-readable shapes that operation responses depend on.
4"""
5
6from datetime import datetime, timezone
7from typing import Any
8
9
10def format_timestamp(value: Any, default: str = "N/A") -> str:
11    """Render a boto3 ``datetime`` value in the AWS-CLI ISO format.
12
13    boto3 returns timestamp fields as native ``datetime`` objects;
14    AWS-CLI-era responses are ISO 8601 strings (``YYYY-MM-DDTHH:MM:SSZ``).
15    callers depend on the latter shape, so anywhere a renderer surfaces
16    an AWS-returned timestamp, it must go through this helper.
17
18    String inputs are passed through unchanged so renderers can safely
19    accept either shape (e.g. tests that hand-roll ISO strings).
20    """
21    if value is None or value == "":
22        return default
23    if isinstance(value, datetime):
24        return value.astimezone(timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ")
25    return str(value)