/* =============================================================================
 * E03_StabSection_Walls_Node.ts
 * E 2D 해석 모형의 벽(옹벽 · 석축 · 돌쌓기 · 관 기슭막이) 단면 꼭짓점을 **서버가** 내는 입구(532-4).
 *
 * 도형은 B06 화면이 그리는 TS 그대로(`computeStoredLayouts` — 정본만 읽는 한 벌 · CLAUDE.md 5장 ②) ·
 * 지표 = B06 면적과 같은 「실제로 그려지는 설계선」(`drawnProfile` · 벽 상단에서 끊김). 여기에 계산 없음.
 * 파이썬 껍데기 = `E03_StabSection_Walls.py` · 번들 = `npm run build:e03-walls`.
 *
 * 실행: node <번들> <입력.json> <출력.json>
 *   입력  { definition?: 구조물 정의 · sections: 형상 얹은 B06 횡단(chainage_m · samples · design · revetment …) }
 *   출력  { stations: [{ chainage_m, walls: [{ kind, name, structure_id, form, polygon: [[offset, z], …] }],
 *           design_line: [[offset, z], …] | null(트림 없음 = 설계선 그대로) }] }  — 입력 차례 그대로
 * 끝 코드: 0 성공 / 2 인자 오류
 * ========================================================================== */

import { readFileSync, writeFileSync } from "node:fs";
import { drawnProfile } from "@util/common_util_cross_structure_areas";
import { useCatalogDefinition, type CatalogDefinition } from "@util/common_util_structure_catalog";
import type { CrossSection } from "../B06_Section/B06_Section_Api_Fetch";
import type { WallLayout } from "../B06_Section/logic/B06_Section_Cross_Culvert_Types";
import {
  computeStoredLayouts,
  trimOfLayouts,
} from "../B06_Section/logic/B06_Section_Structure_Layouts";

/** 트림 경계 바로 바깥 점 — 벽 쪽 연직 단차를 살림(`computeStructureAreas` 와 같은 값). */
const BOUNDARY_EPS_M = 1e-6;

type Pair = [number, number];

function stationWalls(section: CrossSection, sections: readonly CrossSection[]) {
  const layouts = computeStoredLayouts(section, sections);
  const walls: Array<{
    kind: string;
    name: string | null;
    structure_id: string | null;
    form: string | null;
    polygon: Pair[];
  }> = [];
  const push = (kind: string, list: readonly WallLayout[] | undefined, name: string | null) => {
    for (const wall of list ?? []) {
      if (wall.points.length >= 3)
        walls.push({
          kind,
          name,
          structure_id: kind === "own" ? (layouts?.own?.structureId ?? null) : null,
          form: wall.form,
          polygon: wall.points.map((p) => [p.offset, p.elevation]),
        });
    }
  };
  push("own", layouts?.own?.walls, layouts?.own?.name ?? null);
  push("culvert", layouts?.culvert?.walls, "기슭막이");
  push("culvert", layouts?.culvert?.basinExtras, "기슭막이");
  const trim = layouts ? trimOfLayouts(layouts) : null;
  const line = layouts?.design.design_line;
  let design_line: Pair[] | null = null;
  if (trim && Array.isArray(line) && line.length >= 2) {
    const ground = section.samples
      .filter((s) => s.valid !== false && typeof s.elevation_m === "number")
      .map((s) => ({ offset: s.offset_m ?? 0, elevation: s.elevation_m as number }))
      .sort((a, b) => a.offset - b.offset);
    const profile = drawnProfile({
      designLine: line as Array<{ offset_m: number; elevation_m: number }>,
      ground,
      trim,
    });
    if (profile && ground.length >= 2) {
      const lo = ground[0].offset;
      const hi = ground[ground.length - 1].offset;
      const grid = new Set<number>();
      const add = (o: number) => {
        if (o >= lo && o <= hi) grid.add(Math.round(o * 1e6) / 1e6);
      };
      ground.forEach((g) => add(g.offset));
      line.forEach((p) => add(p.offset_m));
      for (const b of [trim.minOffset, trim.maxOffset])
        [b, b - BOUNDARY_EPS_M, b + BOUNDARY_EPS_M].forEach(add);
      trim.minSlope?.points.forEach((p) => add(p.offset));
      trim.maxSlope?.points.forEach((p) => add(p.offset));
      design_line = [...grid].sort((a, b) => a - b).map((o) => [o, profile.drawnZ(o)]);
    }
  }
  return { chainage_m: section.chainage_m, walls, design_line };
}

const [inputPath, outputPath] = process.argv.slice(2);
if (!inputPath || !outputPath) {
  console.error("사용법: node <번들> <입력.json> <출력.json>");
  process.exit(2);
}
const input = JSON.parse(readFileSync(inputPath, "utf8")) as {
  definition?: CatalogDefinition | null;
  sections: CrossSection[];
};
if (input.definition) useCatalogDefinition(input.definition);
const sections = input.sections ?? [];
writeFileSync(
  outputPath,
  JSON.stringify({ stations: sections.map((s) => stationWalls(s, sections)) }),
  "utf8",
);