"""The .env loader, which is only interesting where it disagrees with itself.

These tests exist because of one real incident: the Docker image declares
``ENV DASHSCOPE_API_KEY=`` so the variable shows up in ``docker inspect`` and can
be overridden at ``docker run``. That left it set-but-empty inside every container,
where it shadowed the mounted .env file. Every OCR page failed with "No API key",
the pipeline fell back page by page as designed, and a 25-page run finished
successfully having stored nothing.
"""
from __future__ import annotations

from pathlib import Path

from leanbench.config import load_dotenv


def write_env(directory: Path, body: str) -> Path:
    path = directory / ".env"
    path.write_text(body, encoding="utf-8")
    return path


def test_an_empty_variable_does_not_shadow_the_file(tmp_path: Path, monkeypatch) -> None:
    """The incident, in one assertion."""
    monkeypatch.setenv("LEANBENCH_TEST_KEY", "")
    load_dotenv(write_env(tmp_path, "LEANBENCH_TEST_KEY=from-file\n"))
    import os

    assert os.environ["LEANBENCH_TEST_KEY"] == "from-file"


def test_a_real_value_still_wins(tmp_path: Path, monkeypatch) -> None:
    """Overriding at the command line must keep working -- that is the whole point."""
    monkeypatch.setenv("LEANBENCH_TEST_KEY", "from-environment")
    load_dotenv(write_env(tmp_path, "LEANBENCH_TEST_KEY=from-file\n"))
    import os

    assert os.environ["LEANBENCH_TEST_KEY"] == "from-environment"


def test_an_unset_variable_is_taken_from_the_file(tmp_path: Path, monkeypatch) -> None:
    monkeypatch.delenv("LEANBENCH_TEST_KEY", raising=False)
    load_dotenv(write_env(tmp_path, "LEANBENCH_TEST_KEY=from-file\n"))
    import os

    assert os.environ["LEANBENCH_TEST_KEY"] == "from-file"


def test_comments_blanks_and_quotes(tmp_path: Path, monkeypatch) -> None:
    monkeypatch.delenv("LEANBENCH_A", raising=False)
    monkeypatch.delenv("LEANBENCH_B", raising=False)
    monkeypatch.delenv("LEANBENCH_C", raising=False)
    load_dotenv(write_env(tmp_path, """
# a comment
LEANBENCH_A = "quoted value"

LEANBENCH_B='single'
not a pair
LEANBENCH_C=has=equals=inside
"""))
    import os

    assert os.environ["LEANBENCH_A"] == "quoted value"
    assert os.environ["LEANBENCH_B"] == "single"
    assert os.environ["LEANBENCH_C"] == "has=equals=inside"


def test_a_missing_file_is_not_an_error(tmp_path: Path) -> None:
    load_dotenv(tmp_path / "nope.env")