"""P18/B1 — an identifier that stands in every document identifies none of them.

P7 made stage 0b ``item.code in grounding``: plain containment over ONE concatenated string. P16
then ran it against a delivered corpus and measured what containment cannot tell apart. The
falsification arm ``a4-indeksregulering`` proposed a 250 000 NOK saving on a single cost line whose
code was ``R761`` — the knowledge base's OWN NAME, which every one of its 2 756 concept documents
carries — and the whole gate said ``validated``: stage 0 was skipped (un-anchored run), stage 0b
was satisfied by the letterhead, and the checker approved.

The rule this file measures: a code grounds only if it is at least ``_GROUNDING_MIN_LENGTH``
characters AND appears in fewer than ``_GROUNDING_MAX_DOCUMENT_SHARE`` of the grounding's
DOCUMENTS — with an absolute floor, because a share over a handful of documents is not a
measurement (one of three is 33 % and says nothing).

**N and A are MEASURED, not chosen** (14.09, the four mounted vegnormal bases):

* every ``must_cite`` reference and every mandate ``affected_code`` in the four context sets: the
  shortest real identifier is FOUR characters (``12.1``, ``52.1``), so ``N = 3`` sits one below the
  measurement and cannot refuse anything measured;
* document frequency of every code-shaped token (``generate._IDENTIFIER_FORMS``) in each base:
  1 692 distinct tokens and NOT ONE reaches 5 % of its base's documents. Highest anywhere 6 of 446
  (1.35 %); highest that a fasit names 3 of 446 (0.67 %); ``R761`` 2 756 of 2 756 (100 %). ``A =
  0.05`` therefore sits 3.7x above the highest real token and 20x below the defect.

**The denominator is NAMED in the refusal**, because Step 5 feeds that reason verbatim into the
next attempt's prompt: a proposer told only "ungrounded" answers with another token of the same
kind, while one told "it is in 2 756 of 2 756 documents" has been told what is wrong with it.

The arms that need the delivered bases SKIP with the root named; the rule's own algebra, the
floor, and the composition seam run over synthetic input and are UNCONDITIONAL.
"""

from __future__ import annotations

import json
import os
from pathlib import Path

import pytest

from portfolio_optimiser import okf
from portfolio_optimiser.ir import AffectedItem, SavingsProposal
from portfolio_optimiser.validator import (
    Grounding,
    Rejection,
    ValidatedProposal,
    _inert_in,
    validate_proposal,
)

_DEFAULT_BUNDLE_ROOT = Path.home() / "repos" / "vegnormal-okf" / "build" / "ferdig"
_A4 = Path(
    "scratchpad/p14-stress/kontrakt-sorasen-2027/"
    "kontrakt-sorasen-2027-01-a4-indeksregulering-proposal.json"
)


def _base(name: str) -> Path:
    root = Path(os.environ.get("PORTFOLIO_VEGNORMAL_ROOT", str(_DEFAULT_BUNDLE_ROOT)))
    if not (root / name).is_dir():
        pytest.skip(f"knowledge base {name!r} is not mounted under {root}")
    return root / name


def _grounding_over(name: str) -> Grounding:
    """The delivered base as ``run_project`` composes it: ONE document per concept file."""
    bundle = okf.navigate_bundle(str(_base(name)))
    return Grounding(
        documents=tuple(
            "\n".join([f.name, *f.frontmatter.values(), f.body]) for f in bundle.context_files
        )
    )


def _proposal(code: str, *, saving: float = 1000.0) -> SavingsProposal:
    return SavingsProposal(
        project_id="p",
        measure="m",
        affected_items=[AffectedItem(code=code, quantity=1.0, unit_cost=100_000.0)],
        claimed_saving_nok=saving,
    )


def _corpus(*, documents: int, everywhere: str, once: str) -> Grounding:
    """A synthetic grounding: one token in every document, one in exactly one."""
    return Grounding(
        documents=tuple(
            f"{everywhere} paragraf {n}" + (f" {once}" if n == 0 else "") for n in range(documents)
        )
    )


# --- the measured defect --------------------------------------------------------------------


def test_the_a4_proposal_p16_validated_is_now_refused() -> None:
    """(a) THE KNOWN POSITIVE, and it is a recording rather than a construction: the proposal is
    the artefact P16's paid run wrote, replayed against the base that run was given, with
    ``baseline=None`` — exactly the configuration under which it said ``validated``."""
    if not _A4.is_file():
        pytest.skip("P16's a4 artefact is not present in this checkout")
    proposal = SavingsProposal.model_validate(
        json.loads(_A4.read_text(encoding="utf-8"))["proposal"]
    )
    assert [i.code for i in proposal.affected_items] == ["R761"], "the artefact drifted"

    ruling = validate_proposal(proposal, baseline=None, grounding=_grounding_over("r761-2025"))

    assert isinstance(ruling, Rejection)
    assert "'R761'" in ruling.reason
    assert "2756 of the 2756" in ruling.reason, (
        "the refusal must name the denominator: Step 5 feeds this reason verbatim into the next "
        f"attempt's prompt — got {ruling.reason!r}"
    )


def test_every_fasit_reference_still_grounds() -> None:
    """(b) THE KNOWN NEGATIVE over the same corpora, with its denominator stated. A rule that made
    the defect inert by making real references inert too would pass (a) perfectly."""
    sets = {
        "gate-nordvik-2027": "n100-2023",
        "fv412-dekkefornyelse-2027": "n200-2024",
        "tunnel-hauglia-2027": "n500-2024",
        "kontrakt-sorasen-2027": "r761-2025",
    }
    checked = 0
    for context, base in sets.items():
        fasit = json.loads(Path(f"contexts/{context}/fasit.json").read_text(encoding="utf-8"))
        grounding = _grounding_over(base)
        for reference in sorted({c["ref"] for m in fasit["must_cite"] for c in m["concepts"]}):
            assert reference in grounding.text, f"{reference!r} is absent from {base}"
            assert _inert_in(grounding, reference) is None, (
                f"{reference!r} is a real requirement of {base} and the rule made it inert"
            )
            checked += 1
    assert checked == 26, f"population moved: {checked} references, expected 26"


# --- the rule's own algebra, unconditional ---------------------------------------------------


def test_a_token_in_one_document_grounds_and_one_in_all_of_them_does_not() -> None:
    """(c) The discriminator, over synthetic input so it can never be absent. Both halves in one
    arm on the SAME corpus: a rule that flagged everything and one that flagged nothing each fail
    exactly one of them."""
    grounding = _corpus(documents=100, everywhere="KORPUS-01", once="LINJE-77-01")

    assert _inert_in(grounding, "LINJE-77-01") is None
    assert _inert_in(grounding, "KORPUS-01") is not None
    assert isinstance(
        validate_proposal(_proposal("LINJE-77-01"), grounding=grounding), ValidatedProposal
    )
    assert isinstance(validate_proposal(_proposal("KORPUS-01"), grounding=grounding), Rejection)


def test_a_token_too_short_to_identify_anything_is_inert() -> None:
    """(d) The length conjunct, which the SHARE does not cover: ``R761`` is four characters, so
    length is not what made the measured defect inert. This is the coincidence class the
    measurement did not happen to contain — a one- or two-character token is in any prose."""
    grounding = Grounding(documents=("the line A is here", *("filler" for _ in range(50))))

    assert _inert_in(grounding, "A") is not None
    assert "too short" in str(_inert_in(grounding, "A"))
    assert _inert_in(grounding, "A-1") is None, "three characters is the measured floor, not four"


def test_a_share_is_not_taken_over_a_handful_of_documents() -> None:
    """(e) The absolute floor, and the reason every pre-P18 fixture is untouched by this rule
    rather than exempted from it: one document of three is 33 % and says nothing at all. Measured,
    the highest ABSOLUTE document count any real identifier reaches in the four corpora is 6."""
    tiny = Grounding(documents=("KODE-01 her", "KODE-01 og her", "KODE-01 og her"))

    assert _inert_in(tiny, "KODE-01") is None, "3 of 3 is 100 %, and it is not a measurement"
    assert isinstance(validate_proposal(_proposal("KODE-01"), grounding=tiny), ValidatedProposal)


def test_a_caller_that_declares_no_boundaries_is_byte_for_byte_the_old_gate() -> None:
    """(f) ``Grounding.of`` is the honest reading of a caller with nothing to declare, and it can
    never trip the share: one document cannot reach the floor. This is what keeps every road-path
    run and every pre-P18 test unchanged BY CONSTRUCTION rather than by exemption."""
    text = "en tekst som nevner KODE-99 og ellers ingenting"
    single = Grounding.of(text)

    assert single.text == text, "the one-document form must not reshape the text"
    assert single.document_frequency("KODE-99") == 1
    assert _inert_in(single, "KODE-99") is None


# --- the seam: the boundaries reach the gate from the run ------------------------------------


def test_the_run_hands_the_gate_one_document_per_concept_file() -> None:
    """(g) The COMPOSITION arm. The rule is only as good as the boundaries it is given: a run that
    still composed one blob would satisfy every arm above (which builds its own ``Grounding``) and
    reproduce the measured defect exactly. Driven through ``_grounding_text``, the one composer the
    run passes to the gate, and asserted on the COUNT of documents rather than on the text."""
    from portfolio_optimiser.generate import _grounding_text
    from portfolio_optimiser.ir import CostBaseline, CostBaselineLine
    from portfolio_optimiser.reference_domain import CostItem, Project

    delivered = Grounding(documents=("dokument A", "dokument B", "dokument C"))
    project = Project(
        id="p",
        name="P",
        description="d",
        currency="NOK",
        cost_items=(
            CostItem(code="PRJ-01", description="d", unit="stk", quantity=1.0, unit_cost=1.0),
        ),
        docs_dir="/nonexistent",
    )
    baseline = CostBaseline(
        project_id="p", items={"BAS-01": CostBaselineLine(quantity=1.0, unit_cost=1.0)}
    )

    composed = _grounding_text(project, baseline, delivered)

    assert len(composed.documents) == 5, "each later source is ONE document, never appended to one"
    assert composed.text == "\n".join(
        ["dokument A", "dokument B", "dokument C", "PRJ-01", "BAS-01"]
    )


@pytest.mark.asyncio
async def test_the_boundaries_survive_the_real_run_and_not_only_the_composer(
    tmp_path: Path,
) -> None:
    """(h) BEHAVIOURAL, over the real ``run_project`` bundle arm — and it exists because a mutation
    found the gap, not because it was foreseen.

    Reverting ``run.py`` to compose ONE blob instead of one document per concept file left the WHOLE
    suite green (1698 passed / 5 skipped). Arm (g) above drives ``_grounding_text`` with a
    ``Grounding`` it builds itself, so it can never see what the RUN handed over — exactly the
    vacuity this repo keeps measuring. The rule is only as good as the boundaries it is given, and
    a blob has exactly one: with a single document the absolute floor can never be reached, so the
    share can never fire and the measured defect returns intact.

    The base is crafted so the two implementations must DISAGREE: twelve concept files all carrying
    the same token, which is past ``_GROUNDING_MIN_INERT_DOCUMENTS``. Per document it is in 12 of 13
    and inert; as one blob it is in 1 of 1 and grounds. The CONTROL is the same run with a code only
    ONE file carries, which must still validate — otherwise the arm would also pass on a run that
    rejects everything.
    """
    import shutil

    from portfolio_optimiser.run import run_project
    from portfolio_optimiser.simulation import ScriptedChatClient

    base = tmp_path / "base"
    shutil.copytree(Path("shared/examples/bygg-energi-mikro"), base)
    links = []
    for n in range(12):
        rel = f"seksjon-{n:02d}.md"
        (base / rel).write_text(
            f"---\ntype: concept\ntitle: Seksjon {n:02d}\n---\n\n"
            "KORPUSMERKE-77 gjelder overalt i denne basen.\n"
            + ("Kostlinjen EN-ENESTE-01 star bare her.\n" if n == 0 else ""),
            encoding="utf-8",
        )
        links.append(f"- [Seksjon {n:02d}]({rel})")
    index = base / "index.md"
    index.write_text(
        index.read_text(encoding="utf-8") + "\n" + "\n".join(links) + "\n", encoding="utf-8"
    )

    async def _outcome(code: str) -> object:
        reply = (
            f'{{"measure":"LED-retrofit","affected_items":'
            f'[{{"code":"{code}","quantity":300000,"unit_cost":1.0}}],'
            f'"claimed_saving_nok":30000}}'
        )
        result = await run_project(
            "BYGG-KONTOR-NORD",
            "local",
            docs_dir=str(base),
            bundle_dir=str(base),
            client_factory=lambda role: ScriptedChatClient(
                "Reasoning holds.\nVERDICT: APPROVE" if role == "checker" else reply, role=role
            ),
        )
        return result.outcome

    control = await _outcome("EN-ENESTE-01")
    assert isinstance(control, ValidatedProposal), (
        f"CONTROL: a code only one concept file carries must still ground — {control}"
    )

    everywhere = await _outcome("KORPUSMERKE-77")
    assert isinstance(everywhere, Rejection), (
        "a token every concept file carries grounded a proposal — the run handed the gate one blob"
    )
    # The NUMERATOR is the discriminator: as one blob the token is in 1 of 1, so a refusal naming
    # 12 can only come from a run that kept the concept files apart.
    assert "appears in 12 of the " in everywhere.reason, everywhere.reason