"""S2.5 (Step 9) consolidation guard (T-2.5e): the four scripted ``_inner_get_response`` bodies
collapsed to ONE canonical client (``simulation.ScriptedChatClient``); conftest's three test doubles
now SUBCLASS it. These grep-guards lock that in — they go RED if a divergent ``_inner_get_response``
is re-added, if a ``src``→``tests`` import creeps in, or if a double stops subclassing the canonical.

The guard is a regression lock over an already-verified consolidation: before the collapse there were
five ``def _inner_get_response`` sites (four scripted + test_step5's own-lineage double); after, two.
"""

from __future__ import annotations

import re
from pathlib import Path

_ROOT = Path(__file__).resolve().parents[1]


def _py_files(base: str) -> list[Path]:
    return sorted((_ROOT / base).rglob("*.py"))


# Files permitted to define ``_inner_get_response``. The invariant this guard protects is that the
# scripted BODY is not duplicated — not that the def-site count is frozen. Adding a file here is a
# deliberate act: a new entry must either be the canonical, or a thin override that DELEGATES to it
# (which ``test_delegating_overrides_call_super`` below then enforces mechanically).
_CANONICAL_SITE = "src/portfolio_optimiser/simulation.py"

# Overrides in the SCRIPTED lineage — they subclass ``ScriptedChatClient``, so a body of their own
# would be a copy of the canonical. They must delegate.
_DELEGATING_OVERRIDES = [
    # S3.3 ordering probe: yields to the event loop N times, then delegates. It cannot live in the
    # reply-selector seam, which the canonical calls synchronously and so can never await.
    "tests/test_portfolio_concurrent_loadbearing.py",
    # S3.3 failure-accounting probe: RAISES for one project (after N completed calls), otherwise
    # delegates. Like the ordering probe it cannot live in the reply-selector seam — that seam
    # returns a reply string, and this double's whole subject is the absence of one.
    "tests/test_portfolio_failure_accounting_loadbearing.py",
]

# Doubles in a DIFFERENT lineage (``spikes._harness.FakeChatClient``). There is no canonical
# scripted body above them to delegate to, so the delegation rule does not apply — but the
# separation is asserted rather than assumed, so a file cannot be parked here to dodge the rule.
_FOREIGN_LINEAGE = ["tests/test_step5_refine_loadbearing.py"]


def test_inner_get_response_collapsed_to_two_sites() -> None:
    """The four scripted clients collapse to ONE canonical ``_inner_get_response``
    (``simulation.py``). Every other def-site must be a registered, DELEGATING override — never a
    fourth copy of the body.

    The guard originally pinned a literal count of 2. That made it fail on any new legitimate
    subclass while still passing if someone pasted a duplicated body into an already-listed file —
    a count is the wrong shape for the invariant. The list below plus
    ``test_delegating_overrides_call_super`` pin the property itself."""
    sites = [
        p.relative_to(_ROOT).as_posix()
        for base in ("src", "tests")
        for p in _py_files(base)
        if p.name != Path(__file__).name  # this guard file references the pattern in prose
        and "def _inner_get_response" in p.read_text(encoding="utf-8")
    ]
    expected = sorted([_CANONICAL_SITE, *_DELEGATING_OVERRIDES, *_FOREIGN_LINEAGE])
    assert sorted(sites) == expected, (
        f"unregistered ``_inner_get_response`` def-site — the scripted body must not be copied. "
        f"Expected {expected}, got: {sites}"
    )


def test_foreign_lineage_doubles_are_genuinely_foreign() -> None:
    """A file listed as foreign lineage must NOT subclass the scripted canonical.

    Without this, ``_FOREIGN_LINEAGE`` would be an escape hatch: any scripted-lineage subclass
    could be moved into that list to skip the delegation rule below."""
    for site in _FOREIGN_LINEAGE:
        text = (_ROOT / site).read_text(encoding="utf-8")
        assert "ScriptedChatClient" not in text, (
            f"{site} is registered as foreign lineage but references ``ScriptedChatClient`` — if it "
            "is in the scripted lineage it belongs in _DELEGATING_OVERRIDES and must delegate"
        )


def test_delegating_overrides_call_super() -> None:
    """Every scripted-lineage override actually DELEGATES to the canonical rather than
    reimplementing it.

    This is the strength the literal count never had: without it, a file already on the list could
    grow a full copy of the scripted body and the consolidation would be cosmetic again."""
    for site in _DELEGATING_OVERRIDES:
        text = (_ROOT / site).read_text(encoding="utf-8")
        # Match the delegation ITSELF — ``super()._inner_get_response`` or the explicit
        # ``super(Cls, self)._inner_get_response`` form a nested function needs. Searching for
        # "super(" and "_inner_get_response" independently would pass on any file that merely
        # calls ``super().__init__`` near a def, which is accidental-green, not a guard.
        assert re.search(r"super\([^)]*\)\._inner_get_response", text), (
            f"{site} defines ``_inner_get_response`` but never delegates to the canonical via "
            "``super()._inner_get_response`` — that is a duplicated body, which is exactly what "
            "this guard exists to prevent"
        )


def test_no_src_imports_tests() -> None:
    """No ``src`` module imports from ``tests`` — the canonical lives in ``src/simulation.py`` so
    ``conftest`` imports ``src``, never the reverse (the forbidden src→tests direction)."""
    offenders = [
        p.relative_to(_ROOT).as_posix()
        for p in _py_files("src")
        if ("from tests" in (text := p.read_text(encoding="utf-8")) or "import tests" in text)
    ]
    assert offenders == [], f"src must not import tests: {offenders}"


def test_conftest_doubles_subclass_canonical() -> None:
    """conftest's three test doubles genuinely SUBCLASS the canonical ``ScriptedChatClient``
    (delegating the shared body) — so the consolidation is real, not cosmetic."""
    from conftest import (
        ScriptedChatClient,
        SyntheticUsageChatClient,
        _ProjectAwareUsageChatClient,
        _RecordingChatClient,
    )

    assert issubclass(SyntheticUsageChatClient, ScriptedChatClient)
    assert issubclass(_ProjectAwareUsageChatClient, ScriptedChatClient)
    assert issubclass(_RecordingChatClient, ScriptedChatClient)