"""Unit tests for the runner conftest's skip / xfail enforcement.

We exercise `pytest_collection_modifyitems` directly with a fake config and
a synthetic item list, then assert the post-conditions (marker added, etc.).

This catches regressions where someone changes the skip rules without
updating the traceability matrix — see
`_docs/02_document/tests/traceability-matrix.md` § Uncovered Items Analysis.
"""

from __future__ import annotations

import sys
from pathlib import Path
from types import SimpleNamespace

import pytest

_E2E_ROOT = Path(__file__).resolve().parents[1]
if str(_E2E_ROOT) not in sys.path:
    sys.path.insert(0, str(_E2E_ROOT))

from runner.conftest import pytest_collection_modifyitems  # noqa: E402


class _Marker(SimpleNamespace):
    pass


class _FakeKeywords(set):
    """Mimic pytest.Item.keywords (a set-with-`in` semantics over marker names)."""


class _FakeItem:
    def __init__(
        self,
        keywords: set[str] | None = None,
        markers: dict[str, _Marker] | None = None,
        callspec: SimpleNamespace | None = None,
    ) -> None:
        self.keywords = _FakeKeywords(keywords or set())
        self._markers = markers or {}
        self.callspec = callspec
        self.added_markers: list[_Marker] = []

    def get_closest_marker(self, name: str) -> _Marker | None:
        return self._markers.get(name)

    def add_marker(self, marker: _Marker) -> None:
        self.added_markers.append(marker)


class _FakeConfig:
    def __init__(self, chamber: bool = False, build_kind: str = "production", allow_no_reason: bool = False) -> None:
        self._chamber = chamber
        self._build_kind = build_kind
        self._allow_no_reason = allow_no_reason

    def getoption(self, name: str) -> object:
        return {
            "--enable-chamber": self._chamber,
            "--build-kind": self._build_kind,
            "--allow-no-skip-reason": self._allow_no_reason,
        }[name]


def _skip_reasons(item: _FakeItem) -> list[str]:
    out: list[str] = []
    for m in item.added_markers:
        # pytest.mark.skip(reason=...) returns a MarkDecorator with .mark.kwargs;
        # in our shim we have a SimpleNamespace from pytest.mark.skip itself.
        # Easiest: stringify and look for the reason inside.
        out.append(str(m))
    return out


def test_tier2_only_skipped_on_tier1(monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.setenv("TIER", "tier1-docker")
    item = _FakeItem(keywords={"tier2_only"})
    pytest_collection_modifyitems(_FakeConfig(), [item])
    assert any("Tier-2 only" in r for r in _skip_reasons(item))


def test_tier2_only_runs_on_tier2(monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.setenv("TIER", "tier2-jetson")
    item = _FakeItem(keywords={"tier2_only"})
    pytest_collection_modifyitems(_FakeConfig(), [item])
    assert not item.added_markers, "tier2_only test should run when TIER=tier2-jetson"


def test_chamber_only_skipped_without_flag(monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.setenv("TIER", "tier2-jetson")
    item = _FakeItem(keywords={"chamber_only"})
    pytest_collection_modifyitems(_FakeConfig(chamber=False), [item])
    assert any("Chamber" in r for r in _skip_reasons(item))


def test_chamber_only_runs_with_flag(monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.setenv("TIER", "tier2-jetson")
    item = _FakeItem(keywords={"chamber_only"})
    pytest_collection_modifyitems(_FakeConfig(chamber=True), [item])
    assert not item.added_markers, "chamber_only test should run with --enable-chamber"


def test_vins_mono_skipped_on_production(monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.setenv("TIER", "tier1-docker")
    callspec = SimpleNamespace(params={"vio_strategy": "vins_mono"})
    item = _FakeItem(callspec=callspec)
    pytest_collection_modifyitems(_FakeConfig(build_kind="production"), [item])
    assert any("research-build-only" in r for r in _skip_reasons(item))


def test_vins_mono_runs_on_research(monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.setenv("TIER", "tier1-docker")
    callspec = SimpleNamespace(params={"vio_strategy": "vins_mono"})
    item = _FakeItem(callspec=callspec)
    pytest_collection_modifyitems(_FakeConfig(build_kind="research"), [item])
    assert not item.added_markers, "vins_mono should run on research builds"


def test_deferred_ac_without_reason_blocks_collection(monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.setenv("TIER", "tier1-docker")
    marker = _Marker(args=(), kwargs={})
    item = _FakeItem(markers={"deferred_ac": marker})
    pytest_collection_modifyitems(_FakeConfig(allow_no_reason=False), [item])
    assert any("without reason=" in r for r in _skip_reasons(item))


def test_deferred_ac_with_reason_emits_skip(monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.setenv("TIER", "tier1-docker")
    marker = _Marker(args=(), kwargs={"reason": "AC-7.1 — see traceability matrix"})
    item = _FakeItem(markers={"deferred_ac": marker})
    pytest_collection_modifyitems(_FakeConfig(), [item])
    assert any("AC-7.1" in r for r in _skip_reasons(item))


def test_deferred_ac_xfail_verdict_emits_xfail(monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.setenv("TIER", "tier1-docker")
    marker = _Marker(args=(), kwargs={"reason": "AC-8.6 scene-change PARTIAL", "verdict": "xfail"})
    item = _FakeItem(markers={"deferred_ac": marker})
    pytest_collection_modifyitems(_FakeConfig(), [item])
    # The xfail decorator object stringifies differently from skip; just
    # verify some marker was added.
    assert item.added_markers, "deferred_ac(verdict=xfail) must mark the item"