from __future__ import annotations

import pytest

from app.intelligence.leaver_risk import (
    LEAVER_RISK_VERSION,
    LeaverRiskInput,
    aggregate_leaver_risk,
    build_leaver_risk,
)


def test_empty_leaver_is_low_and_versioned() -> None:
    result = build_leaver_risk(LeaverRiskInput())
    assert result.score == 0 and result.level == "low"
    assert result.blast_radius == 0 and result.risk_version == LEAVER_RISK_VERSION


def test_missing_successor_is_critical_even_without_known_resources() -> None:
    result = build_leaver_risk(LeaverRiskInput(successor_available=False))
    assert result.level == "critical" and result.score == 80
    assert result.reasons == ("successor_missing",)


def test_privileged_overdue_and_handover_facts_are_explainable() -> None:
    result = build_leaver_risk(LeaverRiskInput(
        resource_counts=(("permission", 2), ("cloud_scope", 1)),
        pending_count=2, overdue_count=1, missing_handover_count=1,
        privileged_count=1, data_handover_complete=False, blocked=True,
    ))
    assert result.level == "critical" and result.score == 80
    assert result.blast_radius == 3
    assert result.reasons == (
        "data_handover_incomplete", "pending_items_overdue",
        "privileged_access_present", "ownership_handover_missing",
        "offboarding_blocked",
    )


def test_resources_are_sorted_for_stable_hashes() -> None:
    result = build_leaver_risk(LeaverRiskInput(
        resource_counts=(("seat", 3), ("account", 1)),
    ))
    assert result.resource_counts == (("account", 1), ("seat", 3))


def test_aggregate_is_anonymous_and_empty_safe() -> None:
    assert aggregate_leaver_risk(()) == {
        "leaver_count": 0, "critical_count": 0, "high_count": 0,
        "blocked_count": 0, "pending_count": 0, "overdue_count": 0,
        "blast_radius": 0, "missing_handover_count": 0, "privileged_count": 0,
    }
    totals = aggregate_leaver_risk((
        LeaverRiskInput(resource_counts=(("asset", 2),), blocked=True),
        LeaverRiskInput(pending_count=1, overdue_count=1, successor_available=False),
    ))
    assert totals["leaver_count"] == 2 and totals["critical_count"] == 2
    assert totals["blocked_count"] == 1 and totals["blast_radius"] == 2


@pytest.mark.parametrize("kwargs", [
    {"resource_counts": (("unknown", 1),)},
    {"resource_counts": (("asset", -1),)},
    {"pending_count": -1}, {"pending_count": 1, "overdue_count": 2},
    {"resource_counts": (("asset", 1),), "missing_handover_count": 2},
])
def test_invalid_fact_contract_fails_closed(kwargs: dict[str, object]) -> None:
    with pytest.raises(ValueError):
        LeaverRiskInput(**kwargs)