from __future__ import annotations

from pathlib import Path

import pytest

from k1link.laboratory.vegetation_mission_policy import (
    VegetationMissionPolicyError,
    load_vegetation_mission_policy,
    resolve_terrain_policy,
)

REPOSITORY_ROOT = Path(__file__).resolve().parents[1]
POLICY_PATH = (
    REPOSITORY_ROOT / "config" / "perception" / "lab-v1-vegetation-mission-policy-v1.json"
)


def _policy() -> dict[str, object]:
    return load_vegetation_mission_policy(POLICY_PATH, repository_root=REPOSITORY_ROOT)


def test_presets_are_defaults_and_explicit_mission_rule_wins() -> None:
    policy = _policy()

    urban_default = resolve_terrain_policy(
        policy,
        preset_id="urban",
        material_class="grass",
        evidence_state="VEGETATION_POTENTIALLY_TRAVERSABLE",
    )
    assert urban_default.requested_action == "NO_GO"
    assert urban_default.effective_action == "NO_GO"
    assert urban_default.policy_source == "selected_preset_default"

    explicit_allow = resolve_terrain_policy(
        policy,
        preset_id="urban",
        material_class="grass",
        evidence_state="VEGETATION_POTENTIALLY_TRAVERSABLE",
        mission_rules={"grass": "ALLOW"},
    )
    assert explicit_allow.requested_action == "ALLOW"
    assert explicit_allow.effective_action == "ALLOW"
    assert explicit_allow.policy_source == "explicit_mission_rule"
    assert explicit_allow.actuation_authority is False


def test_offroad_grass_is_high_cost_until_mission_changes_it() -> None:
    decision = resolve_terrain_policy(
        _policy(),
        preset_id="offroad",
        material_class="grass",
        evidence_state="VEGETATION_POTENTIALLY_TRAVERSABLE",
    )
    assert decision.requested_action == "HIGH_COST"
    assert decision.effective_action == "HIGH_COST"
    assert decision.safety_reason is None


@pytest.mark.parametrize(
    "state",
    [
        "UNOBSERVED",
        "NEGATIVE_OR_UNSUPPORTED",
        "RIGID_OR_UNKNOWN_OBSTACLE",
        "VEGETATION_UNKNOWN",
        "VEGETATION_WITH_RIGID_GEOMETRY",
    ],
)
def test_mission_allow_never_clears_hard_safety_interlock(state: str) -> None:
    decision = resolve_terrain_policy(
        _policy(),
        preset_id="offroad",
        material_class="grass",
        evidence_state=state,
        mission_rules={"grass": "ALLOW"},
    )
    assert decision.requested_action == "ALLOW"
    assert decision.effective_action == "NO_GO"
    assert decision.safety_reason == f"hard_safety_interlock:{state}"


def test_missing_semantics_and_support_fail_closed() -> None:
    decision = resolve_terrain_policy(
        _policy(),
        preset_id="rural",
        material_class=None,
        evidence_state=None,
    )
    assert decision.material_class == "vegetation_unknown"
    assert decision.evidence_state == "UNOBSERVED"
    assert decision.effective_action == "NO_GO"


def test_woody_material_cannot_be_enabled_by_mission() -> None:
    with pytest.raises(
        VegetationMissionPolicyError,
        match="material cannot be overridden by a mission: tree_or_trunk",
    ):
        resolve_terrain_policy(
            _policy(),
            preset_id="offroad",
            material_class="tree_or_trunk",
            evidence_state="SUPPORTED_GROUND",
            mission_rules={"tree_or_trunk": "ALLOW"},
        )


def test_unknown_material_is_treated_as_unknown_vegetation() -> None:
    decision = resolve_terrain_policy(
        _policy(),
        preset_id="offroad",
        material_class="provider_specific_leaf",
        evidence_state="SUPPORTED_GROUND",
    )
    assert decision.material_class == "vegetation_unknown"
    assert decision.effective_action == "NO_GO"
    assert decision.safety_reason == "hard_safety_interlock:vegetation_unknown"