/* =============================================================================
 * D03_PlanAnalysis_Expect.ts
 * D03 예상 횡단(PLAN 544-1 · 요구 363-1) — 측점 지반 → 표준 횡단 기본값 설계선 · 절 · 성토 ㎡.
 *   셈 = 공용 `computeCrossDesign`(① 짝 `compute_cross_design` · 거울 `test_b06_cross_design_mirror.py`)
 *   · 기본 = B 초기 설계와 같음(리핑암 · 산쪽 절토 · 일반 측구 · 암 경계 = 서버 기본) · 계획고 = 측점 중심 지반고
 *   · 미교차 = `extendUnclosed`(격자 있을 때) · 곡선 확폭 없음 · 보기만(저장 없음).
 *   3D = 같은 단면을 B05 `buildCorridor` 가 읽는 측점 꼴로(`expectSections`).
 *   시험 `resources/tester/test_544_1_plan_expect.py`.
 * ========================================================================== */

import {
  computeCrossDesign,
  type CrossDesignOptions,
  type CrossDesignResult,
  type StandardCrossSectionSpec,
} from "../../common_util/common_util_cross_design";
import type { DtmGrid } from "../../common_util/common_util_surface_sampler";
import {
  extendUnclosed,
  type CrossGroundPoint,
  type StationGround,
} from "../../B05_Profile/logic/B05_Profile_Sections_Ground";

/** 서버 `sections/context` 의 표준 횡단(config) · 암 경계 기본 오프셋. */
export interface ExpectStandard {
  standard: StandardCrossSectionSpec;
  rockBoundaryM: number | null;
}

export interface ExpectCross {
  design: CrossDesignResult;
  /** 설계에 쓴 지반 표본(미교차로 넓혔으면 넓힌 것). */
  samples: CrossGroundPoint[];
}

/** B 초기 설계 기본 — 리핑암 · 산쪽 절토(모르면 좌) · 일반 측구. */
export function expectOptions(
  uphill: "left" | "right" | null,
  std: ExpectStandard,
): CrossDesignOptions {
  return {
    groundType: "ripping_rock",
    sectionMode: `${uphill ?? "left"}_cut`,
    ditchType: "standard",
    standard: std.standard,
    rockBoundaryOffsetM: std.rockBoundaryM,
  };
}

/** 측점 하나 예상 단면 — 지반고 · 표본이 없으면 null. */
export function expectCross(
  station: StationGround,
  std: ExpectStandard,
  grid?: DtmGrid | null,
): ExpectCross | null {
  const elevation = station.center_z;
  if (elevation === null) return null;
  const options = expectOptions(station.uphill_side, std);
  try {
    let samples = station.samples;
    let design = computeCrossDesign(samples, elevation, options);
    const wide =
      design.slope_unclosed && grid
        ? extendUnclosed(
            samples,
            [station.center_x, station.center_y],
            station.left_xy,
            (next) => computeCrossDesign(next, elevation, options),
            grid,
          )
        : null;
    if (wide) {
      samples = wide.samples as CrossGroundPoint[];
      design = computeCrossDesign(samples, elevation, options);
    }
    return { design, samples };
  } catch {
    return null; // 표본 부족 — B 와 같은 태도(그 측점 건너뜀)
  }
}

/** B06 `CrossSection` 중 `buildCorridor` 가 읽는 칸(B06 형 파일은 별칭 import 라 여기 안 끌어옴). */
export interface ExpectSection {
  station_id: string;
  chainage_m: number;
  label: string;
  kind: "regular";
  center_z: number | null;
  azimuth_deg: null;
  center_x: number;
  center_y: number;
  uphill_side: "left" | "right" | null;
  frame: { left_xy: [number, number] };
  samples: CrossGroundPoint[];
  design: CrossDesignResult;
}

/** 3D 코리도 입력 — 측점마다 예상 단면(못 세운 측점 뺌) · 누가 = 연도 노선 위 누가. */
export function expectSections(
  stations: StationGround[],
  std: ExpectStandard,
  grid?: DtmGrid | null,
): ExpectSection[] {
  return stations.flatMap((station) => {
    const cross = expectCross(station, std, grid);
    if (!cross) return [];
    return [
      {
        station_id: String(station.chainage_m),
        chainage_m: station.chainage_m,
        label: "",
        kind: "regular",
        center_z: station.center_z,
        azimuth_deg: null,
        center_x: station.center_x,
        center_y: station.center_y,
        uphill_side: station.uphill_side,
        frame: { left_xy: station.left_xy },
        samples: cross.samples,
        design: cross.design,
      },
    ];
  });
}