/* =============================================================================
 * A00_Common/design/design_stations_server.ts
 * 계산 자리 stations 「서버」(PLAN 511-B B-2) — 묶음 stations 단계 측점 목록을 서버 Node
 * `stations.list`(같은 `buildStations`)로. 판이 both 면 null(화면 셈) · 서버 값만 · 잠잠 뒤 ·
 * 끊김 · 실패 = undefined(단계가 화면 셈으로). 구조물 정의는 서버 창구가 붙임.
 * ========================================================================== */

import { plusStations } from "@util/common_util_structure_station";
import { calcOnServerNow } from "./design_calc_sites";
import { calcOnServerOnly } from "./design_calc_server";
import type { StationsArgs } from "./logic/design_pipeline_stations";
import type { PipelineStation } from "./logic/design_pipeline_types";

export function stationsOnServer(
  args: StationsArgs,
  signal: AbortSignal,
): Promise<PipelineStation[] | undefined> | null {
  if (!calcOnServerNow("stations")) return null;
  const [line, curves, pipes, structures, options] = args;
  const stations = {
    line,
    curves,
    pipes,
    structures,
    types: options.types,
    plus: [...(options.plus ?? plusStations())],
    interval_m: options.intervalM,
    include_endpoint: options.includeEndpoint,
    station_snap: options.stationSnap ?? false,
    station_snap_step: options.stationSnapStep ?? null,
  };
  return calcOnServerOnly<PipelineStation[]>(
    "stations",
    "stations.list",
    { run: ["stations.list"], inputs: { stations }, pick: (results) => results["stations.list"] },
    signal,
  );
}