"""Corpus-backed tests for dom round-trip, free-branch ownership, and fitness parity.

Skipped when the Urb checkout is absent (these need only its .dom files, not
perl).  Parity against the Perl oracle used to live here; the oracle is gone
(DESIGN.md §39.21) and those tests never ran, so they went with it.
"""

from pathlib import Path

import pytest

from homemaker_layout import dom, solver

CORPUS = Path(__file__).parent.parent / "examples" / "programme-house"

pytestmark = pytest.mark.skipif(not CORPUS.is_dir(), reason="Corpus not available")


def test_roundtrip_idempotent_and_area_preserving(tmp_path):
    # dump() does not reproduce the source bytes (different YAML style); the
    # real invariants are that a dumped file reloads to the same dump (stable
    # fixed point) and that per-leaf geometry survives the trip (§4.1 is the
    # area validation against Urb itself).
    from homemaker_layout import geometry

    for src in sorted(CORPUS.glob("*.dom")):
        root = dom.load(str(src))
        areas = [geometry.area(leaf) for lvl in dom.levels(root) for leaf in lvl.leaves()]
        once = tmp_path / ("once_" + src.name)
        dom.dump(root, str(once))

        root2 = dom.load(str(once))
        areas2 = [geometry.area(leaf) for lvl in dom.levels(root2) for leaf in lvl.leaves()]
        assert areas == pytest.approx(areas2, abs=1e-9), src.name

        twice = tmp_path / ("twice_" + src.name)
        dom.dump(root2, str(twice))
        assert twice.read_bytes() == once.read_bytes(), src.name


def test_free_branches_known_dof():
    # DOF figures from DESIGN.md §4.5
    expected = {
        "2f45907abd9accac2a124d311732f749.dom": 7,
        "candidate-002.dom": 6,
        "c964435454c459f86c3ed9a5a7621132.dom": 6,
    }
    for name, dof in expected.items():
        root = dom.load(str(CORPUS / name))
        assert len(solver.free_branches(root)) == dof, name


def test_free_branches_are_lowest_storey_owners():
    for src in sorted(CORPUS.glob("*.dom")):
        root = dom.load(str(src))
        for b in solver.free_branches(root):
            assert b.divided
            assert b.below is None or not b.below.divided


# ---------------------------------------------------------------------------
# Phase 3 gate: native fitness parity vs oracle (homemaker-py-uxz)
# Oracle scores and failure sets cached as <file>.dom.score / <file>.dom.fails
# generated with URB_NO_OCCLUSION=1 (DESIGN.md §6 descope).
# ---------------------------------------------------------------------------

def _native_evaluate(src: Path):
    """Run native Fitness.evaluate and return (score, frozenset[fail_lines])."""
    from homemaker_layout import fitness as fit_mod, graph as graph_mod, geometry

    root = dom.load(str(src))
    conf, cost = fit_mod.load_config(CORPUS)
    fit = fit_mod.Fitness(conf, cost)

    failures: list[str] = []
    tracking: dict = {
        "has_public_access_outside": False,
        "has_public_access_inside": False,
        "public_length_all": 0.0,
        "public_length_outside": 0.0,
        "private_length_all": 0.0,
        "private_length_outside": 0.0,
        "stair_fit": [],
        "_failures": failures,
    }

    programme = fit._programme or {}
    geometry.clear_cache()

    check_f, missing = graph_mod.check_space_counts(root, programme)
    failures.extend(check_f)
    fit.preprocess_building(root)
    _, gcpre = graph_mod.build_graphs_with_circ(root, fit.conf("door_width") or 1.2, failures.append, fit.usages())
    gbpre = graph_mod.build_graphs(root, fit.conf("door_width") or 1.2)
    failures.extend(graph_mod.check_adjacency(root, programme, gbpre, missing))
    failures.extend(graph_mod.check_level_constraints(root, programme, missing))
    failures.extend(graph_mod.check_vertical_connectivity(root, programme, missing))

    dom.merge_divided(root)
    geometry.clear_cache()
    _, gc = graph_mod.build_graphs_with_circ(root, fit.conf("door_width") or 1.2, failures.append, fit.usages())
    gb = graph_mod.build_graphs(root, fit.conf("door_width") or 1.2)

    cost_v = fit.plot_cost(root)
    value = 0.0
    lvls = dom.levels(root)
    for li, lvl in enumerate(lvls):
        se = fit.process_storey(
            lvl, gb[li], li, failures.append,
            graph_circ=gc, tracking=tracking, lvls=lvls, root=root,
        )
        cost_v += se.cost
        value += se.value

    bf = fit.evaluate_building(root, tracking)
    value *= bf
    value *= 0.5 ** len(failures)
    score = value / cost_v if cost_v else 0.0

    return score, frozenset(failures)