"""What a round must prove before it is kept (learning-harness review round 3, Req 4.1, 5.2, 9.5, 9.6, 9.8).

The round loop was accepting and rejecting on numbers that did not mean what their names said: the
cross-family sweep counted every failing pair rather than the pairs this change broke, unscorable rows
voted against a round they cannot judge, cost was metered once after everything had been paid for, and a
stage that raised left no record at all. Each test here fails on exactly one of those.
"""

from __future__ import annotations

import json
from pathlib import Path

import pytest

from openultrasast.benchmark import ExpectedFinding
from openultrasast.findings import StaticFinding
from openultrasast.learning.detectors import FamilyConfig, write_default_configs
from openultrasast.learning.families import load_families
from openultrasast.learning.journal import Archive, LearningJournal
from openultrasast.learning.proposer import Proposal, ScriptedProposer
from openultrasast.learning.rounds import NoiseFloor, run_learning_round
from openultrasast.pairs import PairCase

VULN = "from flask import request\nimport os\n\n\ndef run():\n    os.system(request.args.get('cmd'))\n"
FIXED = "from flask import request\nimport subprocess\n\n\ndef run():\n    subprocess.run(['echo', 'x'], check=False)\n"


def _case(tmp_path: Path, name: str, *, split: str, family: str = "injection", unscorable: str | None = None) -> PairCase:
    (tmp_path / f"{name}-v.py").write_text(VULN)
    (tmp_path / f"{name}-f.py").write_text(FIXED)
    return PairCase(
        name=name,
        slice="vibe-py",
        language="python",
        origin="test",
        vuln_file=tmp_path / f"{name}-v.py",
        fixed_file=tmp_path / f"{name}-f.py",
        relpath="app.py",
        expected=(
            ExpectedFinding(
                cwe="CWE-78", vulnerability_class="x", path="app.py", evidence="", function="run", mechanism="other", family=family
            ),
        ),
        min_recall=1.0,
        fix_policy="silent",
        split=split,
        review_tier="seeded",
        unscorable=unscorable,
    )


def _finding(family: str) -> StaticFinding:
    return StaticFinding(
        finding_id="detector:app.py:6",
        path="app.py",
        title="t",
        severity="high",
        confidence="low",
        evidence_level="suspicion",
        rationale="r",
        line=6,
        function_name="run",
        reachability_status="unknown",
        reachability_evidence=[],
        reachability_conditions=[],
        tags=[f"family:{family}", "detector:x@0"],
        ranking_priority=0.0,
    )


def _proposal(text: str = "- ask about quoting\n") -> Proposal:
    return Proposal(hypothesis="ask about quoting", lever="checklist", change={"checklist.md": text}, predicted_affected=("train-a",))


@pytest.fixture
def world(tmp_path: Path):  # type: ignore[no-untyped-def]
    configs = tmp_path / "configs"
    write_default_configs(configs, load_families(), prompt="p", version="0")
    (configs / "injection" / "checklist.md").write_text("- old\n")
    return {
        "configs": configs,
        "cases": [_case(tmp_path, "train-a", split="train"), _case(tmp_path, "hold-a", split="holdout")],
        "journal": LearningJournal(tmp_path / "journal.jsonl"),
        "archive": Archive(tmp_path / "archive.jsonl"),
        "out": tmp_path / "out",
        "floors": {"injection": NoiseFloor(family="injection", k_runs=5, pairs=1, flaky_pairs=0, negative_flip_rate=0.0, budget_flips=0)},
        "root": tmp_path,
    }


def _run(world, proposal, build, **kwargs):  # type: ignore[no-untyped-def]
    return run_learning_round(
        world["cases"],
        family="injection",
        taxonomy=load_families(),
        configs_dir=world["configs"],
        proposer=ScriptedProposer([proposal] if proposal else []),
        scan_factory=build,
        model="m",
        journal=world["journal"],
        archive=world["archive"],
        floors=world["floors"],
        out_dir=world["out"],
        **kwargs,
    )


def _injection_improves(config: FamilyConfig):  # type: ignore[no-untyped-def]
    """Injection detects only once the proposed checklist lands; every other family finds nothing, ever."""

    def scan(root: Path) -> list[StaticFinding]:
        if root.name != "vuln" or config.family != "injection":
            return []
        return [_finding("injection")] if config.checklist.strip() == "- ask about quoting" else []

    return scan


# --- the sweep ---------------------------------------------------------------


def test_a_family_that_was_already_failing_does_not_reject_the_round(world) -> None:  # type: ignore[no-untyped-def]
    """Req 9.5 counts *negative flips*, not absolute failures.

    On the real corpus most pairs fail at round zero, so counting failures rejects every round for damage it
    did not do — and the harness then reports that it cannot improve."""
    world["cases"].append(_case(world["root"], "other-hold", split="holdout", family="access_control"))
    world["floors"]["access_control"] = NoiseFloor(
        family="access_control", k_runs=5, pairs=1, flaky_pairs=0, negative_flip_rate=0.0, budget_flips=0
    )
    record = _run(world, _proposal(), _injection_improves, sweep_families=("access_control",))
    assert record.sweep["access_control"] == 0, "access control failed before and after; this change flipped nothing"
    assert record.outcome == "accepted" and record.reason == "improved"


def test_a_family_this_change_really_broke_still_rejects_the_round(world) -> None:  # type: ignore[no-untyped-def]
    """The other arm: a pair that was correct before and is not after is a flip, and one is over the budget."""
    world["cases"].append(_case(world["root"], "other-hold", split="holdout", family="access_control"))
    world["floors"]["access_control"] = NoiseFloor(
        family="access_control", k_runs=5, pairs=1, flaky_pairs=0, negative_flip_rate=0.0, budget_flips=0
    )
    landed = {"yes": False}

    def build(config: FamilyConfig):  # type: ignore[no-untyped-def]
        def scan(root: Path) -> list[StaticFinding]:
            if root.name != "vuln":
                return []
            if config.family == "access_control":
                return [] if landed["yes"] else [_finding("access_control")]
            if config.checklist.strip() == "- ask about quoting":
                landed["yes"] = True
                return [_finding("injection")]
            return []

        return scan

    record = _run(world, _proposal(), build, sweep_families=("access_control",))
    assert record.sweep["access_control"] == 1
    assert record.outcome == "rejected" and record.reason == "collateral_regression"
    assert (world["configs"] / "injection" / "checklist.md").read_text() == "- old\n"


def test_an_unscorable_row_never_votes_in_the_sweep(world) -> None:  # type: ignore[no-untyped-def]
    """Req 4.1: an unscorable row leaves every denominator, and it certainly does not reject a round."""
    world["cases"].append(_case(world["root"], "other-hold", split="holdout", family="access_control", unscorable="identical_twin"))
    world["floors"]["access_control"] = NoiseFloor(
        family="access_control", k_runs=5, pairs=0, flaky_pairs=0, negative_flip_rate=0.0, budget_flips=0
    )
    record = _run(world, _proposal(), _injection_improves, sweep_families=("access_control",))
    assert record.sweep["access_control"] == 0 and record.outcome == "accepted"


def test_attribution_names_the_pairs_this_change_flipped_and_no_others(world) -> None:  # type: ignore[no-untyped-def]
    world["cases"].append(_case(world["root"], "other-hold", split="holdout", family="access_control"))
    world["floors"]["access_control"] = NoiseFloor(
        family="access_control", k_runs=5, pairs=1, flaky_pairs=0, negative_flip_rate=0.0, budget_flips=0
    )
    _run(world, _proposal(), _injection_improves, sweep_families=("access_control",))
    attribution = json.loads((world["out"] / "rounds" / "1" / "attribution.json").read_text())
    assert attribution["flipped_predicted"] == ["hold-a", "train-a"]
    assert attribution["flipped_unpredicted"] == [], "a pair that was already failing was never flipped by this round"


# --- cost, exceptions, the archive ------------------------------------------


def test_the_cap_stops_a_round_before_it_pays_for_the_next_stage(world) -> None:  # type: ignore[no-untyped-def]
    """Req 9.8 says stop, revert and record. Metering once, after every stage, can only ever record."""
    stages: list[str] = []

    def build(config: FamilyConfig):  # type: ignore[no-untyped-def]
        def scan(root: Path) -> list[StaticFinding]:
            stages.append(f"{config.family}:{root.name}")
            return []

        return scan

    spend = {"usd": 0.0}

    def spent() -> float:
        spend["usd"] += 1.0
        return spend["usd"]

    world["cases"].append(_case(world["root"], "other-hold", split="holdout", family="access_control"))
    record = _run(world, _proposal(), build, cost_cap_usd=0.5, spent_usd=spent, sweep_families=("access_control",))
    assert record.outcome == "reverted_cost" and record.reason == "cost_cap_exceeded"
    assert "access_control:vuln" not in stages, "the sweep ran after the cap was already crossed"
    assert (world["configs"] / "injection" / "checklist.md").read_text() == "- old\n"


def test_a_stage_that_raises_is_reverted_journalled_and_re_raised(world) -> None:  # type: ignore[no-untyped-def]
    """An endpoint failure mid-round is an outcome. Losing the round record loses the money it already spent."""

    def build(config: FamilyConfig):  # type: ignore[no-untyped-def]
        def scan(root: Path) -> list[StaticFinding]:
            if config.checklist.strip() == "- ask about quoting":
                raise RuntimeError("endpoint said no")
            return []

        return scan

    with pytest.raises(RuntimeError, match="endpoint said no"):
        _run(world, _proposal(), build)
    assert (world["configs"] / "injection" / "checklist.md").read_text() == "- old\n"
    outcomes = [(item.outcome, item.reason) for item in world["journal"].rounds()]
    assert outcomes == [("reverted", "stage_failed: RuntimeError")]  # the exception type is part of the record
    assert (world["out"] / "rounds" / "1" / "scores.json").is_file()


def test_a_rejected_version_is_archived_so_a_pair_it_alone_wins_is_not_lost(world) -> None:  # type: ignore[no-untyped-def]
    """Req 9.7: per-pair winners, or the loop collapses onto one lineage and forgets what a rejected try could do.

    This round wins both of its own pairs and is still rejected, because it broke another family. Version 1 is the
    only configuration that ever got those two pairs right; dropping it because the round as a whole lost is how a
    search collapses onto one lineage."""
    world["cases"].append(_case(world["root"], "other-hold", split="holdout", family="access_control"))
    world["floors"]["access_control"] = NoiseFloor(
        family="access_control", k_runs=5, pairs=1, flaky_pairs=0, negative_flip_rate=0.0, budget_flips=0
    )
    landed = {"yes": False}

    def build(config: FamilyConfig):  # type: ignore[no-untyped-def]
        def scan(root: Path) -> list[StaticFinding]:
            if root.name != "vuln":
                return []
            if config.family == "access_control":
                return [] if landed["yes"] else [_finding("access_control")]
            if config.checklist.strip() == "- ask about quoting":
                landed["yes"] = True
                return [_finding("injection")]
            return []

        return scan

    record = _run(world, _proposal(), build, sweep_families=("access_control",))
    assert record.outcome == "rejected" and record.reason == "collateral_regression"
    assert world["archive"].winners("injection") == {"train-a": "1", "hold-a": "1"}
    assert 'version = "0"' in (world["configs"] / "injection" / "family.toml").read_text(), "a rejected round is not versioned"


# --- the holdout refusal -----------------------------------------------------


def test_a_proposal_that_names_a_holdout_pair_is_refused_by_name(world) -> None:  # type: ignore[no-untyped-def]
    """Req 5.2: a candidate that touches a holdout pair is refused and the refusal names the pairs."""
    record = _run(
        world,
        Proposal(
            hypothesis="memorize the answer",
            lever="memory",
            change={"hard_negatives.jsonl": json.dumps({"pair": "hold-a", "note": "always flag"}) + "\n"},
            predicted_affected=("hold-a",),
        ),
        _injection_improves,
    )
    assert record.outcome == "refused_holdout"
    assert "hold-a" in record.reason
    assert (world["configs"] / "injection" / "hard_negatives.jsonl").read_text() == ""


def test_a_proposal_that_only_names_train_pairs_is_not_refused(world) -> None:  # type: ignore[no-untyped-def]
    record = _run(
        world,
        Proposal(
            hypothesis="remember this shape",
            lever="memory",
            change={"hard_negatives.jsonl": json.dumps({"pair": "train-a", "note": "shape"}) + "\n"},
            predicted_affected=("train-a",),
        ),
        _injection_improves,
    )
    assert record.outcome != "refused_holdout"


# --- round zero --------------------------------------------------------------


def test_round_zero_measures_each_family_with_its_own_detector(tmp_path: Path) -> None:
    """Req 8.2. One detector for every family means the generalist scores them all, and abstention earns no credit
    (`related(X, "unknown")` is lateral), so every family but `unknown` baselines at a structural zero."""
    from openultrasast.learning.rounds import run_baseline

    configs = tmp_path / "configs"
    write_default_configs(configs, load_families(), prompt="p", version="0")
    seen: list[str] = []

    def factory(config: FamilyConfig):  # type: ignore[no-untyped-def]
        def scan(root: Path) -> list[StaticFinding]:
            seen.append(config.family)
            return [_finding(config.family)] if root.name == "vuln" else []

        return scan

    cases = [_case(tmp_path, "inj", split="train"), _case(tmp_path, "acl", split="train", family="access_control")]
    report = run_baseline(
        cases,
        taxonomy=load_families(),
        configs_dir=configs,
        scan_factory=factory,
        model="m",
        out_dir=tmp_path / "out",
        k_runs=3,
    )
    assert set(seen) == {"injection", "access_control"}, "each family must be measured with its own configuration"
    assert report.metrics["injection"]["recall"] == 1.0 and report.metrics["access_control"]["recall"] == 1.0


def test_round_zero_reports_each_slice_separately(tmp_path: Path) -> None:
    """Req 8.4: vibe-py and agent-vfc are different worlds; one pooled number hides which one moved."""
    from openultrasast.learning.rounds import run_baseline

    configs = tmp_path / "configs"
    write_default_configs(configs, load_families(), prompt="p", version="0")
    web = _case(tmp_path, "web", split="train")
    agent = _case(tmp_path, "agent", split="train")
    object.__setattr__(agent, "slice", "agent-vfc")

    def factory(config: FamilyConfig):  # type: ignore[no-untyped-def]
        def scan(root: Path) -> list[StaticFinding]:
            return [_finding(config.family)] if root.name == "vuln" else []

        return scan

    report = run_baseline(
        [web, agent],
        taxonomy=load_families(),
        configs_dir=configs,
        scan_factory=factory,
        model="m",
        out_dir=tmp_path / "out",
        k_runs=3,
    )
    assert set(report.per_slice) == {"vibe-py/injection", "agent-vfc/injection"}
    payload = json.loads((tmp_path / "out" / "baseline" / "m" / "report.json").read_text())
    assert set(payload["per_slice"]) == {"vibe-py/injection", "agent-vfc/injection"}


def test_round_zero_refuses_fewer_than_three_runs(tmp_path: Path) -> None:
    """The floor exists because a single run misses most real changes; a baseline measured at K=1 is a noise floor
    of zero and every later round then inherits a budget of nothing."""
    from openultrasast.learning.rounds import run_baseline

    configs = tmp_path / "configs"
    write_default_configs(configs, load_families(), prompt="p", version="0")
    with pytest.raises(ValueError, match="three runs"):
        run_baseline(
            [_case(tmp_path, "inj", split="train")],
            taxonomy=load_families(),
            configs_dir=configs,
            scan_factory=lambda config: lambda root: [],
            model="m",
            out_dir=tmp_path / "out",
            k_runs=1,
        )


def test_a_round_journals_why_the_proposer_had_nothing_to_say(world) -> None:  # type: ignore[no-untyped-def]
    """`no_proposal` covers two different worlds: a proposer with nothing to add, and one that could not start.

    Measured: the meta-agent round journalled `no_proposal` while the real cause was an authentication failure in a
    provider seam pointing at the wrong vendor. A round that failed for a fixable configuration reason must not
    look identical to a model that considered the facts and declined."""

    class Mute:
        reason = "meta_agent_failed: RuntimeError"

        def propose(self, facts):  # type: ignore[no-untyped-def]
            del facts
            return None

    from openultrasast.learning.rounds import run_learning_round

    record = run_learning_round(
        world["cases"],
        family="injection",
        taxonomy=load_families(),
        configs_dir=world["configs"],
        proposer=Mute(),
        scan_factory=_injection_improves,
        model="m",
        journal=world["journal"],
        archive=world["archive"],
        floors=world["floors"],
        out_dir=world["out"],
    )
    assert record.outcome == "rejected"
    assert record.reason == "no_proposal: meta_agent_failed: RuntimeError"


def test_a_round_that_dies_before_it_applies_anything_is_still_journalled(world) -> None:  # type: ignore[no-untyped-def]
    """Measured: round 5 died on a network read during its *first* stage and left no record at all.

    The exception path was wrapped around the stages after the proposal is applied, because those are the ones that
    have something to revert. The ones before it had already spent money."""

    def build(config: FamilyConfig):  # type: ignore[no-untyped-def]
        def scan(root: Path) -> list[StaticFinding]:
            raise ConnectionError("the body stopped arriving")

        return scan

    with pytest.raises(ConnectionError):
        _run(world, _proposal(), build)
    outcomes = [(item.outcome, item.reason) for item in world["journal"].rounds()]
    assert outcomes == [("reverted", "stage_failed: ConnectionError")]
    assert (world["out"] / "rounds" / "1").is_dir()
    assert (world["configs"] / "injection" / "checklist.md").read_text() == "- old\n"