Aislo/D03_PlanAnalysis/D03_PlanAnalysis_ZeroOrder.py

"""D 노선분석 지도 0차곡 겹 — 지형 추정 골짜기 머리(PLAN 584-1 · 요구 443).

0차곡 = 뚜렷한 유로가 없는 곡두의 집수지형(`노선_배치.md:31` · 교본 `3. 임도망의 배치 절차.md:156`)
→ 사업 DEM(평활 안 한 `models_plan/dtm_sheet_<방법>.npz`)을 2 m 로 솎아 D8 흐름누적 ·
위 집수 넓이가 `min_m2` 이상 · `max_m2` 미만인 칸 = 0차곡(그보다 크면 1차 계류) →
세선화 · 선 뽑기(B05 `_mask_to_polylines`) · 경위도 선 + 가닥 · 길이 합.
임계값 = 지식DB 수치 없음 → 정함(브레인) 0.1 ha · 1 ha · 바꿈 = 요청 `min_m2` · `max_m2`.
파생 저장본(열쇠 = 격자 지문 · 임계 · 칸).

계산 자리 = ③ 서버 단독.
"""

from __future__ import annotations

import math
from pathlib import Path
from typing import Any

import numpy as np

from common_util.common_util_derived_store import (
    derived_key,
    file_stamp,
    read_derived,
    write_derived,
)
from config.config_system_terrain import SHEET_SURFACE_DEFAULT_METHOD

ZERO_ORDER_KIND = "plan_zero_order"
ZERO_ORDER_VERSION = 1
ZERO_ORDER_MIN_M2 = 1_000.0  # 집수 시작(0.1 ha)
ZERO_ORDER_MAX_M2 = 10_000.0  # 이 넓이부터 1차 계류(1 ha)
ZERO_ORDER_CELL_M = 2.0  # 흐름누적 칸(1 m 격자는 솎음)
ZERO_ORDER_MIN_LEN_M = 10.0  # 세선화 갈림목 토막 거름
SIMPLIFY_M = 1.0

_D8 = ((-1, -1), (-1, 0), (-1, 1), (0, -1), (0, 1), (1, -1), (1, 0), (1, 1))


def _shift(grid: np.ndarray, dr: int, dc: int, fill: Any) -> np.ndarray:
    """칸마다 (dr, dc) 이웃 값 — 격자 밖 = `fill`."""
    rows, cols = grid.shape
    pad = np.pad(grid, 1, constant_values=fill)
    return pad[1 + dr : 1 + dr + rows, 1 + dc : 1 + dc + cols]


def d8_accumulation(z: np.ndarray, valid: np.ndarray) -> np.ndarray:
    """D8 흐름누적(칸 수 · 자기 칸 포함 · 빈 칸 0).

    웅덩이 메움(형태 재구성 · 가장자리 · 빈 칸 곁 = 출구) → 가장 가파른 아래 이웃 하나로 흐름 →
    평지(등고선 칸 · 메운 웅덩이)는 이미 흐르는 같은 높이 이웃으로 이어 감 → 위에서 아래로 더함.
    """
    from skimage.morphology import reconstruction

    rows, cols = z.shape
    height = np.where(valid, np.asarray(z, float), np.nan)
    floor = np.nanmin(height) if valid.any() else 0.0
    edge = valid & ~np.all([_shift(valid, dr, dc, False) for dr, dc in _D8], axis=0)
    ground = np.where(valid, height, floor)
    seed = np.where(edge | ~valid, ground, ground.max())
    filled = np.where(valid, reconstruction(seed, ground, method="erosion"), np.nan)
    index = np.arange(rows * cols).reshape(rows, cols)
    best = np.zeros(z.shape)
    receiver = np.full(z.shape, -1, np.int64)
    with np.errstate(invalid="ignore"):
        for dr, dc in _D8:
            drop = (filled - _shift(filled, dr, dc, np.nan)) / math.hypot(dr, dc)
            better = drop > best
            best = np.where(better, drop, best)
            receiver = np.where(better, index + dr * cols + dc, receiver)
        done = (receiver >= 0) | edge | ~valid
        while True:
            grew = False
            for dr, dc in _D8:
                take = ~done & _shift(done & valid, dr, dc, False)
                take &= _shift(filled, dr, dc, np.nan) == filled
                if take.any():
                    receiver[take] = index[take] + dr * cols + dc
                    done |= take
                    grew = True
            if not grew:
                break
    down = receiver.ravel().tolist()
    acc = valid.astype(float).ravel().tolist()
    upstream = np.bincount(receiver[receiver >= 0], minlength=rows * cols).tolist()
    stack = [i for i, n in enumerate(upstream) if n == 0]
    while stack:
        i = stack.pop()
        j = down[i]
        if j >= 0:
            acc[j] += acc[i]
            upstream[j] -= 1
            if upstream[j] == 0:
                stack.append(j)
    return np.asarray(acc).reshape(rows, cols)


def zero_order_mask(
    acc: np.ndarray, valid: np.ndarray, cell_m: float, min_m2: float, max_m2: float
) -> np.ndarray:
    """위 집수 넓이(칸 수 × 칸 넓이)가 [min_m2, max_m2) 인 칸."""
    area = acc * cell_m * cell_m
    return valid & (area >= min_m2) & (area < max_m2)


def zero_order_lines(
    z: np.ndarray,
    valid: np.ndarray,
    x: np.ndarray,
    y: np.ndarray,
    cell_m: float,
    min_m2: float = ZERO_ORDER_MIN_M2,
    max_m2: float = ZERO_ORDER_MAX_M2,
) -> list[list[tuple[float, float]]]:
    """격자(행 = 남 → 북) → 0차곡 선(작업 좌표계 m 점 목록 · `ZERO_ORDER_MIN_LEN_M` 미만 거름)."""
    from B05_Profile.B05_Profile_Engine_Skeleton import _mask_to_polylines

    mask = zero_order_mask(d8_accumulation(z, valid), valid, cell_m, min_m2, max_m2)
    lines = [[(p[0], p[1]) for p in line["polyline"]] for line in _mask_to_polylines(mask, x, y, z)]
    return [
        line
        for line in lines
        if sum(math.dist(a, b) for a, b in zip(line, line[1:])) >= ZERO_ORDER_MIN_LEN_M
    ]


def zero_order_layer(
    project_root: Path,
    models_dir: Path,
    epsg: int,
    min_m2: float = ZERO_ORDER_MIN_M2,
    max_m2: float = ZERO_ORDER_MAX_M2,
) -> dict[str, Any]:
    """0차곡 겹 — 지문(격자 파일 · 임계 · 칸) 같으면 저장본 · 경위도 선 + 가닥 · 길이 합 m."""
    from shapely.geometry import LineString, mapping
    from shapely.ops import transform

    from D03_PlanAnalysis.D03_PlanAnalysis_Layers import _transforms

    npz = models_dir / f"dtm_sheet_{SHEET_SURFACE_DEFAULT_METHOD}.npz"
    stamp = file_stamp(npz)
    if stamp is None:
        raise FileNotFoundError("사업 지형면이 없습니다 — 지형 받기 뒤 보입니다.")
    key = derived_key(
        ZERO_ORDER_KIND,
        ZERO_ORDER_VERSION,
        npz.name,
        stamp,
        int(epsg),
        float(min_m2),
        float(max_m2),
        ZERO_ORDER_CELL_M,
        ZERO_ORDER_MIN_LEN_M,
        SIMPLIFY_M,
    )
    saved = read_derived(project_root, ZERO_ORDER_KIND, key)
    if saved is not None:
        return saved["value"]
    with np.load(npz) as dem:
        x, y = np.asarray(dem["x"], float), np.asarray(dem["y"], float)
        cell = float(dem["resolution"][0]) if "resolution" in dem.files else float(x[1] - x[0])
        step = max(1, round(ZERO_ORDER_CELL_M / cell))
        z = np.asarray(dem["z"], float)[::step, ::step]
        valid = np.asarray(dem["valid_mask"], bool)[::step, ::step]
    lines = zero_order_lines(z, valid, x[::step], y[::step], cell * step, min_m2, max_m2)
    _, to_ll = _transforms(epsg)
    shapes = [LineString(line).simplify(SIMPLIFY_M) for line in lines]
    value = {
        "min_m2": float(min_m2),
        "max_m2": float(max_m2),
        "cell_m": cell * step,
        "count": len(shapes),
        "length_m": round(sum(s.length for s in shapes), 1),
        "collection": {
            "type": "FeatureCollection",
            "features": [
                {"type": "Feature", "geometry": mapping(transform(to_ll, s)), "properties": {}}
                for s in shapes
            ],
        },
    }
    write_derived(project_root, ZERO_ORDER_KIND, key, value)
    return value