/* =============================================================================
 * M02_MasterTemplete_UI_Side_Library.ts
 * 좌측 서고 칸(716-4) — 일위대가(`precombo`) · 단가산출(`sangeun`) 두 칸이 같이 쓰는 층 단추 + 그 층 나무.
 * 칸마다 다른 것(종류 · 목록 고름 · 새 문서 몸 · 글)은 `LibraryOptions` 로 받음(일위대가 = `UI_Side_Precombo`).
 * 나무 = 자유 폴더(158-1 · 깊이 자유 · 층마다 따로 · 자리 없는 문서 = 뿌리) — 폴더 자리만 서버
 * (`{종류}-tree`)에 적음 · 문서 파일은 안 옮김. 폴더 오른쪽 클릭 [새 폴더] · [여기에 새 …] · [이름 바꾸기] ·
 * [지우기](안에 든 문서째 + 확인 창 · 쓰는 곳 있으면 서버 409 까닭 그대로) · 빈 자리 = 뿌리 메뉴 · 끌어 옮기기.
 * 여럿(구조물 조합 나무 꼴 · `TreePanel_Pick`) — Ctrl · Shift 클릭 고름 · 오른쪽 클릭 · Ctrl+C · Ctrl+V ·
 * Delete 가 고른 것 전부에 · 복사는 읽을 수 있는 층 어디서나 → 쓸 수 있는 층에 붙여넣기(새 키).
 * 문서 누름 = 편집 칸 · 켜진 층 단추 다시 누름 = 목록표(페이지 몫).
 * ========================================================================== */

import { isCtrlKey } from "../A00_Common/key_shortcut";
import { el, showConfirmDialog, showToast } from "@ui/ui_template_elements";
import { createEmpty } from "@ui/ui_template_empty";
import { t as L } from "@ui/ui_template_locale";
import {
  createTreeRow,
  openTreeMenu,
  renderTree,
  type TreeMenuItem,
  type TreeNode,
} from "@ui/ui_template_tree";
import {
  StaleError,
  editPrecomboTree,
  fetchPrecomboTree,
  listTemplates,
  newLibrary,
  pasteLibraryTree,
  type Layer,
  type LibraryKind,
  type PrecomboTree,
} from "./M02_MasterTemplete_Api_Fetch";
import { nameDialog } from "./M02_MasterTemplete_Library_List";
import type { Root } from "./M02_MasterTemplete_Layer";
import { tc } from "./M02_MasterTemplete_Labor_Text";
import { askText } from "./M02_MasterTemplete_TreePanel_Dialogs";
import { attachTreeDrag } from "./M02_MasterTemplete_TreePanel_Drag";
import { folderIdOf, samePath } from "./M02_MasterTemplete_TreePanel_Model";
import {
  clipOf,
  keepClip,
  pickClick,
  refOf,
  type Target,
} from "./M02_MasterTemplete_TreePanel_Pick";
import type { Selection } from "./M02_MasterTemplete_UI_Main";

/** 서고 칸 층(134-3) — 페이지 층과 따로 · `owner` null = 자기 층 */
export interface LibraryScope {
  root: Root;
  layer: Layer;
  owner: string | null;
  canWrite: boolean;
}

export interface LibraryOptions {
  kind: LibraryKind;
  scope: () => LibraryScope;
  /** 층 단추 줄(페이지가 만듦 · 그릴 때마다 새로 — 켜진 단추가 바뀜) */
  bar: () => HTMLElement;
  confirmLeave: () => Promise<boolean>;
  onOpen: (sel: Selection | null) => void;
  getOpen: () => Selection | null;
  /** 그 층 목록표 고름 — 문서 열기의 바탕(종류 · 층 · 주인 · 권한) */
  list: (scope: LibraryScope) => Selection;
  /** [여기에 새 …] 문서 몸 */
  blank: (name: string) => Record<string, unknown>;
  /** 빈 나무 글 · 새 문서 메뉴 글 */
  text: { none: string; newHere: string };
  /** 문서 줄 덧메뉴(706-1 회사에 올리기 요청) — 없거나 빈 목록이면 메뉴 없음 */
  more?: (key: string, name: string) => TreeMenuItem[];
}

export interface LibraryHandle {
  body: HTMLElement;
  /** 고름 표시만 */
  paint: () => void;
  /** 층 단추 · 나무를 그 층 목록으로 다시 그림 */
  refresh: () => Promise<void>;
}

export interface LibraryRow {
  이름: string;
  종류: string;
  제목?: string | null;
  구분?: string | null;
  상세구분?: string | null;
}

export interface LibraryFolder {
  path: string[];
  folders: LibraryFolder[];
  docs: LibraryRow[];
}

/** 폴더 나무(158-1) — 적어 둔 폴더(그 차례) + 문서 자리(없으면 뿌리 · 모르는 폴더면 그 폴더를 만듦) */
export function buildLibraryFolders(
  rows: LibraryRow[],
  view: Pick<PrecomboTree, "폴더" | "자리">,
): LibraryFolder {
  const root: LibraryFolder = { path: [], folders: [], docs: [] };
  const at = (path: string[]): LibraryFolder =>
    path.reduce((node, name, i) => {
      let next = node.folders.find((f) => f.path[i] === name);
      if (!next) {
        next = { path: path.slice(0, i + 1), folders: [], docs: [] };
        node.folders.push(next);
      }
      return next;
    }, root);
  view.폴더.forEach(at);
  for (const row of rows) at(view.자리[row.이름] ?? []).docs.push(row);
  return root;
}

/** 폴더 안 문서 수(아래 폴더까지) */
export const docCount = (node: LibraryFolder): number =>
  node.docs.length + node.folders.reduce((n, f) => n + docCount(f), 0);

type TreeBody = Parameters<typeof editPrecomboTree>[1];
const why = (error: unknown): string => (error instanceof Error ? error.message : "");

export function buildLibrarySection(opt: LibraryOptions): LibraryHandle {
  const kind = opt.kind;
  const clipKind = `library:${kind}`;
  const barHost = el("div");
  const treeHost = el("div", {
    className: "ui-tree m02-tree__body",
    attrs: { "data-library-tree": kind, tabindex: "0" },
  });
  const leaves = new Map<string, HTMLElement>();
  const toggled = new Map<string, boolean>(); // 손으로 펴고 접은 폴더 — 다시 그려도 그대로
  const targets = new Map<string, Target>();
  const counts = new Map<string, number>();
  let picked = new Set<string>();
  let anchor: string | null = null;
  let rows: LibraryRow[] = [];
  let view: PrecomboTree | null = null;
  let seq = 0;
  let busy = false;

  const open = async (row: LibraryRow): Promise<void> => {
    const at = opt.scope();
    if (!(await opt.confirmLeave())) return;
    opt.onOpen({
      ...opt.list(at),
      name: row.이름,
      label: row.제목 ? `${row.이름} ${row.제목}` : row.이름,
    });
  };

  /** 나무 고침 한 번 — 판 다름 = 다시 읽음 · 막힘 까닭(같은 이름 · 쓰는 곳) 그대로 */
  const apply = async (run: (판: string) => Promise<PrecomboTree>): Promise<void> => {
    if (!view || busy) return;
    busy = true;
    try {
      view = await run(view.판);
      const gone = view.알림?.지운문서 ?? [];
      if (gone.length) {
        rows = rows.filter((r) => !gone.includes(r.이름));
        const cur = opt.getOpen();
        if (cur && cur.kind === kind && gone.includes(cur.name)) opt.onOpen(null);
      }
      if (view.알림?.만든문서?.length) await refresh(true);
      else draw();
      showToast(L("M02_TreeDone"), "success");
    } catch (error) {
      if (error instanceof StaleError && error.message === "HTTP 409") {
        await refresh();
        showToast(L("M02_TreeStale"), "error");
      } else {
        showToast(L("M02_ActionFailed").replace("{value}", why(error)), "error");
      }
    } finally {
      busy = false;
    }
  };
  const edit = async (body: TreeBody): Promise<void> => {
    const at = opt.scope();
    for (const path of [body.경로, body.새경로])
      path?.forEach((_, i) => toggled.set(folderIdOf(path.slice(0, i + 1)), true));
    await apply((판) => editPrecomboTree(at.layer, body, 판, at.owner, kind));
  };

  /** [여기에 새 …] — 뿌리에 생성 → 폴더면 그 자리로 옮김 → 나무 다시 · 상세 엶 */
  const make = (path: string[]): void => {
    const at = opt.scope();
    nameDialog(opt.text.newHere, "", async (name) => {
      const got = await newLibrary(at.layer, kind, { 문서: opt.blank(name) }, at.owner);
      showToast(L("M02_Created"), "success");
      await refresh();
      if (path.length) await edit({ op: "move", 키: got.이름, 새경로: path });
      await open({ 이름: got.이름, 종류: kind, 제목: name });
    });
  };
  const addFolder = async (parent: string[]): Promise<void> => {
    const got = await askText(L("M02_TreeAddFolder"), [
      { key: "name", label: L("M02_TreeFolderName") },
    ]);
    if (got) await edit({ op: "add-folder", 경로: parent, 이름: got.name });
  };
  const rename = async (path: string[]): Promise<void> => {
    const was = path[path.length - 1];
    const got = await askText(L("M02_TreeRename"), [
      { key: "name", label: L("M02_TreeFolderName"), value: was },
    ]);
    if (got && got.name !== was) await edit({ op: "rename", 경로: path, 이름: got.name });
  };

  /* --- 지우기 · 여럿 · 복사 붙여넣기(구조물 조합 나무 꼴) --- */
  const pickedTargets = (): Target[] =>
    [...picked].map((id) => targets.get(id)).filter((t): t is Target => !!t);
  /** 지우기 — 확인 창(폴더 = 안의 문서 수) 뒤 한 번에 · 쓰는 곳이 있으면 서버가 막음(그 이름) */
  const remove = async (list: Target[]): Promise<void> => {
    if (!list.length || !opt.scope().canWrite) return;
    const [one] = list;
    const ask =
      list.length > 1
        ? L("M02_TreeDeleteManyAsk").replace("{n}", String(list.length))
        : one.kind === "item"
          ? L("M02_TreeDeleteItem").replace("{value}", one.item.이름)
          : L("M02_TreeDeleteFolder")
              .replace("{value}", one.path[one.path.length - 1])
              .replace("{n}", String(counts.get(folderIdOf(one.path)) ?? 0));
    if (!(await showConfirmDialog(ask, L("M02_Delete")))) return;
    await edit({ op: "delete", 대상: list.map(refOf) });
  };
  const copy = (list: Target[]): void => {
    if (!list.length) return;
    const at = opt.scope();
    keepClip({ kind: clipKind, from: { layer: at.layer, owner: at.owner }, refs: list.map(refOf) });
    showToast(L("M02_TreeCopied").replace("{n}", String(list.length)), "success");
  };
  const paste = async (dest: string[]): Promise<void> => {
    const got = clipOf(clipKind);
    const at = opt.scope();
    if (!got || !at.canWrite) return;
    toggled.set(folderIdOf(dest), true);
    await apply(() => pasteLibraryTree(kind, at.layer, at.owner, got, dest));
  };

  const menuAt = (path: string[]): TreeMenuItem[] => {
    const off = opt.scope().canWrite ? undefined : tc("ReadOnly");
    const item = (label: string, run: () => void): TreeMenuItem => ({
      label,
      run,
      disabledReason: off,
    });
    const got = clipOf(clipKind);
    const target: Target = { kind: "folder", path };
    return [
      item(L("M02_TreeAddFolder"), () => void addFolder(path)),
      item(opt.text.newHere, () => make(path)),
      ...(path.length
        ? [
            item(L("M02_TreeRename"), () => void rename(path)),
            item(L("M02_Delete"), () => void remove([target])),
            { label: L("M02_TreeCopy").replace("{n}", "1"), run: () => copy([target]) },
          ]
        : []),
      ...(got
        ? [item(L("M02_TreePaste").replace("{n}", String(got.refs.length)), () => void paste(path))]
        : []),
    ];
  };
  /** 오른쪽 클릭 — 고른 것 안의 줄이면 고른 것 전부(복사 · 지우기) · 아니면 그 줄 하나 */
  const menuFor = (id: string, single: () => TreeMenuItem[]): TreeMenuItem[] => {
    if (!picked.has(id)) setPicked(new Set([id]), id);
    const list = pickedTargets();
    if (list.length < 2) return single();
    const n = String(list.length);
    const off = opt.scope().canWrite ? undefined : tc("ReadOnly");
    return [
      { label: L("M02_TreeCopy").replace("{n}", n), run: () => copy(list) },
      {
        label: L("M02_TreeDeleteMany").replace("{n}", n),
        run: () => void remove(list),
        disabledReason: off,
      },
    ];
  };

  const leaf = (row: LibraryRow, folder: string[]): TreeNode => {
    const id = `doc:${row.이름}`;
    const label = row.제목 || row.이름;
    const item = { key: row.이름, 열: row.이름, 경로: [...folder, label], 이름: label };
    const target: Target = { kind: "item", item };
    targets.set(id, target);
    const single = (): TreeMenuItem[] => [
      { label: L("M02_TreeCopy").replace("{n}", "1"), run: () => copy([target]) },
      {
        label: L("M02_Delete"),
        run: () => void remove([target]),
        disabledReason: opt.scope().canWrite ? undefined : tc("ReadOnly"),
      },
      ...(opt.more?.(row.이름, label) ?? []),
    ];
    const menu = () => menuFor(id, single);
    return { id, label, tip: row.이름, count: null, run: () => void open(row), menu };
  };
  const folderNode = (node: LibraryFolder): TreeNode => {
    const id = folderIdOf(node.path);
    const count = docCount(node);
    targets.set(id, { kind: "folder", path: node.path });
    counts.set(id, count);
    return {
      id,
      label: node.path[node.path.length - 1],
      count,
      folder: true,
      open: toggled.get(id) ?? count > 0,
      children: kids(node),
      menu: () => menuFor(id, () => menuAt(node.path)),
    };
  };
  const kids = (node: LibraryFolder): TreeNode[] => [
    ...node.folders.map(folderNode),
    ...node.docs.map((row) => leaf(row, node.path)),
  ];

  /** 끌어 옮기기(구조물 조합 나무와 같은 부품) — 고른 것 전부 · 폴더 줄 위 = 그 안 · 빈 자리 = 뿌리 */
  const drag = attachTreeDrag({
    body: treeHost,
    targetOf: (id) => targets.get(id),
    listFor: (id) =>
      picked.size > 1 && picked.has(id)
        ? pickedTargets()
        : targets.has(id)
          ? [targets.get(id)!]
          : null,
    move: (list, dest) => {
      const from = (t: Target): string[] =>
        t.kind === "item" ? t.item.경로.slice(0, -1) : t.path.slice(0, -1);
      const moving = list.filter((t) => !samePath(from(t), dest));
      if (moving.length) void edit({ op: "move", 대상: moving.map(refOf), 새경로: dest });
    },
  });

  const visibleIds = (): string[] =>
    [...treeHost.querySelectorAll<HTMLElement>("[data-node]")]
      .filter((b) => !b.closest("[hidden]"))
      .map((b) => b.dataset.node ?? "");
  const setPicked = (next: Set<string>, at: string | null): void => {
    picked = next;
    anchor = at;
    for (const row of treeHost.querySelectorAll<HTMLElement>("[data-node]"))
      row.classList.toggle("is-picked", picked.size > 1 && picked.has(row.dataset.node ?? ""));
  };

  const draw = (): void => {
    leaves.clear();
    targets.clear();
    counts.clear();
    const tree = buildLibraryFolders(rows, view ?? { 폴더: [], 자리: {} });
    if (!tree.docs.length && !tree.folders.length)
      return void treeHost.replaceChildren(createEmpty({ text: opt.text.none, small: true }));
    const canWrite = opt.scope().canWrite;
    treeHost.replaceChildren(
      ...renderTree(kids(tree), (node, caret, depth, onClick) => {
        const row = createTreeRow(node, caret, depth, () => {
          onClick();
          if (!node.children?.length) return;
          toggled.set(node.id, row.querySelector(".ui-tree__caret")?.textContent !== "▸");
        });
        row.dataset.node = node.id;
        // Ctrl · Shift 클릭 = 고르기만(열기 · 접기 안 함) — 줄 본디 click 보다 먼저(capture)
        row.addEventListener(
          "click",
          (event) => {
            const mod = { ctrl: event.ctrlKey || event.metaKey, shift: event.shiftKey };
            const got = pickClick(picked, anchor, node.id, mod, visibleIds());
            if (got.handled) event.stopImmediatePropagation();
            setPicked(got.picked, got.anchor);
          },
          { capture: true },
        );
        if (node.run) {
          row.dataset.libraryKey = node.id.slice(4);
          leaves.set(node.id.slice(4), row);
        }
        if (canWrite) drag.arm(row, node.id);
        return row;
      }),
    );
    setPicked(new Set([...picked].filter((id) => targets.has(id))), anchor);
    paint();
  };

  // 빈 자리 오른쪽 클릭 = 뿌리 메뉴(새 폴더 · 새 문서 · 붙여넣기)
  treeHost.addEventListener("contextmenu", (event) => {
    if (!view || (event.target as HTMLElement).closest("[data-node]")) return;
    event.preventDefault();
    openTreeMenu(event, menuAt([]));
  });
  // 키 — Delete = 고른 것(없으면 초점 줄) 지움 · Ctrl+C 복사 · Ctrl+V = 초점 폴더 안(아니면 뿌리)
  treeHost.addEventListener("keydown", (event) => {
    const row = (event.target as HTMLElement).closest<HTMLElement>("[data-node]");
    const id = row?.dataset.node ?? "";
    const target = targets.get(id);
    const list = picked.has(id) ? pickedTargets() : target ? [target] : [];
    if (event.key === "Delete" && list.length) {
      event.preventDefault();
      void remove(list);
    } else if (isCtrlKey(event, "c") && list.length) {
      event.preventDefault();
      copy(list);
    } else if (isCtrlKey(event, "v")) {
      event.preventDefault();
      void paste(target?.kind === "folder" ? target.path : []);
    }
  });

  const paint = (): void => {
    const cur = opt.getOpen();
    const at = opt.scope();
    const mine =
      cur && cur.kind === kind && cur.layer === at.layer && (cur.owner ?? null) === at.owner;
    for (const [key, row] of leaves) row.classList.toggle("is-active", !!mine && cur.name === key);
  };

  /** `keep` = 나무 자리 그대로 두고 목록만 다시(붙여넣기 뒤 새 문서) */
  const refresh = async (keep = false): Promise<void> => {
    const mine = ++seq;
    const at = opt.scope();
    barHost.replaceChildren(opt.bar());
    if (!keep) treeHost.replaceChildren(createEmpty({ text: tc("Loading"), small: true }));
    const [got, tree] = await Promise.all([
      // 못 받으면 빈 나무(목록표에서 까닭) · 폴더를 못 받으면 문서는 모두 뿌리
      listTemplates(at.layer, null, at.owner).then(
        (list): LibraryRow[] => list.filter((r) => r.종류 === kind),
        (): LibraryRow[] => [],
      ),
      keep && view
        ? Promise.resolve(view)
        : fetchPrecomboTree(at.layer, at.owner, kind).catch(() => null),
    ]);
    if (mine !== seq) return;
    rows = got;
    view = tree;
    draw();
  };

  const body = el("div", {
    className: "m02-side__items ui-sidebar-list",
    attrs: { "data-library": kind },
    children: [barHost, treeHost],
  });
  return { body, paint, refresh: () => refresh() };
}