"""사토장 — 용량에서 폭을 정해 측점마다 단면을 세운다 (2026-09-09).

⚠ 잠그는 것
  ① 용량이 커질수록 폭이 넓어지고, 상한에서 멈추면 못 담은 몫이 값으로 남는다.
  ② 사토장이 선 측점은 **노선 성토가 줄고** 그만큼이 사토장 몫으로 간다(두 번 세지 않기).
  ③ 「자동」이면 그 측점의 **성토 쪽**에 선다.
  ④ 구간 밖 측점은 안 건드린다 — **새 측점을 만들지 않는다**.
"""

from __future__ import annotations

import json
import sys
from pathlib import Path

import pytest

PROJECT_ROOT = Path(__file__).resolve().parents[2]
if str(PROJECT_ROOT) not in sys.path:
    sys.path.insert(0, str(PROJECT_ROOT))

from B06_Section.B06_Section_Engine_Design import compute_cross_design  # noqa: E402
from B06_Section.B06_Section_Engine_SpoilFill import enforce_spoil_fills  # noqa: E402


def _samples() -> list[dict]:
    """우측(-offset)이 높고 좌측(+offset)이 낮은 지반 — 좌가 성토 쪽이다."""
    return [
        {"offset_m": round(offset, 3), "elevation_m": round(100.0 - 0.5 * offset, 4), "valid": True}
        for offset in [x * 0.5 for x in range(-30, 31)]
    ]


def _sections(chainages: list[float]) -> list[dict]:
    return [
        {
            "chainage_m": chainage,
            "samples": _samples(),
            "design": compute_cross_design(
                _samples(),
                99.8,
                ground_type="soil",
                section_mode="right_cut",
                ditch_side="right",
            ),
        }
        for chainage in chainages
    ]


_LONGITUDINAL = {
    "design_profiles": [
        {"samples": [{"chainage_m": float(c), "elevation_m": 99.8} for c in range(0, 201, 20)]}
    ]
}


def _write_site(root: Path, capacity_m3: float, **options) -> None:
    (root / "B05_Profile" / "route").mkdir(parents=True, exist_ok=True)
    (root / "B05_Profile" / "route" / "structures.json").write_text(
        json.dumps(
            {
                "revision": 1,
                "structures": [
                    {
                        "structure_id": "sp-1",
                        "type_id": "spoil_bank",
                        "placement": "interval",
                        "start_m": 100.0,
                        "end_m": 160.0,
                        "options": {"capacity_m3": capacity_m3, **options},
                    }
                ],
            },
            ensure_ascii=False,
        ),
        encoding="utf-8",
    )


def _run(root: Path, capacity_m3: float, **options) -> list[dict]:
    _write_site(root, capacity_m3, **options)
    sections = _sections([80.0, 100.0, 120.0, 140.0, 160.0, 180.0])
    enforce_spoil_fills(_LONGITUDINAL, sections, root)
    return sections


def _placed(sections: list[dict]) -> float:
    inside = [s for s in sections if 100.0 <= s["chainage_m"] <= 160.0]
    return float(inside[0]["design"].get("spoil_fill_placed_m3") or 0.0)


def test_용량이_클수록_폭이_넓어진다(tmp_path: Path) -> None:
    small = _run(tmp_path, 200.0)
    large = _run(tmp_path, 800.0)
    narrow = small[1]["design"]["spoil_fill_width_m"]
    wide = large[1]["design"]["spoil_fill_width_m"]
    assert 0 < narrow < wide
    assert _placed(small) == pytest.approx(200.0, rel=0.02)
    assert _placed(large) == pytest.approx(800.0, rel=0.02)


def test_담을_수_없으면_남은_몫이_값으로_남는다(tmp_path: Path) -> None:
    """상한에서 멈춘다 — 임의로 더 넓히지 않는다."""
    sections = _run(tmp_path, 1_000_000.0)
    design = sections[1]["design"]
    assert design["spoil_fill_unplaced_m3"] > 0
    assert design["spoil_fill_width_m"] == pytest.approx(design["spoil_fill_max_width_m"])


def test_노선_성토가_그만큼_줄어든다(tmp_path: Path) -> None:
    """같은 흙을 두 번 세지 않는다(확정 ㉠)."""
    plain = _sections([120.0])[0]["design"]
    sections = _run(tmp_path, 400.0)
    inside = sections[2]["design"]
    assert inside["spoil_fill_area_m2"] > 0
    assert inside["spoil_fill_replaced_fill_m2"] > 0
    assert inside["fill_area_m2"] == pytest.approx(
        plain["fill_area_m2"] - inside["spoil_fill_replaced_fill_m2"], abs=1e-6
    )


def test_자동이면_성토_쪽에_선다(tmp_path: Path) -> None:
    sections = _run(tmp_path, 400.0, side="자동(성토 쪽)")
    # right_cut = 우측 절토 ⇒ 성토는 좌측(+offset).
    assert sections[1]["design"]["spoil_fill_side"] == "left"


def test_구간_밖_측점은_안_건드린다(tmp_path: Path) -> None:
    """새 측점을 만들지 않고, 구간 밖은 종전 그대로다(확정 ③)."""
    sections = _run(tmp_path, 400.0)
    assert len(sections) == 6
    for section in sections:
        design = section["design"]
        if 100.0 <= section["chainage_m"] <= 160.0:
            assert design["spoil_fill_area_m2"] > 0
        else:
            assert design.get("spoil_fill_area_m2", 0) == 0


def test_용량이_없으면_아무것도_안_세운다(tmp_path: Path) -> None:
    (tmp_path / "B05_Profile" / "route").mkdir(parents=True, exist_ok=True)
    (tmp_path / "B05_Profile" / "route" / "structures.json").write_text(
        json.dumps(
            {
                "revision": 1,
                "structures": [
                    {
                        "structure_id": "sp-1",
                        "type_id": "spoil_bank",
                        "placement": "interval",
                        "start_m": 100.0,
                        "end_m": 160.0,
                        "options": {},
                    }
                ],
            }
        ),
        encoding="utf-8",
    )
    sections = _sections([120.0])
    assert enforce_spoil_fills(_LONGITUDINAL, sections, tmp_path) == 0
    assert sections[0]["design"]["spoil_fill_area_m2"] == 0


def test_사토장을_지우면_값도_사라진다(tmp_path: Path) -> None:
    """⚠ 화면 실측으로 잡은 자리(2026-09-09) — 얹기만 하고 **지우지 않아** 구조물을 없앤 뒤에도
    횡단도에 계속 그려지고 면적표에도 서 있었다.
    """
    sections = _run(tmp_path, 400.0)
    inside = sections[2]["design"]
    assert inside["spoil_fill_area_m2"] > 0
    plain_fill = _sections([120.0])[0]["design"]["fill_area_m2"]

    # 구조물을 지운다 — 빈 목록으로 덮어쓴다.
    (tmp_path / "B05_Profile" / "route" / "structures.json").write_text(
        json.dumps({"revision": 2, "structures": []}, ensure_ascii=False), encoding="utf-8"
    )
    changed = enforce_spoil_fills(_LONGITUDINAL, sections, tmp_path)
    assert changed > 0, "지운 사토장을 되돌리지 않았다"
    for section in sections:
        design = section["design"]
        # 칸은 남아도 **값이 0** 이어야 한다 — 설계 결과는 사토장이 없어도 칸을 늘 싣는다.
        assert float(design.get("spoil_fill_area_m2") or 0) == 0, section["chainage_m"]
        assert float(design.get("spoil_fill_width_m") or 0) == 0, section["chainage_m"]
        assert design.get("spoil_fill_capacity_m3") in (None, 0), section["chainage_m"]
    # 노선 성토도 원래 값으로 돌아온다 — 사토장 몫을 빼 두었던 것이 복구된다.
    assert sections[2]["design"]["fill_area_m2"] == pytest.approx(plain_fill, abs=1e-6)