/* =============================================================================
 * M02_MasterTemplete_Sangeun_SheetFormula.ts
 * 단가산출(SK) 시트 식 칸(PLAN 792 · E4 · _분석_650-H3 2 장 「식 고침」) — 시트(`_Sangeun_Sheet`)가 부름.
 *   식 칸 = 이름 꼴 글(`[노임 보통인부] × 무게 / 운반량`) · 칠 때마다 검사 길(`formula-check` · 옛 요청 끊기)
 *     → 틀리면 빨간 칸 + 까닭 한 줄 · 되면 바꿀 때(Enter · 떠남) 엔진 식을 문서에(`setFormula`) → 서버 셈
 *   변수 줄 = 이름 · 식 · 값 · [+ 변수 줄] · 빼기(`addVar` · `editVar` · `dropVar`)
 *   빈 칸 · M01 식 그대로 = 식 덮개 풂 · 같은 자리 상수 · 표값 · 품 덮개는 식 덮개와 같이 못 둠 → 걷고 넣음
 *   문서 고치기 = `logic/M02_Sangeun_Formula_Model`(792-1 짝) · 금액은 늘 서버 셈 · 자동저장 없음
 * ========================================================================== */

import { createBadge } from "@ui/ui_template_badge";
import { createButton } from "@ui/ui_template_button";
import { createCalcSheetRow } from "@ui/ui_template_calc_row";
import { el } from "@ui/ui_template_elements";
import { createInputField } from "@ui/ui_template_input";
import { currentLanguageIndex } from "@ui/ui_template_locale";
import { createText } from "@ui/ui_template_text";
import { call, type Layer } from "./M02_MasterTemplete_Api_Fetch";
import type { EditCtx } from "./M02_MasterTemplete_Sangeun_SheetEdit";
import {
  addVar,
  dropVar,
  editVar,
  setFormula,
  type FormulaDoc,
  type VarLine,
} from "./logic/M02_Sangeun_Formula_Model";
import { num, type SpotInfo } from "./logic/M02_Sangeun_Sheet_Model";

const TEXT = {
  Formula: ["식", "Formula"],
  Edit: ["식 고침", "Edit formula"],
  Close: ["식 닫기", "Close formula"],
  Hint: ["예) 무게 / 운반량 × (1 + 할증율 / 100)", "e.g. weight / load × 1.2"],
  Var: ["변수", "Variable"],
  VarName: ["변수 이름", "Variable name"],
  AddVar: ["+ 변수 줄", "+ Variable"],
  DropVar: ["변수 빼기", "Remove variable"],
  Bad: ["식이 틀려 안 넣음", "Invalid formula — not applied"],
  Checking: ["검사 중", "Checking…"],
} as const satisfies Record<string, readonly [string, string]>;
const t = (k: keyof typeof TEXT): string => TEXT[k][currentLanguageIndex as 0 | 1] ?? TEXT[k][0];

export interface CheckAnswer {
  되나: boolean;
  까닭: string[];
  알림: string[];
  /** 엔진 식(문서에 넣을 것) */
  식: string;
  /** 이름 꼴 글 */
  글: string;
}

export interface FormulaCtx extends EditCtx {
  scope: { layer: Layer; owner: string | null };
  /** 식 칸 연 자리(화면 캐시) */
  open: Set<string>;
  /** 치는 중 글(다시 그려도 안 잃음) — 넣으면 지움 */
  drafts: Map<string, string>;
  redraw: () => void;
}

const q = (c: FormulaCtx): string =>
  c.scope.owner && c.scope.layer !== "system" ? `?owner=${encodeURIComponent(c.scope.owner)}` : "";

/** 검사 길(792-1) — 셈 · 저장 없음 */
export const checkFormula = (
  c: FormulaCtx,
  spot: string,
  text: string,
  signal?: AbortSignal,
): Promise<CheckAnswer> =>
  call<CheckAnswer>(`/layers/${c.scope.layer}/sangeun/formula-check${q(c)}`, {
    method: "POST",
    body: JSON.stringify({ 문서: c.doc, 자리: spot, 식: text }),
    signal,
  });

/** 식 덮개와 같이 못 두는 같은 자리 상수 · 표값 · 품 덮개 걷음(배율은 둠) */
export function clearNums<T extends FormulaDoc>(doc: T, spot: string): T {
  const out: FormulaDoc = { ...doc };
  for (const name of ["상수덮개", "표값덮개"] as const) {
    const all = { ...(doc[name] ?? {}) };
    delete all[spot];
    if (Object.keys(all).length) out[name] = all;
    else delete out[name];
  }
  const one = doc.덮개?.[spot];
  if (one && "qty" in one) {
    const rest = { ...one };
    delete rest.qty;
    const covers = { ...doc.덮개 };
    if (Object.keys(rest).length) covers[spot] = rest;
    else delete covers[spot];
    out.덮개 = covers;
  }
  return out as T;
}

/** 식 칸 — 칠 때마다 검사(앞 요청 끊음) · 바꿀 때 넣음 · `put(엔진 식 | null)` */
function formulaBox(
  c: FormulaCtx,
  spot: string,
  key: string,
  shown: string,
  origin: string,
  put: (engine: string | null) => void,
): HTMLElement {
  const box = createInputField({
    value: c.drafts.get(key) ?? shown,
    compact: true,
    size: 24,
    placeholder: t("Hint"),
  });
  box.input.setAttribute("aria-label", t("Formula"));
  box.input.dataset.sheetCell = key;
  box.input.spellcheck = false;
  const note = createText("", "muted", 12);
  note.dataset.sheetCheck = key;
  let timer = 0;
  let ctl: AbortController | null = null;
  let last: Promise<CheckAnswer | null> | null = null;
  const run = (text: string): Promise<CheckAnswer | null> => {
    ctl?.abort();
    const mine = (ctl = new AbortController());
    note.textContent = t("Checking");
    last = checkFormula(c, spot, text, mine.signal).then(
      (got) => {
        if (mine !== ctl) return got;
        box.setError(got.되나 ? undefined : got.까닭.join(" · "));
        note.textContent = got.알림.join(" · ");
        return got;
      },
      (error: unknown) => {
        if (mine !== ctl || mine.signal.aborted) return null;
        box.setError(error instanceof Error ? error.message : String(error));
        note.textContent = "";
        return null;
      },
    );
    return last;
  };
  box.input.addEventListener("input", () => {
    c.drafts.set(key, box.input.value);
    window.clearTimeout(timer);
    const text = box.input.value.trim();
    if (!text) return void (ctl?.abort(), box.setError(undefined), (note.textContent = ""));
    timer = window.setTimeout(() => void run(text), 150);
  });
  box.input.addEventListener("change", async () => {
    window.clearTimeout(timer);
    const text = box.input.value.trim();
    if (!text || text === origin) {
      c.drafts.delete(key);
      return put(null);
    }
    const got = await run(text);
    if (!got?.되나) return void (note.textContent = t("Bad"));
    c.drafts.delete(key);
    put(got.식);
  });
  return el("div", {
    className: "m02-sks__fx",
    attrs: { "data-sheet-fx": spot },
    children: [box.root, note],
  });
}

/** 줄 식 칸 — 열었거나 식 덮개 있는 자리만 · 못 고치는 자리(로직 · 율 더한줄) = null */
export function rowFormula(
  c: FormulaCtx,
  spot: string,
  info: SpotInfo | undefined,
): HTMLElement | null {
  if (!c.edit || !spot || !info || (!c.open.has(spot) && !info.식덮개)) return null;
  const shown = info.식글 ?? info.식 ?? "";
  const origin = info.원식글 ?? "";
  return formulaBox(c, spot, `${spot}|f`, shown, origin, (engine) => {
    const doc = engine ? clearNums(c.doc as FormulaDoc, spot) : (c.doc as FormulaDoc);
    c.apply(setFormula(doc, spot, engine));
  });
}

/** 꼬리 [식 고침] · [식 닫기] — 식 덮개 있으면 늘 열림(닫기 없음) */
export function formulaToggle(
  c: FormulaCtx,
  spot: string,
  info: SpotInfo | undefined,
): HTMLElement[] {
  const addOne = /^add:#\d+$/.test(spot); // 더한줄 수량식(율 · 로직 줄은 부르는 쪽이 뺌)
  if (!c.edit || !spot || !info || info.식덮개 || (info.식 == null && !addOne)) return [];
  const on = c.open.has(spot);
  const b = createButton({
    label: on ? t("Close") : t("Edit"),
    variant: "ghost",
    size: 22,
    onClick: () => {
      if (on) c.open.delete(spot);
      else c.open.add(spot);
      c.drafts.delete(`${spot}|f`);
      c.focus(on ? "" : `${spot}|f`);
      c.redraw();
    },
  });
  b.dataset.sheetFxOpen = spot;
  return [b];
}

const vars = (c: FormulaCtx): VarLine[] => (c.doc as FormulaDoc).변수줄 ?? [];

/** 자리 뒤 변수 줄들(이어 붙은 변수까지) */
export function varRows(c: FormulaCtx, after: (v: VarLine) => boolean): HTMLElement[] {
  return vars(c).flatMap((v) =>
    after(v) ? [varRow(c, v), ...varRows(c, (x) => x.자리 === `mid:${v.이름}`)] : [],
  );
}

function varRow(c: FormulaCtx, v: VarLine): HTMLElement {
  const spot = `mid:${v.이름}`;
  const info = c.spots?.자리[spot];
  const label = c.edit
    ? (() => {
        const box = createInputField({ value: v.이름, compact: true, size: 24 });
        box.input.setAttribute("aria-label", t("VarName"));
        box.input.dataset.sheetCell = `var|${v.이름}`;
        box.input.addEventListener("change", () => {
          const to = box.input.value.trim();
          if (!to || to === v.이름 || vars(c).some((x) => x.이름 === to))
            return void (box.input.value = v.이름);
          c.focus(`var|${to}`);
          c.apply(editVar(c.doc as FormulaDoc, v.이름, { 이름: to }));
        });
        return box.root;
      })()
    : el("span", { className: "ui-calc-row__label", text: v.이름 });
  const middle = c.edit
    ? formulaBox(c, spot, `${spot}|f`, info?.식글 ?? v.식, "", (engine) =>
        c.apply(editVar(c.doc as FormulaDoc, v.이름, { 식: engine ?? "0" })),
      )
    : el("span", { className: "ui-calc-formula", text: info?.식글 ?? v.식 });
  const value = el("span", {
    className: "ui-calc-row__out",
    text: typeof info?.지금 === "number" ? num(info.지금) : "—",
  });
  const tail = el("span", {
    children: [
      createBadge(t("Var"), "accent"),
      ...(c.edit
        ? [
            createButton({
              label: t("DropVar"),
              variant: "danger-ghost",
              size: 22,
              onClick: () => c.apply(dropVar(c.doc as FormulaDoc, v.이름)),
            }),
          ]
        : []),
    ],
  });
  const row = createCalcSheetRow(label, middle, value, tail);
  row.dataset.sheetKind = "변수";
  row.dataset.sheetSpot = spot;
  row.classList.add("is-changed");
  return row;
}

/** [+ 변수 줄] — 맨 위(자리 "") · 이름 = 안 겹치는 「변수n」 */
export function addVarButton(c: FormulaCtx): HTMLElement[] {
  if (!c.edit) return [];
  const b = createButton({
    label: t("AddVar"),
    variant: "ghost",
    size: 22,
    onClick: () => {
      const used = new Set([
        ...vars(c).map((v) => v.이름),
        ...(c.spots?.이름표 ?? []).map((x) => x.글),
      ]);
      let n = 1;
      while (used.has(`변수${n}`)) n++;
      c.focus(`var|변수${n}`);
      c.apply(addVar(c.doc as FormulaDoc, { 이름: `변수${n}`, 식: "0", 자리: "" }, 0));
    },
  });
  b.dataset.sheetAddVar = "";
  return [b];
}