portfolio-optimiser/tests/test_s40_cost_baseline_loadbearing.py

"""S4.0 load-bearing seam: the deterministic gate is ANCHORED to the project's real cost baseline.

Review finding F3: every stage of ``validate_proposal`` reasoned about the numbers the *proposal
itself* supplied, so a hallucinated cost line (an invented code, or a real code at an invented
magnitude) could clear the whole gate as long as its own arithmetic was internally consistent. The
reconciliation stage closes that: each ``affected_item`` must correspond to a line in the project's
cost baseline, within a configured tolerance.

Every RED here is a genuine OUTCOME FLIP, not a reason-string check: the fabricated proposals are
deliberately built to pass the P90 / nominal / method stages, so detaching the reconciliation makes
them ``ValidatedProposal`` again. Controls prove causality (a real baseline line, same shape,
validates), and the no-baseline arm proves the argument stays OPTIONAL (``None`` = pre-S4.0
behaviour, which is why the existing suite stands).

Measured detach points (see the session log): the reconciliation stage · the magnitude tolerance ·
the road-path wiring in ``run.py`` · the bundle-path wiring · the method-cap registry key (F8).
"""

from __future__ import annotations

import json
from pathlib import Path

import pytest
from conftest import SyntheticUsageChatClient
from pydantic import ValidationError

from portfolio_optimiser import okf
from portfolio_optimiser.ir import AffectedItem, CostBaseline, CostBaselineLine, SavingsProposal
from portfolio_optimiser.reference_domain import load_reference_projects
from portfolio_optimiser.run import run_project
from portfolio_optimiser.validator import (
    Rejection,
    ValidatedProposal,
    baseline_from_project,
    validate_proposal,
)

# The repo-local S4.0 fixture bundle: the ONLY bundle carrying a ``cost-baseline.json`` (the pre-
# amendment bundles deliberately have none — that is the optional-argument control below).
_DATA = Path(__file__).resolve().parents[1] / "src" / "portfolio_optimiser" / "data" / "bundles"
BASELINE_BUNDLE = _DATA / "bygg-energi-baseline-mikro"
PRE_AMENDMENT_BUNDLE = _DATA / "bygg-energi-mikro-a"

_VERDICT_INPUT = {"decision": "approved", "rationale": "expert reviewed (sim)"}

# FV42-GSV-E1's real cost line 05.2 (Asfalt Ab11): 4300 m2 x 215 NOK. Affected total 924500 ->
# degenerate P90 = 0.30 x 924500 = 277350, so claimed 200000 clears every pre-S4.0 stage.
_REAL_CODE = "05.2"
_REAL_QTY = 4300.0
_REAL_UNIT_COST = 215.0
_REAL_CLAIM = 200000.0

# The F3 scenario: an invented code carrying a 10 MNOK line. The claim is set at exactly the generic
# feasible (0.30 x 10 MNOK) so the fabrication is numerically IMPECCABLE — every pre-S4.0 stage
# passes it. Only the baseline reconciliation can reject it, which is what makes the detach a flip.
_FAKE_CODE = "XX"
_FAKE_UNIT_COST = 10_000_000.0
_FAKE_CLAIM = 3_000_000.0


def _fv42_baseline() -> CostBaseline:
    return baseline_from_project(
        next(p for p in load_reference_projects() if p.id == "FV42-GSV-E1")
    )


def _proposal(code: str, quantity: float, unit_cost: float, claimed: float) -> SavingsProposal:
    return SavingsProposal(
        project_id="FV42-GSV-E1",
        measure="Reduce scope",
        affected_items=[AffectedItem(code=code, quantity=quantity, unit_cost=unit_cost)],
        claimed_saving_nok=claimed,
        assumptions={},
    )


# --- Arm 1: the reconciliation stage itself -------------------------------------------------------


def test_fabricated_cost_code_is_rejected() -> None:
    """RED (F3): a proposal citing a cost code that exists nowhere in the project's baseline is
    rejected, even though its own arithmetic clears the LP/P90/nominal stages. Detach the
    reconciliation stage and the SAME proposal validates."""
    result = validate_proposal(
        _proposal(_FAKE_CODE, 1.0, _FAKE_UNIT_COST, _FAKE_CLAIM), baseline=_fv42_baseline()
    )
    assert isinstance(result, Rejection), "a hallucinated cost code must never reach validated"
    assert "unknown cost code" in result.reason
    assert _FAKE_CODE in result.reason


def test_real_baseline_line_still_validates() -> None:
    """Causality control: the same shape of proposal on a REAL baseline line validates — so the
    rejection above is caused by the code being absent from the baseline, not by the new stage
    rejecting everything."""
    result = validate_proposal(
        _proposal(_REAL_CODE, _REAL_QTY, _REAL_UNIT_COST, _REAL_CLAIM), baseline=_fv42_baseline()
    )
    assert isinstance(result, ValidatedProposal)


def test_baseline_is_optional_and_none_is_pre_s40_behaviour() -> None:
    """The baseline argument is OPTIONAL: with ``None`` the fabricated proposal validates exactly as
    it did before S4.0. This is the property the existing suite rests on — and the reason the RED
    above is a flip rather than a tightening of an already-rejecting path."""
    result = validate_proposal(_proposal(_FAKE_CODE, 1.0, _FAKE_UNIT_COST, _FAKE_CLAIM))
    assert isinstance(result, ValidatedProposal)


# --- Arm 2: the magnitude tolerance ---------------------------------------------------------------


def test_inflated_unit_cost_on_a_real_code_is_rejected() -> None:
    """RED: a REAL cost code at an invented unit_cost (+20%, well past the 5% default tolerance) is
    rejected. Detach the tolerance check and only the code-membership test remains — the inflated
    line then validates, because the code itself is genuine."""
    inflated = _REAL_UNIT_COST * 1.20
    result = validate_proposal(
        _proposal(_REAL_CODE, _REAL_QTY, inflated, _REAL_CLAIM), baseline=_fv42_baseline()
    )
    assert isinstance(result, Rejection)
    assert "unit_cost" in result.reason and _REAL_CODE in result.reason


def test_inflated_quantity_on_a_real_code_is_rejected() -> None:
    """RED: the same for quantity — a real code at an invented quantity (+20%) is rejected."""
    result = validate_proposal(
        _proposal(_REAL_CODE, _REAL_QTY * 1.20, _REAL_UNIT_COST, _REAL_CLAIM),
        baseline=_fv42_baseline(),
    )
    assert isinstance(result, Rejection)
    assert "quantity" in result.reason


def test_within_tolerance_deviation_is_admitted() -> None:
    """Causality control for the tolerance: a 2% deviation (rounding-scale, inside the 5% default)
    validates — the rejections above are caused by the SIZE of the deviation, not by any deviation
    at all."""
    result = validate_proposal(
        _proposal(_REAL_CODE, _REAL_QTY, _REAL_UNIT_COST * 1.02, _REAL_CLAIM),
        baseline=_fv42_baseline(),
    )
    assert isinstance(result, ValidatedProposal)


def test_tolerance_is_configurable() -> None:
    """The tolerance is config, not a constant: the same 2% deviation is rejected under a stricter
    caller-supplied tolerance."""
    result = validate_proposal(
        _proposal(_REAL_CODE, _REAL_QTY, _REAL_UNIT_COST * 1.02, _REAL_CLAIM),
        baseline=_fv42_baseline(),
        tolerance=0.001,
    )
    assert isinstance(result, Rejection)


# --- Arm 3: the loader (fail-fast, mirroring ``load_ir_projection``) -------------------------------


def test_bundle_baseline_loads_from_the_fixture() -> None:
    baseline = okf.load_cost_baseline(str(BASELINE_BUNDLE))
    assert baseline.project_id == "BYGG-ENERGI-BASELINE-MIKRO"
    assert baseline.items["ENERGI-TOTAL-EL"] == CostBaselineLine(quantity=180000, unit_cost=1.0)


def test_missing_baseline_is_fail_fast_but_optional_loader_returns_none() -> None:
    """Two deliberately different contracts over the same absence: the fail-fast loader raises (it
    is authoritative startup input, like ``load_ir_projection``), while the OPTIONAL loader the run
    path uses returns ``None`` — a bundle written before the amendment is not an error, it is simply
    un-anchored."""
    with pytest.raises(FileNotFoundError):
        okf.load_cost_baseline(str(PRE_AMENDMENT_BUNDLE))
    assert okf.load_optional_cost_baseline(str(PRE_AMENDMENT_BUNDLE)) is None


def test_malformed_baseline_raises_even_on_the_optional_path(tmp_path) -> None:
    """Fail-closed where it matters: a baseline that EXISTS but is malformed raises on BOTH loaders.
    Tolerating it would silently un-anchor the gate — the RAW-inbox skip rule stops at this layer."""
    (tmp_path / "cost-baseline.json").write_text(
        json.dumps({"project_id": "P", "items": {"01.1": {"quantity": 1}}}), encoding="utf-8"
    )
    with pytest.raises(ValidationError):
        okf.load_optional_cost_baseline(str(tmp_path))


# --- Arm 4: the run-path wiring (road + bundle) ---------------------------------------------------


def _reply(code: str, quantity: float, unit_cost: float, claimed: float) -> str:
    return json.dumps(
        {
            "measure": "Reduce scope",
            "affected_items": [{"code": code, "quantity": quantity, "unit_cost": unit_cost}],
            "claimed_saving_nok": claimed,
        }
    )


def _factory(reply: str):
    def factory(role: str):
        return SyntheticUsageChatClient(default_reply=reply)

    return factory


async def test_road_path_anchors_the_gate_to_the_reference_baseline(docs_dir, fresh_store) -> None:
    """RED (road wiring): a numerically-impeccable fabricated cost line is REJECTED end-to-end
    through ``run_project``. Detach the road-path baseline (stop passing it) and the same run
    returns a ValidatedProposal."""
    result = await run_project(
        "FV42-GSV-E1",
        "local",
        docs_dir=docs_dir,
        verdict_input=_VERDICT_INPUT,
        client_factory=_factory(_reply(_FAKE_CODE, 1.0, _FAKE_UNIT_COST, _FAKE_CLAIM)),
        store=fresh_store,
    )
    assert isinstance(result.outcome, Rejection)
    assert "unknown cost code" in result.outcome.reason


async def test_road_path_control_real_line_validates(docs_dir, fresh_store) -> None:
    """Causality control for the road wiring: the real 05.2 line validates through the same path."""
    result = await run_project(
        "FV42-GSV-E1",
        "local",
        docs_dir=docs_dir,
        verdict_input=_VERDICT_INPUT,
        client_factory=_factory(_reply(_REAL_CODE, _REAL_QTY, _REAL_UNIT_COST, _REAL_CLAIM)),
        store=fresh_store,
    )
    assert isinstance(result.outcome, ValidatedProposal)


async def test_bundle_path_anchors_when_the_bundle_declares_a_baseline(fresh_store) -> None:
    """RED (bundle wiring): a bundle that ships ``cost-baseline.json`` anchors its run — the
    fabricated line is rejected. Detach the bundle-path load and it validates again."""
    result = await run_project(
        "BYGG-ENERGI-BASELINE-MIKRO",
        "local",
        docs_dir=str(BASELINE_BUNDLE),
        bundle_dir=str(BASELINE_BUNDLE),
        verdict_input=_VERDICT_INPUT,
        client_factory=_factory(_reply(_FAKE_CODE, 1.0, 300000.0, 90000.0)),
        store=fresh_store,
    )
    assert isinstance(result.outcome, Rejection)
    assert "unknown cost code" in result.outcome.reason


async def test_pre_amendment_bundle_runs_unchanged(fresh_store) -> None:
    """Control + backward compatibility: the SAME fabricated reply validates against a bundle with
    no ``cost-baseline.json``. Anchoring is opt-in per bundle, so every pre-S4.0 bundle (including
    the commons-owned goldens) runs byte-identically to before."""
    result = await run_project(
        "BYGG-ENERGI-MIKRO-A",
        "local",
        docs_dir=str(PRE_AMENDMENT_BUNDLE),
        bundle_dir=str(PRE_AMENDMENT_BUNDLE),
        verdict_input=_VERDICT_INPUT,
        client_factory=_factory(_reply(_FAKE_CODE, 1.0, 300000.0, 90000.0)),
        store=fresh_store,
    )
    assert isinstance(result.outcome, ValidatedProposal)


# --- Arm 5: F8 — method caps keyed by config, not the literal measure string ----------------------


def test_method_cap_is_keyed_by_config_not_a_hardcoded_string() -> None:
    """F8: the method-specific cap comes from a REGISTRY the caller can supply. A caller-configured
    cap for a measure with no built-in entry rejects a proposal the generic P90 stage passes — so
    the rule is keyed by configuration, not by the ``energy_efficiency`` literal."""
    proposal = SavingsProposal(
        project_id="P-ASFALT",
        measure="asfalt_reduction",
        affected_items=[AffectedItem(code="05.2", quantity=100000, unit_cost=1.0)],
        claimed_saving_nok=20000,
        assumptions={},
    )
    assert isinstance(validate_proposal(proposal), ValidatedProposal)  # generic P90 = 30000
    capped = validate_proposal(proposal, method_caps={"asfalt_reduction": 0.10})
    assert isinstance(capped, Rejection)
    assert "method cap" in capped.reason