"""Unit tests for the dual-read env helper (core/env.py, D-108, REQ-159).

Covers the four cases:
  - both NOVA_* and ACDL_* set (NOVA wins)
  - only NOVA_* set
  - only ACDL_* set (fallback)
  - neither set (default returned)

The ACDL_* fallback is the intentional dual-read source and is removed
in P5 (REQ-164). These fixtures deliberately keep the ACDL_* names as
the fallback source — they are the one allowed ACDL_* reference.
"""

from __future__ import annotations

import pytest

from core import env


@pytest.fixture(autouse=True)
def _isolate_env(monkeypatch):
    """Ensure no ACDL_*/NOVA_* leakage between tests."""
    for key in list(__import__("os").environ):
        if key.startswith(("ACDL_", "NOVA_")):
            monkeypatch.delenv(key, raising=False)
    yield


def test_both_set_nova_wins(monkeypatch):
    monkeypatch.setenv("NOVA_AWS_ACCOUNT_ID", "nova-value")
    monkeypatch.setenv("ACDL_AWS_ACCOUNT_ID", "acdl-value")
    assert env.get_env("AWS_ACCOUNT_ID") == "nova-value"


def test_only_nova_set(monkeypatch):
    monkeypatch.setenv("NOVA_AWS_ACCOUNT_ID", "nova-value")
    assert env.get_env("AWS_ACCOUNT_ID") == "nova-value"


def test_only_acdl_set_fallback(monkeypatch):
    # ACDL_* is the intentional dual-read fallback source (removed in P5).
    monkeypatch.setenv("ACDL_AWS_ACCOUNT_ID", "acdl-value")
    assert env.get_env("AWS_ACCOUNT_ID") == "acdl-value"


def test_neither_set_returns_default():
    assert env.get_env("AWS_ACCOUNT_ID") is None
    assert env.get_env("AWS_ACCOUNT_ID", default="581513795199") == "581513795199"


def test_blank_nova_falls_back_to_acdl(monkeypatch):
    # An explicitly-empty NOVA key must not shadow the ACDL fallback.
    monkeypatch.setenv("NOVA_AWS_ACCOUNT_ID", "")
    monkeypatch.setenv("ACDL_AWS_ACCOUNT_ID", "acdl-value")
    assert env.get_env("AWS_ACCOUNT_ID") == "acdl-value"