/* =============================================================================
 * 종단면 패널 자료 어댑터 (B05)
 *
 * 저장된 종단면 자료(`longitudinal_sections.data`)를 화면이 쓰는 모양으로 바꾸는 순수 함수들.
 * 상태를 갖지 않으며 DOM도 만들지 않는다 — 패널 본체가 700줄 한계에 닿아 분리했다.
 * ========================================================================== */

import type { DesignProfile, LongitudinalSection } from "../B06_Section/B06_Section_Api_Fetch";
import type { ProfileAlignment } from "./B05_Profile_UI_Profile_Alignment";

export function readAlignment(data: LongitudinalSection): ProfileAlignment | null {
  const candidate = data.profile_alignment as ProfileAlignment | undefined;
  if (!candidate?.base_pvi?.length || !candidate.samples?.length) return null;
  if (!Number.isFinite(candidate.policy?.default_curve_radius_m)) return null;
  if (!candidate.stations || !candidate.segments || !candidate.curves) return null;
  candidate.edits = {
    station_offsets: candidate.edits?.station_offsets ?? {},
    curve_radii: candidate.edits?.curve_radii ?? {},
  };
  return candidate;
}

/** 저장분이 구버전이라 편집을 붙일 수 없는 상태인가 (재계산 안내용). */
export function hasLegacyAlignment(data: LongitudinalSection): boolean {
  return Boolean(data.profile_alignment) && readAlignment(data) === null;
}

/** 편집 결과를 종단면도 렌더러가 받는 계획선 형태로 감싼다. */
export function toDesignProfile(
  alignment: ProfileAlignment,
  original: DesignProfile | undefined,
): DesignProfile {
  const balance = alignment.balance;
  return {
    id: original?.id ?? "design_grade_line",
    name: original?.name ?? "계획선",
    basis: original?.basis ?? "station_alignment",
    samples: alignment.samples,
    balance_segments: [
      {
        index: 0,
        start_chainage_m: alignment.samples[0]?.chainage_m ?? 0,
        end_chainage_m: alignment.samples[alignment.samples.length - 1]?.chainage_m ?? 0,
        cut_area_m2: balance.cut_area_m2,
        fill_area_m2: balance.fill_area_m2,
        balance_error_m2: balance.net_area_m2,
      },
    ],
    summary: {
      ...(original?.summary ?? {
        max_grade_pct: 0,
        vertical_curve_count: 0,
        pvi_count: 0,
        balance_segment_count: 1,
        main_direction: "none",
        suggested_elevation_offset_m: null,
        warnings: [],
      }),
      cut_area_m2: balance.cut_area_m2,
      fill_area_m2: balance.fill_area_m2,
      balance_error_m2: balance.net_area_m2,
      balanced: balance.within_tolerance,
    },
  };
}

export function normalizedLongitudinal(data: LongitudinalSection): LongitudinalSection {
  return {
    ...data,
    samples: data.samples.map((sample: LongitudinalSection["samples"][number]) => ({
      ...sample,
      elevation_m: sample.elevation_m ?? sample.z ?? null,
    })),
  };
}