"""test_programme_gates.py — T21.2 §21.2G: mandatory-gate accounting."""
from __future__ import annotations
import sys
from pathlib import Path
import pytest
REPO = Path(__file__).resolve().parent.parent
sys.path.insert(0, str(REPO / "src"))
from rune import programme_gates as pg  # noqa: E402


def test_212g1_mandatory_cannot_become_optional():
    g = pg.GateAccounting()
    g.declare("A", mandatory=True, requirement="do the thing")
    with pytest.raises(pg.GateDemotionError):
        g.record("A", "OPTIONAL_SKIPPED")


def test_212g2_unrun_mandatory_blocks_acceptance():
    g = pg.GateAccounting()
    g.declare("A", mandatory=True, requirement="a")
    g.declare("B", mandatory=True, requirement="b")
    g.declare("C", mandatory=True, requirement="c")
    g.record("A", "PASS", evidence="done")
    g.record("B", "PASS", evidence="done")
    # C not run
    ok, blockers = g.can_accept()
    assert ok is False
    assert "C: UNRUN" in blockers[0]


def test_212g3_blocked_gate_visible_not_pass():
    g = pg.GateAccounting()
    g.declare("C", mandatory=True, requirement="c")
    g.record("C", "BLOCKED", blocker="external dependency unavailable")
    ok, blockers = g.can_accept()
    assert ok is False
    assert "BLOCKED" in blockers[0]


def test_212g4_user_waiver_allows():
    g = pg.GateAccounting()
    g.declare("C", mandatory=True, requirement="c")
    g.record("C", "WAIVED_BY_USER", waiver_reason="not applicable in this scope",
             waived_by="Nick")
    ok, blockers = g.can_accept()
    assert ok is True


def test_212g5_optional_skip_does_not_block():
    g = pg.GateAccounting()
    g.declare("D", mandatory=False, requirement="nice to have")
    g.record("D", "OPTIONAL_SKIPPED")
    ok, _ = g.can_accept()
    assert ok is True


def test_212g6_all_pass_accepts():
    g = pg.GateAccounting()
    g.declare("A", mandatory=True, requirement="a")
    g.declare("B", mandatory=True, requirement="b")
    g.record("A", "PASS", evidence="ok")
    g.record("B", "PASS", evidence="ok")
    ok, _ = g.can_accept()
    assert ok is True