"""D 노선분석 지도 겹 — 도엽 겹 · 지적도 · 급경사 그림 (요구 395-2 · PLAN 569-1).

- 도엽 겹(하천중심선 · 도로중심선 …) = 지형 받기 병합본 · 없으면 지난 병합 도엽에서 그 겹만 풀어 냄
- 지적도 = 브이월드 WFS LX맵(`lt_c_landinfobasemap`) · B04 `request_vworld_wfs` 를 1 km 조각으로 ·
  한 번 1,000 필지 한도 → 꽉 차면 넷으로 다시 쪼갬 · `pnu` 로 겹친 필지 거름 ·
  저장 = `processed/연속지적도_bounds.geojson`(B04 `/geojson?layer=지적도` 자리) + 곁 열쇠
- 급경사 = 평활 안 한 사업 DEM(`models_plan/dtm_sheet_<방법>.npz`) · E07 `slope_rad` ·
  15° · 35° · 40° 단계 PNG · 파생 저장본(열쇠 = 격자 지문)

계산 자리 = ③ 서버 단독.
"""

from __future__ import annotations

import base64
import io
import json
import logging
import math
import tempfile
from concurrent.futures import ThreadPoolExecutor
from pathlib import Path
from typing import Any

import numpy as np

from B04_PreProcess.B04_PreProcess_Engine_GisVector import request_vworld_wfs
from B04_PreProcess.B04_PreProcess_Engine_SheetParser import SHEET_LAYERS, parse_and_merge_sheets
from B04_PreProcess.B04_PreProcess_Engine_SheetStore import get_project_map_sheets_dir
from common_util.common_util_derived_store import (
    derived_key,
    file_stamp,
    read_derived,
    write_derived,
)
from common_util.common_util_json import atomic_write_json
from config.config_system_terrain import SHEET_SURFACE_DEFAULT_METHOD

logger = logging.getLogger(__name__)

Box = tuple[float, float, float, float]  # x0, y0, x1, y1(작업 좌표계 m)

CADASTRAL_TYPENAME = "lt_c_landinfobasemap"
CADASTRAL_FILE = "연속지적도_bounds.geojson"
CADASTRAL_KEY = "연속지적도_bounds.key.json"
TILE_M = 1000.0
WFS_LIMIT = 1000
MAX_SPLIT = 3  # 1 km → 125 m 까지 쪼갬
WFS_WORKERS = 4

SLOPE_KIND = "plan_slope"
SLOPE_VERSION = 1
# (아래 °, 위 °, 색 RGBA) — 임도망_편성 완 · 중 · 급경사지 · 타당성평가 35° · 노선_배치 40° 연속
SLOPE_BANDS = (
    (15.0, 35.0, (250, 204, 21, 110)),
    (35.0, 40.0, (249, 115, 22, 140)),
    (40.0, 90.0, (220, 38, 38, 160)),
)
MAX_SIDE_PX = 4096  # ponytail: 한 변 넘으면 솎음 · 넓은 사업은 조각 그림으로


def _read_json(path: Path) -> Any:
    try:
        return json.loads(path.read_text(encoding="utf-8"))
    except (OSError, ValueError):
        return None


# ── 도엽 겹 ─────────────────────────────────────────────


def ensure_sheet_layer(project_root: Path, key: str) -> Path:
    """`processed/도엽_{key}.geojson` — 없으면 지난 병합 도엽에서 그 겹만 풀어 냄(0 건 = 빈 것)."""
    if key not in SHEET_LAYERS:
        raise KeyError(key)
    processed = project_root / "B04_PreProcess" / "processed"
    path = processed / f"도엽_{key}.geojson"
    if path.is_file():
        return path
    sheets = (_read_json(processed / "sheet_merge.key.json") or {}).get("sheets") or []
    if not sheets:
        raise FileNotFoundError("병합한 도엽이 없습니다 — 지형 받기 뒤 보입니다.")
    parse_and_merge_sheets(get_project_map_sheets_dir(project_root), sheets, processed, [key])
    if not path.is_file():
        atomic_write_json(path, {"type": "FeatureCollection", "features": []})
    return path


# ── 지적도 ──────────────────────────────────────────────


def tiles(box: Box, size: float = TILE_M) -> list[Box]:
    """상자를 `size` 칸으로 쪼갬(끝 칸은 남은 만큼)."""
    x0, y0, x1, y1 = box
    nx, ny = max(1, math.ceil((x1 - x0) / size)), max(1, math.ceil((y1 - y0) / size))
    return [
        (x0 + i * size, y0 + j * size, min(x1, x0 + (i + 1) * size), min(y1, y0 + (j + 1) * size))
        for j in range(ny)
        for i in range(nx)
    ]


def quarter(box: Box) -> list[Box]:
    x0, y0, x1, y1 = box
    xm, ym = (x0 + x1) / 2, (y0 + y1) / 2
    return [(x0, y0, xm, ym), (xm, y0, x1, ym), (x0, ym, xm, y1), (xm, ym, x1, y1)]


def _lonlat_bounds(box: Box, epsg: int) -> dict[str, float]:
    from common_util.common_util_crs import tm_to_lonlat

    x0, y0, x1, y1 = box
    ring = [tm_to_lonlat(x, y, epsg) for x, y in ((x0, y0), (x1, y0), (x1, y1), (x0, y1))]
    lons, lats = [p[0] for p in ring], [p[1] for p in ring]
    return {"min_lon": min(lons), "min_lat": min(lats), "max_lon": max(lons), "max_lat": max(lats)}


def _wfs(box: Box, epsg: int) -> list[dict[str, Any]] | None:
    """조각 하나 — B04 WFS 받기(실패 = 파일 없음 · 키 값은 남기지 않음). None = 실패."""
    with tempfile.TemporaryDirectory() as folder:
        request_vworld_wfs(
            CADASTRAL_TYPENAME, "tile.geojson", _lonlat_bounds(box, epsg), Path(folder)
        )
        data = _read_json(Path(folder) / "tile.geojson")
    if not isinstance(data, dict) or not isinstance(data.get("features"), list):
        return None
    return data["features"]


def fetch_tile(box: Box, epsg: int, depth: int = 0) -> tuple[list[dict[str, Any]], int]:
    """(필지, 실패 조각 수) — 1,000 꽉 차면 넷으로 다시 쪼갬."""
    features = _wfs(box, epsg)
    if features is None:
        return [], 1
    if len(features) < WFS_LIMIT or depth >= MAX_SPLIT:
        return features, 0
    out: list[dict[str, Any]] = []
    failed = 0
    for part in quarter(box):
        got, bad = fetch_tile(part, epsg, depth + 1)
        out.extend(got)
        failed += bad
    return out, failed


def dedup_parcels(features: list[dict[str, Any]]) -> list[dict[str, Any]]:
    """조각 경계에 걸친 필지 — `pnu`(없으면 지물 id) 첫 것만."""
    seen: set[str] = set()
    out = []
    for feature in features:
        props = feature.get("properties") or {}
        key = str(props.get("pnu") or feature.get("id") or json.dumps(feature.get("geometry")))
        if key not in seen:
            seen.add(key)
            out.append(feature)
    return out


def _covers(have: Any, box: Box) -> bool:
    try:
        return have[0] <= box[0] and have[1] <= box[1] and have[2] >= box[2] and have[3] >= box[3]
    except (TypeError, IndexError):
        return False


def ensure_cadastral(processed: Path, box: Box, epsg: int) -> dict[str, Any]:
    """지적도 — 열쇠 상자가 덮고 실패 조각 없으면 그대로 · 아니면 상자 통째로 다시 받음."""
    path, key_path = processed / CADASTRAL_FILE, processed / CADASTRAL_KEY
    key = _read_json(key_path) or {}
    if path.is_file() and not key.get("failed") and _covers(key.get("box"), box):
        return {"path": path, "fetched": False, "count": key.get("count"), "failed": 0}
    parts = tiles(box)
    with ThreadPoolExecutor(max_workers=WFS_WORKERS) as pool:
        results = list(pool.map(lambda part: fetch_tile(part, epsg), parts))
    failed = sum(bad for _, bad in results)
    if failed == len(parts):
        raise RuntimeError(f"지적도를 받지 못했습니다 — 브이월드 WFS 조각 {failed}개 실패")
    features = dedup_parcels([f for got, _ in results for f in got])
    processed.mkdir(parents=True, exist_ok=True)
    atomic_write_json(path, {"type": "FeatureCollection", "features": features})
    atomic_write_json(
        key_path,
        {
            "box": [float(v) for v in box],
            "epsg": int(epsg),
            "count": len(features),
            "failed": failed,
        },
    )
    logger.info("D 지적도 받기: 조각 %d · 실패 %d · 필지 %d", len(parts), failed, len(features))
    return {"path": path, "fetched": True, "count": len(features), "failed": failed}


# ── 급경사 ──────────────────────────────────────────────


def slope_bands_png(z: np.ndarray, valid: np.ndarray, cell_m: float) -> dict[str, Any]:
    """격자(행 = 남 → 북) → 단계 PNG(위 = 북 · 15° 미만 · 빈 칸 투명) + 단계 칸 비율."""
    from PIL import Image

    from E07_StabArea.E07_StabArea_Engine import slope_rad

    stride = max(1, math.ceil(max(z.shape) / MAX_SIDE_PX))
    grid = np.where(valid, np.asarray(z, float), np.nan)[::stride, ::stride]
    deg = np.degrees(slope_rad(grid, cell_m * stride))
    known = np.isfinite(deg)
    index = np.zeros(deg.shape, np.uint8)
    for i, (low, high, _) in enumerate(SLOPE_BANDS, start=1):
        index[known & (deg >= low) & (deg < high)] = i
    total = max(1, int(known.sum()))
    image = Image.fromarray(np.flipud(index), mode="P")
    palette = [0, 0, 0] + [c for _, _, rgba in SLOPE_BANDS for c in rgba[:3]]
    image.putpalette(palette + [0] * (768 - len(palette)))
    alpha = bytes([0] + [rgba[3] for _, _, rgba in SLOPE_BANDS])
    buffer = io.BytesIO()
    image.save(buffer, format="PNG", optimize=True, transparency=alpha)
    return {
        "width": image.width,
        "height": image.height,
        "image": "data:image/png;base64," + base64.b64encode(buffer.getvalue()).decode("ascii"),
        "bands": [
            {
                "min_deg": low,
                "max_deg": high,
                "color": "#{:02x}{:02x}{:02x}".format(*rgba[:3]),
                "ratio": round(int((index == i).sum()) / total, 4),
            }
            for i, (low, high, rgba) in enumerate(SLOPE_BANDS, start=1)
        ],
    }


def slope_layer(project_root: Path, models_dir: Path, epsg: int) -> dict[str, Any]:
    """급경사 겹 — 지문(격자 파일 · 단계 · 판) 같으면 저장본 그대로."""
    from common_util.common_util_crs import tm_to_lonlat

    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(
        SLOPE_KIND, SLOPE_VERSION, npz.name, stamp, int(epsg), SLOPE_BANDS, MAX_SIDE_PX
    )
    saved = read_derived(project_root, SLOPE_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])
        value = slope_bands_png(dem["z"], np.asarray(dem["valid_mask"], bool), cell)
    half = cell / 2
    box = (x[0] - half, y[0] - half, x[-1] + half, y[-1] + half)
    value["box_m"] = [float(v) for v in box]
    value["box"] = [
        list(tm_to_lonlat(px, py, epsg))
        for px, py in ((box[0], box[1]), (box[2], box[1]), (box[2], box[3]), (box[0], box[3]))
    ]
    write_derived(project_root, SLOPE_KIND, key, value)
    return value