/* 스프레드시트 D 시험용 가짜 부품 — 남의 몫(A 엔진 · B 채우기 · C 격자 · E 도구)이 아직 빈 몸일 때만
 * 번들 도우미(helper_spreadsheet_d_bundle.cjs)가 이것으로 바꿔 끼움. 진짜가 들어오면 안 씀.
 * 뜻은 엑셀 흉내의 최소 — D 입력(고름 · 편집 · 가리키기 · 채우기 끌기 · 되돌리기)을 재기 위한 것뿐. */

const MAX_ROWS = 1048576;
const MAX_COLS = 16384;

// ── @ui el ────────────────────────────────────────────────────────────────
function el(tag, o = {}) {
  const n = document.createElement(tag);
  if (o.className) n.className = o.className;
  if (o.text !== undefined) n.textContent = o.text;
  for (const [k, v] of Object.entries(o.attrs || {})) n.setAttribute(k, v);
  for (const c of o.children || []) n.append(c);
  return n;
}

// ── A 주소 ────────────────────────────────────────────────────────────────
function colName(c) {
  let s = "";
  for (c += 1; c > 0; c = Math.floor((c - 1) / 26))
    s = String.fromCharCode(65 + ((c - 1) % 26)) + s;
  return s;
}
function colIndex(t) {
  if (!/^[A-Za-z]{1,3}$/.test(t)) return -1;
  let n = 0;
  for (const ch of t.toUpperCase()) n = n * 26 + ch.charCodeAt(0) - 64;
  return n - 1;
}
const toA1 = (r, c) => colName(c) + (r + 1);
function parseA1(t) {
  const m = /^\$?([A-Za-z]{1,3})\$?(\d+)$/.exec(t.trim());
  if (!m) return null;
  return { r: Number(m[2]) - 1, c: colIndex(m[1]) };
}
function rangeToA1(g) {
  if (g.c0 === 0 && g.c1 === MAX_COLS - 1) return `${g.r0 + 1}:${g.r1 + 1}`;
  if (g.r0 === 0 && g.r1 === MAX_ROWS - 1) return `${colName(g.c0)}:${colName(g.c1)}`;
  if (g.r0 === g.r1 && g.c0 === g.c1) return toA1(g.r0, g.c0);
  return `${toA1(g.r0, g.c0)}:${toA1(g.r1, g.c1)}`;
}
function parseRange(t) {
  t = t.replace(/\$/g, "").trim();
  const [a, b = a] = t.split(":");
  const pa = parseA1(a);
  const pb = parseA1(b);
  if (pa && pb)
    return {
      r0: Math.min(pa.r, pb.r),
      c0: Math.min(pa.c, pb.c),
      r1: Math.max(pa.r, pb.r),
      c1: Math.max(pa.c, pb.c),
    };
  if (/^\d+$/.test(a) && /^\d+$/.test(b))
    return { r0: Math.min(a, b) - 1, r1: Math.max(a, b) - 1, c0: 0, c1: MAX_COLS - 1 };
  if (colIndex(a) >= 0 && colIndex(b) >= 0)
    return {
      r0: 0,
      r1: MAX_ROWS - 1,
      c0: Math.min(colIndex(a), colIndex(b)),
      c1: Math.max(colIndex(a), colIndex(b)),
    };
  return null;
}
const address = {
  colName,
  colIndex,
  toA1,
  parseA1,
  rangeToA1,
  parseRange,
  quoteSheet: (n) => (/^[\w가-힣]+$/.test(n) ? n : `'${n.replace(/'/g, "''")}'`),
  cellId: (r, c) => r * MAX_COLS + c,
  fromCellId: (id) => ({ r: Math.floor(id / MAX_COLS), c: id % MAX_COLS }),
};

// ── A 낱말 (참조만 정확히) ──────────────────────────────────────────────────
const REF =
  /(?:(?:'(?:[^']|'')+'|[A-Za-z_가-힣][\w.가-힣]*)!)?\$?[A-Za-z]{1,3}\$?\d+(?::\$?[A-Za-z]{1,3}\$?\d+)?/y;
function tokenize(f) {
  const out = [];
  let i = 0;
  while (i < f.length) {
    REF.lastIndex = i;
    const m = REF.exec(f);
    if (m && !/[A-Za-z0-9_]/.test(f[i - 1] || "") && f[i + m[0].length] !== "(") {
      out.push({ kind: "ref", text: m[0], start: i, end: i + m[0].length });
      i += m[0].length;
      continue;
    }
    out.push({ kind: "unknown", text: f[i], start: i, end: i + 1 });
    i++;
  }
  return out;
}
const parser = {
  tokenize,
  parseFormula: () => ({ ok: false, message: "가짜", at: 0 }),
  formulaToText: () => "",
};

// ── A 참조 옮김 ────────────────────────────────────────────────────────────
function moveFormula(f, dr, dc) {
  return f.replace(/(\$?)([A-Z]{1,3})(\$?)(\d+)/g, (all, ac, col, ar, row) => {
    const c = ac ? colIndex(col) : colIndex(col) + dc;
    const r = ar ? Number(row) - 1 : Number(row) - 1 + dr;
    if (c < 0 || r < 0) return "#REF!";
    return `${ac}${colName(c)}${ar}${r + 1}`;
  });
}
const refshift = { moveFormula, shiftForCommand: (f) => f, r1c1ToA1: (f) => f };

// ── B 채우기 (복사 + 두 수 간격만) ─────────────────────────────────────────
function fillCells(book, sheetId, src, target) {
  const sheet = book.시트.find((s) => s.id === sheetId);
  const out = {};
  const vertical = target.r0 !== src.r0 || target.r1 !== src.r1;
  const len = vertical ? src.r1 - src.r0 + 1 : src.c1 - src.c0 + 1;
  for (let r = target.r0; r <= target.r1; r++)
    for (let c = target.c0; c <= target.c1; c++) {
      if (r >= src.r0 && r <= src.r1 && c >= src.c0 && c <= src.c1) continue;
      const k = vertical ? (((r - src.r0) % len) + len) % len : (((c - src.c0) % len) + len) % len;
      const sr = vertical ? src.r0 + k : r;
      const sc = vertical ? c : src.c0 + k;
      const cell = sheet.칸[toA1(sr, sc)];
      if (!cell) {
        out[toA1(r, c)] = null;
        continue;
      }
      const next = { ...cell };
      if (cell.식) next.식 = moveFormula(cell.식, r - sr, c - sc);
      // 수 두 칸 이상이면 간격 이음
      const first = sheet.칸[toA1(vertical ? src.r0 : r, vertical ? c : src.c0)];
      const second = sheet.칸[toA1(vertical ? src.r0 + 1 : r, vertical ? c : src.c0 + 1)];
      if (len >= 2 && typeof first?.값 === "number" && typeof second?.값 === "number") {
        const step = second.값 - first.값;
        const n = vertical ? r - src.r0 : c - src.c0;
        next.값 = first.값 + step * n;
      }
      out[toA1(r, c)] = next;
    }
  return out;
}
const fill = { fillCells };

// ── A 명령 · 이력 (칸 · 내용지움 · 묶음) ────────────────────────────────────
class CommandError extends Error {}
function cellsIn(sheet, ranges) {
  const keys = [];
  for (const key of Object.keys(sheet.칸)) {
    const a = parseA1(key);
    if (ranges.some((g) => a.r >= g.r0 && a.r <= g.r1 && a.c >= g.c0 && a.c <= g.c1))
      keys.push(key);
  }
  return keys;
}
function applyCommand(book, cmd) {
  const sheetOf = (id) => book.시트.find((s) => s.id === id);
  if (cmd.종류 === "칸") {
    const sheet = sheetOf(cmd.시트);
    const undo = {};
    const cells = [];
    for (const [k, v] of Object.entries(cmd.칸)) {
      undo[k] = sheet.칸[k] ? structuredClone(sheet.칸[k]) : null;
      if (v === null) delete sheet.칸[k];
      else sheet.칸[k] = structuredClone(v);
      cells.push({ 시트: cmd.시트, ...parseA1(k) });
    }
    return { undo: { 종류: "칸", 시트: cmd.시트, 칸: undo }, cells, rebuild: false };
  }
  if (cmd.종류 === "내용지움") {
    const sheet = sheetOf(cmd.시트);
    const next = {};
    for (const k of cellsIn(sheet, cmd.범위)) {
      const { 서식 } = sheet.칸[k];
      next[k] = 서식 === undefined ? null : { 서식 };
    }
    return applyCommand(book, { 종류: "칸", 시트: cmd.시트, 칸: next });
  }
  if (cmd.종류 === "묶음") {
    const undos = [];
    const cells = [];
    for (const c of cmd.명령) {
      const e = applyCommand(book, c);
      undos.unshift(e.undo);
      cells.push(...e.cells);
    }
    return { undo: { 종류: "묶음", 명령: undos }, cells, rebuild: false };
  }
  throw new CommandError(`가짜 명령 없음: ${cmd.종류}`);
}
const commands = {
  CommandError,
  applyCommand,
  emptyWorkbook: (col, name) => ({
    종류: "통합문서",
    판: 1,
    열: col,
    서식: [{}],
    시트: [{ id: "s1", 이름: name, 칸: {} }],
  }),
  emptySheet: (id, name) => ({ id, 이름: name, 칸: {} }),
  compactStyles: () => {},
};
const history = {
  createHistory(limit = 100) {
    let done = [];
    let undone = [];
    return {
      push(cmd, undo) {
        done.push({ cmd, undo });
        if (done.length > limit) done.shift();
        undone = [];
      },
      undo() {
        const e = done.pop();
        if (!e) return null;
        undone.push(e);
        return e.undo;
      },
      redo() {
        const e = undone.pop();
        if (!e) return null;
        done.push(e);
        return e.cmd;
      },
      canUndo: () => done.length > 0,
      canRedo: () => undone.length > 0,
      clear() {
        done = [];
        undone = [];
      },
    };
  },
};

// ── A 계산 엔진 (사칙 · SUM 만 · double) ────────────────────────────────────
function createCalcEngine(book0) {
  let book = book0;
  const sheetOf = (id) => book.시트.find((s) => s.id === id);
  function value(sid, r, c, depth = 0) {
    const cell = sheetOf(sid)?.칸[toA1(r, c)];
    if (!cell) return null;
    if (cell.식 === undefined) return cell.값 ?? null;
    if (depth > 50) return { error: "#CYCLE!" };
    const num = (v) => (typeof v === "number" ? v : v === true ? 1 : 0);
    let f = cell.식.replace(/SUM\(([A-Z]+\d+):([A-Z]+\d+)\)/gi, (_, a, b) => {
      const g = parseRange(`${a}:${b}`);
      let s = 0;
      for (let rr = g.r0; rr <= g.r1; rr++)
        for (let cc = g.c0; cc <= g.c1; cc++) s += num(value(sid, rr, cc, depth + 1));
      return `(${s})`;
    });
    f = f.replace(/\$?([A-Z]{1,3})\$?(\d+)/g, (_, col, row) => {
      const v = value(sid, Number(row) - 1, colIndex(col), depth + 1);
      return `(${num(v)})`;
    });
    if (!/^[\d+\-*/(). e]*$/.test(f)) return { error: "#NAME?" };
    try {
      return Function(`return (${f})`)();
    } catch {
      return { error: "#NAME?" };
    }
  }
  return {
    update: (changed) => {
      const out = [...changed];
      for (const s of book.시트)
        for (const k of Object.keys(s.칸))
          if (s.칸[k].식 !== undefined) out.push({ 시트: s.id, ...parseA1(k) });
      return out;
    },
    rebuild: (b) => (book = b),
    value: (s, r, c) => value(s, r, c),
    precedents: () => [],
    snapshot: () => ({}),
  };
}
const graph = { createCalcEngine };

// ── C 격자 (고정 칸 크기 · 병합 · 고름 · 참조 테두리 · 채우기 손잡이) ────────────
const W = 72;
const H = 22;
const HW = 40;
const HH = 22;
const ROWS = 60;
const COLS = 20;
const REF_COLORS = ["#1f6feb", "#cf222e", "#8250df", "#1a7f37", "#bc4c00"];

function createGrid(ctx) {
  const root = el("div", { className: "fg" });
  root.style.cssText = "position:relative;overflow:auto;height:420px;border:1px solid #ccc";
  const content = el("div");
  content.style.cssText = `position:relative;width:${HW + COLS * W}px;height:${HH + ROWS * H}px;font:12px sans-serif`;
  root.append(content);
  const cellLayer = el("div");
  const overlay = el("div");
  content.append(cellLayer, overlay);
  let refs = [];
  const merges = () => (ctx.sheet().병합 || []).map(parseRange).filter(Boolean);
  const mergeAt = (r, c) => merges().find((m) => r >= m.r0 && r <= m.r1 && c >= m.c0 && c <= m.c1);

  function cellBox(r, c) {
    const m = mergeAt(r, c) || { r0: r, c0: c, r1: r, c1: c };
    return {
      x: HW + m.c0 * W,
      y: HH + m.r0 * H,
      w: (m.c1 - m.c0 + 1) * W,
      h: (m.r1 - m.r0 + 1) * H,
    };
  }
  const rangeBox = (g) => {
    const a = cellBox(g.r0, g.c0);
    const b = cellBox(Math.min(g.r1, ROWS - 1), Math.min(g.c1, COLS - 1));
    return { x: a.x, y: a.y, w: b.x + b.w - a.x, h: b.y + b.h - a.y };
  };
  const place = (n, b) =>
    Object.assign(n.style, {
      position: "absolute",
      left: `${b.x}px`,
      top: `${b.y}px`,
      width: `${b.w}px`,
      height: `${b.h}px`,
      boxSizing: "border-box",
    });
  function show(v) {
    if (v === null || v === undefined) return "";
    if (typeof v === "object" && "n" in v) return String(Number(v.n) / Number(v.d)); // 진짜 엔진 분수
    if (typeof v === "object") return v.error;
    if (typeof v === "boolean") return v ? "TRUE" : "FALSE";
    return String(v);
  }
  function render() {
    cellLayer.textContent = "";
    const sheet = ctx.sheet();
    for (let c = 0; c < COLS; c++) {
      const h = el("div", { text: colName(c) });
      place(h, { x: HW + c * W, y: 0, w: W, h: HH });
      h.style.cssText += ";background:#f3f3f3;border:1px solid #ddd;text-align:center";
      cellLayer.append(h);
    }
    for (let r = 0; r < ROWS; r++) {
      const h = el("div", { text: String(r + 1) });
      place(h, { x: 0, y: HH + r * H, w: HW, h: H });
      h.style.cssText += ";background:#f3f3f3;border:1px solid #ddd;text-align:center";
      cellLayer.append(h);
    }
    for (let r = 0; r < ROWS; r++)
      for (let c = 0; c < COLS; c++) {
        const m = mergeAt(r, c);
        if (m && (m.r0 !== r || m.c0 !== c)) continue;
        const d = el("div", {
          className: "fg-cell",
          attrs: { "data-a1": toA1(r, c), "data-addr": toA1(r, c) }, // data-addr = C 격자와 같은 꼴
          text: show(ctx.engine.value(sheet.id, r, c)),
        });
        place(d, cellBox(r, c));
        d.style.cssText +=
          ";border-right:1px solid #eee;border-bottom:1px solid #eee;padding:2px 3px;overflow:hidden;white-space:nowrap";
        const v = ctx.engine.value(sheet.id, r, c);
        if (typeof v === "number" || (v && typeof v === "object" && "n" in v))
          d.style.textAlign = "right";
        cellLayer.append(d);
      }
    renderSelection();
  }
  function renderSelection() {
    overlay.textContent = "";
    const sel = ctx.selection;
    for (const g of sel.범위) {
      const b = el("div", { className: "fg-sel" });
      place(b, rangeBox(g));
      b.style.cssText +=
        ";border:2px solid #217346;background:rgba(33,115,70,.08);pointer-events:none";
      overlay.append(b);
    }
    const g = sel.범위[0];
    const rb = rangeBox(g);
    const hd = el("div", { className: "fg-handle" });
    place(hd, { x: rb.x + rb.w - 4, y: rb.y + rb.h - 4, w: 7, h: 7 });
    hd.style.cssText += ";background:#217346;border:1px solid #fff;pointer-events:none";
    overlay.append(hd);
    refs.forEach((x) => {
      if (x.시트 !== ctx.selection.시트) return;
      const b = el("div", { className: "fg-ref", attrs: { "data-ref": rangeToA1(x.범위) } });
      place(b, rangeBox(x.범위));
      const col = REF_COLORS[x.색번호 % REF_COLORS.length];
      b.style.cssText += `;border:2px solid ${col};pointer-events:none`;
      overlay.append(b);
    });
  }
  function hitTest(cx, cy) {
    const rect = content.getBoundingClientRect();
    const x = cx - rect.left;
    const y = cy - rect.top;
    const outer = root.getBoundingClientRect();
    if (cx < outer.left || cx > outer.right || cy < outer.top || cy > outer.bottom) return null;
    const c = Math.floor((x - HW) / W);
    const r = Math.floor((y - HH) / H);
    const rb = rangeBox(ctx.selection.범위[0]);
    if (Math.abs(x - (rb.x + rb.w)) <= 4 && Math.abs(y - (rb.y + rb.h)) <= 4)
      return {
        kind: "fillHandle",
        r: Math.min(ctx.selection.범위[0].r1, ROWS - 1),
        c: Math.min(ctx.selection.범위[0].c1, COLS - 1),
      };
    if (x < HW && y < HH) return { kind: "corner", r: -1, c: -1 };
    if (y < HH) return { kind: "colHead", r: -1, c: Math.max(0, Math.min(COLS - 1, c)) };
    if (x < HW) return { kind: "rowHead", r: Math.max(0, Math.min(ROWS - 1, r)), c: -1 };
    return {
      kind: "cell",
      r: Math.max(0, Math.min(ROWS - 1, r)),
      c: Math.max(0, Math.min(COLS - 1, c)),
    };
  }
  return {
    root,
    render,
    invalidate: () => render(),
    renderSelection,
    setRefHighlights(list) {
      refs = list;
      renderSelection();
    },
    cellBox,
    hitTest,
    reveal(r, c) {
      const b = cellBox(Math.min(r, ROWS - 1), Math.min(c, COLS - 1));
      if (b.y - HH < root.scrollTop) root.scrollTop = b.y - HH;
      if (b.y + b.h > root.scrollTop + root.clientHeight)
        root.scrollTop = b.y + b.h - root.clientHeight;
      if (b.x - HW < root.scrollLeft) root.scrollLeft = b.x - HW;
      if (b.x + b.w > root.scrollLeft + root.clientWidth)
        root.scrollLeft = b.x + b.w - root.clientWidth;
    },
    visibleRange() {
      const r0 = Math.floor(root.scrollTop / H);
      return { r0, r1: r0 + Math.floor(root.clientHeight / H) - 2, c0: 0, c1: COLS - 1 };
    },
    // C 와 같은 꼴 — box 는 격자 뿌리 기준(스크롤 뺌)
    editorSlot: (r, c) => {
      const b = cellBox(r, c);
      return { layer: content, box: { ...b, x: b.x - root.scrollLeft, y: b.y - root.scrollTop } };
    },
    destroy: () => root.remove(),
  };
}
const grid = { createGrid };

// ── E 부품 (탭만 단추 · 나머지 빈 손잡이) ───────────────────────────────────
const none = () => ({ root: null, refresh() {}, destroy() {} });
function mountTabs(ctx) {
  const root = el("div", { className: "fg-tabs" });
  root.style.cssText = "display:flex;gap:4px;padding:4px";
  function refresh() {
    root.textContent = "";
    for (const s of ctx.book.시트) {
      const b = el("button", { text: s.이름, attrs: { "data-sheet": s.id } });
      if (s.id === ctx.selection.시트) b.style.fontWeight = "bold";
      b.addEventListener("click", () => ctx.showSheet(s.id));
      root.append(b);
    }
  }
  refresh();
  return { root, refresh, destroy: () => root.remove() };
}

module.exports = {
  el: { el },
  // B 함수 — 없음(진짜 엔진이 부르면 #NAME?)
  functions: { getFunction: () => undefined, functionNames: () => [] },
  address,
  parser,
  refshift,
  fill,
  commands,
  history,
  graph,
  grid,
  toolbar: { mountToolbar: none },
  tabs: { mountTabs },
  menu: { attachMenu: none },
  clipboard: {
    attachClipboard: none,
    parseClipboard: () => null,
    blockToClipboard: () => ({ html: "", text: "" }),
  },
};