portfolio-optimiser/tests/test_costsim_loadbearing.py

"""S3.6 costsim (kostnadssimulering) — offline, MAF-free, deterministic load-bearing seams.

``costsim`` estimates token/cost for a portfolio run BEFORE running (what-if over the model-map ×
effort levels), with pricing as schema-validated config. It is MAF-free (reads ``model_map.json`` as
plain data via ``__file__``-relative path, never imports ``backends``/``budget``/``contracts``) —
proven load-bearing by BOTH the direct-import AST guard (``test_okf_is_maf_free`` covering
``costsim.py``) AND the transitive import-graph seam below.
"""

from __future__ import annotations

import ast
import subprocess
import sys
from pathlib import Path

import pytest

from portfolio_optimiser import costsim

_COSTSIM = Path(__file__).resolve().parents[1] / "src" / "portfolio_optimiser" / "costsim.py"

_PRICING = {
    "source": "loadbearing-test prices",
    "date": "2026-07-15",
    "models": {
        "m-known": {
            "ore_per_1k_tokens": 20,
            "quality_guidance": {"note": "known model", "source": "test-src"},
        }
    },
}

_TWO_MODEL_PRICING = {
    "source": "loadbearing-test prices",
    "date": "2026-07-15",
    "models": {
        "m-cheap": {"ore_per_1k_tokens": 10},
        "m-dear": {"ore_per_1k_tokens": 50},
    },
}


def test_costsim_registered_maf_free() -> None:
    """Meta: costsim.py is registered in the MAF-free guard list, so ``test_okf_is_maf_free``
    actually scans it — otherwise the MAF-free claim would be green-but-dead (never checked)."""
    from tests.test_okf import _MAF_FREE_MODULES

    assert "costsim.py" in _MAF_FREE_MODULES


def test_costsim_import_is_maf_free() -> None:
    """The genuine transitive-import seam: loading costsim.py's module body in ISOLATION must NOT
    pull ``agent_framework``/``mcp`` into ``sys.modules``. Loaded standalone via
    ``spec_from_file_location`` — NOT as ``portfolio_optimiser.costsim``, since the package
    ``__init__`` imports MAF-bound ``run``/``contracts`` and would mask costsim's own cleanliness.
    The AST guard (``test_okf_is_maf_free``) only catches DIRECT imports; a transitive
    ``from portfolio_optimiser.contracts import ...`` in costsim would slip past it but trip THIS
    check — ``exec_module`` runs costsim's import statements, so any MAF-bound import lands
    ``agent_framework`` in ``sys.modules``. Detach point: add such an import → RED."""
    check = (
        "import importlib.util, sys\n"
        f"spec = importlib.util.spec_from_file_location('costsim_standalone', {str(_COSTSIM)!r})\n"
        "mod = importlib.util.module_from_spec(spec)\n"
        "spec.loader.exec_module(mod)\n"
        "assert 'agent_framework' not in sys.modules, 'agent_framework leaked into costsim import graph'\n"
        "assert 'mcp' not in sys.modules, 'mcp leaked into costsim import graph'\n"
    )
    result = subprocess.run([sys.executable, "-c", check], capture_output=True, text=True)
    assert result.returncode == 0, result.stderr


def test_missing_price_for_model_fails_fast() -> None:
    """SC1: a genuine (non-placeholder) model absent from the price map fails fast. Detach point:
    remove the presence-check raise in ``_price_ore_per_1k`` → a guessed/0 price is returned → RED."""
    pricing = costsim.PricingContract(**_PRICING)
    with pytest.raises(ValueError, match="missing price for"):
        costsim._price_ore_per_1k("m-unknown", pricing)


def test_priced_model_returns_ore_rate() -> None:
    """Control for the fail-fast seam: a priced model returns its øre rate (proves the raise fires
    only on genuine absence, not always)."""
    pricing = costsim.PricingContract(**_PRICING)
    assert costsim._price_ore_per_1k("m-known", pricing) == 20


def test_placeholder_model_is_unpriced() -> None:
    """The defined azure-placeholder path: a ``REPLACE-WITH-*`` deployment id returns ``None`` (not
    priced, not a crash) — so ``--profile azure`` (all placeholders) is well-defined."""
    pricing = costsim.PricingContract(**_PRICING)
    assert costsim._price_ore_per_1k("REPLACE-WITH-FOUNDRY-DEPLOYMENT", pricing) is None


def test_quality_guidance_is_sourced_never_number() -> None:
    """Brief Goal 4: per-model quality trade-offs are sourced GUIDANCE (prose note + provenance
    source), never a bare measured number. Detach point: ship a guidance entry without a source →
    the ``QualityGuidance.source`` (min_length=1) requirement makes load RED."""
    pricing = costsim.load_pricing()
    guided = [p for p in pricing.models.values() if p.quality_guidance is not None]
    assert guided, "bundled pricing must carry per-model quality guidance"
    for price in guided:
        assert price.quality_guidance is not None
        assert price.quality_guidance.source.strip()
        assert price.quality_guidance.note.strip()


def test_estimate_is_deterministic() -> None:
    """SC2 (determinism): identical inputs → identical integer-øre estimate, reproducibly."""
    pricing = costsim.PricingContract(**_PRICING)
    a = costsim.estimate_portfolio_ore("m-known", "high", pricing, n_projects=4)
    b = costsim.estimate_portfolio_ore("m-known", "high", pricing, n_projects=4)
    assert a == b


def test_estimate_scales_with_model_and_effort() -> None:
    """SC2 (scaling): the estimate varies with BOTH model and effort. Detach point: drop the
    ``EFFORT_FACTORS[effort]`` term (e.g. hard-code 100%) → low and high collapse to equal → the
    ``low != high`` assertion goes RED. Control: same model + same effort → identical (isolates the
    effort variable, so a pass cannot be incidental)."""
    pricing = costsim.PricingContract(**_TWO_MODEL_PRICING)
    low = costsim.estimate_run_ore("m-cheap", "low", pricing)
    high = costsim.estimate_run_ore("m-cheap", "high", pricing)
    dear_high = costsim.estimate_run_ore("m-dear", "high", pricing)
    assert low != high, "effort must scale the estimate"
    assert dear_high != high, "model must scale the estimate"
    # control: same model + same effort → identical (not incidental)
    assert costsim.estimate_run_ore("m-cheap", "high", pricing) == high


def test_azure_placeholder_rows_unpriced() -> None:
    """The defined azure path: ``--profile azure`` ships REPLACE-WITH-* placeholders → rows are
    unpriced (``estimat_ore`` None, placeholder label), NEVER a crash. Uses the bundled config."""
    pricing = costsim.load_pricing()
    table = costsim.build_estimate_table("azure", ["standard"], pricing, n_projects=4)
    assert table["rows"], "azure profile must still produce rows"
    for row in table["rows"]:
        assert row["estimat_ore"] is None
        assert "placeholder" in row["estimat_type"]


def test_table_carries_kost_mot_verdi_field() -> None:
    """SC5: the table carries a top-level ``kost_mot_verdi`` field ready for the S5.4 value report.
    Detach point: remove the field from ``build_estimate_table`` → RED."""
    pricing = costsim.PricingContract(**_TWO_MODEL_PRICING)
    table = costsim.build_estimate_table(
        "p", ["standard"], pricing, n_projects=1, model_map={"p": {"proposer": "m-cheap"}}
    )
    assert "kost_mot_verdi" in table
    assert "kjoring_kostet_ore" in table["kost_mot_verdi"]


def test_row_carries_sourced_quality_guidance() -> None:
    """Brief Goal 4: a priced row surfaces ``kvalitets_veiledning`` with a source (guidance with
    kilde, never a bare number). Detach point: drop ``kvalitets_veiledning`` from the row → RED."""
    pricing = costsim.PricingContract(**_PRICING)  # m-known carries guidance
    table = costsim.build_estimate_table(
        "p", ["standard"], pricing, n_projects=1, model_map={"p": {"proposer": "m-known"}}
    )
    row = table["rows"][0]
    assert row["kvalitets_veiledning"] is not None
    assert row["kvalitets_veiledning"]["source"].strip()


def test_table_is_byte_deterministic() -> None:
    """Serialized table is byte-stable across identical inputs (sort_keys/indent/LF)."""
    pricing = costsim.PricingContract(**_TWO_MODEL_PRICING)
    mm = {"p": {"proposer": "m-cheap", "checker": "m-dear"}}
    t1 = costsim.build_estimate_table("p", ["low", "high"], pricing, n_projects=3, model_map=mm)
    t2 = costsim.build_estimate_table("p", ["low", "high"], pricing, n_projects=3, model_map=mm)
    assert costsim.dump_estimate_table(t1).encode() == costsim.dump_estimate_table(t2).encode()


def _costsim_ast() -> ast.Module:
    return ast.parse(_COSTSIM.read_text(encoding="utf-8"))


def test_no_network_path_in_module() -> None:
    """SC4: costsim imports NO network library — offline by construction. Detach point: add a
    ``urllib``/``http``/``socket`` import → RED."""
    net = {"socket", "urllib", "http", "requests", "httpx", "ftplib", "smtplib"}
    imported: list[str] = []
    for node in ast.walk(_costsim_ast()):
        if isinstance(node, ast.Import):
            imported += [a.name.split(".")[0] for a in node.names]
        elif isinstance(node, ast.ImportFrom):
            imported.append((node.module or "").split(".")[0])
    offenders = sorted(set(imported) & net)
    assert offenders == [], f"costsim must have no network import, found: {offenders}"


def test_costsim_source_has_no_float_literal() -> None:
    """SC3 supporting guard (well-defined): costsim is pure integer-øre, so ANY ``float`` literal in
    its source is either a stray hardcoded price or a no-float-invariant violation. Detach point:
    hardcode a float price (e.g. ``0.03``) → RED. The behavioral sentinel test below is the PRIMARY
    price-from-config seam; this literal check backs it up without the brittle allowlist a
    'price-shaped number' scan would need."""
    floats = [
        node.value
        for node in ast.walk(_costsim_ast())
        if isinstance(node, ast.Constant) and isinstance(node.value, float)
    ]
    assert floats == [], (
        f"costsim must contain no float literal (integer øre only), found: {floats}"
    )


def test_price_comes_from_config() -> None:
    """SC3 PRIMARY seam (behavioral): a sentinel price in injected config flows into the estimate. A
    hardcoded price shadowing config would NOT yield the sentinel-derived value → RED."""
    sentinel = {
        "source": "sentinel",
        "date": "2026-07-15",
        "models": {"m-x": {"ore_per_1k_tokens": 999_999}},
    }
    pricing = costsim.PricingContract(**sentinel)
    expected = 100_000 * 999_999 // 1000  # standard effort (100%), default max_tokens
    assert costsim.estimate_run_ore("m-x", "standard", pricing) == expected