/* =============================================================================
 * D03_PlanAnalysis_UI_Points.ts
 * D03 지점(PLAN 591-2 · 요구 452 · 453) — 옛 기준 지정(D02) 지점 마킹을 노선분석으로.
 *   지점 = 긋기에 붙는 점 · 목록 하나(줄 왼 띠 = 지점 색 `pointColor` · 이름 · 🗑) · 핀 = 늘 맨 위(`pointLayer`).
 *   [추가] = 지도 보기 가운데에 바로 놓음(597-2) · 줄 누름 = 그 줄만 펼침(이름 · 경도 · 위도 — 칸 떠남 · Enter 가 한 걸음).
 *   핀 끌기 = 지점 + 그 자리 노선 노드 같이(`moveNodesAt`) · 노드 12 px 안에 놓으면 그 노드에 붙음(598-3) ·
 *     놓을 때 한 걸음(되돌리기 · 캐시 = 페이지).
 *   지도 우클릭 메뉴 = `D03_PlanAnalysis_UI_Menu`(핀 집기 · 놓기 · 지우기를 여기서 빌림).
 *   겹 둘 — `input`(핀 누름 · 끌기 · 고르기 겹보다 앞) · `pins`(그림 · 겹 맨 끝 = 맨 위).
 * ========================================================================== */

import { createIconButton } from "@ui/ui_template_button";
import { createButton } from "@ui/ui_template_elements";
import { createInputField } from "@ui/ui_template_input";
import { createListRow } from "@ui/ui_template_list_row";
import { pointColor } from "@ui/ui_template_palette";
import {
  moveNodesAt,
  nameError,
  samePoint,
  type PlanNetwork,
  type Vertex,
} from "./logic/D03_PlanAnalysis_Plan";
import {
  addPoint,
  MAX_POINTS,
  movePointTo,
  parseLonLat,
  pointLabel,
  renamePoint,
  type PointsState,
} from "./logic/D03_PlanAnalysis_PointEdit";
import { tmParams, tmToLonLat } from "./logic/D03_PlanAnalysis_Tm";
import { pointLayer, screenGap, SNAP_PX } from "./D03_PlanAnalysis_UI_DrawPaint";
import type { PlanMapLayer, ScreenMap } from "./D03_PlanAnalysis_UI_Map";

/** 핀 머리 = 꼭지 위 px(`pointLayer` 그림과 같음). */
const PIN_HEAD_PX = 18;

export interface PlanPointsParams {
  points: () => Vertex[];
  /** 지점 이름(차례 = `points` · 빈 값 = 「지점 N」). */
  names: () => string[];
  network: () => PlanNetwork;
  epsg: () => number;
  /** 한 걸음 — 지점 · 이름 · 노선 함께. */
  commit: (points: Vertex[], names: string[], network: PlanNetwork) => void;
  /** 지도 보기 가운데(작업 좌표 · 못 잼 = null) — [추가] 자리. */
  center: () => Vertex | null;
  /** 끌기 중 — 화면만. */
  show: (points: Vertex[], network: PlanNetwork) => void;
  /** 쉴 때(긋기 · 재기 아님)만 핀을 끎. */
  idle: () => boolean;
  editable: () => boolean;
}

export interface PlanPoints {
  /** 좌측 「지점」 칸 몸. */
  panel: HTMLElement;
  input: PlanMapLayer;
  pins: PlanMapLayer;
  render: () => void;
  /** 우클릭 메뉴가 빌림 — 핀 집기 · 지점 놓기(노드 둘레면 그 노드) · 지우기 · 이름 · 더 놓을 수 있나. */
  pinAt: (px: number, py: number, map: ScreenMap) => number | null;
  place: (px: number, py: number, map: ScreenMap) => void;
  remove: (i: number) => void;
  name: (i: number) => string;
  full: () => boolean;
}

export function createPlanPoints(params: PlanPointsParams): PlanPoints {
  const list = document.createElement("div");
  list.className = "d03-plan__points";
  const addButton = createButton({
    label: "추가",
    iconStart: "plus",
    variant: "ghost",
    size: 24,
    onClick: addAtCenter,
  });
  addButton.dataset.role = "points-add";
  const head = document.createElement("div");
  head.className = "d03-plan__points-head";
  head.append(addButton);
  const panel = document.createElement("div");
  panel.append(head, list);
  let openIndex: number | null = null; // 펼친 줄(하나만)
  let syncEditor: (() => void) | null = null;
  let shown = ""; // 지금 그린 틀 열쇠 — 같으면 값만 갈아 끼움(칸 초점 지키기)
  let drag: {
    index: number;
    points: Vertex[];
    network: PlanNetwork;
    last: [Vertex[], PlanNetwork] | null;
  } | null = null;

  const name = (i: number): string => pointLabel(params.names(), i);
  const state = (): PointsState => ({
    points: params.points(),
    names: params.names(),
    network: params.network(),
  });
  const commitState = (next: PointsState): void =>
    params.commit(next.points, next.names, next.network);

  /** 핀 집기 — 꼭지 · 머리(보이는 화면 위쪽) 둘레 · 뒤 지점(위에 그려짐) 먼저. */
  function pinAt(px: number, py: number, map: ScreenMap): number | null {
    const [cx, cy] = map.rerotate(px, py);
    let best: number | null = null;
    let bestGap = SNAP_PX;
    params.points().forEach((point, i) => {
      const [sx, sy] = map.rerotate(...map.toScreen(point));
      const gap = Math.min(
        Math.hypot(cx - sx, cy - sy),
        Math.hypot(cx - sx, cy - sy + PIN_HEAD_PX),
      );
      if (gap <= bestGap) [best, bestGap] = [i, gap];
    });
    return best;
  }

  function remove(i: number): void {
    openIndex = null;
    params.commit(
      params.points().filter((_, k) => k !== i),
      params.names().filter((_, k) => k !== i),
      params.network(),
    );
  }

  /** 붙음(598-3) — 화면 px 둘레(SNAP_PX) 가장 가까운 노드 자리 · `skip` 자리 노드(같이 가는 것) 빼고. */
  function nodeNear(px: number, py: number, map: ScreenMap, skip?: Vertex): Vertex | null {
    const node = params
      .network()
      .lines.flatMap((line) => line.vertices)
      .filter((point) => !skip || !samePoint(point, skip))
      .map((point) => ({ point, gap: screenGap(map, point, px, py) }))
      .filter((item) => item.gap <= SNAP_PX)
      .sort((a, b) => a.gap - b.gap)[0];
    return node ? node.point : null;
  }

  /** 지점 놓기 — 노드 둘레면 그 노드 자리(노드에 붙음). */
  function place(px: number, py: number, map: ScreenMap): void {
    if (params.points().length >= MAX_POINTS) return;
    const at = nodeNear(px, py, map) ?? map.toMetric(px, py);
    params.commit([...params.points(), [at[0], at[1]]], [...params.names(), ""], params.network());
  }

  const pins = pointLayer(params.points, params.names);

  const input: PlanMapLayer = {
    draw: () => undefined,
    press(px, py, map, button) {
      if (button !== 0 || !params.editable() || !params.idle()) return false;
      const index = pinAt(px, py, map);
      if (index === null || nodeNear(px, py, map) !== null) return false; // 노드 위 = 고르기 겹(노드 고름 · 끌면 지점 같이)
      drag = { index, points: params.points(), network: params.network(), last: null };
      return true;
    },
    hover(px, py, map) {
      if (!drag) return;
      const from = drag.points[drag.index];
      const to = nodeNear(px, py, map, from) ?? map.toMetric(px, py);
      const points = drag.points.map((p, k): Vertex => (k === drag!.index ? to : p));
      drag.last = [points, moveNodesAt(drag.network, from, to)];
      params.show(...drag.last);
    },
    release() {
      const done = drag;
      drag = null;
      if (!done?.last) return;
      params.show(done.points, done.network);
      params.commit(done.last[0], params.names(), done.last[1]);
    },
  };

  /** [추가] — 지도 보기 가운데에 바로 놓고 그 줄을 펼침. */
  function addAtCenter(): void {
    const at = params.center();
    if (!at || !params.editable() || params.points().length >= MAX_POINTS) return;
    openIndex = params.points().length;
    commitState(addPoint(state(), at));
  }

  /** 펼친 줄 — 이름 · 경도 · 위도 칸(Enter · 칸 떠남 = 한 걸음 · 잘못 쓴 값은 까닭만 보이고 안 받음). */
  function editorOf(i: number): { root: HTMLElement; sync: () => void } {
    const tm = tmParams(params.epsg());
    const editable = params.editable();
    const field = (label: string, role: string, placeholder?: string) => {
      const f = createInputField({ label, size: 24, placeholder });
      f.input.dataset.role = role;
      f.input.disabled = !editable || (role !== "point-name" && !tm);
      return f;
    };
    const nameField = field("이름", "point-name", `지점 ${i + 1}`);
    const lonField = field("경도", "point-lon");
    const latField = field("위도", "point-lat");
    const lonLatNow = (): [number, number] | null => {
      const p = params.points()[i];
      return tm && p ? tmToLonLat(tm, p[0], p[1]) : null;
    };
    const sync = (): void => {
      const set = (f: ReturnType<typeof field>, text: string): void => {
        if (document.activeElement !== f.input) f.input.value = text;
      };
      set(nameField, params.names()[i] ?? "");
      const ll = lonLatNow();
      set(lonField, ll ? ll[0].toFixed(6) : "");
      set(latField, ll ? ll[1].toFixed(6) : "");
    };
    nameField.input.addEventListener("input", () =>
      nameField.setError(nameError(nameField.input.value.trim()) ?? undefined),
    );
    nameField.input.addEventListener("change", () => {
      const text = nameField.input.value.trim();
      const error = nameError(text);
      nameField.setError(error ?? undefined);
      if (!error && text !== (params.names()[i] ?? "")) commitState(renamePoint(state(), i, text));
    });
    const moved = (): void => {
      const parsed = parseLonLat(lonField.input.value, latField.input.value);
      const bad = typeof parsed === "string";
      lonField.setError(bad && parsed.startsWith("경도") ? parsed : undefined);
      latField.setError(bad && parsed.startsWith("위도") ? parsed : undefined);
      if (bad || !tm) return;
      const now = lonLatNow();
      if (
        now &&
        now[0].toFixed(6) === parsed[0].toFixed(6) &&
        now[1].toFixed(6) === parsed[1].toFixed(6)
      )
        return;
      commitState(movePointTo(state(), i, tm, parsed[0], parsed[1]));
    };
    lonField.input.addEventListener("change", moved);
    latField.input.addEventListener("change", moved);
    const root = document.createElement("div");
    root.className = "d03-plan__point-edit";
    root.append(nameField.root, lonField.root, latField.root);
    sync();
    return { root, sync };
  }

  function render(): void {
    const tm = tmParams(params.epsg());
    const editable = params.editable();
    const points = params.points();
    if (openIndex !== null && openIndex >= points.length) openIndex = null;
    addButton.hidden = !editable;
    addButton.disabled = points.length >= MAX_POINTS || !params.center();
    const key = `${points.length}|${openIndex}|${editable}|${tm ? 1 : 0}`;
    const lonLatOf = (i: number): string | undefined => {
      const ll = tm ? tmToLonLat(tm, points[i][0], points[i][1]) : null;
      return ll ? `${ll[0].toFixed(6)}, ${ll[1].toFixed(6)}` : undefined;
    };
    if (key === shown) {
      // 틀 그대로 — 이름 · 좌표 글과 펼친 칸 값만 갈아 끼움
      points.forEach((_, i) => {
        const row = list.children[i]?.querySelector(".ui-list-row");
        const label = row?.querySelector(".ui-list-row__label");
        const sub = row?.querySelector(".ui-list-row__sub");
        if (label) label.textContent = name(i);
        if (sub) sub.textContent = lonLatOf(i) ?? "";
      });
      syncEditor?.();
      return;
    }
    shown = key;
    syncEditor = null;
    list.replaceChildren(
      ...points.map((_, i) => {
        const drop = createIconButton({
          icon: "trash",
          title: `${name(i)} 지우기`,
          size: 24,
          onClick: () => remove(i),
        });
        drop.hidden = !editable;
        const row = createListRow({
          label: name(i),
          sub: lonLatOf(i),
          stripe: pointColor(i),
          size: 28,
          trailing: drop,
          active: i === openIndex,
        });
        row.dataset.point = String(i);
        row.tabIndex = 0;
        const toggle = (): void => {
          openIndex = openIndex === i ? null : i;
          render();
        };
        row.addEventListener("click", (event) => {
          if (!(event.target as Element).closest(".ui-list-row__trailing")) toggle();
        });
        row.addEventListener("keydown", (event) => {
          if (event.key === "Enter" && event.target === row) toggle();
        });
        const item = document.createElement("div");
        item.append(row);
        if (i === openIndex) {
          const editor = editorOf(i);
          syncEditor = editor.sync;
          item.append(editor.root);
        }
        return item;
      }),
    );
  }

  return {
    panel,
    input,
    pins,
    render,
    pinAt,
    place,
    remove,
    name,
    full: () => params.points().length >= MAX_POINTS,
  };
}