/* =============================================================================
 * B07_DesignDetail_Cross_Extent_Node.ts
 * 횡단도 **덧그림 범위**를 서버가 재는 Node 진입점(68-3, CLAUDE.md 5장 「계산 자리」 ②).
 *
 * 화면은 B06 산식으로 설계선·구조물을 덧그린다(`_Cross_Overlay`). 서버 장 배치가 그
 * 범위를 모르면 박스가 그림보다 작아 가장자리에서 잘렸다. 화면과 **같은 코드**를
 * 오프스크린 SVG 대신 아래 최소 DOM 위에서 돌려 측점마다 범위(m)를 낸다.
 *
 * 실행: node <번들> <입력.json> <출력.json>
 *   입력  { detail: 종횡단 상세(API와 같은 꼴) }
 *   출력  { extents: [{ chainage_m, x_min, x_max, y_min, y_max }] } — 오프셋·표고(m)
 * 끝 코드: 0 성공 / 2 인자 오류
 * ========================================================================== */

import { readFileSync, writeFileSync } from "node:fs";
import type { SectionDetailResponse } from "../B06_Section/B06_Section_Api_Fetch";
import { overlayEntities, type Entity } from "./B07_DesignDetail_Cross_Overlay";

/** 화면과 같은 종이 축척(1/100 → 1 m = 10 mm) — 공선점 허용 오차가 종이 mm 라 같아야 한다. */
const MM_PER_M = 10;
const OPEN_FRAME = [-1e12, -1e12, 1e12, 1e12];

/* ── 최소 DOM: 그리기 코드가 쓰는 만큼만 ─────────────────────────────────── */

type Child = FakeElement | string;

/** 선택자 하나(`tag`, `tag[attr]`)가 이 요소에 맞나 — 그리기·수확이 쓰는 꼴만 안다. */
function matches(element: FakeElement, selectors: string): boolean {
  return selectors.split(",").some((raw) => {
    const found = /^([\w-]*)(?:\[([\w-]+)\])?$/.exec(raw.trim());
    if (!found) return false;
    const [, tag, attribute] = found;
    if (tag && element.tagName !== tag) return false;
    return !attribute || element.attributes.has(attribute);
  });
}

class FakeElement {
  readonly attributes = new Map<string, string>();
  readonly childNodes: Child[] = [];
  parentNode: FakeElement | null = null;
  readonly dataset: Record<string, string> = {};
  readonly style: Record<string, unknown> = { setProperty: () => undefined };
  readonly classList = {
    add: (...names: string[]) => this.setClasses([...this.classes(), ...names]),
    remove: (...names: string[]) =>
      this.setClasses(this.classes().filter((name) => !names.includes(name))),
    toggle: (name: string, force?: boolean) => {
      const on = force ?? !this.classes().includes(name);
      this.setClasses(on ? [...this.classes(), name] : this.classes().filter((c) => c !== name));
      return on;
    },
    contains: (name: string) => this.classes().includes(name),
  };

  constructor(readonly tagName: string) {}

  get ownerDocument(): typeof fakeDocument {
    return fakeDocument;
  }
  get parentElement(): FakeElement | null {
    return this.parentNode;
  }
  get children(): FakeElement[] {
    return this.childNodes.filter((child): child is FakeElement => typeof child !== "string");
  }
  get firstChild(): Child | null {
    return this.childNodes[0] ?? null;
  }
  get lastChild(): Child | null {
    return this.childNodes[this.childNodes.length - 1] ?? null;
  }
  get textContent(): string {
    return this.childNodes
      .map((child) => (typeof child === "string" ? child : child.textContent))
      .join("");
  }
  set textContent(value: string | null) {
    this.replaceChildren(...(value ? [String(value)] : []));
  }

  private classes(): string[] {
    return (this.attributes.get("class") ?? "").split(/\s+/).filter(Boolean);
  }
  private setClasses(names: string[]): void {
    this.attributes.set("class", [...new Set(names)].join(" "));
  }
  private adopt(child: Child): Child {
    if (typeof child !== "string") {
      child.parentNode?.removeChild(child);
      child.parentNode = this;
    }
    return child;
  }

  setAttribute(name: string, value: unknown): void {
    this.attributes.set(name, String(value));
  }
  setAttributeNS(_ns: string | null, name: string, value: unknown): void {
    this.setAttribute(name, value);
  }
  getAttribute(name: string): string | null {
    return this.attributes.get(name) ?? null;
  }
  hasAttribute(name: string): boolean {
    return this.attributes.has(name);
  }
  removeAttribute(name: string): void {
    this.attributes.delete(name);
  }
  append(...nodes: Child[]): void {
    for (const node of nodes) this.childNodes.push(this.adopt(node));
  }
  appendChild<T extends Child>(node: T): T {
    this.append(node);
    return node;
  }
  prepend(...nodes: Child[]): void {
    this.childNodes.unshift(...nodes.map((node) => this.adopt(node)));
  }
  insertBefore<T extends Child>(node: T, reference: Child | null): T {
    const index = reference ? this.childNodes.indexOf(reference) : -1;
    if (index < 0) return this.appendChild(node);
    this.childNodes.splice(index, 0, this.adopt(node));
    return node;
  }
  removeChild<T extends Child>(node: T): T {
    const index = this.childNodes.indexOf(node);
    if (index >= 0) this.childNodes.splice(index, 1);
    if (typeof node !== "string") node.parentNode = null;
    return node;
  }
  replaceChildren(...nodes: Child[]): void {
    for (const child of [...this.childNodes]) this.removeChild(child);
    this.append(...nodes);
  }
  remove(): void {
    this.parentNode?.removeChild(this);
  }
  closest(selectors: string): FakeElement | null {
    for (let node: FakeElement | null = this; node; node = node.parentNode) {
      if (matches(node, selectors)) return node;
    }
    return null;
  }
  querySelectorAll(selectors: string): FakeElement[] {
    const found: FakeElement[] = [];
    const walk = (node: FakeElement): void => {
      for (const child of node.children) {
        if (matches(child, selectors)) found.push(child);
        walk(child);
      }
    };
    walk(this);
    return found;
  }
  querySelector(selectors: string): FakeElement | null {
    return this.querySelectorAll(selectors)[0] ?? null;
  }
  addEventListener(): void {}
  removeEventListener(): void {}
}

const fakeDocument = {
  createElementNS: (_ns: string, tag: string) => new FakeElement(tag),
  createElement: (tag: string) => new FakeElement(tag),
  createTextNode: (text: string) => text,
  // 오프스크린 SVG 는 문서에 안 붙어 있다 — 브라우저도 여기서 null 을 낸다(클립 해칭은 안 자름).
  getElementById: () => null,
};

(globalThis as Record<string, unknown>).document = fakeDocument;

/* ── 범위 재기 ─────────────────────────────────────────────────────────── */

/**
 * 글자 폭(종이 mm) 어림 — Node 에는 글꼴이 없다. 한글은 글자 크기만큼, 나머지는 0.6 배로
 * 잡는다(sans-serif 실측: 한글 0.92 · 숫자 0.56 · 기호 0.28~0.56 · m 0.93). 넉넉한 쪽이라 글자가 박스
 * 끝에 걸리면 간격이 1 mm 보다 조금 넓게 나온다.
 */
function textWidth(label: string, fontSize: number): number {
  let width = 0;
  for (const char of label) width += /[ㄱ-힣]/.test(char) ? fontSize : fontSize * 0.6;
  return width;
}

function extentOf(entities: Entity[]): [number, number, number, number] | null {
  const xs: number[] = [];
  const ys: number[] = [];
  const walk = (node: Entity): void => {
    const shape = (node.shapeData ?? null) as Record<string, unknown> | null;
    const label = shape?.label;
    const base = shape?.basePoint as { x: number; y: number } | undefined;
    if (typeof label === "string" && base) {
      // CAD 는 글자를 기준점 세로 가운데(textBaseline middle)에 정렬 쪽으로 그린다.
      const options = (shape?.options ?? {}) as { fontSize?: number; textAlign?: string };
      const size = Number(options.fontSize ?? 2);
      const width = textWidth(label, size);
      const left =
        options.textAlign === "center"
          ? base.x - width / 2
          : options.textAlign === "right"
            ? base.x - width
            : base.x;
      xs.push(left, left + width);
      ys.push(base.y - size / 2, base.y + size / 2);
    }
    for (const key of ["startPoint", "endPoint", "basePoint"]) {
      const point = shape?.[key] as { x: number; y: number } | undefined;
      if (point) {
        xs.push(point.x);
        ys.push(point.y);
      }
    }
    const center = shape?.center as { x: number; y: number } | undefined;
    if (center) {
      const radius = Number(shape?.radius ?? 0);
      xs.push(center.x - radius, center.x + radius);
      ys.push(center.y - radius, center.y + radius);
    }
    for (const child of (node.children as Entity[] | undefined) ?? []) walk(child);
  };
  entities.forEach(walk);
  if (!xs.length) return null;
  return [Math.min(...xs), Math.max(...xs), Math.min(...ys), Math.max(...ys)];
}

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 { detail?: SectionDetailResponse };
const sections = input.detail?.cross_sections ?? [];
const extents: Record<string, number>[] = [];
for (const section of sections) {
  let entities: Entity[] | null = null;
  try {
    entities = overlayEntities(
      section,
      sections,
      (offset) => offset * MM_PER_M,
      (elevation) => -(elevation * MM_PER_M),
      OPEN_FRAME,
    );
  } catch (error) {
    // 한 측점의 기하 실패가 전체를 막지 않는다 — 화면도 그 측점만 건너뛴다.
    console.error(`측점 ${section.chainage_m} 덧그림 실패: ${String(error)}`);
  }
  const extent = entities?.length ? extentOf(entities) : null;
  if (!extent) continue;
  const [xMin, xMax, yMin, yMax] = extent.map((value) => value / MM_PER_M);
  extents.push({
    chainage_m: section.chainage_m,
    x_min: xMin,
    x_max: xMax,
    y_min: yMin,
    y_max: yMax,
  });
}
writeFileSync(outputPath, JSON.stringify({ extents }), "utf8");