/* =============================================================================
 * M01_MasterData_UI_LogicLab_Side.ts
 * 로직 상세 오른쪽 두 패널 — 「흐름도」(다이어그램 · 상세 내용 = M02_DF_Panel) · 「원문」(품셈 본문 절)
 * 둘 중 하나만 열림(하나 열면 다른 하나 접힘) · 둘 다 접기 됨 · 접힌 패널 = 얇은 띠(머리 단추 그대로)
 * 열린 패널은 계정 취향(`m01-logic-panel`)으로 기억 · 원문은 출처 글로 서버가 찾음(`GET /m01/logic/source`)
 * ========================================================================== */

import { currentLanguageIndex } from "@ui/ui_template_locale";
import { createButton, el } from "@ui/ui_template_elements";
import { API_BASE_URL } from "@config/config_frontend";
import { readStateRaw, writeStateRaw } from "../A00_Common/b_page_state";
import type { SplitHandle } from "./M01_MasterData_UI_LogicLab_Flow";
import "../M02_MasterTemplete/DataFlow/M02_DF_Panel.css";
import "./M01_MasterData_UI_LogicLab_Side.css";

const TEXT = {
  Toggle: ["원문", "Source"],
  Open: ["원문 펴기", "Open the source panel"],
  Close: ["원문 접기", "Collapse the source panel"],
  Loading: ["원문 찾는 중", "Looking up the source"],
  None: ["원문 연결 없음", "No linked source"],
  From: ["출처", "Source"],
  NoSource: ["출처 없음", "No source"],
  Near: ["{v} 절이 없어 위 절", "No {v} section — showing the parent"],
} as const;

const ts = (key: keyof typeof TEXT, v = ""): string =>
  TEXT[key][currentLanguageIndex === 1 ? 1 : 0].replace("{v}", v);

/** 접힌 띠 너비 — M02_DF_Panel 의 STRIP_WIDTH 와 같음(패널 모듈은 늦게 받으므로 따로 둠) */
const STRIP = 40;

export type PanelPick = "flow" | "source" | "none";

interface Block {
  h?: number;
  text?: string;
  p?: string;
  table?: string[][];
}
interface Found {
  number: string;
  matched: string;
  file: string;
  blocks: Block[];
}

export interface LogicSide {
  /** 흐름도 패널에 넘길 칸 — right = 흐름도 자리 · setRight = 흐름도 패널이 알린 너비 */
  flowSplit: SplitHandle;
  flowFolded(): boolean;
  pick(next: PanelPick): void;
  /** 흐름도 패널이 뜨면 접기 함수 · 내리면 null */
  bindFlow(fold: ((on: boolean) => void) | null): void;
  /** 연 로직의 출처 글 — 원문 패널이 열려 있으면 찾음 */
  showSource(src: string): void;
}

const readPick = (): PanelPick => {
  const got = readStateRaw("m01-logic-panel");
  return got === "source" || got === "none" ? got : "flow";
};

function blockNode(b: Block): HTMLElement {
  if (b.table)
    return el("div", {
      className: "m01-logic__scroll",
      children: [
        el("table", {
          className: "m01-logic__grid m01lab-src__table",
          children: [
            el("tbody", {
              children: b.table.map((r) =>
                el("tr", { children: r.map((c) => el("td", { text: c })) }),
              ),
            }),
          ],
        }),
      ],
    });
  if (b.h) return el("h4", { className: "m01lab-src__head", text: b.text ?? "" });
  return el("p", { className: "m01lab-src__p", text: b.p ?? "" });
}

export function buildLogicSide(split: SplitHandle): LogicSide {
  const flowSlot = el("div", { className: "m01lab-side__slot" });
  const body = el("div", { className: "m01lab-src__body" });
  const title = el("strong", { className: "m02-dfp__title" });
  const toggle = createButton({
    label: ts("Toggle"),
    size: "sm",
    variant: "ghost",
    onClick: () => pick(now === "source" ? "none" : "source"),
  });
  toggle.classList.add("m02-dfp__toggle");
  const head = el("header", { className: "m02-dfp__head", children: [toggle, title] });
  const open = el("div", { className: "m02-dfp__open", children: [head, body] });
  const strip = el("div", { className: "m02-dfp__strip" });
  const source = el("aside", { className: "m02-dfp m01lab-src", children: [open, strip] });
  const sourceSlot = el("div", { className: "m01lab-side__slot", children: [source] });
  split.right.replaceChildren(
    el("div", { className: "m01lab-side", children: [flowSlot, sourceSlot] }),
  );

  let now = readPick();
  let flowPx: number | null = null;
  let flowFold: ((on: boolean) => void) | null = null;
  let want = "";
  let shown: string | null = null;

  /** 칸 너비 — 원문(또는 흐름도가 아직 안 뜸) = 두 칸 비율 · 흐름도 = 패널 너비 + 띠 · 둘 다 접힘 = 띠 둘 */
  const width = (): void =>
    split.setRight(
      now === "source" || (now === "flow" && flowPx === null)
        ? null
        : now === "flow"
          ? (flowPx ?? 0) + STRIP
          : STRIP * 2,
    );

  const load = (): void => {
    if (now !== "source" || shown === want) return;
    const src = (shown = want);
    title.textContent = src || ts("NoSource");
    body.replaceChildren(el("p", { className: "m01-logic__muted", text: ts("Loading") }));
    const none = (): void =>
      body.replaceChildren(
        el("p", { className: "m01lab-src__none", text: ts("None") }),
        el("p", { className: "m01-logic__muted", text: `${ts("From")} · ${src || "—"}` }),
      );
    if (!src.trim()) return none();
    void fetch(`${API_BASE_URL}/m01/logic/source?${new URLSearchParams({ src })}`, {
      credentials: "include",
    })
      .then((r) => (r.ok ? (r.json() as Promise<{ found: Found[] }>) : { found: [] }))
      .catch(() => ({ found: [] as Found[] }))
      .then(({ found }) => {
        if (shown !== src) return;
        if (!found.length) return none();
        body.replaceChildren(
          ...found.flatMap((f) => [
            el("p", {
              className: "m01-logic__muted m01lab-src__file",
              text: f.matched === f.number ? f.file : `${f.file} · ${ts("Near", f.number)}`,
            }),
            ...f.blocks.map(blockNode),
          ]),
        );
      });
  };

  const fold = (on: boolean): void => {
    open.hidden = on;
    strip.hidden = !on;
    (on ? strip : head).prepend(toggle);
    toggle.setAttribute("aria-expanded", String(!on));
    toggle.title = ts(on ? "Open" : "Close");
  };

  const pick = (next: PanelPick): void => {
    if (next !== now) writeStateRaw("m01-logic-panel", next);
    now = next;
    flowFold?.(now !== "flow"); // 칸을 줄이기 전에 — 흐름도 패널이 접기 전 너비를 재어 둠
    flowSlot.classList.toggle("is-open", now === "flow");
    sourceSlot.classList.toggle("is-open", now === "source");
    fold(now !== "source");
    width();
    load();
  };

  pick(now);
  return {
    flowSplit: {
      root: split.root,
      right: flowSlot,
      setRight: (px) => {
        flowPx = px;
        width();
      },
    },
    flowFolded: () => now !== "flow",
    pick,
    bindFlow: (f) => {
      flowFold = f;
    },
    showSource: (src) => {
      want = src;
      load();
    },
  };
}