"""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).  The parity tests compare native Python fitness against cached oracle
scores and failure sets (generated with URB_NO_OCCLUSION=1).
"""

import math
from pathlib import Path

import pytest

from homemaker import dom, solver

CORPUS = Path("/home/bruno/src/urb/examples/programme-house")

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


def _oracle_result(src: Path):
    """Read cached oracle score and failure set (URB_NO_OCCLUSION=1)."""
    from homemaker.oracle import Score

    score_file = Path(str(src) + ".score")
    fails_file = Path(str(src) + ".fails")
    if not score_file.exists():
        pytest.skip(f"No cached oracle score for {src.name}")
    oracle_score = float(score_file.read_text().strip())
    oracle_fails = Score(
        fitness=oracle_score,
        fails=fails_file.read_text() if fails_file.exists() else "",
    ).fail_lines
    return oracle_score, frozenset(oracle_fails)


@pytest.mark.parametrize("src", sorted(CORPUS.glob("*.dom")), ids=lambda p: p.name)
def test_native_fitness_score_parity(src):
    """Native score matches oracle within 1e-4 relative tolerance."""
    native_score, _ = _native_evaluate(src)
    oracle_score, _ = _oracle_result(src)
    assert math.isclose(native_score, oracle_score, rel_tol=1e-4, abs_tol=1e-15), (
        f"{src.name}: native={native_score:.6e} oracle={oracle_score:.6e}"
    )


@pytest.mark.parametrize("src", sorted(CORPUS.glob("*.dom")), ids=lambda p: p.name)
def test_native_fitness_fail_set_parity(src):
    """Native failure set matches oracle failure set exactly."""
    _, native_fails = _native_evaluate(src)
    _, oracle_fails = _oracle_result(src)
    only_native = native_fails - oracle_fails
    only_oracle = oracle_fails - native_fails
    assert not only_native and not only_oracle, (
        f"{src.name}: only_native={sorted(only_native)} only_oracle={sorted(only_oracle)}"
    )