"""Admission, crystallization and intent revisions must agree on safe evidence."""
from copy import deepcopy
from dataclasses import replace
import json

import pytest

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


def pack(*mutations, change=None, abort=False):
    world, driver, observer, asset, oracle = build(*mutations)
    if change:
        asset.scenario = replace(asset.scenario, use_case=change(asset.scenario.use_case))
    if abort:
        steps = list(asset.scenario.steps)
        steps[1] = replace(steps[1], action=replace(
            steps[1].action, permitted_surfaces=frozenset({"browser"})))
        asset.scenario = replace(asset.scenario, steps=tuple(steps))
    return json.loads(Runner(world, driver, observer, oracle).run(asset).evidence.to_json())


def change_claim(**changes):
    return lambda case: replace(case, claims=tuple(
        replace(c, **changes) if c.id == "c-bob-revoked" else c for c in case.claims
    ))


@pytest.mark.parametrize("mutation", ["M17", "M15", "M16", "M18"])
def test_failing_baseline_cannot_authorize_same_failure_or_fixed_run(mutation):
    failing = pack(mutation)
    assert any(v["verdict"] == "FAIL" for v in failing["verdicts"])
    for candidate in (deepcopy(failing), pack()):
        outcome = classify(failing, candidate)
        assert not outcome.safe_to_accept
        assert outcome.classification is Classification.AMBIGUOUS
        assert "baseline" in outcome.reason


@pytest.mark.parametrize("damage", ["abort", "snapshots", "verdict", "failure", "inconclusive"])
def test_repeated_invalid_runs_cannot_crystallize(damage):
    packs = [pack("M17") if damage == "failure" else pack(abort=damage == "abort")
             for _ in range(3)]
    for candidate in packs:
        if damage == "snapshots":
            candidate["observations"] = [o for o in candidate["observations"]
                                          if o["kind"] != "state_snapshot"]
        elif damage == "verdict":
            candidate["verdicts"].pop()
        elif damage == "inconclusive":
            candidate["verdicts"][0]["verdict"] = "INCONCLUSIVE"
    report = assess_stability(packs)
    assert not report.stable
    assert not report.trajectories
    assert report.reason


def test_one_bad_run_in_an_otherwise_stable_window_prevents_freezing():
    packs = [pack(), pack(abort=True), pack()]
    assert not assess_stability(packs).stable


def test_replaying_one_receipt_does_not_count_as_three_runs():
    baseline = pack()
    assert not assess_stability([deepcopy(baseline) for _ in range(3)]).stable


def test_complete_passing_runs_still_classify_and_crystallize():
    packs = [pack() for _ in range(3)]
    assert classify(packs[0], packs[1]).classification is Classification.UNCHANGED
    assert assess_stability(packs).stable


@pytest.mark.parametrize("changes", [
    {"text": "Revocation is optional"},
    {"source_ref": "new-independent-spec/revocation-v2"},
    {"predicate": lambda obs: True},
])
def test_same_id_does_not_hide_a_changed_claim(changes):
    before, after = pack(), pack(change=change_claim(**changes))
    assert classify(before, after).classification is Classification.INTENT_CHANGED
    assert not assess_stability([before, after, pack()]).stable


def test_invariant_changes_are_intent_changes_too():
    def change(case):
        return replace(case, invariants=(replace(case.invariants[0], predicate=lambda obs: True),
                                         *case.invariants[1:]))
    assert classify(pack(), pack(change=change)).classification is Classification.INTENT_CHANGED


def test_narrative_changes_require_intent_review():
    assert classify(pack(), pack(change=lambda c: replace(c, narrative="New policy"))) \
        .classification is Classification.INTENT_CHANGED


def threshold(value):
    return lambda obs: len(obs["audit:R"]) >= value


def default_threshold(value):
    return lambda obs, floor=value: len(obs["audit:R"]) >= floor


@pytest.mark.parametrize("factory", [threshold, default_threshold])
def test_captured_predicate_values_are_part_of_the_revision(factory):
    first = pack(change=change_claim(predicate=factory(0)))
    second = pack(change=change_claim(predicate=factory(1)))
    assert classify(first, second).classification is Classification.INTENT_CHANGED
    assert classify(first, pack(change=change_claim(predicate=factory(0)))).safe_to_accept


POLICY_FLOOR = 0


def helper(obs):
    return len(obs["audit:R"]) >= POLICY_FLOOR


def predicate_using_helper(obs):
    return helper(obs)


def test_global_values_and_helpers_are_part_of_the_revision(monkeypatch):
    first = pack(change=change_claim(predicate=predicate_using_helper))
    monkeypatch.setitem(globals(), "POLICY_FLOOR", 1)
    second = pack(change=change_claim(predicate=predicate_using_helper))
    assert classify(first, second).classification is Classification.INTENT_CHANGED
    monkeypatch.setitem(globals(), "helper", lambda obs: True)
    third = pack(change=change_claim(predicate=predicate_using_helper))
    assert classify(second, third).classification is Classification.INTENT_CHANGED


def test_unidentifiable_callable_cannot_be_automatically_accepted():
    class Opaque:
        def __call__(self, obs):
            return True
    packs = [pack(change=change_claim(predicate=Opaque())) for _ in range(3)]
    assert not classify(packs[0], packs[1]).safe_to_accept
    assert not assess_stability(packs).stable


def test_legacy_pack_without_intent_revisions_requires_rerun():
    before, after = pack(), pack()
    after.pop("intent_revisions", None)
    assert not classify(before, after).safe_to_accept
    assert not assess_stability([after, pack(), pack()]).stable


def test_predicate_location_does_not_change_revision():
    from types import FunctionType
    from scenarios.alice_bob_carol import USE_CASE
    from testdriver.revisions import intent_revisions

    original = USE_CASE.claims[0].predicate
    moved = FunctionType(original.__code__.replace(
        co_filename="/a/different/checkout/scenario.py", co_firstlineno=999,
    ), original.__globals__)
    changed = replace(USE_CASE, claims=(replace(USE_CASE.claims[0], predicate=moved),
                                       *USE_CASE.claims[1:]))
    assert intent_revisions(USE_CASE) == intent_revisions(changed)


def test_revisions_are_stable_across_processes():
    import os
    import subprocess
    import sys
    from pathlib import Path
    from scenarios.alice_bob_carol import USE_CASE
    from testdriver.revisions import intent_revisions

    root = Path(__file__).resolve().parents[1]
    output = subprocess.check_output([
        sys.executable, "-c",
        "import json; from scenarios.alice_bob_carol import USE_CASE; "
        "from testdriver.revisions import intent_revisions; "
        "print(json.dumps(intent_revisions(USE_CASE)))",
    ], cwd=root, env={**os.environ, "PYTHONPATH": os.pathsep.join((str(root / "src"), str(root)))},
       text=True)
    assert json.loads(output) == intent_revisions(USE_CASE)


def test_captured_values_are_hashed_not_retained():
    secret = "synthetic-private-dependency-do-not-retain"
    predicate = lambda obs: bool(secret) and obs["probe_read:bob:R"] is False
    result = pack(change=change_claim(predicate=predicate))
    assert result["intent_revisions"]["c-bob-revoked"] is not None
    assert secret not in json.dumps(result)


def test_schedule_change_is_an_intent_change():
    before = pack()
    after = pack(change=change_claim(after_step="s1-create", predicate=lambda obs: True))
    assert classify(before, after).classification is Classification.INTENT_CHANGED


def test_failed_baseline_realization_does_not_authorize_automatic_acceptance():
    before, after = pack(), pack()
    next(o for o in before["observations"]
         if o["kind"] == "realization")["data"]["raised"] = "Unrealized"
    assert not classify(before, after).safe_to_accept


def test_unknown_baseline_postcondition_does_not_authorize_automatic_acceptance():
    before, after = pack(), pack()
    next(o for o in before["observations"]
         if o["kind"] == "realization_check")["data"]["postcondition_met"] = None
    assert not classify(before, after).safe_to_accept


def test_dynamic_global_lookup_is_not_given_a_misleading_revision():
    def dynamic(obs):
        return globals()["POLICY_FLOOR"] <= len(obs["audit:R"])
    before, after = pack(change=change_claim(predicate=dynamic)), pack(change=change_claim(predicate=dynamic))
    assert before["intent_revisions"]["c-bob-revoked"] is None
    assert not classify(before, after).safe_to_accept


@pytest.mark.parametrize("invalid", [None, "true", 1])
def test_one_unverified_postcondition_prevents_acceptance_and_freezing(invalid):
    runs = [pack() for _ in range(3)]
    next(o for o in runs[1]["observations"]
         if o["kind"] == "realization_check")["data"]["postcondition_met"] = invalid
    assert not classify(runs[0], runs[1]).safe_to_accept
    assert not assess_stability(runs).stable