"""AZ-507 — Layer-0 typed-error envelope shim tests.

Covers AC-2 (shim re-exports resolve and are identical to the c7
canonical classes) and AC-1 / AC-5 (module-layout.md + architecture.md
documentation invariants).
"""

from __future__ import annotations

import re
from pathlib import Path

from gps_denied_onboard._types.inference_errors import (
    CalibrationCacheError as ShimCalibrationCacheError,
)
from gps_denied_onboard._types.inference_errors import (
    EngineBuildError as ShimEngineBuildError,
)
from gps_denied_onboard.components.c7_inference.errors import (
    CalibrationCacheError as CanonicalCalibrationCacheError,
)
from gps_denied_onboard.components.c7_inference.errors import (
    EngineBuildError as CanonicalEngineBuildError,
)

_REPO_ROOT = Path(__file__).resolve().parents[2]


def test_ac2_shim_engine_build_error_identity_with_canonical() -> None:
    # The shim must NOT introduce a fresh subclass — consumers catching
    # ShimEngineBuildError MUST catch what c7 actually raises.
    assert ShimEngineBuildError is CanonicalEngineBuildError


def test_ac2_shim_calibration_cache_error_identity_with_canonical() -> None:
    assert ShimCalibrationCacheError is CanonicalCalibrationCacheError


def test_ac2_shim_module_has_no_runtime_side_effects() -> None:
    # Importing the shim must not register a component config block or
    # otherwise mutate global state. Re-importing the module twice in the
    # same process must remain a no-op.
    import importlib

    import gps_denied_onboard._types.inference_errors as shim

    first = importlib.reload(shim)
    second = importlib.reload(shim)
    assert first.EngineBuildError is second.EngineBuildError
    assert first.CalibrationCacheError is second.CalibrationCacheError


def test_ac1_module_layout_has_no_cross_component_public_api_imports() -> None:
    # AZ-507's primary deliverable: every line that previously said
    # `components.X (Public API)` in an "Imports from" line must now point
    # at `_types` (or be removed). We grep for the offending pattern and
    # assert zero matches.
    layout = (
        _REPO_ROOT / "_docs" / "02_document" / "module-layout.md"
    ).read_text(encoding="utf-8")
    offenders = re.findall(
        r"components\.[a-z0-9_]+\s*\(Public API\)",
        layout,
    )
    assert offenders == [], (
        "module-layout.md still names cross-component Public API imports "
        f"after AZ-507: {offenders}"
    )


def test_ac5_architecture_doc_codifies_cross_component_rule() -> None:
    # AZ-507 AC-5: the architecture doc must carry a one-paragraph rule
    # that cross-component imports go through `_types/*.py` (DTOs +
    # typed-error envelopes), never `components.X (Public API)`.
    arch = (
        _REPO_ROOT / "_docs" / "02_document" / "architecture.md"
    ).read_text(encoding="utf-8")
    # Look for the rule sentence (case-insensitive) and the explicit
    # AZ-507 reference so future readers can trace the decision.
    assert "AZ-507" in arch, "architecture.md must reference AZ-507"
    assert re.search(
        r"cross-component imports go through `_types",
        arch,
        flags=re.IGNORECASE,
    ), (
        "architecture.md must state the cross-component import rule "
        "introduced by AZ-507"
    )