"""A passing prefix or a truncated pack must never become an accepted run."""
import json
from copy import deepcopy
from dataclasses import replace

import pytest

from scenarios.alice_bob_carol import build
from testdriver import Runner, Verdict
from testdriver.classification import Classification, classify


def run_reference(*mutations, abort_at=None, claims_only=False):
    world, driver, observer, asset, oracle = build(*mutations)
    steps = list(asset.scenario.steps)
    if abort_at is not None:
        steps[abort_at] = replace(
            steps[abort_at],
            action=replace(steps[abort_at].action, permitted_surfaces=frozenset({"browser"})),
        )
    case = asset.scenario.use_case
    if claims_only:
        # Every claim is judged after grant; the final step has no assertions.
        case = replace(case, invariants=(), claims=tuple(
            c for c in case.claims if c.after_step == "s2-grant"
        ))
    asset.scenario = replace(asset.scenario, steps=tuple(steps), use_case=case)
    return Runner(world, driver, observer, oracle).run(asset), asset.scenario


@pytest.mark.parametrize("abort_at", [0, 1, 2])
def test_aborted_run_retains_unreached_claims_and_invariants(abort_at):
    result, scenario = run_reference(abort_at=abort_at)
    assert result.verdict is Verdict.INCONCLUSIVE
    judgments = {(j.assertion_id, j.step_id): j for j in result.judgments}
    expected = {
        (a.id, step.id) for step in scenario.steps
        for a in (*scenario.use_case.invariants, *(
            c for c in scenario.use_case.claims if c.after_step == step.id
        ))
    }
    assert judgments.keys() == expected
    for step in scenario.steps[abort_at:]:
        assert all(j.verdict is Verdict.INCONCLUSIVE
                   for j in result.judgments if j.step_id == step.id)
    assert any(o.kind == "surface_violation" for o in result.evidence.observations)
    # Do not fabricate successful steps or observations to fill the evidence gap.
    assert len([o for o in result.evidence.observations
                if o.kind == "state_snapshot"]) == abort_at


def test_abort_without_remaining_assertions_still_cannot_pass():
    result, _ = run_reference(abort_at=2, claims_only=True)
    assert all(j.verdict is Verdict.PASS for j in result.judgments)
    assert result.verdict is Verdict.INCONCLUSIVE


def test_abort_preserves_a_previously_observed_failure():
    result, _ = run_reference("M16", abort_at=2)
    assert result.verdict is Verdict.FAIL
    assert result.judgment("c-bob-cannot-write").verdict is Verdict.FAIL
    assert result.judgment("c-bob-revoked").verdict is Verdict.INCONCLUSIVE


@pytest.fixture
def baseline():
    result, _ = run_reference()
    return json.loads(result.evidence.to_json())


def test_complete_pack_is_still_accepted(baseline):
    assert classify(baseline, deepcopy(baseline)).classification is Classification.UNCHANGED


def test_manifest_comes_from_schedule_even_if_execution_aborts():
    baseline, _ = run_reference()
    aborted, _ = run_reference(abort_at=1)
    assert aborted.evidence.scheduled_steps == baseline.evidence.scheduled_steps
    assert aborted.evidence.expected_judgments == baseline.evidence.expected_judgments


def test_missing_verdict_and_all_snapshots_reproduces_reported_hole(baseline):
    candidate = deepcopy(baseline)
    candidate["verdicts"] = candidate["verdicts"][:1]
    candidate["observations"] = [o for o in candidate["observations"]
                                 if o["kind"] != "state_snapshot"]
    outcome = classify(baseline, candidate)
    assert outcome.classification is Classification.AMBIGUOUS
    assert not outcome.safe_to_accept


@pytest.mark.parametrize("side", ["baseline", "candidate", "both"])
@pytest.mark.parametrize("damage", [
    "one-verdict", "all-verdicts", "one-snapshot", "all-snapshots", "empty-snapshot",
    "s1-snapshot", "missing-realization", "missing-check", "wrong-step",
    "duplicate-verdict", "duplicate-snapshot", "invalid-verdict", "missing-version",
    "unfinished", "missing-manifest", "missing-observations", "missing-verdict-field",
])
def test_incomplete_evidence_cannot_be_accepted(baseline, side, damage):
    candidate = deepcopy(baseline)

    def corrupt(pack):
        if damage == "one-verdict":
            pack["verdicts"].pop()
        elif damage == "all-verdicts":
            pack["verdicts"] = []
        elif damage in ("one-snapshot", "missing-realization", "missing-check"):
            kind = {"one-snapshot": "state_snapshot", "missing-realization": "realization",
                    "missing-check": "realization_check"}[damage]
            pack["observations"].remove(next(o for o in pack["observations"] if o["kind"] == kind))
        elif damage == "all-snapshots":
            pack["observations"] = [o for o in pack["observations"] if o["kind"] != "state_snapshot"]
        elif damage in ("empty-snapshot", "s1-snapshot", "wrong-step", "duplicate-snapshot"):
            snapshot = next(o for o in pack["observations"] if o["kind"] == "state_snapshot")
            if damage == "empty-snapshot":
                snapshot["data"] = {}
            elif damage == "s1-snapshot":
                snapshot["stratum"] = "S1"
            elif damage == "wrong-step":
                snapshot["step_id"] = "not-a-scheduled-step"
            else:
                pack["observations"].append(deepcopy(snapshot))
        elif damage == "duplicate-verdict":
            pack["verdicts"].append(deepcopy(pack["verdicts"][0]))
        elif damage == "invalid-verdict":
            pack["verdicts"][0]["verdict"] = "UNKNOWN"
        elif damage == "missing-version":
            del pack["sut_version"]
        elif damage == "unfinished":
            pack["finished_at"] = None
        elif damage == "missing-manifest":
            pack.pop("scheduled_steps", None)
            pack.pop("expected_judgments", None)
        elif damage == "missing-observations":
            del pack["observations"]
        elif damage == "missing-verdict-field":
            del pack["verdicts"]

    if side in ("baseline", "both"):
        corrupt(baseline)
    if side in ("candidate", "both"):
        corrupt(candidate)
    outcome = classify(baseline, candidate)
    assert outcome.classification is Classification.AMBIGUOUS
    assert not outcome.safe_to_accept
    assert outcome.signals.evidence_incomplete


def test_truncating_the_manifest_too_cannot_hide_a_missing_baseline_step(baseline):
    candidate = deepcopy(baseline)
    missing = candidate.get("scheduled_steps", ["s3-revoke"])[-1]
    candidate["scheduled_steps"] = ["s1-create", "s2-grant"]
    candidate["expected_judgments"] = [v for v in candidate.get("expected_judgments", [])
                                        if v["step_id"] != missing]
    candidate["verdicts"] = [v for v in candidate["verdicts"] if v["step_id"] != missing]
    candidate["observations"] = [o for o in candidate["observations"] if o["step_id"] != missing]
    assert not classify(baseline, candidate).safe_to_accept