"""Read the real installer for focused tests; no installation logic is copied."""

from pathlib import Path
from types import ModuleType


ROOT = Path(__file__).resolve().parents[2]
ENTRY = ROOT / "install"


def entry_parts():
    entry = ENTRY.read_text()
    opening = "<<'DEVER_INSTALL_PYTHON'\n"
    closing = "\nDEVER_INSTALL_PYTHON\n"
    if entry.count(opening) != 1 or entry.count(closing) != 1:
        raise ValueError("root install must contain exactly one Python heredoc")
    before, remainder = entry.split(opening)
    source, after = remainder.split(closing)
    return before + opening, source, closing + after


def load_installer():
    _, source, _ = entry_parts()
    module = ModuleType("dever_installer")
    exec(compile(source, str(ENTRY) + "::python", "exec"), module.__dict__)
    return module


def entry_with_python(probe):
    """Keep the actual shell wrapper while a harmless probe observes its contract."""
    before, _, after = entry_parts()
    return before + probe.rstrip("\n") + after