"""The measurements read a FROZEN copy of the vegnormal bases, pinned by sha256 — never another
repository's live build directory.

Measured 2026-09-17 17:43: ``vegnormal-okf`` rebuilt ``build/ferdig/r761-2025`` while this
repository's gate pointed straight at it. Rows 6-7 went "IKKE MÅLT" and five tests fell, for a
change no one here made. The failure mode was never falsehood — the gate says IKKE MÅLT and exits
non-zero, never green — it was that two projects shared a directory neither owns, so what this
repository MEASURES could change without a commit here.

The fix is a copy outside both repositories plus a pin this repository tracks. The pin is the whole
point: a copy with no pin is the same shared directory one move further away. So the three states
are separated by construction, and each has its own arm below:

* the copy matches the pin      -> it resolves, and that is the only green path;
* the copy is GONE              -> ``FrozenBundleMissing`` (an ``OSError``): the gate says
  IKKE MÅLT and fails the exit code exactly as it did before this change; the delivered-corpus
  tests SKIP, which is MAJOR-3's ceiling rule (a hard error would break ``uv run pytest`` in the
  handover archive, where no corpus is mounted);
* the copy DIFFERS from the pin -> ``FrozenBundleDrift`` (a ``ValueError``): loud, named, and
  NEVER a skip. A drifted copy is not an unreadable measurement, it is a measurement of the wrong
  corpus, which is the one thing that produces a silently wrong number.

The two exception classes are deliberately unrelated: a caller that catches "missing" to skip must
not swallow "drift". ``test_drift_is_not_a_missing_copy`` is that gate.
"""

from __future__ import annotations

import json
import re
import shutil
from pathlib import Path
from typing import Any

import pytest

from portfolio_optimiser import frozen_bundles as fb
from portfolio_optimiser.evals import v1_gate as gate
from portfolio_optimiser.stress import read_bundle_declarations

_REPO = Path(__file__).resolve().parent.parent
#: Joined at run time on purpose: this file NAMES the forbidden path spellings, and a literal
#: would make the gate below red against its own source. (Implicit concatenation is not enough —
#: ``ruff format`` folds ``"a" "b"`` back into one literal, measured here.)
_OTHER_REPO = "-".join(("vegnormal", "okf"))
#: The two spellings a path to that repository's build directory takes in this codebase. Both were
#: present before this change (3 + 4 hits, the known positives recorded in the order's evidence).
#: Each is paired with the line that PROVES it can match: a pattern that matches nothing makes a
#: gate that can only be green, and the two spellings do not match each other's sample.
_FORBIDDEN = (
    (
        re.compile(re.escape(_OTHER_REPO + "/build")),
        f'ROOT = Path("~/repos/{_OTHER_REPO}/build/ferdig")',
    ),
    (
        re.compile("[\"']" + re.escape(_OTHER_REPO) + "[\"']"),
        'ROOT = Path.home() / "repos" / "' + _OTHER_REPO + '" / "build" / "ferdig"',
    ),
)
#: Prose that documents history is explicitly allowed by the order; only paths are forbidden.
_SCANNED = ("src", "tests", "contexts")


# ---------------------------------------------------------------------------------------------
# helpers
# ---------------------------------------------------------------------------------------------


def _bundle(root: Path, body: str = "one") -> Path:
    root.mkdir(parents=True, exist_ok=True)
    (root / "index.md").write_text("# base\n\n- [a](krav/a.md)\n", encoding="utf-8")
    (root / "krav").mkdir(exist_ok=True)
    (root / "krav" / "a.md").write_text(
        f"---\ntype: Krav\ntitle: A\n---\n\n{body}\n", encoding="utf-8"
    )
    return root


def _store(tmp_path: Path, name: str = "n500-2024", body: str = "one") -> tuple[Path, Path]:
    """A frozen store holding ONE pinned bundle, and the pin file that names it."""
    store = tmp_path / "store"
    digest, files = fb.digest_bundle(_bundle(tmp_path / "src-of-truth", body))
    directory = f"{name}-{digest[: fb.SHORT]}"
    _bundle(store / directory, body)
    pin = tmp_path / "pin.json"
    pin.write_text(
        json.dumps(
            {
                "bundles": {name: {"directory": directory, "sha256": digest, "files": files}},
            }
        ),
        encoding="utf-8",
    )
    return store, pin


def _use(monkeypatch: pytest.MonkeyPatch, store: Path, pin: Path) -> None:
    monkeypatch.setenv(fb.STORE_ENV, str(store))
    monkeypatch.setattr(fb, "PIN_FILE", pin)


def _touch_one_byte(base: Path) -> None:
    doc = base / "krav" / "a.md"
    doc.write_text(doc.read_text(encoding="utf-8").replace("one", "ONE"), encoding="utf-8")


# ---------------------------------------------------------------------------------------------
# (a)-(b) the digest
# ---------------------------------------------------------------------------------------------


def test_the_digest_covers_every_byte_and_every_name(tmp_path: Path) -> None:
    """Stable across recomputation; moved by one byte AND by a rename that changes no byte —
    without the name in the hash, a corpus reshuffled under the same bytes would pin clean."""
    base = _bundle(tmp_path / "b")
    first, files = fb.digest_bundle(base)
    assert (first, files) == fb.digest_bundle(base)
    assert files == 2

    _touch_one_byte(base)
    changed, _ = fb.digest_bundle(base)
    assert changed != first

    renamed = _bundle(tmp_path / "c")
    (renamed / "krav" / "a.md").rename(renamed / "krav" / "b.md")
    assert fb.digest_bundle(renamed)[0] != fb.digest_bundle(_bundle(tmp_path / "d"))[0]


def test_an_added_or_removed_file_is_drift_even_when_no_kept_byte_changes(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    """The two arms nothing pinned (measured 2026-09-18: a mutant that ignored an extra or a
    missing file left 197 tests green). Every surviving file is byte-identical to the pin here —
    only the SET of files moved, and the set is what a copy is."""
    store, pin = _store(tmp_path)
    _use(monkeypatch, store, pin)
    base = fb.bundle_dir("n500-2024")  # control: green before either edit

    extra = base / "krav" / "b.md"
    extra.write_text("---\ntype: Krav\ntitle: B\n---\n", encoding="utf-8")
    with pytest.raises(fb.FrozenBundleDrift):
        fb.bundle_dir("n500-2024")
    extra.unlink()
    assert fb.bundle_dir("n500-2024") == base  # the edit, not the fixture, was the cause

    (base / "krav" / "a.md").unlink()
    with pytest.raises(fb.FrozenBundleDrift) as exc:
        fb.bundle_dir("n500-2024")
    assert "1 filer" in str(exc.value)  # what disk holds now: one file of the pinned two


def test_the_digest_does_not_depend_on_directory_listing_order(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    """Determinism with no corpus mounted: the same tree listed in ANOTHER order digests the same.
    Only the corpus tests used to catch a removed sort, and they skip where no corpus exists."""
    base = _bundle(tmp_path / "b")
    for extra in ("z.md", "m.md", "krav/q.md"):
        (base / extra).write_text(extra, encoding="utf-8")
    baseline = fb.digest_bundle(base)
    listed = list(base.rglob("*"))
    assert len(listed) > 3

    real = Path.rglob
    for order in (list(reversed(listed)), listed[1:] + listed[:1]):
        monkeypatch.setattr(Path, "rglob", lambda self, pattern, _o=order: iter(_o))
        assert fb.digest_bundle(base) == baseline
    monkeypatch.setattr(Path, "rglob", real)


def test_a_matching_copy_resolves_to_the_pinned_directory(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    store, pin = _store(tmp_path)
    _use(monkeypatch, store, pin)
    resolved = fb.bundle_dir("n500-2024")
    assert resolved.parent == store
    assert (resolved / "index.md").is_file()


# ---------------------------------------------------------------------------------------------
# (c)-(e) the three states
# ---------------------------------------------------------------------------------------------


def test_one_changed_byte_is_drift_named_with_both_digests(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    store, pin = _store(tmp_path)
    _use(monkeypatch, store, pin)
    base = fb.bundle_dir("n500-2024")  # green before the edit — the control
    expected = json.loads(pin.read_text(encoding="utf-8"))["bundles"]["n500-2024"]["sha256"]
    _touch_one_byte(base)

    with pytest.raises(fb.FrozenBundleDrift) as exc:
        fb.bundle_dir("n500-2024")
    message = str(exc.value)
    assert "avviker fra pin" in message
    assert "n500-2024" in message
    assert expected[: fb.SHORT] in message  # what was pinned
    assert fb.digest_bundle(base)[0][: fb.SHORT] in message  # what is on disk


def test_a_missing_copy_is_missing_and_stays_an_oserror(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    """``measure_stress`` already catches ``OSError`` -> IKKE MÅLT + exit 1; that path is unchanged."""
    store, pin = _store(tmp_path)
    _use(monkeypatch, store, pin)
    shutil.rmtree(store / fb.load_pins()["n500-2024"].directory)

    with pytest.raises(fb.FrozenBundleMissing) as exc:
        fb.bundle_dir("n500-2024")
    assert isinstance(exc.value, OSError)
    assert "n500-2024" in str(exc.value)


def test_drift_is_not_a_missing_copy(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
    """A caller that catches "missing" in order to SKIP must never swallow drift: skipping on a
    wrong corpus is the silent failure this whole change exists to remove."""
    assert not issubclass(fb.FrozenBundleDrift, fb.FrozenBundleMissing)
    assert not issubclass(fb.FrozenBundleMissing, fb.FrozenBundleDrift)
    assert not isinstance(fb.FrozenBundleDrift("x"), OSError)

    store, pin = _store(tmp_path)
    _use(monkeypatch, store, pin)
    _touch_one_byte(fb.bundle_dir("n500-2024"))
    with pytest.raises(fb.FrozenBundleDrift):
        try:
            fb.bundle_dir("n500-2024")
        except fb.FrozenBundleMissing:  # pragma: no cover - the defect this arm forbids
            pytest.fail("drift was answered as a missing copy")


def test_an_unknown_name_is_refused_by_name(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    store, pin = _store(tmp_path)
    _use(monkeypatch, store, pin)
    with pytest.raises(fb.FrozenBundleMissing) as exc:
        fb.bundle_dir("n100-2023")
    assert "n100-2023" in str(exc.value) and "n500-2024" in str(exc.value)


def test_an_explicit_override_is_unpinned_and_the_operator_named_it(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    """``--bundle-root`` / ``PORTFOLIO_VEGNORMAL_ROOT`` stays an escape hatch: the operator who
    names a live mount gets it, pin or no pin. Absent it, the frozen store answers."""
    store, pin = _store(tmp_path)
    _use(monkeypatch, store, pin)
    live = tmp_path / "live"
    _bundle(live / "n500-2024", body="something else entirely")
    assert fb.bundle_dir("n500-2024", override=live) == live / "n500-2024"
    monkeypatch.setenv(fb.OVERRIDE_ENV, str(live))
    assert fb.bundle_dir("n500-2024") == live / "n500-2024"


# ---------------------------------------------------------------------------------------------
# (f)-(g) the tracked pin
# ---------------------------------------------------------------------------------------------


def test_the_pin_names_every_base_the_context_sets_declare() -> None:
    declared = {
        d["name"]
        for path in sorted((_REPO / "contexts").glob("*/bundle.txt"))
        for d in read_bundle_declarations(path)
    }
    assert declared, "no context set declares a base — the denominator would be vacuous"
    assert declared <= set(fb.load_pins())


def test_the_pinned_directory_name_carries_the_short_digest() -> None:
    """A stale copy is visible in ``ls``, not only to the verifier."""
    pins = fb.load_pins()
    assert pins, "the pin file names no bundle"
    for name, pin in pins.items():
        assert pin.directory == f"{name}-{pin.sha256[: fb.SHORT]}"
        assert pin.files > 0


def test_the_pin_file_carries_no_key_nobody_reads() -> None:
    """``store`` sat in the pin file with no reader: the store is ``DEFAULT_STORE`` / the env var,
    and a second, silent spelling of it would drift from the first."""
    keys = set(json.loads(fb.PIN_FILE.read_text(encoding="utf-8")))
    assert keys == {"source", "renewal", "bundles"}


def test_the_bundle_itself_is_never_tracked_here() -> None:
    """Vegnormal corpora must not reach a public remote: only the pin is tracked."""
    tracked = (_REPO / "src" / "portfolio_optimiser" / "frozen_bundles.json").read_text("utf-8")
    assert "index.md" not in tracked


# ---------------------------------------------------------------------------------------------
# (h) nothing reads the other repository's build directory any more
# ---------------------------------------------------------------------------------------------


#: Every text form a path to that build directory could be written in. ``.py/.json/.txt`` alone
#: left prose-and-config (md, yaml, toml) outside the denominator, unmeasured.
_SUFFIXES = {".py", ".json", ".txt", ".md", ".yaml", ".yml", ".toml"}


def _forbidden_hits(root: Path, tops: tuple[str, ...]) -> tuple[list[str], int]:
    """(hits, files scanned). The count is the denominator: a scan of zero files is not green."""
    hits: list[str] = []
    scanned = 0
    for top in tops:
        for path in sorted((root / top).rglob("*")):
            if not path.is_file() or path.suffix not in _SUFFIXES:
                continue
            scanned += 1
            for n, line in enumerate(path.read_text(encoding="utf-8").splitlines(), 1):
                if any(p.search(line) for p, _ in _FORBIDDEN):
                    hits.append(f"{path.relative_to(root)}:{n}: {line.strip()}")
    return hits, scanned


def test_the_forbidden_path_scan_finds_a_known_positive_in_every_scanned_suffix(
    tmp_path: Path,
) -> None:
    """Shown, not assumed: plant each spelling in a file of EACH suffix and see the scan report
    exactly those files. A suffix the scan skips would read clean here and be red in this test."""
    suffixes = (".py", ".json", ".txt", ".md", ".yaml", ".yml", ".toml")  # literal, not _SUFFIXES
    for suffix in suffixes:
        for i, (_, sample) in enumerate(_FORBIDDEN):
            planted = tmp_path / "src" / f"planted{i}{suffix}"
            planted.parent.mkdir(exist_ok=True)
            planted.write_text(f"before\n{sample}\nafter\n", encoding="utf-8")
    hits, scanned = _forbidden_hits(tmp_path, ("src",))
    assert scanned == len(suffixes) * len(_FORBIDDEN)
    assert len(hits) == scanned, hits


def test_no_measurement_reads_the_other_repos_build_directory() -> None:
    """Both spellings, each with a known-positive control: a pattern that cannot match anything
    is a gate that can only be green."""
    for pattern, known_positive in _FORBIDDEN:
        assert pattern.search(known_positive), pattern.pattern
    hits, scanned = _forbidden_hits(_REPO, _SCANNED)
    assert scanned > 0
    assert hits == [], "\n".join(hits)


# ---------------------------------------------------------------------------------------------
# (i)-(j) the gate
# ---------------------------------------------------------------------------------------------


def _evidence(tmp_path: Path) -> tuple[dict[str, Any], Path]:
    stress_root = tmp_path / "stress"
    (stress_root / "o").mkdir(parents=True)
    return {
        "label": "s",
        "root": "scratchpad",
        "runs": [
            {
                "context": "contexts/tunnel-hauglia-2027",
                "outbox": "o",
                "run_id": "r",
                "bundle": None,
            }
        ],
    }, stress_root


def test_a_drifted_copy_fails_the_gate_with_the_reason_said(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    store, pin = _store(tmp_path)
    _use(monkeypatch, store, pin)
    _touch_one_byte(fb.bundle_dir("n500-2024"))
    evidence, stress_root = _evidence(tmp_path)

    m = gate.measure_stress(evidence, _REPO, stress_root, None)
    assert "avviker fra pin" in m.drift
    assert m.missing == ""  # drift is NOT "artefakter mangler" — the two are named apart
    row = gate.score_undeclared(["p"], {"p": "passed"}, m, "s")
    assert (row.k, row.status, row.failing) == (None, gate.NOT_MEASURED, True)
    assert "pin-drift" in row.reason and "artefakter mangler" not in row.reason
    assert "pin-drift" in gate.score_named(m, "s").reason
    assert gate.exit_code([row]) == 1


def test_a_missing_copy_is_not_measured_and_never_green(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    store, pin = _store(tmp_path)
    _use(monkeypatch, store, pin)
    evidence, stress_root = _evidence(tmp_path)
    monkeypatch.setenv(fb.STORE_ENV, str(tmp_path / "gone"))

    m = gate.measure_stress(evidence, _REPO, stress_root, None)
    assert m.missing and not m.drift and m.validated == 0
    row = gate.score_undeclared(["p"], {"p": "passed"}, m, "s")
    assert (row.status, row.failing) == (gate.NOT_MEASURED, True)
    assert "artefakter mangler" in row.reason and "pin-drift" not in row.reason
    assert gate.exit_code([row]) == 1


# ---------------------------------------------------------------------------------------------
# (k) the delivered-corpus tests: missing SKIPS, drift FAILS
# ---------------------------------------------------------------------------------------------


@pytest.mark.parametrize(
    "module,helper",
    [
        ("test_context_sets_loadbearing", "_bundle_dir"),
        ("test_navigation_window_loadbearing", "_delivered"),
        ("test_inert_identifier_loadbearing", "_base"),
        ("test_requirement_number_gate_loadbearing", "_base"),
    ],
)
def test_the_corpus_tests_skip_when_absent_but_fail_on_drift(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch, module: str, helper: str
) -> None:
    mod = __import__(module)
    resolve = getattr(mod, helper)
    store, pin = _store(tmp_path)
    _use(monkeypatch, store, pin)

    assert resolve("n500-2024").is_dir()  # control: the matching copy resolves
    _touch_one_byte(fb.bundle_dir("n500-2024"))
    # A skip is caught EXPLICITLY, never left to ``pytest.raises``: measured against the mutation
    # that makes drift a subclass of missing, these four arms SKIPPED instead of failing (5 -> 9
    # skipped over the whole suite) and stayed green — a gate that cannot see the one defect it
    # exists for.
    try:
        resolve("n500-2024")
    except fb.FrozenBundleDrift:
        pass
    except pytest.skip.Exception as exc:
        raise AssertionError(f"{module}.{helper} SKIPPED a drifted copy: {exc}") from None
    else:
        raise AssertionError(f"{module}.{helper} accepted a drifted copy")

    monkeypatch.setenv(fb.STORE_ENV, str(tmp_path / "gone"))
    with pytest.raises(pytest.skip.Exception):
        resolve("n500-2024")