/* =============================================================================
 * D03_PlanAnalysis_UI_Cross.ts
 * D03 하 패널 — 누른 측점의 지반선 + 예상 횡단(PLAN 530-3 · 544-2). 계산 = 화면 TS 즉시(① 짝 `sectionsGround` ↔
 *   `generate_sections` · 격자 = 그 연도 DEM 평활본) · 예상 = `logic/D03_PlanAnalysis_Expect`(표준 횡단 기본값 ·
 *   계획고 = 중심 지반고 · 표준값 = `sections/context` 세션 캐시) · 그림 = B05 `buildCrossSvg`.
 * ========================================================================== */

import "../B05_Profile/B05_Profile_UI_Style_RouteEdit.css";
import { CURRENT_PROJECT_ID_KEY } from "@config/config_frontend";
import { createWorkflowPanelHandle } from "@ui/ui_template_overlay";
import { stationLabel } from "../common_util/common_util_station";
import type { DtmGrid } from "../common_util/common_util_surface_sampler";
import { buildCrossSvg } from "../B05_Profile/B05_Profile_UI_RouteEdit_Cross_Draw";
import {
  sectionsGround,
  type StationGround,
} from "../B05_Profile/logic/B05_Profile_Sections_Ground";
import { fetchSectionContext } from "../B06_Section/B06_Section_Api_Context";
import type { Vertex } from "./logic/D03_PlanAnalysis_Plan";
import { expectCross, type ExpectStandard } from "./logic/D03_PlanAnalysis_Expect";
import { PLAN_STATION_INTERVAL_M } from "./D03_PlanAnalysis_UI_Map";

export interface PlanCross {
  root: HTMLElement;
  /** `chainage` = 등록 누가 · `localM` = 그 연도 노선 위 누가 · 돌려줌 = 그린 측점 지반(못 읽으면 null). */
  show: (
    chainage: number,
    year: number,
    line: Vertex[],
    localM: number,
    grid: DtmGrid,
  ) => StationGround | null;
  clear: (text: string) => void;
}

/** 표준 횡단 기본값(config · 서버 한 번 · 세션 캐시) — 못 받으면 null(지반선만). */
export function loadExpectStandard(projectId: string): Promise<ExpectStandard | null> {
  return fetchSectionContext(projectId).then(
    (context) => ({
      standard: context.standard_cross_section as ExpectStandard["standard"],
      rockBoundaryM: context.rock_boundary_default_offset_m,
    }),
    () => null,
  );
}

export function createPlanCross(): PlanCross {
  const root = document.createElement("section");
  root.className = "d03-plan__cross";
  const handle = createWorkflowPanelHandle("bottom", "down", "횡단");
  const head = document.createElement("div");
  head.className = "d03-plan__cross-head";
  const body = document.createElement("div");
  body.className = "d03-plan__cross-body";
  root.append(handle.root, head, body);
  let open = true;
  handle.setOpen(open);
  handle.root.addEventListener("click", () => {
    open = !open;
    root.classList.toggle("is-collapsed", !open);
    handle.setOpen(open);
  });

  const clear = (text: string): void => {
    head.textContent = "";
    body.replaceChildren(Object.assign(document.createElement("p"), { textContent: text }));
    delete root.dataset.chainage;
  };
  clear("평면에서 측점을 누르면 그 자리 지반선 · 예상 횡단이 보입니다.");
  let standard: ExpectStandard | null = null;
  let asked: Promise<ExpectStandard | null> | null = null;

  return {
    root,
    clear,
    show(chainage, year, line, localM, grid) {
      const station = sectionsGround(line, [localM], grid).stations[0];
      if (!station) {
        clear("이 측점의 지반을 읽지 못했습니다.");
        return null;
      }
      const name = stationLabel(chainage, PLAN_STATION_INTERVAL_M, 1);
      const z = station.center_z === null ? "—" : `${station.center_z.toFixed(2)} m`;
      root.dataset.chainage = String(chainage);
      const draw = (): void => {
        const expect = standard ? expectCross(station, standard, grid) : null;
        const area = expect
          ? ` · 예상(표준 횡단 기본값 · 계획고 = 지반고) 절토 ${expect.design.cut_area_m2.toFixed(2)}㎡ · 성토 ${expect.design.fill_area_m2.toFixed(2)}㎡`
          : "";
        head.textContent = `${year}년 · ${name} · 중심 지반고 ${z}${area}`;
        const rect = body.getBoundingClientRect();
        const plot = buildCrossSvg(
          {
            status: "success",
            chainage_m: chainage,
            label: name,
            uphill_side: station.uphill_side,
            plan_radius_m: null,
            curve_widening_m: null,
            cross_half_width_m: 20,
            samples: expect?.samples ?? station.samples,
            design: expect ? { ...expect.design } : null,
          },
          Math.max(rect.width, 320),
          Math.max(rect.height, 160),
          !expect,
        );
        body.replaceChildren(plot.svg);
      };
      draw();
      if (!standard) {
        const projectId = localStorage.getItem(CURRENT_PROJECT_ID_KEY) ?? "";
        asked ??= loadExpectStandard(projectId);
        void asked.then((value) => {
          standard = value;
          // 그사이 다른 측점을 눌렀으면 그 측점이 다시 그림
          if (value && root.dataset.chainage === String(chainage)) draw();
        });
      }
      return station;
    },
  };
}