/* =============================================================================
 * B05_Profile_UI_Profile_CrossModal.ts
 * 종단 원지반선 점 → 그 자리 임시 횡단 작은 창(368-3 · 요구 240-21).
 *
 * 열기 = 도구가 꺼진 때 원지반선 근처 누름(정수 m) · 추가 측점 세로선 누름. 창은 종단 칸 안에 겹침
 * (유토 배지처럼 · [창 분할]에 따라감 · 다시 그려도 남음). 내용 = 지금 계획선(초안 포함 · 묶음 같은 계산
 * `pipelineCrossAtChainage` · 368-4) — 격자 없음 · 분석 지형 다름이면 서버 미리 뜬 횡단(`preview-stations` ·
 * 저장 계획선 기준 · 글 한 줄) · 평면 우측 횡단과 같은 그림(`buildCrossSvg`) · 확대 · 이동 · 묶음 cross 차례마다 다시.
 * [측점 추가] = 추가 측점 초안(일반측점 · [저장] 한 번) · 같은 m 에 측점이 있으면 막음 · [삭제] = 추가
 * 측점일 때만 · [닫기].
 * ========================================================================== */

import "./B05_Profile_UI_Profile_CrossModal.css";
import { attachSvgZoomPan } from "../A00_Common/b_svg_zoom_pan";
import { draftProjectId } from "../A00_Common/design/design_store";
import {
  chartYAtElevation,
  parseWindowTransform,
  type ChartWindow,
} from "../A00_Common/design/logic/design_profile_free";
import { Y_WINDOW_ATTRS, Y_WINDOW_CLASS } from "../B06_Section/B06_Section_UI_Longitudinal";
import { previewStructureSections } from "../B06_Section/B06_Section_Api_Fetch";
import { pagePipeline } from "../A00_Common/design/design_pipeline_page";
import { pipelineCrossAtChainage } from "../A00_Common/design/design_pipeline_probe";
import { stationLabel } from "../common_util/common_util_station";
import { plusStationsOf, writePlusDraft } from "./B05_Profile_Api_PlusStations";
import type { CrossPreviewResponse } from "./B05_Profile_Api_Replan";
import {
  buildCrossSvg,
  CROSS_PLOT_PAD,
  summarizeCross,
} from "./B05_Profile_UI_RouteEdit_Cross_Draw";

/** 원지반선을 눌렀다고 볼 위아래 여유(px). */
const GROUND_SLACK_PX = 8;
/** 같은 측점으로 볼 거리(m) — 정수 m 측점끼리. */
const SAME_M = 0.5;

export interface CrossModalOpen {
  chainageM: number;
  /** 지금 종단 측점 누가거리(일반 · 구조물 · 추가) — 같은 m 막음. */
  stations: readonly number[];
  intervalM: number;
}

/** 그래프 누름 → 원지반선 근처면 그 누가거리(정수 m) · 아니면 null. */
export function groundPickAt(
  chart: HTMLElement,
  event: MouseEvent,
  chainageAtPx: (px: number) => number,
  samples: ReadonlyArray<{ chainage_m?: number; elevation_m?: number | null }>,
): number | null {
  const svg = chart.querySelector<SVGSVGElement>(`svg[${Y_WINDOW_ATTRS.auto}="1"]`);
  if (!svg) return null;
  const read = (name: string): number => Number(svg.getAttribute(name));
  const view: ChartWindow = {
    center: read(Y_WINDOW_ATTRS.center),
    pxPerM: read(Y_WINDOW_ATTRS.pxPerM),
    zero: read(Y_WINDOW_ATTRS.zero),
    ...parseWindowTransform(
      svg.querySelector(`.${Y_WINDOW_CLASS}`)?.getAttribute("transform") ?? null,
    ),
  };
  if (![view.center, view.pxPerM, view.zero].every(Number.isFinite) || view.pxPerM <= 0)
    return null;
  const rect = chart.getBoundingClientRect();
  const chainage = chainageAtPx(event.clientX - rect.left);
  const valid = samples.filter(
    (s): s is { chainage_m: number; elevation_m: number } =>
      Number.isFinite(s.chainage_m ?? NaN) && Number.isFinite(s.elevation_m ?? NaN),
  );
  const after = valid.findIndex((s) => s.chainage_m >= chainage);
  if (!Number.isFinite(chainage) || after <= 0) return null;
  const [a, b] = [valid[after - 1], valid[after]];
  const t = (chainage - a.chainage_m) / (b.chainage_m - a.chainage_m || 1);
  const ground = a.elevation_m + (b.elevation_m - a.elevation_m) * t;
  const top = svg.getBoundingClientRect().top - rect.top;
  const groundY = chartYAtElevation(view, ground) + top;
  return Math.abs(event.clientY - rect.top - groundY) <= GROUND_SLACK_PX
    ? Math.round(chainage)
    : null;
}

interface CrossModal {
  open(request: CrossModalOpen): void;
}

const modals = new WeakMap<HTMLElement, CrossModal>();

function createCrossModal(host: HTMLElement): CrossModal {
  const root = document.createElement("section");
  root.className = "b05-crossmodal";
  root.setAttribute("role", "dialog");
  root.hidden = true;
  root.innerHTML = `
    <div class="b05-crossmodal__head">
      <strong>임시 횡단</strong>
      <span class="b05-crossmodal__station"></span>
    </div>
    <div class="b05-crossmodal__box"></div>
    <div class="b05-crossmodal__foot"></div>
    <div class="b05-crossmodal__actions">
      <button type="button" class="ui-button" data-act="add">측점 추가</button>
      <button type="button" class="ui-button" data-act="remove">삭제</button>
      <button type="button" class="ui-button" data-act="close">닫기</button>
    </div>`;
  const $ = <T extends HTMLElement>(selector: string): T => root.querySelector<T>(selector)!;
  const station = $(".b05-crossmodal__station");
  const box = $(".b05-crossmodal__box");
  const foot = $(".b05-crossmodal__foot");
  const add = $<HTMLButtonElement>('[data-act="add"]');
  const remove = $<HTMLButtonElement>('[data-act="remove"]');
  // 종단 그래프 누름 · 우클릭으로 새지 않게(창 안 조작은 창 몫)
  ["click", "pointerdown", "contextmenu"].forEach((type) =>
    root.addEventListener(type, (event) => event.stopPropagation()),
  );
  host.append(root);

  let current: CrossModalOpen | null = null;
  let turn = 0;
  const projectId = (): string => draftProjectId();
  const isPlus = (m: number): boolean => plusStationsOf(projectId()).includes(m);

  function syncButtons(): void {
    if (!current) return;
    const m = current.chainageM;
    const plus = isPlus(m);
    const taken = !plus && current.stations.some((at) => Math.abs(at - m) < SAME_M);
    add.hidden = plus;
    add.disabled = taken;
    add.title = taken ? "이미 측점이 있는 자리입니다." : "";
    remove.hidden = !plus;
  }

  async function draw(m: number): Promise<void> {
    const mine = (turn += 1);
    box.replaceChildren();
    foot.textContent = "횡단을 뜨는 중…";
    try {
      // 지금 계획선(초안 포함 · 묶음 같은 계산) — 격자 없음 · 분석 지형 다름이면 서버(저장 계획선)
      const now = await pipelineCrossAtChainage(projectId(), m, current?.intervalM ?? 20).catch(
        () => null,
      );
      const [cross] = now ? [now] : await previewStructureSections(projectId(), [m]);
      if (mine !== turn) return;
      if (!cross) {
        foot.textContent = "이 자리의 횡단을 뜨지 못했습니다.";
        return;
      }
      const preview = cross as unknown as CrossPreviewResponse;
      const rect = box.getBoundingClientRect();
      const plot = buildCrossSvg(
        preview,
        Math.round(rect.width) || 320,
        Math.round(rect.height) || 180,
      );
      box.replaceChildren(plot.svg);
      attachSvgZoomPan({
        svg: plot.svg,
        layer: plot.layer,
        widthPx: plot.width,
        heightPx: plot.height,
        pad: CROSS_PLOT_PAD,
        content: plot.content,
        wheelZoom: true,
      });
      const planZ = Number(
        (preview.design as { design_elevation_m?: unknown } | null)?.design_elevation_m,
      );
      root.dataset.planZ = Number.isFinite(planZ) ? planZ.toFixed(3) : "";
      foot.textContent = [
        Number.isFinite(planZ) ? `계획고 ${planZ.toFixed(2)} m` : "",
        summarizeCross(preview),
        now ? "" : "저장 계획선 기준",
      ]
        .filter(Boolean)
        .join(" · ");
    } catch (error) {
      if (mine === turn)
        foot.textContent = error instanceof Error ? error.message : "횡단을 뜨지 못했습니다.";
    }
  }

  // 계획고 · 노선이 바뀌면(묶음 cross 차례) 떠 있는 창을 다시 그림
  let watched: unknown = null;
  let stopPipe = (): void => undefined;
  function watchPipe(): void {
    const pipe = pagePipeline(projectId());
    if (pipe === watched) return;
    stopPipe();
    watched = pipe;
    stopPipe =
      pipe?.subscribe((event) => {
        if (event.kind === "stage" && event.stage === "cross" && current)
          void draw(current.chainageM);
      }, "종단 작은 창") ?? ((): void => undefined);
  }

  function close(): void {
    root.hidden = true;
    current = null;
    turn += 1;
  }

  add.addEventListener("click", () => {
    if (!current || add.disabled) return;
    writePlusDraft(projectId(), [...plusStationsOf(projectId()), current.chainageM]);
    syncButtons();
  });
  remove.addEventListener("click", () => {
    if (!current) return;
    const m = current.chainageM;
    writePlusDraft(
      projectId(),
      plusStationsOf(projectId()).filter((at) => at !== m),
    );
    syncButtons();
  });
  $('[data-act="close"]').addEventListener("click", close);

  return {
    open(request) {
      current = request;
      station.textContent = stationLabel(request.chainageM, request.intervalM);
      root.hidden = false;
      syncButtons();
      watchPipe();
      void draw(request.chainageM);
    },
  };
}

/** 종단 칸(`host` · 다시 그려도 남는 칸)에 작은 창을 열고 그 자리 임시 횡단을 그린다. */
export function openCrossModal(host: HTMLElement, request: CrossModalOpen): void {
  let modal = modals.get(host);
  if (!modal) modals.set(host, (modal = createCrossModal(host)));
  modal.open(request);
}

/** 추가 측점 지움 — 우클릭 「측점 삭제」(368-3). */
export function removePlusStation(chainageM: number): void {
  const projectId = draftProjectId();
  writePlusDraft(
    projectId,
    plusStationsOf(projectId).filter((at) => at !== Math.round(chainageM)),
  );
}