"""초기 계획노선 갈래(PLAN 20장) — `B05_Profile_Engine_RouteInitial` 합성 지형 시험.

./venv/Scripts/python.exe -m pytest resources/tester/test_route_initial.py -q
"""

import numpy as np
import pytest

from B05_Profile.B05_Profile_Engine_RouteInitial import (
    MODES,
    PENDING,
    STREAM_OFFSET_M,
    Terrain,
    generate_initial_route,
    grade_line,
    resolve_weights,
    stream_lines,
)

GRADE = 0.14
RADIUS = 12.0


def _terrain(z_of) -> Terrain:
    x = np.arange(0.0, 802.0, 2.0)
    y = np.arange(0.0, 402.0, 2.0)
    xx, yy = np.meshgrid(x, y)
    return Terrain(x, y, z_of(xx, yy), np.ones(xx.shape, dtype=bool))


def _line(y: float) -> list[tuple[float, float]]:
    return [(float(x), y) for x in np.arange(50.0, 752.0, 4.0)]


@pytest.fixture(scope="module")
def hill() -> Terrain:
    """가운데 솟은 언덕(높이 40 m) — 곧은 예상노선이 꼭대기를 넘는다."""
    return _terrain(
        lambda xx, yy: 40.0 * np.exp(-((xx - 400.0) ** 2 + (yy - 200.0) ** 2) / 90.0**2)
    )


def _run(terrain: Terrain, mode: str, streams=(), weights=None) -> dict:
    return generate_initial_route(
        _line(200.0),
        terrain,
        list(streams),
        mode=mode,
        weights=weights,
        max_grade=GRADE,
        min_radius_m=RADIUS,
    )


def test_follow_keeps_expected_route(hill: Terrain) -> None:
    result = _run(hill, "follow")
    assert result["metrics"]["offset_max_m"] < 1.0
    assert result["weights"] == {"expected": 100.0, "earthwork": 0.0, "grade": 0.0}
    assert result["criteria"]["pending"] == list(PENDING)


@pytest.mark.parametrize("mode", ["earthwork", "gentle", "weighted"])
def test_search_modes_beat_follow_on_hill(hill: Terrain, mode: str) -> None:
    follow = _run(hill, "follow")["metrics"]
    result = _run(hill, mode)
    metrics = result["metrics"]
    # 언덕을 돌아가 기울기 · 토공이 준다
    assert metrics["max_grade_pct"] < follow["max_grade_pct"]
    assert metrics["cut_m3"] + metrics["fill_m3"] < follow["cut_m3"] + follow["fill_m3"]
    assert metrics["over_limit"]["grade"] <= follow["over_limit"]["grade"]
    # 기점 · 종점은 옮기지 않고 복도(100 m) 밖으로 안 나감
    assert result["planned"][0] == [50.0, 200.0]
    assert result["planned"][-1] == [750.0, 200.0]
    assert metrics["offset_max_m"] <= result["criteria"]["corridor_m"] + 4.0
    assert result["nodes"] and result["curves"] is not None


def test_weighted_expected_share_pulls_route_back(hill: Terrain) -> None:
    near = _run(hill, "weighted", weights={"expected": 90, "earthwork": 5, "grade": 5})
    far = _run(hill, "weighted", weights={"expected": 10, "earthwork": 45, "grade": 45})
    assert near["metrics"]["offset_avg_m"] < far["metrics"]["offset_avg_m"]


def test_stream_offset_is_common_constraint() -> None:
    """평지 · 예상노선 20 m 옆을 나란히 흐르는 소하천 — 추종은 초과 1 · 탐색은 비켜 감."""
    flat = _terrain(lambda xx, yy: np.zeros_like(xx))
    stream = [[(0.0, 220.0), (800.0, 220.0)]]
    follow = _run(flat, "follow", streams=stream)["metrics"]
    moved = _run(flat, "earthwork", streams=stream)["metrics"]
    assert follow["over_limit"]["stream"] == 1
    assert moved["over_limit"]["stream"] == 0
    assert moved["offset_avg_m"] > STREAM_OFFSET_M - 20.0 - 10.0


def test_stream_crossing_is_allowed() -> None:
    flat = _terrain(lambda xx, yy: np.zeros_like(xx))
    crossing = [[(400.0, 0.0), (400.0, 400.0)]]
    assert _run(flat, "follow", streams=crossing)["metrics"]["over_limit"]["stream"] == 0


def test_grade_line_stays_within_limit() -> None:
    ground = np.array([0.0, 0.0, 5.0, 10.0, 10.0, 2.0, 0.0])
    line = grade_line(ground, 2.0, GRADE)
    assert np.all(np.abs(np.diff(line)) <= GRADE * 2.0 + 1e-9)


def test_weights_and_stream_filter() -> None:
    assert resolve_weights("weighted", None) == {"expected": 50.0, "earthwork": 25.0, "grade": 25.0}
    assert resolve_weights("gentle", {"expected": 99})["grade"] == 100.0
    assert set(MODES) == {"follow", "earthwork", "gentle", "weighted"}
    features = [
        {
            "properties": {"구분": "세류"},
            "geometry": {"type": "LineString", "coordinates": [[0, 0], [1, 1]]},
        },
        {
            "properties": {"구분": "소하천"},
            "geometry": {"type": "LineString", "coordinates": [[0, 0], [1, 1]]},
        },
    ]
    assert len(stream_lines(features)) == 1


def test_unknown_mode_rejected(hill: Terrain) -> None:
    with pytest.raises(ValueError):
        _run(hill, "shortest")