/* =============================================================================
 * common_util_structure_pavement.ts
 * 노면공(G군) 구조물 → 횡단 측점 포장 제원(`section.pavement`).
 * 파이썬 `common_util/common_util_structure_pavement.py` 의 **짝** — 거울 시험
 * `resources/tester/test_b06_structure_pavement_mirror.py`.
 *
 * 서버는 저장분으로 · 브라우저는 저장 전 목록으로 같은 제원을 얹음.
 * 두께 = options.height_m · 무늬 = options.pave_spec · 확폭 끈 구간 = options.widening_off.
 * ========================================================================== */

/** 구조물 정본 한 건(필요한 칸만) — `structures.json` 과 같은 이름. */
export interface PavementStructureInput {
  type_id: string;
  chainage_m?: number | null;
  start_m?: number | null;
  end_m?: number | null;
  options?: Record<string, unknown> | null;
}

/** 측점에 얹는 포장 한 건 — `section.pavement[]`. */
export interface PavementEntry {
  type_id: string;
  /** 포장사양 — 콘크리트 · 아스콘 · 쇄석(비면 표준 그림). */
  spec: string | null;
  /** 두께(m) — 노면선 아래로. 비면 표준 횡단 포장 두께. */
  thickness_m: number | null;
  start_m: number;
  end_m: number;
  /** false = 확폭 끈 구간(규격 폭 끝까지만). */
  widening_on: boolean;
}

export interface PavementSpec extends Omit<PavementEntry, "widening_on"> {
  widening_off: Array<[number, number]>;
}

/** 파이썬 `_EDGE_TOLERANCE_M` — C군 벽과 같은 값. */
const EDGE_TOLERANCE_M = 0.02;

const num = (value: unknown): number | null =>
  typeof value === "number" && Number.isFinite(value) ? value : null;

/** 「시작-끝,시작-끝」(측점 m) → 구간 목록. 못 읽는 조각은 버림(= 켬). */
export function wideningOffRanges(text: unknown): Array<[number, number]> {
  const ranges: Array<[number, number]> = [];
  for (const part of String(text ?? "").split(",")) {
    const bounds = part.split("-");
    if (bounds.length !== 2 || !bounds[0].trim() || !bounds[1].trim()) continue;
    const start = Number(bounds[0]);
    const end = Number(bounds[1]);
    if (Number.isFinite(start) && Number.isFinite(end))
      ranges.push([Math.min(start, end), Math.max(start, end)]);
  }
  return ranges;
}

/** G군 구조물 → 구간 제원(파이썬 `pavement_specs_from`). */
export function pavementSpecsFrom(
  structures: readonly PavementStructureInput[],
  typeIds: ReadonlySet<string>,
): PavementSpec[] {
  const specs: PavementSpec[] = [];
  for (const item of structures) {
    if (!typeIds.has(item.type_id)) continue;
    const anchor = num(item.chainage_m);
    const start = num(item.start_m) ?? anchor;
    const end = num(item.end_m) ?? anchor;
    if (start === null || end === null) continue;
    const options = (item.options ?? {}) as Record<string, unknown>;
    const spec = options.pave_spec;
    specs.push({
      type_id: item.type_id,
      spec: typeof spec === "string" && spec ? spec : null,
      thickness_m: num(options.height_m),
      start_m: Math.min(start, end),
      end_m: Math.max(start, end),
      widening_off: wideningOffRanges(options.widening_off),
    });
  }
  return specs;
}

const inside = (chainage: number, start: number, end: number): boolean =>
  start - EDGE_TOLERANCE_M <= chainage && chainage <= end + EDGE_TOLERANCE_M;

/** 범위 안 측점에 `pavement` 목록을 얹음(파이썬 `attach_pavement_specs`). 얹은 측점 수. */
export function attachPavementSpecs(
  sections: Array<Record<string, unknown>>,
  specs: readonly PavementSpec[],
): number {
  let attached = 0;
  for (const section of sections) {
    const chainage = num(section.chainage_m);
    if (chainage === null) continue;
    const found: PavementEntry[] = specs
      .filter((spec) => inside(chainage, spec.start_m, spec.end_m))
      .map((spec) => ({
        type_id: spec.type_id,
        spec: spec.spec,
        thickness_m: spec.thickness_m,
        start_m: spec.start_m,
        end_m: spec.end_m,
        widening_on: !spec.widening_off.some(([start, end]) => inside(chainage, start, end)),
      }));
    if (found.length) {
      section.pavement = found;
      attached += 1;
    }
  }
  return attached;
}