"""P4 pkt. 0 — the demo's RESERVE bundle must anchor the deterministic gate to real cost lines.

The gap (egnethetsreview Funn 1, corrected by objection I1): the validator CAN reconcile a proposal
against the project's actual cost lines (S4.0, stage 0), but only when the knowledge base ships a
``cost-baseline.json``. No bundle under ``shared/examples/`` has that file — so in the demo the
validator reasoned only about numbers the proposal itself supplied, and an internally consistent
hallucination would clear the gate on stage.

The reserve cannot receive the file IN ``shared/``: the subtree is pull-only and demo criterion 8
requires the commons-owned goldens byte-unchanged. But that is a PLACEMENT constraint, not an
impossibility — the demo already runs on a COPY of the bundle, so a copy-and-extend variant gives an
anchored run without touching commons.

**Direction of derivation, and why it matters.** Here the baseline is derived FROM the scripted
register: the reserve's numbers are synthetic, so the script is the only ground truth available.
On GO day the direction reverses (plan P3 b) — the register's numbers are written FROM the
delivered ``cost-baseline.json``. Deriving in code, not by hand, is what stops the two from drifting
apart; drift is precisely the failure the 10 % test below models.

**The 10 % test** is the answer to "you generated the ground truth from the answer, so of course it
passes": deviate the baseline beyond the 5 % tolerance and the same, unchanged script must be
FORKASTET at stage 0 — before the solver — while the undeviated run is FORESLÅTT.
"""

from __future__ import annotations

import json
import subprocess
import sys

import pytest

from portfolio_optimiser import okf
from portfolio_optimiser.ir import CostBaseline, CostBaselineLine
from portfolio_optimiser.simulation import (
    ScriptedCandidate,
    _default_bundle_dir,
    baseline_from_scripted_candidate,
    materialize_anchored_bundle,
    simulate_learning_loop,
)
from portfolio_optimiser.validator import Rejection, ValidatedProposal


def _deviated(baseline: CostBaseline, factor: float) -> CostBaseline:
    """The same baseline with every quantity scaled — the delivered numbers disagreeing with the
    script's by ``factor``, which is exactly the GO-day risk this models."""
    return CostBaseline(
        project_id=baseline.project_id,
        items={
            code: CostBaselineLine(quantity=line.quantity * factor, unit_cost=line.unit_cost)
            for code, line in baseline.items.items()
        },
    )


async def test_the_anchored_reserve_runs_the_whole_demo(tmp_path) -> None:
    """CONTROL: with the baseline derived from the script, the anchored reserve behaves exactly as
    the demo narrates — hypothesis #1 falsified by the P90 stage, the corrected one validated.

    This is the control that gives the 10 % test its meaning: a gate that rejects everything proves
    nothing. It also pins WHICH stage rejects hypothesis #1 — if stage 0 started rejecting it, demo
    criterion 2 would still show a REJECTED and a VALIDATED line while silently demonstrating a
    different mechanism."""
    bundle = materialize_anchored_bundle(tmp_path / "forankret")
    result = await simulate_learning_loop(str(bundle), str(tmp_path))

    assert isinstance(result.run_a.outcome, ValidatedProposal)
    assert isinstance(result.run_b.outcome, ValidatedProposal)
    assert result.run_a.refinements, "no falsification was fed back — Step 5 is not being shown"
    assert "exceeds P90 feasible" in result.run_a.refinements[0].reason, (
        "hypothesis #1 was rejected by some other stage than the P90 one the demo narrates"
    )


async def test_a_deviating_baseline_forkaster_the_demo_run_before_the_solver(tmp_path) -> None:
    """LOAD-BEARING (the 10 % test): when the project's declared cost lines deviate by 10 % from
    the numbers the script asserts, the run is FORKASTET at stage 0 — with the reconciliation
    reason, not the P90 one.

    Goes RED the moment the demo stops being anchored: without the ``cost-baseline.json`` in the
    bundle the run path passes ``baseline=None``, stage 0 is skipped, and this same deviating
    number changes nothing at all (the run ends FORESLÅTT, as ``test_..._runs_the_whole_demo``
    above shows). The script is byte-identical in both tests — only the declared baseline moves."""
    baseline = _deviated(baseline_from_scripted_candidate(_only_candidate()), 1.10)
    bundle = materialize_anchored_bundle(tmp_path / "forankret", baseline=baseline)
    result = await simulate_learning_loop(str(bundle), str(tmp_path))

    outcome = result.run_a.outcome
    assert isinstance(outcome, Rejection), (
        "a proposal 10 % away from the project's declared cost lines was NOT rejected — the "
        "deterministic gate is not anchored to the baseline"
    )
    assert "outside the 5.0% tolerance" in outcome.reason
    assert "ENERGI-TOTAL-EL" in outcome.reason
    assert "P90" not in outcome.reason, (
        "rejected by the solver stage, not by the reconciliation stage 0 that must run BEFORE it"
    )


def test_the_reserve_itself_ships_no_baseline(tmp_path) -> None:
    """The materializer must ADD something the reserve genuinely lacks — and must leave the
    commons-owned bundle alone (criterion 8: the goldens stay byte-unchanged)."""
    reserve = _default_bundle_dir()
    assert okf.load_optional_cost_baseline(str(reserve)) is None, (
        "the shared reserve now ships a cost baseline — the copy-and-extend variant is obsolete "
        "and this whole seam should be re-measured"
    )

    bundle = materialize_anchored_bundle(tmp_path / "forankret")
    assert okf.load_optional_cost_baseline(str(bundle)) is not None, (
        "the materialized bundle is not readable by okf's own loader — the filename has drifted"
    )
    assert okf.load_optional_cost_baseline(str(reserve)) is None


def test_the_baseline_is_derived_from_the_scripted_register() -> None:
    """The baseline is DERIVED from the script's own cost lines, never typed alongside them: a
    hand-written copy is a second source of the same numbers, and two sources drift."""
    candidate = _only_candidate()
    derived = baseline_from_scripted_candidate(candidate)

    for reply in (candidate.overclaimed, candidate.corrected):
        for item in json.loads(reply)["affected_items"]:
            line = derived.items[item["code"]]
            assert (line.quantity, line.unit_cost) == (item["quantity"], item["unit_cost"])
    assert derived.project_id == candidate.project_id


def test_a_candidate_whose_two_replies_disagree_is_refused() -> None:
    """Validation, never repair. The two scripted replies must state the SAME cost lines: were they
    to differ, hypothesis #1 would be rejected by stage 0 instead of by P90, and the demo's
    REJECTED line would silently come from another mechanism than the one it narrates."""
    candidate = _only_candidate()
    skewed = ScriptedCandidate(
        project_id=candidate.project_id,
        overclaimed=candidate.overclaimed.replace("300000", "310000"),
        corrected=candidate.corrected,
        flip_key=candidate.flip_key,
    )
    with pytest.raises(ValueError):
        baseline_from_scripted_candidate(skewed)


def test_the_demo_entry_point_runs_the_anchored_reserve() -> None:
    """LOAD-BEARING on the CALL SITE: the thing the operator actually runs on stage must be the
    anchored variant. Goes RED if ``main`` is pointed back at the plain reserve.

    The declared baseline is printed because an anchoring nobody can see is an anchoring nobody can
    check: every other line of the demo is byte-identical whether the gate is anchored or not.

    **The first form of this test was vacuous, and the mutation caught it.** It asserted
    ``"kostbaseline erklært" in stdout`` — but the un-anchored branch read "ingen kostbaseline
    erklært", which CONTAINS that substring; and ``"ENERGI-TOTAL-EL" in stdout`` holds either way,
    because the Step-2 line prints the proposal's own cost lines. Both survived the mutation. The
    assertions below name the whole declared line and rule the other branch out explicitly."""
    proc = subprocess.run(
        [sys.executable, "-m", "portfolio_optimiser.simulation"],
        capture_output=True,
        text=True,
        check=False,
    )
    assert proc.returncode == 0, proc.stderr
    assert "kostbaseline erklært (ENERGI-TOTAL-EL 300000 x 1)" in proc.stdout, (
        "the demo ran against a bundle with no cost baseline — the deterministic gate on stage is "
        "reasoning only about the numbers the proposal supplied itself"
    )
    assert "validatorens stage 0 avstemmer" in proc.stdout
    assert "uten kostbaseline" not in proc.stdout


def _only_candidate() -> ScriptedCandidate:
    from portfolio_optimiser.simulation import _CANDIDATES, _PROJECT_ID

    (candidate,) = [c for c in _CANDIDATES if c.project_id == _PROJECT_ID]
    return candidate