/* =============================================================================
 * spreadsheet.ts  (주인 D)
 * 산출근거 스프레드시트 진입 — `createSpreadsheet(칸, 통합문서, {readOnly, onChange, onSelect})` →
 * `{getDoc, setDoc, recalc, destroy}`(표 부품 `createSheet` 와 같은 모양 · M02 는 부르는 줄만 바꿈).
 * 문맥(`SpreadsheetContext`)을 만들어 C 격자 · E 도구 · 탭 · 메뉴 · 클립보드를 붙이고 D 입력(고름 · 편집기 ·
 * 키 · 마우스)을 잇음. 한글 조합 = 숨은 textarea 에 늘 초점 · compositionstart 로 편집 시작(keydown 글자 방식 금지).
 * ⚠ M02 만 `import()` 로 불러옴 — 정적 import 금지(다른 페이지 번들에 안 섞이게).
 * 저장은 부른 쪽 몫(`onChange` 로 문서 · 자동저장 없음 · [저장] 때 서버가 Node 로 다시 풂).
 * 화면 차례: 도구 모음(E) · 주소 상자 + 수식 입력줄(D) · 격자(C) · 시트 탭(E).
 * 2단계 부품(찾기 · 메모 · 서식 붓 · 골라 붙여넣기)은 `spreadsheet_extras.ts` 로 이음.
 * ========================================================================== */

import "./spreadsheet.css";
import { el } from "@ui/ui_template_elements";
import { parseA1, rangeToA1, toA1 } from "./spreadsheet_address";
import { attachClipboard } from "./spreadsheet_clipboard";
import { applyCommand, CommandError } from "./spreadsheet_commands";
import { createEditor } from "./spreadsheet_editor";
import { attachExtras } from "./spreadsheet_extras";
import { createCalcEngine } from "./spreadsheet_graph";
import { createGrid } from "./spreadsheet_grid";
import { createHistory } from "./spreadsheet_history";
import { attachKeys } from "./spreadsheet_keys";
import { attachMenu } from "./spreadsheet_menu";
import { attachMouse } from "./spreadsheet_mouse";
import { LAST_C, LAST_R, selectCell } from "./spreadsheet_selection";
import { mountTabs } from "./spreadsheet_tabs";
import { mountToolbar } from "./spreadsheet_toolbar";
import type {
  CalcValues,
  Command,
  CommandEffect,
  SheetCellAddress,
  Workbook,
} from "./spreadsheet_types";
import type {
  EditorHandle,
  GridHandle,
  PartHandle,
  Selection,
  SpreadsheetContext,
} from "./spreadsheet_view_types";

export type { Workbook, CalcValues } from "./spreadsheet_types";

export interface SpreadsheetOptions {
  /** 읽기만 — 도구 모음 · 메뉴 없음 · 편집 · 붙여넣기 · 끌기 막음(고르기 · 복사는 됨) */
  readOnly?: boolean;
  /** 명령마다 문서 사본 — 페이지가 캐시(sessionStorage)에 쌓고 [저장] 단추를 켬 */
  onChange?: (book: Workbook) => void;
  /** 고름이 바뀜 — 시트 id · 활성 칸 A1 · 범위 A1 */
  onSelect?: (selection: { 시트: string; 칸: string; 범위: string }) => void;
  /** ⚠ 임시 — 브레인 브라우저 검증용: 문맥을 `window.__aisloSheet` 에 걺(book · 고름 · 명령 읽기).
   * M02 [스프레드시트 시험] 단추만 켬 · 산출근거 카드는 안 켬 · 1단계 검증 뒤 지움. */
  inspect?: boolean;
}

declare global {
  interface Window {
    /** ⚠ 임시 — `inspect` 로 연 표의 문맥(브레인 검증용) */
    __aisloSheet?: SpreadsheetContext;
  }
}

export interface SpreadsheetHandle {
  /** 문서 사본 */
  getDoc(): Workbook;
  /** 문서 바꿔 끼움 — 되돌리기 이력 비움 · 고름 A1 */
  setDoc(book: Workbook): void;
  /** 전부 다시 풀고 다시 그림 · 결과(저장 모양) */
  recalc(): CalcValues;
  destroy(): void;
}

/** 움직이는 끝(닻에서 먼 쪽) — 행열 전체면 활성 칸 쪽 */
function farCorner(sel: Selection): { r: number; c: number } {
  const g = sel.범위[sel.범위.length - 1];
  const a = sel.기준;
  const whole = (lo: number, hi: number, last: number): boolean => lo === 0 && hi === last;
  return {
    r: whole(g.r0, g.r1, LAST_R)
      ? sel.활성.r
      : Math.abs(g.r1 - a.r) >= Math.abs(a.r - g.r0)
        ? g.r1
        : g.r0,
    c: whole(g.c0, g.c1, LAST_C)
      ? sel.활성.c
      : Math.abs(g.c1 - a.c) >= Math.abs(a.c - g.c0)
        ? g.c1
        : g.c0,
  };
}

export function createSpreadsheet(
  host: HTMLElement,
  book: Workbook,
  opts: SpreadsheetOptions = {},
): SpreadsheetHandle {
  const readOnly = !!opts.readOnly;
  const root = el("div", { className: readOnly ? "ss ss--readonly" : "ss" });
  host.append(root);
  const firstSheet = (b: Workbook) => b.시트.find((s) => s.id === b.활성) ?? b.시트[0];
  /** 시트마다 마지막 고름(탭을 오가도 그대로) */
  const memory = new Map<string, Selection>();

  const ctx: SpreadsheetContext = {
    root,
    book,
    readOnly,
    engine: createCalcEngine(book),
    history: createHistory(),
    selection: selectCell(firstSheet(book), 0, 0),
    sheet: () => ctx.book.시트.find((s) => s.id === ctx.selection.시트) ?? ctx.book.시트[0],
    dispatch,
    undo: () => replay(ctx.history.undo()),
    redo: () => replay(ctx.history.redo()),
    select,
    showSheet,
    grid: null as unknown as GridHandle,
    editor: null as unknown as EditorHandle,
  };

  const grid = createGrid(ctx);
  ctx.grid = grid;
  const ed = createEditor(ctx);
  ctx.editor = ed;
  const toolbar: PartHandle | null = readOnly ? null : mountToolbar(ctx);
  const tabs = mountTabs(ctx);
  const menu: PartHandle | null = readOnly ? null : attachMenu(ctx);
  const clip = attachClipboard(ctx);
  const others = [toolbar, tabs, menu, clip].filter((p): p is PartHandle => !!p);

  grid.root.classList.add("ss-grid-host");
  for (const node of [toolbar?.root, ed.bar, grid.root, tabs.root]) if (node) root.append(node);
  const extras = attachExtras(ctx, ed, toolbar?.root ?? null);
  others.push(...extras.parts);
  const detachKeys = attachKeys(ctx, ed, extras.keys);
  const detachMouse = attachMouse(ctx, ed, extras.mouse);
  const toast = el("div", { className: "ss-toast" });
  let toastTimer = 0;

  grid.render();
  select(ctx.selection);
  if (opts.inspect) window.__aisloSheet = ctx; // ⚠ 임시 — 브레인 검증용

  function notify(message: string): void {
    toast.textContent = message;
    root.append(toast);
    clearTimeout(toastTimer);
    toastTimer = window.setTimeout(() => toast.remove(), 3000);
  }

  function apply(command: Command): CommandEffect | null {
    try {
      return applyCommand(ctx.book, command);
    } catch (e) {
      if (e instanceof CommandError) return (notify(e.message), null);
      throw e;
    }
  }

  function dispatch(command: Command): void {
    if (readOnly) return;
    const eff = apply(command);
    if (!eff) return;
    ctx.history.push(command, eff.undo);
    after(command, eff);
  }

  function replay(command: Command | null): void {
    if (readOnly || !command || ed.editing()) return;
    const eff = apply(command);
    if (eff) after(command, eff);
  }

  function after(command: Command, eff: CommandEffect): void {
    if (eff.rebuild) {
      ctx.engine.rebuild(ctx.book);
      if (!ctx.book.시트.some((s) => s.id === ctx.selection.시트)) {
        const s = firstSheet(ctx.book);
        ctx.selection = memory.get(s.id) ?? selectCell(s, 0, 0);
      }
      grid.render();
    } else {
      const again = ctx.engine.update(eff.cells);
      if (command.종류 === "칸") grid.invalidate([...again, ...touched(command.시트, command.칸)]);
      else grid.render();
    }
    select(ctx.selection);
    opts.onChange?.(structuredClone(ctx.book));
  }

  /** 칸 명령이 건드린 칸(서식만 바뀐 칸도 다시 그리게) */
  function touched(sheet: string, cells: Record<string, unknown>): SheetCellAddress[] {
    const out: SheetCellAddress[] = [];
    for (const key of Object.keys(cells)) {
      const a = parseA1(key);
      if (a) out.push({ 시트: sheet, ...a });
    }
    return out;
  }

  function select(selection: Selection, reveal = false): void {
    ctx.selection = selection;
    memory.set(selection.시트, selection);
    grid.renderSelection();
    if (reveal) {
      const far = farCorner(selection);
      grid.reveal(far.r, far.c);
    }
    ed.sync();
    for (const p of others) p.refresh();
    const g = selection.범위[0];
    opts.onSelect?.({
      시트: selection.시트,
      칸: toA1(selection.활성.r, selection.활성.c),
      범위: g ? rangeToA1(g) : toA1(selection.활성.r, selection.활성.c),
    });
  }

  function showSheet(sheetId: string): void {
    const sheet = ctx.book.시트.find((s) => s.id === sheetId);
    if (!sheet || sheetId === ctx.selection.시트) return;
    ed.commit();
    if (ed.editing()) return; // 유효성에 막힘
    ctx.book.활성 = sheetId;
    ctx.selection = memory.get(sheetId) ?? selectCell(sheet, 0, 0);
    grid.render();
    select(ctx.selection, true);
    ed.focus();
  }

  return {
    getDoc: () => structuredClone(ctx.book),
    setDoc(next: Workbook) {
      ed.cancel();
      ctx.book = next;
      ctx.engine.rebuild(next);
      ctx.history.clear();
      memory.clear();
      ctx.selection = selectCell(firstSheet(next), 0, 0);
      grid.render();
      select(ctx.selection);
    },
    recalc() {
      ctx.engine.rebuild(ctx.book);
      grid.render();
      for (const p of others) p.refresh();
      return ctx.engine.snapshot();
    },
    destroy() {
      if (window.__aisloSheet === ctx) delete window.__aisloSheet;
      clearTimeout(toastTimer);
      detachKeys();
      detachMouse();
      for (const p of others) p.destroy();
      ed.destroy();
      grid.destroy();
      root.remove();
    },
  };
}