/* =============================================================================
 * spreadsheet_functions_misc.ts  (주인 B)
 * 논리 · 글 · 정보 · 날짜 함수. 찾기 · 조건부 세기/합/평균/최대/최소는
 * `spreadsheet_functions_lookup.ts` 로 옮김(700 줄 규칙 · 2026-09-27).
 * 형 바꾸기 도우미는 `spreadsheet_functions_math.ts` 공용 것을 씀.
 * ========================================================================== */

import {
  ZERO,
  cmp,
  frac,
  mul,
  parseDecimal,
  roundAt,
  toInteger,
  type Frac,
} from "@ui/sheet/ui_template_sheet_frac";
import type { ErrorValue, LazyArg, SheetFunction } from "./spreadsheet_types";
import { formatValue } from "./spreadsheet_numfmt";
import {
  bool,
  fracToDouble,
  fromDouble,
  isErr,
  isFrac,
  isRange,
  mkErr,
  num,
  str,
  toBool,
  toScalar,
  toText,
} from "./spreadsheet_functions_math";

const ONE = frac(1n);

/** SEARCH — 통짜 맞춤이 아니라 안 어디서든 찾음(자리 없이 그대로 씀). */
function wildcardToSearchRegex(text: string): RegExp {
  const escaped = text
    .replace(/[.+^${}()|[\]\\]/g, "\\$&")
    .replace(/\*/g, ".*")
    .replace(/\?/g, ".");
  return new RegExp(escaped, "i");
}

// ── 숫자 → 고정 소수 글(FIXED) ───────────────────────────────────────────────

function groupThousands(digits: string): string {
  return digits.replace(/\B(?=(\d{3})+(?!\d))/g, ",");
}

function formatFixed(n: Frac, decimals: number, commas: boolean): string {
  const d = Math.max(0, decimals);
  const rounded = roundAt(n, d, "round");
  const negative = cmp(rounded, ZERO) < 0;
  const magnitude = negative ? frac(-rounded.n, rounded.d) : rounded;
  const scaled = toInteger(mul(magnitude, frac(10n ** BigInt(d))), "round");
  const digits = scaled.toString().padStart(d + 1, "0");
  let whole = d > 0 ? digits.slice(0, -d) : digits;
  const fraction = d > 0 ? digits.slice(-d) : "";
  if (commas) whole = groupThousands(whole);
  const body = fraction ? `${whole}.${fraction}` : whole;
  return negative ? `-${body}` : body;
}

function collectBools(args: LazyArg[]): boolean[] | ErrorValue {
  const out: boolean[] = [];
  for (const a of args) {
    const v = a();
    if (isRange(v)) {
      for (let r = 0; r < v.rows; r++) {
        for (let c = 0; c < v.cols; c++) {
          const cell = v.at(r, c);
          if (isErr(cell)) return cell;
          if (typeof cell === "boolean") out.push(cell);
          else if (isFrac(cell)) out.push(cmp(cell, ZERO) !== 0);
        }
      }
    } else if (isErr(v)) {
      return v;
    } else if (v !== null) {
      const b = toBool(v);
      if (isErr(b)) return b;
      out.push(b);
    }
  }
  return out;
}

// ── 날짜 일련번호(엑셀 1900 체계 · 1970-01-01 = 25569) ───────────────────────
// 1900 을 윤년 취급하는 옛 버그는 그대로 두지 않음(1900 년대 자체를 실무가 안 씀) —
// 유닉스 자정 기준으로 바로 셈해 1900 년 2 월 안쪽만 어긋남(1단계 밖).

const MS_PER_DAY = 86400000;
const UNIX_EPOCH_AS_EXCEL_SERIAL = 25569;

function serialToDate(serial: number): Date {
  return new Date(Math.round((serial - UNIX_EPOCH_AS_EXCEL_SERIAL) * MS_PER_DAY));
}

function dateToSerial(d: Date): number {
  return d.getTime() / MS_PER_DAY + UNIX_EPOCH_AS_EXCEL_SERIAL;
}

/** DATEDIF 낱자리(Y·M·D·YM·MD·YD) — 끝이 처음보다 이르면 `#NUM!` */
function dateDiff(startSerial: number, endSerial: number, unit: string): number | ErrorValue {
  const start = serialToDate(startSerial);
  const end = serialToDate(endSerial);
  if (end.getTime() < start.getTime()) return mkErr("#NUM!");
  const u = unit.toUpperCase();
  const sy = start.getUTCFullYear();
  const sm = start.getUTCMonth();
  const sd = start.getUTCDate();
  const ey = end.getUTCFullYear();
  const em = end.getUTCMonth();
  const ed = end.getUTCDate();
  if (u === "Y") {
    let y = ey - sy;
    if (em < sm || (em === sm && ed < sd)) y--;
    return y;
  }
  if (u === "M") {
    let m = (ey - sy) * 12 + (em - sm);
    if (ed < sd) m--;
    return m;
  }
  if (u === "D") return Math.round((end.getTime() - start.getTime()) / MS_PER_DAY);
  if (u === "YM") {
    let m = em - sm;
    if (ed < sd) m--;
    return ((m % 12) + 12) % 12;
  }
  if (u === "MD") {
    let d = ed - sd;
    if (d < 0) d += new Date(Date.UTC(ey, em, 0)).getUTCDate();
    return d;
  }
  if (u === "YD") {
    let days = Math.round((end.getTime() - Date.UTC(ey, sm, sd)) / MS_PER_DAY);
    if (days < 0) days = Math.round((end.getTime() - Date.UTC(ey - 1, sm, sd)) / MS_PER_DAY);
    return days;
  }
  return mkErr("#NUM!");
}

/** 일련번호의 소수부(하루 안 시각) → 시 · 분 · 초 */
function timeParts(serial: number): { h: number; mnt: number; s: number } {
  const dayFrac = serial - Math.floor(serial);
  const totalSeconds = Math.round(dayFrac * 86400);
  return {
    h: Math.floor(totalSeconds / 3600) % 24,
    mnt: Math.floor(totalSeconds / 60) % 60,
    s: totalSeconds % 60,
  };
}

// ── 함수 표 ──────────────────────────────────────────────────────────────

export const MISC_FUNCTIONS: Record<string, SheetFunction> = {
  IF: {
    min: 2,
    max: 3,
    call: (args) => {
      const c = bool(args[0]());
      if (isErr(c)) return c;
      if (c) return args[1]();
      return args.length > 2 ? args[2]() : false;
    },
  },
  AND: {
    min: 1,
    call: (args) => {
      const bs = collectBools(args);
      if (isErr(bs)) return bs;
      if (bs.length === 0) return mkErr("#VALUE!");
      return bs.every(Boolean);
    },
  },
  OR: {
    min: 1,
    call: (args) => {
      const bs = collectBools(args);
      if (isErr(bs)) return bs;
      if (bs.length === 0) return mkErr("#VALUE!");
      return bs.some(Boolean);
    },
  },
  NOT: {
    min: 1,
    max: 1,
    call: (args) => {
      const b = bool(args[0]());
      return isErr(b) ? b : !b;
    },
  },
  IFERROR: {
    min: 2,
    max: 2,
    call: (args) => {
      const v = args[0]();
      if (!isRange(v) && isErr(v)) return args[1]();
      return v;
    },
  },
  CONCATENATE: {
    min: 1,
    call: (args) => {
      let out = "";
      for (const a of args) {
        const v = a();
        if (isRange(v)) {
          for (let r = 0; r < v.rows; r++) {
            for (let c = 0; c < v.cols; c++) {
              const t = toText(v.at(r, c));
              if (isErr(t)) return t;
              out += t;
            }
          }
        } else {
          const t = str(v);
          if (isErr(t)) return t;
          out += t;
        }
      }
      return out;
    },
  },
  FIXED: {
    min: 1,
    max: 3,
    call: (args) => {
      const n = num(args[0]());
      if (isErr(n)) return n;
      const decArg = args.length > 1 ? num(args[1]()) : frac(2n);
      if (isErr(decArg)) return decArg;
      const decimals = Math.trunc(fracToDouble(decArg));
      const noCommaArg = args.length > 2 ? bool(args[2]()) : false;
      if (isErr(noCommaArg)) return noCommaArg;
      return formatFixed(n, decimals, !noCommaArg);
    },
  },
  TEXT: {
    min: 2,
    max: 2,
    call: (args) => {
      const v = toScalar(args[0]());
      if (isErr(v)) return v;
      const code = str(args[1]());
      if (isErr(code)) return code;
      return formatValue(v, code).글;
    },
  },
  LEN: {
    min: 1,
    max: 1,
    call: (args) => {
      const s = str(args[0]());
      return isErr(s) ? s : frac(BigInt(s.length));
    },
  },
  LEFT: {
    min: 1,
    max: 2,
    call: (args) => {
      const s = str(args[0]());
      if (isErr(s)) return s;
      const nArg = args.length > 1 ? num(args[1]()) : ONE;
      if (isErr(nArg)) return nArg;
      const n = Math.max(0, Math.trunc(fracToDouble(nArg)));
      return s.slice(0, n);
    },
  },
  RIGHT: {
    min: 1,
    max: 2,
    call: (args) => {
      const s = str(args[0]());
      if (isErr(s)) return s;
      const nArg = args.length > 1 ? num(args[1]()) : ONE;
      if (isErr(nArg)) return nArg;
      const n = Math.max(0, Math.trunc(fracToDouble(nArg)));
      return n === 0 ? "" : s.slice(-n);
    },
  },
  MID: {
    min: 3,
    max: 3,
    call: (args) => {
      const s = str(args[0]());
      if (isErr(s)) return s;
      const startN = num(args[1]());
      if (isErr(startN)) return startN;
      const lenN = num(args[2]());
      if (isErr(lenN)) return lenN;
      const start = Math.trunc(fracToDouble(startN));
      const len = Math.max(0, Math.trunc(fracToDouble(lenN)));
      if (start < 1) return mkErr("#VALUE!");
      return s.slice(start - 1, start - 1 + len);
    },
  },
  VALUE: {
    min: 1,
    max: 1,
    call: (args) => {
      const s = str(args[0]());
      if (isErr(s)) return s;
      const trimmed = s.trim();
      const pct = trimmed.endsWith("%");
      const body = pct ? trimmed.slice(0, -1) : trimmed;
      try {
        const v = parseDecimal(body);
        return pct ? { n: v.n, d: v.d * 100n } : v;
      } catch {
        return mkErr("#VALUE!", `글을 수로 못 읽음: ${s}`);
      }
    },
  },
  TEXTJOIN: {
    min: 3,
    call: (args) => {
      const delim = str(args[0]());
      if (isErr(delim)) return delim;
      const ignoreEmpty = bool(args[1]());
      if (isErr(ignoreEmpty)) return ignoreEmpty;
      const parts: string[] = [];
      for (let i = 2; i < args.length; i++) {
        const v = args[i]();
        if (isRange(v)) {
          for (let r = 0; r < v.rows; r++) {
            for (let c = 0; c < v.cols; c++) {
              const t = toText(v.at(r, c));
              if (isErr(t)) return t;
              if (!(ignoreEmpty && t === "")) parts.push(t);
            }
          }
        } else {
          const t = str(v);
          if (isErr(t)) return t;
          if (!(ignoreEmpty && t === "")) parts.push(t);
        }
      }
      return parts.join(delim);
    },
  },
  TRIM: {
    min: 1,
    max: 1,
    call: (args) => {
      const s = str(args[0]());
      return isErr(s) ? s : s.split(" ").filter(Boolean).join(" ");
    },
  },
  UPPER: {
    min: 1,
    max: 1,
    call: (args) => {
      const s = str(args[0]());
      return isErr(s) ? s : s.toUpperCase();
    },
  },
  LOWER: {
    min: 1,
    max: 1,
    call: (args) => {
      const s = str(args[0]());
      return isErr(s) ? s : s.toLowerCase();
    },
  },
  SUBSTITUTE: {
    min: 3,
    max: 4,
    call: (args) => {
      const text = str(args[0]());
      if (isErr(text)) return text;
      const oldT = str(args[1]());
      if (isErr(oldT)) return oldT;
      const newT = str(args[2]());
      if (isErr(newT)) return newT;
      if (oldT === "") return text;
      if (args.length <= 3) return text.split(oldT).join(newT);
      const nthArg = num(args[3]());
      if (isErr(nthArg)) return nthArg;
      const nth = Math.trunc(fracToDouble(nthArg));
      let idx = -1;
      let count = 0;
      let pos = 0;
      for (;;) {
        const found = text.indexOf(oldT, pos);
        if (found < 0) break;
        count++;
        if (count === nth) {
          idx = found;
          break;
        }
        pos = found + oldT.length;
      }
      return idx < 0 ? text : text.slice(0, idx) + newT + text.slice(idx + oldT.length);
    },
  },
  REPLACE: {
    min: 4,
    max: 4,
    call: (args) => {
      const text = str(args[0]());
      if (isErr(text)) return text;
      const startN = num(args[1]());
      if (isErr(startN)) return startN;
      const lenN = num(args[2]());
      if (isErr(lenN)) return lenN;
      const newText = str(args[3]());
      if (isErr(newText)) return newText;
      const start = Math.trunc(fracToDouble(startN));
      const len = Math.max(0, Math.trunc(fracToDouble(lenN)));
      if (start < 1) return mkErr("#VALUE!");
      return text.slice(0, start - 1) + newText + text.slice(start - 1 + len);
    },
  },
  FIND: {
    min: 2,
    max: 3,
    call: (args) => {
      const findT = str(args[0]());
      if (isErr(findT)) return findT;
      const within = str(args[1]());
      if (isErr(within)) return within;
      const startArg = args.length > 2 ? num(args[2]()) : ONE;
      if (isErr(startArg)) return startArg;
      const start = Math.trunc(fracToDouble(startArg));
      if (start < 1) return mkErr("#VALUE!");
      const idx = within.indexOf(findT, start - 1);
      return idx < 0 ? mkErr("#VALUE!") : frac(BigInt(idx + 1));
    },
  },
  SEARCH: {
    min: 2,
    max: 3,
    call: (args) => {
      const findT = str(args[0]());
      if (isErr(findT)) return findT;
      const within = str(args[1]());
      if (isErr(within)) return within;
      const startArg = args.length > 2 ? num(args[2]()) : ONE;
      if (isErr(startArg)) return startArg;
      const start = Math.trunc(fracToDouble(startArg));
      if (start < 1) return mkErr("#VALUE!");
      const pat = wildcardToSearchRegex(findT);
      const m = pat.exec(within.slice(start - 1));
      return m ? frac(BigInt(m.index + start)) : mkErr("#VALUE!");
    },
  },
  REPT: {
    min: 2,
    max: 2,
    call: (args) => {
      const s = str(args[0]());
      if (isErr(s)) return s;
      const nArg = num(args[1]());
      if (isErr(nArg)) return nArg;
      const n = Math.trunc(fracToDouble(nArg));
      return n < 0 ? mkErr("#VALUE!") : s.repeat(n);
    },
  },
  ISNUMBER: { min: 1, max: 1, call: (args) => isFrac(toScalar(args[0]())) },
  ISTEXT: { min: 1, max: 1, call: (args) => typeof toScalar(args[0]()) === "string" },
  ISBLANK: { min: 1, max: 1, call: (args) => toScalar(args[0]()) === null },
  ISERROR: { min: 1, max: 1, call: (args) => isErr(toScalar(args[0]())) },
  NA: { min: 0, max: 0, call: () => mkErr("#N/A") },
  TODAY: {
    min: 0,
    max: 0,
    call: () => {
      const now = new Date();
      const midnight = Date.UTC(now.getUTCFullYear(), now.getUTCMonth(), now.getUTCDate());
      return fromDouble(dateToSerial(new Date(midnight)));
    },
  },
  DATE: {
    min: 3,
    max: 3,
    call: (args) => {
      const y = num(args[0]());
      if (isErr(y)) return y;
      const m = num(args[1]());
      if (isErr(m)) return m;
      const d = num(args[2]());
      if (isErr(d)) return d;
      const date = new Date(
        Date.UTC(
          Math.trunc(fracToDouble(y)),
          Math.trunc(fracToDouble(m)) - 1,
          Math.trunc(fracToDouble(d)),
        ),
      );
      return fromDouble(dateToSerial(date));
    },
  },
  YEAR: {
    min: 1,
    max: 1,
    call: (args) => {
      const n = num(args[0]());
      return isErr(n) ? n : frac(BigInt(serialToDate(fracToDouble(n)).getUTCFullYear()));
    },
  },
  MONTH: {
    min: 1,
    max: 1,
    call: (args) => {
      const n = num(args[0]());
      return isErr(n) ? n : frac(BigInt(serialToDate(fracToDouble(n)).getUTCMonth() + 1));
    },
  },
  DAY: {
    min: 1,
    max: 1,
    call: (args) => {
      const n = num(args[0]());
      return isErr(n) ? n : frac(BigInt(serialToDate(fracToDouble(n)).getUTCDate()));
    },
  },
  NOW: { min: 0, max: 0, call: () => fromDouble(dateToSerial(new Date())) },
  WEEKDAY: {
    min: 1,
    max: 2,
    call: (args) => {
      const n = num(args[0]());
      if (isErr(n)) return n;
      const typeArg = args.length > 1 ? num(args[1]()) : ONE;
      if (isErr(typeArg)) return typeArg;
      const type = Math.trunc(fracToDouble(typeArg));
      const dow = serialToDate(fracToDouble(n)).getUTCDay(); // 0=일 .. 6=토
      if (type === 2) return frac(BigInt(((dow + 6) % 7) + 1));
      if (type === 3) return frac(BigInt((dow + 6) % 7));
      return frac(BigInt(dow + 1));
    },
  },
  EDATE: {
    min: 2,
    max: 2,
    call: (args) => {
      const n = num(args[0]());
      if (isErr(n)) return n;
      const mArg = num(args[1]());
      if (isErr(mArg)) return mArg;
      const months = Math.trunc(fracToDouble(mArg));
      const d = serialToDate(fracToDouble(n));
      const targetMonth = d.getUTCMonth() + months;
      // 달 끝을 넘는 날짜(1/31 + 1개월 등)는 다음 달로 넘기지 않고 그 달 말일로 눌러 담음(엑셀과 같음).
      const lastDay = new Date(Date.UTC(d.getUTCFullYear(), targetMonth + 1, 0)).getUTCDate();
      const day = Math.min(d.getUTCDate(), lastDay);
      const date = new Date(Date.UTC(d.getUTCFullYear(), targetMonth, day));
      return fromDouble(dateToSerial(date));
    },
  },
  EOMONTH: {
    min: 2,
    max: 2,
    call: (args) => {
      const n = num(args[0]());
      if (isErr(n)) return n;
      const mArg = num(args[1]());
      if (isErr(mArg)) return mArg;
      const months = Math.trunc(fracToDouble(mArg));
      const d = serialToDate(fracToDouble(n));
      const date = new Date(Date.UTC(d.getUTCFullYear(), d.getUTCMonth() + months + 1, 0));
      return fromDouble(dateToSerial(date));
    },
  },
  DATEDIF: {
    min: 3,
    max: 3,
    call: (args) => {
      const s = num(args[0]());
      if (isErr(s)) return s;
      const e = num(args[1]());
      if (isErr(e)) return e;
      const unit = str(args[2]());
      if (isErr(unit)) return unit;
      const result = dateDiff(fracToDouble(s), fracToDouble(e), unit);
      return isErr(result) ? result : frac(BigInt(result));
    },
  },
  NETWORKDAYS: {
    min: 2,
    max: 3,
    call: (args) => {
      const s = num(args[0]());
      if (isErr(s)) return s;
      const e = num(args[1]());
      if (isErr(e)) return e;
      let startSerial = Math.round(fracToDouble(s));
      let endSerial = Math.round(fracToDouble(e));
      let sign = 1;
      if (startSerial > endSerial) {
        [startSerial, endSerial] = [endSerial, startSerial];
        sign = -1;
      }
      const holidays = new Set<number>();
      if (args.length > 2) {
        const holidayArg = args[2]();
        if (isRange(holidayArg)) {
          for (let r = 0; r < holidayArg.rows; r++) {
            for (let c = 0; c < holidayArg.cols; c++) {
              const cell = holidayArg.at(r, c);
              if (isFrac(cell)) holidays.add(Math.round(fracToDouble(cell)));
            }
          }
        } else if (isFrac(holidayArg)) {
          holidays.add(Math.round(fracToDouble(holidayArg)));
        }
      }
      let count = 0;
      for (let day = startSerial; day <= endSerial; day++) {
        const dow = serialToDate(day).getUTCDay();
        if (dow === 0 || dow === 6) continue;
        if (holidays.has(day)) continue;
        count++;
      }
      return frac(BigInt(sign * count));
    },
  },
  HOUR: {
    min: 1,
    max: 1,
    call: (args) => {
      const n = num(args[0]());
      return isErr(n) ? n : frac(BigInt(timeParts(fracToDouble(n)).h));
    },
  },
  MINUTE: {
    min: 1,
    max: 1,
    call: (args) => {
      const n = num(args[0]());
      return isErr(n) ? n : frac(BigInt(timeParts(fracToDouble(n)).mnt));
    },
  },
  TIME: {
    min: 3,
    max: 3,
    call: (args) => {
      const hArg = num(args[0]());
      if (isErr(hArg)) return hArg;
      const mArg = num(args[1]());
      if (isErr(mArg)) return mArg;
      const sArg = num(args[2]());
      if (isErr(sArg)) return sArg;
      const totalSeconds =
        Math.trunc(fracToDouble(hArg)) * 3600 +
        Math.trunc(fracToDouble(mArg)) * 60 +
        Math.trunc(fracToDouble(sArg));
      const dayFraction = ((totalSeconds % 86400) + 86400) % 86400;
      return fromDouble(dayFraction / 86400);
    },
  },
};