/* =============================================================================
 * spreadsheet_clipboard.ts  (주인 E)
 * 복사 · 잘라내기 · 붙여넣기 — `copy` · `cut` · `paste` 사건만(허락 창 없음 · navigator.clipboard 안 씀).
 * 형 · 수식 살리기 규칙은 `spreadsheet_types.ts` `ClipBlock` 머리. 잘라내기 = 복사 + `내용지움`(누른 순간
 * 바로 지움) · 붙여넣기 = `칸` 명령(식은 A `moveFormula` · 구글 R1C1 은 `r1c1ToA1`) + 서식 · 병합 명령
 * 묶음(칸 하나하나). ⚠ 잘라내기는 OS 클립보드를 거치는 비동기 사건(다른 창 · 다른 앱에 붙일 수 있음)이라
 * `옮기기` 명령(같은 문서 안에서 그 칸을 가리키던 다른 식도 따라감) 은 못 씀 — 잘라낸 칸을 가리키던
 * 다른 칸의 식은 안 따라옴(엑셀의 「점선 테두리 유지 · 붙일 때만 지움」 도 아님). 편집 중
 * (`ctx.editor.editing()`)이면 사건을 편집기에 맡김.
 *
 * 이음(D `spreadsheet.ts` 잇는 자리) — `attachClipboard(ctx)` 한 번 부름(반환 `root` 없음 · 안 붙여도 됨).
 * `ctx.root` 의 copy/cut/paste 사건을 직접 받으므로 그 요소가 포커스를 받을 수 있어야 함
 * (D 의 숨은 textarea 가 늘 그 안에 있어야 함).
 * ========================================================================== */

import { showToast } from "@ui/ui_template_elements";
import { colName, parseRange, toA1 } from "./spreadsheet_address";
import { formatValue } from "./spreadsheet_numfmt";
import { moveFormula, r1c1ToA1 } from "./spreadsheet_refshift";
import { st } from "./spreadsheet_text";
import type {
  BorderLine,
  Cell,
  CellAddress,
  CellInput,
  CellRange,
  CellStyle,
  ClipBlock,
  ClipCell,
  Command,
  Scalar,
  Sheet,
  Workbook,
} from "./spreadsheet_types";
import type { PartHandle, SpreadsheetContext } from "./spreadsheet_view_types";

/* ── 안 → 밖 ─────────────────────────────────────────────────────────────── */

const BORDER_CSS: Record<BorderLine, string> = {
  hair: "dotted",
  thin: "solid",
  medium: "solid",
  thick: "solid",
  double: "double",
  dotted: "dotted",
  dashed: "dashed",
};

function styleAt(book: Workbook, sheet: Sheet, r: number, c: number): CellStyle {
  const cell = sheet.칸[toA1(r, c)];
  const idx = cell?.서식 ?? sheet.열?.[colName(c)]?.서식 ?? sheet.행?.[String(r + 1)]?.서식 ?? 0;
  return book.서식[idx] ?? {};
}

function styleToCss(style: CellStyle): string {
  const parts: string[] = [];
  if (style.글꼴) parts.push(`font-family:${style.글꼴}`);
  if (style.크기) parts.push(`font-size:${style.크기}pt`);
  if (style.굵게) parts.push("font-weight:bold");
  if (style.기울임) parts.push("font-style:italic");
  const deco = [style.밑줄 && "underline", style.취소선 && "line-through"]
    .filter(Boolean)
    .join(" ");
  if (deco) parts.push(`text-decoration:${deco}`);
  if (style.글자색) parts.push(`color:${style.글자색}`);
  if (style.채움) parts.push(`background-color:${style.채움}`);
  if (style.가로 && style.가로 !== "general") {
    parts.push(`text-align:${style.가로 === "centerContinuous" ? "center" : style.가로}`);
  }
  if (style.세로) parts.push(`vertical-align:${style.세로 === "center" ? "middle" : style.세로}`);
  if (style.줄바꿈) parts.push("white-space:pre-wrap");
  if (style.테두리) {
    (["위", "아래", "왼", "오른"] as const).forEach((side) => {
      const s = style.테두리?.[side];
      if (!s) return;
      const prop = {
        위: "border-top",
        아래: "border-bottom",
        왼: "border-left",
        오른: "border-right",
      }[side];
      parts.push(`${prop}:1px ${BORDER_CSS[s.선]} ${s.색 ?? "#000"}`);
    });
  }
  return parts.join(";");
}

function escapeHtml(s: string): string {
  return s.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;");
}

/** 안 → 안 왕복용 — 칸 원래 값 · 식 · 서식(인라인, 표 번호 아님) 그대로. */
function buildAisloBlock(book: Workbook, sheet: Sheet, range: CellRange): ClipBlock {
  const { r0, c0, r1, c1 } = range;
  const 칸: Record<string, ClipCell> = {};
  for (let r = r0; r <= r1; r++) {
    for (let c = c0; c <= c1; c++) {
      const cell = sheet.칸[toA1(r, c)];
      if (!cell) continue;
      const clip: ClipCell = {};
      if (cell.값 !== undefined) clip.값 = cell.값;
      if (cell.식 !== undefined) clip.식 = cell.식;
      if (cell.서식 !== undefined) clip.서식 = book.서식[cell.서식];
      if (Object.keys(clip).length) 칸[`${r - r0},${c - c0}`] = clip;
    }
  }
  const 병합 = (sheet.병합 ?? [])
    .map((m) => parseRange(m))
    .filter((m): m is CellRange => !!m && m.r0 >= r0 && m.c0 >= c0 && m.r1 <= r1 && m.c1 <= c1)
    .map((m) => ({ r0: m.r0 - r0, c0: m.c0 - c0, r1: m.r1 - r0, c1: m.c1 - c0 }));
  return { rows: r1 - r0 + 1, cols: c1 - c0 + 1, 칸, 병합, 원점: { r: r0, c: c0 }, 출처: "aislo" };
}

/** 범위 → 클립보드 글 둘(TSV = 보이는 값 · HTML = 인라인 서식 표 + 안쪽 뭉치 JSON). */
export function blockToClipboard(
  book: Workbook,
  sheetId: string,
  range: CellRange,
  valueAt: (r: number, c: number) => Scalar,
): { html: string; text: string } {
  const sheet = book.시트.find((s) => s.id === sheetId);
  if (!sheet) return { html: "", text: "" };
  const { r0, c0, r1, c1 } = range;
  const aisloBlock = buildAisloBlock(book, sheet, range);
  const rowsHtml: string[] = [];
  const tsvRows: string[] = [];
  const skip = new Set<string>();
  for (let r = r0; r <= r1; r++) {
    const cellsHtml: string[] = [];
    const tsvCells: string[] = [];
    for (let c = c0; c <= c1; c++) {
      const key = `${r},${c}`;
      if (skip.has(key)) continue;
      const style = styleAt(book, sheet, r, c);
      const text = formatValue(valueAt(r, c), style.형식).글;
      tsvCells.push(text.replace(/\t/g, " "));
      let span = "";
      const merge = (sheet.병합 ?? [])
        .map((m) => parseRange(m))
        .find((m): m is CellRange => !!m && m.r0 === r && m.c0 === c && m.r1 <= r1 && m.c1 <= c1);
      if (merge) {
        const rs = merge.r1 - merge.r0 + 1;
        const cs = merge.c1 - merge.c0 + 1;
        if (rs > 1) span += ` rowspan="${rs}"`;
        if (cs > 1) span += ` colspan="${cs}"`;
        for (let dr = 0; dr < rs; dr++)
          for (let dc = 0; dc < cs; dc++) skip.add(`${r + dr},${c + dc}`);
      }
      cellsHtml.push(
        `<td${span} style="${escapeHtml(styleToCss(style))}">${escapeHtml(text)}</td>`,
      );
    }
    rowsHtml.push(`<tr>${cellsHtml.join("")}</tr>`);
    tsvRows.push(tsvCells.join("\t"));
  }
  const table = `<table>${rowsHtml.join("")}</table>`;
  const html = `<!--aislo:${encodeURIComponent(JSON.stringify(aisloBlock))}-->${table}`;
  return { html, text: tsvRows.join("\r\n") };
}

/* ── 밖 → 안 ─────────────────────────────────────────────────────────────── */

/** 「1,234.56」 · 「TRUE」 는 값으로 · 나머지는 글로. */
function coerceValue(text: string): CellInput {
  const t = text.trim();
  if (/^[+-]?\d[\d,]*(\.\d+)?$/.test(t)) {
    const n = Number(t.replace(/,/g, ""));
    if (Number.isFinite(n)) return n;
  }
  if (/^(TRUE|FALSE)$/i.test(t)) return t.toUpperCase() === "TRUE";
  return text;
}

/** 「=」 뒤에 글이 있고 식으로 보이면 식 — 엑셀 「수식 표시」 복사 대응(「=」 한 글자는 글). */
function cellFromText(text: string): ClipCell {
  if (text.startsWith("=") && text.length > 1) return { 식: text.slice(1) };
  return { 값: coerceValue(text) };
}

interface TableWalk {
  rows: number;
  cols: number;
  owner: Map<string, HTMLTableCellElement>;
  merges: CellRange[];
}

function walkTable(table: HTMLTableElement): TableWalk {
  const occupied = new Set<string>();
  const owner = new Map<string, HTMLTableCellElement>();
  const merges: CellRange[] = [];
  const rows = Array.from(table.rows);
  rows.forEach((row, r) => {
    let c = 0;
    Array.from(row.cells).forEach((cellEl) => {
      while (occupied.has(`${r},${c}`)) c++;
      const rowspan = cellEl.rowSpan || 1;
      const colspan = cellEl.colSpan || 1;
      owner.set(`${r},${c}`, cellEl);
      for (let dr = 0; dr < rowspan; dr++) {
        for (let dc = 0; dc < colspan; dc++) occupied.add(`${r + dr},${c + dc}`);
      }
      if (rowspan > 1 || colspan > 1) {
        merges.push({ r0: r, c0: c, r1: r + rowspan - 1, c1: c + colspan - 1 });
      }
      c += colspan;
    });
  });
  let cols = 0;
  for (const key of occupied) {
    const c = Number(key.split(",")[1]);
    if (c + 1 > cols) cols = c + 1;
  }
  return { rows: rows.length, cols, owner, merges };
}

function parseHtmlTable(html: string, at: CellAddress): ClipBlock | null {
  const doc = new DOMParser().parseFromString(html, "text/html");
  const table = doc.querySelector("table");
  if (!table) return null;
  const walk = walkTable(table);
  const sheetsMode = /data-sheets-formula/.test(html);
  const 칸: Record<string, ClipCell> = {};
  for (const [key, cellEl] of walk.owner) {
    const [r, c] = key.split(",").map(Number);
    const text = cellEl.textContent ?? "";
    const formula = sheetsMode ? cellEl.getAttribute("data-sheets-formula") : null;
    if (formula) {
      const target = { r: at.r + r, c: at.c + c };
      칸[key] = { 식: r1c1ToA1(formula.replace(/^=/, ""), target) };
      continue;
    }
    if (!text) continue;
    칸[key] = cellFromText(text);
  }
  return {
    rows: walk.rows,
    cols: walk.cols,
    칸,
    병합: walk.merges,
    원점: null,
    출처: sheetsMode ? "google" : "excel",
  };
}

function parseTsv(text: string): ClipBlock {
  const lines = text.replace(/\r\n/g, "\n").split("\n");
  while (lines.length && lines[lines.length - 1] === "") lines.pop();
  const grid = lines.map((line) => line.split("\t"));
  let cols = 0;
  for (const row of grid) if (row.length > cols) cols = row.length;
  const 칸: Record<string, ClipCell> = {};
  grid.forEach((row, r) => {
    row.forEach((text, c) => {
      if (text === "") return;
      칸[`${r},${c}`] = cellFromText(text);
    });
  });
  return { rows: grid.length, cols, 칸, 병합: [], 원점: null, 출처: "text" };
}

/** 클립보드 글 → 뭉치(HTML 먼저 · 없으면 TSV) · 읽을 것 없으면 null · `at` = 붙일 왼위(구글 R1C1 풀이). */
export function parseClipboard(html: string, text: string, at: CellAddress): ClipBlock | null {
  const aislo = /<!--aislo:([^>]*)-->/.exec(html);
  if (aislo) {
    try {
      return JSON.parse(decodeURIComponent(aislo[1])) as ClipBlock;
    } catch {
      // 손상됐으면 아래 일반 경로로 폴백.
    }
  }
  if (/<table/i.test(html)) return parseHtmlTable(html, at);
  if (text) return parseTsv(text);
  return null;
}

/* ── 화면 붙임 — copy · cut · paste 사건 ────────────────────────────────── */

function activeRange(ctx: SpreadsheetContext): CellRange {
  return (
    ctx.selection.범위[0] ?? {
      r0: ctx.selection.활성.r,
      c0: ctx.selection.활성.c,
      r1: ctx.selection.활성.r,
      c1: ctx.selection.활성.c,
    }
  );
}

function pasteBlock(ctx: SpreadsheetContext, block: ClipBlock, at: CellAddress): void {
  const shift = block.원점 ? { dr: at.r - block.원점.r, dc: at.c - block.원점.c } : null;
  const 칸: Record<string, Cell | null> = {};
  const styleCmds: Command[] = [];
  for (const [key, clip] of Object.entries(block.칸)) {
    const [lr, lc] = key.split(",").map(Number);
    const r = at.r + lr;
    const c = at.c + lc;
    const cell: Cell = {};
    if (clip.값 !== undefined) cell.값 = clip.값;
    if (clip.식 !== undefined) cell.식 = shift ? moveFormula(clip.식, shift.dr, shift.dc) : clip.식;
    칸[toA1(r, c)] = Object.keys(cell).length ? cell : null;
    if (clip.서식) {
      styleCmds.push({
        종류: "서식",
        시트: ctx.selection.시트,
        범위: [{ r0: r, c0: c, r1: r, c1: c }],
        바꿀: clip.서식,
      });
    }
  }
  const commands: Command[] = [{ 종류: "칸", 시트: ctx.selection.시트, 칸 }, ...styleCmds];
  for (const m of block.병합) {
    commands.push({
      종류: "병합",
      시트: ctx.selection.시트,
      범위: { r0: at.r + m.r0, c0: at.c + m.c0, r1: at.r + m.r1, c1: at.c + m.c1 },
    });
  }
  ctx.dispatch(commands.length === 1 ? commands[0] : { 종류: "묶음", 명령: commands });
}

/** `ctx.root` 의 copy · cut · paste 를 받음(root null) */
export function attachClipboard(ctx: SpreadsheetContext): PartHandle {
  function onCopy(ev: ClipboardEvent): void {
    if (ctx.editor.editing()) return;
    const range = activeRange(ctx);
    const { html, text } = blockToClipboard(ctx.book, ctx.selection.시트, range, (r, c) =>
      ctx.engine.value(ctx.selection.시트, r, c),
    );
    ev.clipboardData?.setData("text/html", html);
    ev.clipboardData?.setData("text/plain", text);
    ev.preventDefault();
  }

  function onCut(ev: ClipboardEvent): void {
    if (ctx.editor.editing() || ctx.readOnly) return;
    onCopy(ev);
    ctx.dispatch({ 종류: "내용지움", 시트: ctx.selection.시트, 범위: [activeRange(ctx)] });
  }

  function onPaste(ev: ClipboardEvent): void {
    if (ctx.editor.editing() || ctx.readOnly) return;
    const html = ev.clipboardData?.getData("text/html") ?? "";
    const text = ev.clipboardData?.getData("text/plain") ?? "";
    const at = ctx.selection.활성;
    const block = parseClipboard(html, text, at);
    if (!block) {
      showToast(st("ClipboardPasteFailed"), "error");
      return;
    }
    ev.preventDefault();
    pasteBlock(ctx, block, at);
  }

  ctx.root.addEventListener("copy", onCopy);
  ctx.root.addEventListener("cut", onCut);
  ctx.root.addEventListener("paste", onPaste);

  return {
    root: null,
    refresh() {},
    destroy() {
      ctx.root.removeEventListener("copy", onCopy);
      ctx.root.removeEventListener("cut", onCut);
      ctx.root.removeEventListener("paste", onPaste);
    },
  };
}