"""Tests for the IN-SEARCH global collapse (homemaker-py-qpk, DESIGN.md §17
follow-on): running Fitness.collapse_global inside every fitness eval instead
of once at finish time.

Covers:
  - default-OFF guarantee + conf-driven knobs (adjacency, iters)
  - _evaluate_full wiring: collapse_global is invoked (with the right kwargs)
    when the flag is on, never when it is off
  - end-to-end effect on a real evolved layout, cross-checked against the
    documented 94g finish-time result (DESIGN.md §17: 15 -> 12 fails on
    evolved-3M-nols-3.dom)
"""

import copy
from pathlib import Path
from unittest.mock import patch

import pytest

from _helpers import with_usage
from homemaker_layout import dom as dom_mod
from homemaker_layout.dom import Node, _link_subtree
from homemaker_layout.fitness import Fitness, load_config

HARBOR = Path(__file__).parent.parent / "examples" / "harbor-house"


def _two_leaf_root(t_left: str, t_right: str, side: float = 6.0, div: float = 0.4):
    from homemaker_layout import geometry
    geometry.clear_cache()
    root = Node(
        node=[[0, 0], [side, 0], [side, side], [0, side]],
        rotation=0, division=[div, div],
        left=Node(type=t_left), right=Node(type=t_right),
    )
    _link_subtree(root, None, "")
    return root


# --------------------------------------------------------------------------- #
# Defaults + conf-driven knobs
# --------------------------------------------------------------------------- #

def test_collapse_insearch_default_off():
    fit = Fitness()
    assert fit._collapse_insearch is False
    assert fit._collapse_insearch_adjacency is True
    assert fit._collapse_insearch_iters == 3


def test_collapse_insearch_flag_on():
    fit = Fitness(conf={"collapse_insearch": True})
    assert fit._collapse_insearch is True


def test_collapse_insearch_adjacency_knob_off():
    fit = Fitness(conf={"collapse_insearch": True,
                        "collapse_insearch_adjacency": False})
    assert fit._collapse_insearch_adjacency is False


def test_collapse_insearch_iters_knob():
    fit = Fitness(conf={"collapse_insearch": True, "collapse_insearch_iters": 5})
    assert fit._collapse_insearch_iters == 5


# --------------------------------------------------------------------------- #
# _evaluate_full wiring
# --------------------------------------------------------------------------- #

def test_evaluate_full_calls_collapse_global_when_on():
    fit = Fitness(conf={"collapse_insearch": True, "collapse_insearch_iters": 2,
                        "spaces": with_usage({"b1": {"size": [16.0, 4.0], "count": 2}})})
    root = _two_leaf_root("b1", "b1")
    with patch.object(Fitness, "collapse_global", wraps=fit.collapse_global) as m:
        fit.score_with_fails(root)
    m.assert_called_once()
    _, kw = m.call_args
    assert kw["adjacency"] is True
    assert kw["objective"] == "threshold"
    assert kw["preserve_public_access"] is True
    assert kw["iters"] == 2


def test_evaluate_full_does_not_call_collapse_global_when_off():
    fit = Fitness(conf={"spaces": with_usage({"b1": {"size": [16.0, 4.0], "count": 2}})})
    root = _two_leaf_root("b1", "b1")
    with patch.object(Fitness, "collapse_global", wraps=fit.collapse_global) as m:
        fit.score_with_fails(root)
    m.assert_not_called()


# --------------------------------------------------------------------------- #
# End-to-end: matches the documented 94g finish-time result
# --------------------------------------------------------------------------- #

@pytest.mark.skipif(not HARBOR.is_dir(), reason="harbor-house example absent")
def test_collapse_insearch_matches_finish_time_collapse():
    """in-search collapse must reach the SAME layout as finish-time collapse.

    That equality is the actual guarantee: `collapse_insearch` runs the same
    `collapse_global` earlier in the same pipeline (before the Phase-1 checks
    rather than after the whole search), so on a FIXED geometry the two must
    agree. Both sides are computed here rather than hard-coded.

    This test previously asserted the §17 constants directly -- `15` fails
    before collapse and `12` after. Those were measured before §39.4, when
    harbor's effective programme was silently 32 instances because codes like
    `cr1` were being read as generic circulation; the same layout now scores 82
    -> 58. Pinning the endpoints made a live invariant fail whenever the
    programme or the objective legitimately changed, while not actually
    checking the invariant at all (two independent constants can both drift and
    still be equal, or both hold and mask an inequality). See
    `homemaker-py-ut5` for restating the reference figure itself.
    """
    conf, cost = load_config(HARBOR)
    conf_ci, _ = load_config(HARBOR, overrides={"collapse_insearch": True})
    root = dom_mod.load(str(HARBOR / "evolved-3M-nols-3.dom"))

    _, f_base = Fitness(conf, cost).score_with_fails(copy.deepcopy(root))
    _, f_ci = Fitness(conf_ci, cost).score_with_fails(copy.deepcopy(root))

    # the same collapse, applied once at finish time, scored canonically
    finished = copy.deepcopy(root)
    Fitness(conf, cost).collapse_global(
        finished, adjacency=True, objective="threshold",
        preserve_public_access=True, iters=3)
    _, f_finish = Fitness(conf, cost).score_with_fails(finished)

    assert len(f_ci) == len(f_finish), (
        "in-search collapse diverged from finish-time collapse on fixed geometry")
    assert len(f_ci) < len(f_base), "collapse must not make the layout worse"


@pytest.mark.skipif(not HARBOR.is_dir(), reason="harbor-house example absent")
def test_collapse_insearch_off_reproduces_baseline():
    conf, cost = load_config(HARBOR)
    fit = Fitness(conf, cost)
    root = dom_mod.load(str(HARBOR / "evolved-3M-nols-3.dom"))
    s1, f1 = fit.score_with_fails(copy.deepcopy(root))
    s2, f2 = Fitness(conf, cost).score_with_fails(copy.deepcopy(root))
    assert s1 == pytest.approx(s2)
    assert f1 == f2