/**
 * @file PoolGroups.tsx
 * @description The account POOLS board (`/api/accounts/groups`,
 * server/lib/pool-groups.js — a pool is a group on the server): one column per
 * pool holding its accounts of every AI tool (each drawn by the caller, with
 * its plan and quota) and its members, plus the shared pool — the members in
 * no pool and the accounts no pool lists. An admin drags a member or an
 * account from one column to another (an account sits in ONE pool, so a drop
 * moves it); drops one on the trailing New pool column to SPLIT it into a new
 * pool; and drops a pool's ONLY account into another column to MERGE that pool
 * there (its members come along and the emptied pool is deleted on save). A
 * column's menu moves an account — or a saved login profile, moved into the
 * pool on save — in without dragging; Pick members ticks members by role; a
 * pool is renamed in place. Nothing is sent until Save, which asks for the
 * admin's own password ONCE and applies every change: profiles moved in
 * (`POST /api/accounts`), new pools created, each changed pool set exactly
 * (`PATCH`), merged pools deleted (`DELETE`). The trash on a saved pool
 * deletes it on its own.
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

import { useEffect, useMemo, useRef, useState, type DragEvent, type ReactNode } from "react";
import { useTranslation } from "react-i18next";
import type { TFunction } from "i18next";
import { Combine, Plus, Trash2, UserPlus, X } from "lucide-react";
import {
  api,
  type AccountPool,
  type PoolGroup,
  type PoolProfile,
  type PoolTool,
  type ServerUserUsage,
} from "../../lib/api";
import { isSubmitEnter } from "../../lib/keys";
import { toast } from "../../lib/toast";
import { ConfirmModal } from "../ConfirmModal";
import { AiToolIcon } from "../AiToolIcon";
import { MemberPicker } from "./MemberPicker";

/** Pool tools with their labels, in display order. */
export const POOL_TOOL_LABELS: { id: PoolTool; label: string }[] = [
  { id: "claude", label: "Claude Code" },
  { id: "codex", label: "Codex" },
  { id: "cursor", label: "Cursor CLI" },
];
const TOOLS = POOL_TOOL_LABELS.map((x) => x.id);
const toolLabel = (tool: PoolTool) => POOL_TOOL_LABELS.find((x) => x.id === tool)!.label;
/** Tools whose saved login profiles can be moved into the pool. */
const PROFILE_TOOLS: PoolTool[] = ["claude", "codex"];
/** A pool's account entry that is a saved profile still to be moved in. */
const PROFILE = "profile:";
const DND = "application/x-agenthub-pool";
/** Drop-zone keys of the shared pool and of the trailing New pool column. */
const SHARED = "shared";
const NEW = "new";

/** Account names of `tool` in the pool. */
function accountNames(pool: AccountPool, tool: PoolTool): string[] {
  const list = tool === "claude" ? pool.accounts : tool === "codex" ? pool.codex : pool.cursor;
  return (list ?? []).map((a) => a.name);
}

function errorText(t: TFunction<"users">, e: unknown): string {
  const err = e as Error & { code?: string };
  return err.code && t(`pool.errors.${err.code}`, { defaultValue: "" })
    ? t(`pool.errors.${err.code}`)
    : err.message;
}

/** A pool as the board edits it; `id` null = not created yet. */
type Draft = {
  key: string;
  id: number | null;
  name: string;
  userIds: number[];
  accounts: Record<PoolTool, string[]>;
};
/** A saved pool merged into another: deleted on Save. */
type Removed = { id: number; name: string; into: string };
/** What is being dragged; `from` = the column key it left (null = shared). */
type Drag =
  | { kind: "user"; id: number; from: string | null }
  | { kind: "account"; tool: PoolTool; name: string; from: string | null };

const fromPool = (pool: AccountPool): Draft[] =>
  (pool.groups ?? []).map((g) => ({
    key: `g${g.id}`,
    id: g.id,
    name: g.name,
    userIds: g.users.map((u) => u.userId),
    accounts: Object.fromEntries(TOOLS.map((x) => [x, [...(g.accounts[x] ?? [])]])) as Record<
      PoolTool,
      string[]
    >,
  }));
/** Order-free fingerprint of a draft, to tell what changed. */
const sig = (d: Draft) =>
  JSON.stringify([
    d.name,
    [...d.userIds].sort((a, b) => a - b),
    TOOLS.map((x) => [...d.accounts[x]].sort()),
  ]);
const sigAll = (ds: Draft[]) => ds.map((d) => `${d.key}:${sig(d)}`).join("|");
const accountCount = (d: Pick<Draft, "accounts">) =>
  TOOLS.reduce((n, tool) => n + d.accounts[tool].length, 0);
const emptyAccounts = (): Record<PoolTool, string[]> => ({ claude: [], codex: [], cursor: [] });

export function PoolGroups({
  pool,
  isAdmin,
  onChanged,
  renderAccount,
}: {
  pool: AccountPool;
  isAdmin: boolean;
  onChanged: () => void;
  /** One pool account as a card (plan, quota, live panes, its actions). */
  renderAccount: (tool: PoolTool, name: string) => ReactNode;
}) {
  const { t } = useTranslation("users");
  const [draft, setDraft] = useState<Draft[]>(() => fromPool(pool));
  const [removed, setRemoved] = useState<Removed[]>([]);
  const base = useRef(pool);
  // Set by Save: the next pool read replaces the board whatever it holds.
  const saved = useRef(false);
  const [users, setUsers] = useState<ServerUserUsage[] | null>(null);
  const [profiles, setProfiles] = useState<Record<PoolTool, PoolProfile[]>>({
    claude: [],
    codex: [],
    cursor: [],
  });
  const [dragging, setDragging] = useState<Drag | null>(null);
  const [over, setOver] = useState<string | null>(null);
  const [picking, setPicking] = useState<string | null>(null);
  const [saving, setSaving] = useState(false);
  const [deleting, setDeleting] = useState<PoolGroup | null>(null);
  const seq = useRef(0);

  const dirty = removed.length > 0 || sigAll(draft) !== sigAll(fromPool(pool));
  // A re-read pool replaces an untouched board; a touched one keeps its edits
  // but drops a pool that is gone.
  useEffect(() => {
    if (base.current === pool) return;
    const untouched =
      saved.current || (removed.length === 0 && sigAll(draft) === sigAll(fromPool(base.current)));
    base.current = pool;
    saved.current = false;
    if (untouched) {
      setDraft(fromPool(pool));
      setRemoved([]);
    } else {
      const ids = new Set((pool.groups ?? []).map((g) => g.id));
      setDraft((ds) => ds.filter((d) => d.id === null || ids.has(d.id)));
      setRemoved((rs) => rs.filter((r) => ids.has(r.id)));
    }
  }, [pool]);

  useEffect(() => {
    api.users
      .list()
      .then((r) => setUsers(r.users))
      .catch(() => setUsers([]));
  }, []);
  useEffect(() => {
    if (!isAdmin) return;
    for (const tool of PROFILE_TOOLS) {
      api.accountPool
        .profiles(tool)
        .then((r) => setProfiles((p) => ({ ...p, [tool]: r.profiles })))
        .catch(() => {});
    }
  }, [isAdmin, pool]);

  // Everyone the board knows: the user list, or at least each pool's members.
  const people = useMemo<ServerUserUsage[]>(() => {
    if (users && users.length) return users;
    const seen = new Map<number, ServerUserUsage>();
    for (const g of pool.groups ?? [])
      for (const u of g.users)
        seen.set(u.userId, {
          id: u.userId,
          username: u.username,
          role: "developer",
        } as ServerUserUsage);
    return [...seen.values()];
  }, [users, pool.groups]);
  const byId = new Map(people.map((u) => [u.id, u]));
  const nameOf = (d: Draft) => d.name.trim() || t("pool.board.untitled");
  const groupNameOf = (userId: number) => {
    const d = draft.find((x) => x.userIds.includes(userId));
    return d ? nameOf(d) : null;
  };
  const profileLabel = (tool: PoolTool, name: string) =>
    profiles[tool].find((p) => p.name === name)?.label ?? name;
  /** The pool a dragged account would empty — the one a drop merges. */
  const mergeSource = (drag: Drag | null): Draft | null => {
    if (!drag || drag.kind !== "account" || !drag.from) return null;
    const src = draft.find((d) => d.key === drag.from);
    return src && accountCount(src) === 1 ? src : null;
  };

  // ── Edits (staged) ────────────────────────────────────────────────────
  const patch = (key: string, fn: (d: Draft) => Draft) =>
    setDraft((ds) => ds.map((d) => (d.key === key ? fn(d) : d)));
  /** A member is in one pool: take them out of every other. `to` null = shared. */
  const moveUsers = (ids: number[], to: string | null) =>
    setDraft((ds) =>
      ds.map((d) => {
        const kept = d.userIds.filter((id) => !ids.includes(id));
        return { ...d, userIds: d.key === to ? [...kept, ...ids] : kept };
      })
    );
  /** An account is in one pool too: a move takes it out of every other. */
  const moveAccount = (tool: PoolTool, name: string, to: string | null) =>
    setDraft((ds) =>
      ds.map((d) => {
        const kept = d.accounts[tool].filter((n) => n !== name);
        return {
          ...d,
          accounts: { ...d.accounts, [tool]: d.key === to ? [...kept, name] : kept },
        };
      })
    );
  const nextKey = () => {
    seq.current += 1;
    return `new${seq.current}`;
  };
  const newPool = (seed?: Partial<Pick<Draft, "userIds" | "accounts">>) => {
    const key = nextKey();
    setDraft((ds) => [
      ...ds,
      { key, id: null, name: "", userIds: [], accounts: emptyAccounts(), ...seed },
    ]);
    return key;
  };
  /** Split: what was dropped on New pool leaves its column for a pool of its own. */
  const split = (drag: Drag) => {
    if (drag.kind === "user") {
      moveUsers([drag.id], null);
      newPool({ userIds: [drag.id] });
    } else {
      moveAccount(drag.tool, drag.name, null);
      newPool({ accounts: { ...emptyAccounts(), [drag.tool]: [drag.name] } });
    }
  };
  /** Merge: `src`'s only account and every member join `to`; `src` goes away. */
  const merge = (src: Draft, tool: PoolTool, name: string, to: string | null) => {
    const target = to ? draft.find((d) => d.key === to) : null;
    setDraft((ds) =>
      ds
        .filter((d) => d.key !== src.key)
        .map((d) =>
          d.key === to
            ? {
                ...d,
                userIds: [...d.userIds, ...src.userIds.filter((id) => !d.userIds.includes(id))],
                accounts: { ...d.accounts, [tool]: [...d.accounts[tool], name] },
              }
            : d
        )
    );
    const into = target ? nameOf(target) : t("pool.groups.shared");
    if (src.id !== null) {
      const id = src.id;
      setRemoved((rs) => [...rs, { id, name: nameOf(src), into }]);
    }
    toast.info(t("pool.board.merged", { from: nameOf(src), into }));
  };
  const onDrop = (e: DragEvent, to: string | null) => {
    e.preventDefault();
    setOver(null);
    setDragging(null);
    let drag: Drag;
    try {
      drag = JSON.parse(e.dataTransfer.getData(DND)) as Drag;
    } catch {
      return;
    }
    if (to === NEW) return split(drag);
    if (drag.from === to) return;
    if (drag.kind === "user") return moveUsers([drag.id], to);
    const src = mergeSource(drag);
    if (src) return merge(src, drag.tool, drag.name, to);
    moveAccount(drag.tool, drag.name, to);
  };
  const dragProps = (drag: Drag) =>
    isAdmin
      ? {
          draggable: true,
          onDragStart: (e: DragEvent) => {
            e.stopPropagation();
            e.dataTransfer.setData(DND, JSON.stringify(drag));
            e.dataTransfer.effectAllowed = "move";
            // After the browser took its drag image, so the image is not faded.
            requestAnimationFrame(() => setDragging(drag));
          },
          onDragEnd: () => {
            setDragging(null);
            setOver(null);
          },
        }
      : {};
  const isDragged = (drag: Drag) =>
    dragging !== null &&
    dragging.kind === drag.kind &&
    (drag.kind === "user"
      ? dragging.kind === "user" && dragging.id === drag.id
      : dragging.kind === "account" && dragging.tool === drag.tool && dragging.name === drag.name);
  const dropZone = (key: string | null) =>
    isAdmin
      ? {
          onDragOver: (e: DragEvent) => {
            if (!e.dataTransfer.types.includes(DND)) return;
            e.preventDefault();
            e.dataTransfer.dropEffect = "move";
            setOver(key ?? SHARED);
          },
          onDragLeave: (e: DragEvent) => {
            // Leaving for a child of the same column is still over it.
            if (e.currentTarget.contains(e.relatedTarget as Node | null)) return;
            setOver((o) => (o === (key ?? SHARED) ? null : o));
          },
          onDrop: (e: DragEvent) => onDrop(e, key),
        }
      : {};

  // ── What Save will do ─────────────────────────────────────────────────
  const original = new Map(fromPool(pool).map((d) => [d.key, sig(d)]));
  const changedGroups = draft.filter((d) => d.id === null || original.get(d.key) !== sig(d));
  const pendingProfiles = [
    ...new Set(
      draft.flatMap((d) =>
        TOOLS.flatMap((tool) =>
          d.accounts[tool].filter((n) => n.startsWith(PROFILE)).map((n) => `${tool}|${n}`)
        )
      )
    ),
  ];
  const unnamed = draft.some((d) => !d.name.trim());

  const sharedAccounts = Object.fromEntries(
    TOOLS.map((tool) => [
      tool,
      accountNames(pool, tool).filter((n) => !draft.some((d) => d.accounts[tool].includes(n))),
    ])
  ) as Record<PoolTool, string[]>;
  const ungrouped = people.filter((u) => groupNameOf(u.id) === null).map((u) => u.id);
  const discard = () => {
    setDraft(fromPool(pool));
    setRemoved([]);
  };

  const memberChip = (id: number, from: string | null) => {
    const u = byId.get(id);
    const name = u?.username ?? `#${id}`;
    const drag: Drag = { kind: "user", id, from };
    return (
      <span
        key={id}
        {...dragProps(drag)}
        className={`inline-flex animate-fade-in items-center gap-1.5 rounded-full border border-border bg-surface-1 py-0.5 pl-0.5 text-[11px] text-fg-primary shadow-sm transition-[opacity,border-color] hover:border-accent/50 ${
          isAdmin ? "cursor-grab active:cursor-grabbing pr-0.5" : "pr-2"
        } ${isDragged(drag) ? "opacity-40" : ""}`}
        data-testid="pool-member"
      >
        <span
          className="flex h-4 w-4 items-center justify-center rounded-full bg-accent/15 text-[9px] font-semibold uppercase text-accent"
          aria-hidden
        >
          {name.charAt(0)}
        </span>
        {name}
        {u && <span className="text-[10px] text-fg-muted">{t(`roles.${u.role}`)}</span>}
        {isAdmin && from && (
          <button
            type="button"
            onClick={() => moveUsers([id], null)}
            aria-label={t("pool.board.toShared", { name })}
            title={t("pool.board.toShared", { name })}
            className="rounded-full p-0.5 text-fg-muted hover:bg-surface-3 hover:text-fg-primary"
          >
            <X className="h-3 w-3" />
          </button>
        )}
      </span>
    );
  };
  const accountItem = (tool: PoolTool, name: string, from: string | null) => {
    const profile = name.startsWith(PROFILE);
    const label = profile ? profileLabel(tool, name.slice(PROFILE.length)) : name;
    const drag: Drag = { kind: "account", tool, name, from };
    return (
      <div
        key={`${tool}|${name}`}
        {...dragProps(drag)}
        className={`animate-fade-in transition-opacity ${
          isAdmin ? "cursor-grab active:cursor-grabbing" : ""
        } ${isDragged(drag) ? "opacity-40" : ""}`}
        data-testid="pool-group-account"
      >
        {profile ? (
          <div
            title={t("pool.board.profilePending")}
            className="flex items-center gap-1.5 rounded-lg border border-dashed border-accent/50 bg-accent/5 px-3 py-2 text-xs text-accent"
          >
            <AiToolIcon tool={{ id: tool, label: tool }} className="h-3.5 w-3.5" />
            <span className="flex-1 truncate">{label}</span>
            {isAdmin && from && (
              <button
                type="button"
                onClick={() => moveAccount(tool, name, null)}
                aria-label={t("pool.board.removeAccount", { name: label })}
                className="rounded p-0.5 text-fg-muted hover:text-fg-primary"
              >
                <X className="h-3 w-3" />
              </button>
            )}
          </div>
        ) : (
          renderAccount(tool, name)
        )}
      </div>
    );
  };
  /** A column's accounts, under a heading per tool that has any. */
  const accountList = (accounts: Record<PoolTool, string[]>, from: string | null) => {
    const tools = TOOLS.filter((tool) => accounts[tool].length > 0);
    if (tools.length === 0)
      return (
        <p className="rounded-lg border border-dashed border-border px-3 py-5 text-center text-[11px] text-fg-muted">
          {isAdmin ? t("pool.board.dropAccounts") : t("pool.board.noAccounts")}
        </p>
      );
    return tools.map((tool) => (
      <div key={tool} className="space-y-1.5">
        <div className="flex items-center gap-1.5 text-[10px] font-semibold uppercase tracking-wider text-fg-muted">
          <AiToolIcon tool={{ id: tool, label: tool }} className="h-3.5 w-3.5" />
          {toolLabel(tool)}
          <span className="rounded-full bg-surface-3 px-1.5 tabular-nums">
            {accounts[tool].length}
          </span>
        </div>
        {accounts[tool].map((n) => accountItem(tool, n, from))}
      </div>
    ));
  };
  /** Move-here menu: accounts in other pools, and saved profiles (pools only). */
  const moveMenu = (key: string | null, here: Record<PoolTool, string[]>, name: string) => {
    const options = TOOLS.map((tool) => ({
      tool,
      accounts: accountNames(pool, tool).filter((n) => !here[tool].includes(n)),
      profiles: (key && PROFILE_TOOLS.includes(tool) ? profiles[tool] : []).filter(
        (p) => !draft.some((d) => d.accounts[tool].includes(PROFILE + p.name))
      ),
    }));
    if (!options.some((o) => o.accounts.length || o.profiles.length)) return null;
    return (
      <select
        className="input w-full border-dashed bg-transparent py-1 text-xs text-fg-muted"
        value=""
        onChange={(e) => {
          const [tool, n] = e.target.value.split("|") as [PoolTool, string];
          if (!n) return;
          const from = draft.find((d) => d.accounts[tool].includes(n))?.key ?? null;
          const src = n.startsWith(PROFILE)
            ? null
            : mergeSource({ kind: "account", tool, name: n, from });
          if (src && src.key !== key) merge(src, tool, n, key);
          else moveAccount(tool, n, key);
        }}
        aria-label={t("pool.board.addAccount", { name })}
      >
        <option value="">{t("pool.board.addAccountOption")}</option>
        {options.map(
          (o) =>
            o.accounts.length > 0 && (
              <optgroup key={o.tool} label={toolLabel(o.tool)}>
                {o.accounts.map((n) => {
                  const inPool = draft.find((d) => d.accounts[o.tool].includes(n));
                  return (
                    <option key={n} value={`${o.tool}|${n}`}>
                      {n} — {inPool ? nameOf(inPool) : t("pool.groups.shared")}
                    </option>
                  );
                })}
              </optgroup>
            )
        )}
        {options.map(
          (o) =>
            o.profiles.length > 0 && (
              <optgroup
                key={`p-${o.tool}`}
                label={t("pool.board.profilesOf", { tool: toolLabel(o.tool) })}
              >
                {o.profiles.map((p) => (
                  <option key={p.name} value={`${o.tool}|${PROFILE}${p.name}`}>
                    {p.label}
                    {p.email ? ` — ${p.email}` : ""}
                  </option>
                ))}
              </optgroup>
            )
        )}
      </select>
    );
  };
  const counts = (accounts: Record<PoolTool, string[]>, members: number[]) => (
    <div className="mt-0.5 flex gap-2 text-[11px] text-fg-muted">
      <span>{t("pool.board.accountsCount", { count: accountCount({ accounts }) })}</span>
      <span aria-hidden>·</span>
      <span>{t("pool.groups.members", { count: members.length })}</span>
    </div>
  );
  const src = mergeSource(dragging);
  const column = (
    key: string | null,
    head: ReactNode,
    accounts: Record<PoolTool, string[]>,
    members: number[],
    testId: string,
    name: string
  ) => {
    const zone = key ?? SHARED;
    const isOver = over === zone && dragging?.from !== key;
    const merging = src && src.key !== key;
    return (
      <div
        {...dropZone(key)}
        className={`relative flex flex-col gap-3 rounded-xl border p-3 transition-[border-color,background-color,box-shadow] duration-150 ${
          key ? "border-t-2 border-t-accent/60 bg-surface-2" : "bg-surface-1"
        } ${
          isOver
            ? "border-accent bg-accent/5 shadow-lg ring-2 ring-accent/30"
            : dragging && dragging.from !== key
              ? "border-dashed border-accent/40"
              : "border-border"
        }`}
        data-testid={testId}
      >
        {head}
        {isOver && merging && (
          <div className="flex animate-fade-in items-center gap-1.5 rounded-md bg-accent/10 px-2 py-1 text-[11px] text-accent">
            <Combine className="h-3.5 w-3.5" aria-hidden />
            {t("pool.board.mergeHint", { from: nameOf(src), into: name })}
          </div>
        )}
        <div className="space-y-3">{accountList(accounts, key)}</div>
        {isAdmin && moveMenu(key, accounts, name)}
        <div className="border-t border-border/60 pt-2">
          <div className="mb-1.5 text-[10px] font-semibold uppercase tracking-wider text-fg-muted">
            {t("pool.members.title")}
          </div>
          <div className="flex flex-wrap gap-1">
            {members.length === 0 ? (
              <span className="text-[11px] text-fg-muted">
                {isAdmin ? t("pool.board.dropMembers") : t("pool.board.noMembers")}
              </span>
            ) : (
              members.map((id) => memberChip(id, key))
            )}
          </div>
        </div>
      </div>
    );
  };

  return (
    <div className="px-5 py-4" data-testid="pool-groups">
      <p className="text-xs text-fg-muted">
        {t("pool.groups.description")} {isAdmin && t("pool.board.howTo")}
      </p>

      <div className="mt-3 grid items-start gap-3 md:grid-cols-2 xl:grid-cols-3">
        {column(
          null,
          <div>
            <div className="text-sm font-semibold text-fg-primary">{t("pool.groups.shared")}</div>
            <div className="text-[11px] text-fg-muted">{t("pool.board.sharedHint")}</div>
            {counts(sharedAccounts, ungrouped)}
          </div>,
          sharedAccounts,
          ungrouped,
          "pool-shared",
          t("pool.groups.shared")
        )}
        {draft.map((d) => {
          const existing = d.id !== null ? (pool.groups ?? []).find((g) => g.id === d.id) : null;
          const name = nameOf(d);
          return (
            <div key={d.key} className="contents">
              {column(
                d.key,
                <div className="flex items-start gap-1">
                  <div className="flex-1 min-w-0">
                    {isAdmin ? (
                      <input
                        className="w-full rounded border border-transparent bg-transparent px-1 -mx-1 text-sm font-semibold text-fg-primary transition-colors hover:border-border focus:border-accent focus:outline-none"
                        value={d.name}
                        autoFocus={d.id === null && !d.name}
                        onChange={(e) => patch(d.key, (x) => ({ ...x, name: e.target.value }))}
                        placeholder={t("pool.groups.name")}
                        aria-label={t("pool.groups.name")}
                      />
                    ) : (
                      <div className="truncate text-sm font-semibold text-fg-primary">{d.name}</div>
                    )}
                    <div className="flex items-center gap-2">
                      {counts(d.accounts, d.userIds)}
                      {d.id === null && (
                        <span className="mt-0.5 rounded-full bg-accent/10 px-1.5 text-[10px] text-accent">
                          {t("pool.board.new")}
                        </span>
                      )}
                    </div>
                  </div>
                  {isAdmin && (
                    <>
                      <button
                        type="button"
                        onClick={() => setPicking(d.key)}
                        title={t("pool.board.pick", { name })}
                        aria-label={t("pool.board.pick", { name })}
                        className="btn-icon"
                      >
                        <UserPlus className="h-4 w-4" />
                      </button>
                      <button
                        type="button"
                        onClick={() =>
                          existing
                            ? setDeleting(existing)
                            : setDraft((ds) => ds.filter((x) => x.key !== d.key))
                        }
                        title={t("pool.groups.delete", { name })}
                        aria-label={t("pool.groups.delete", { name })}
                        className="btn-icon hover:text-status-danger"
                      >
                        <Trash2 className="h-4 w-4" />
                      </button>
                    </>
                  )}
                </div>,
                d.accounts,
                d.userIds,
                "pool-group",
                name
              )}
            </div>
          );
        })}
        {isAdmin && (
          <button
            type="button"
            {...dropZone(NEW)}
            onClick={() => newPool()}
            aria-label={t("pool.groups.new")}
            className={`flex min-h-[10rem] flex-col items-center justify-center gap-2 rounded-xl border-2 border-dashed p-4 text-center transition-all duration-150 ${
              over === NEW
                ? "border-accent bg-accent/10 text-accent shadow-lg ring-2 ring-accent/30"
                : dragging
                  ? "border-accent/50 bg-accent/5 text-accent"
                  : "border-border text-fg-muted hover:border-accent/50 hover:text-fg-secondary"
            }`}
            data-testid="pool-new"
          >
            <Plus className="h-6 w-6" aria-hidden />
            <span className="text-sm font-medium">{t("pool.groups.new")}</span>
            <span className="max-w-[16rem] text-[11px] opacity-80">
              {dragging ? t("pool.board.newDrop") : t("pool.board.newHint")}
            </span>
          </button>
        )}
      </div>

      {isAdmin && dirty && (
        <div
          className="sticky bottom-3 z-10 mt-3 flex animate-slide-up flex-wrap items-center gap-2 rounded-xl border border-accent/40 bg-surface-1/95 px-3 py-2 shadow-xl backdrop-blur"
          data-testid="pool-board-save"
        >
          <span className="flex-1 text-xs text-fg-secondary">
            {t("pool.board.pending", {
              count: changedGroups.length + pendingProfiles.length + removed.length,
            })}
            {unnamed && (
              <span className="ml-2 text-status-warning">{t("pool.board.needsName")}</span>
            )}
          </span>
          <button type="button" onClick={discard} className="btn-ghost text-xs">
            {t("pool.board.discard")}
          </button>
          <button
            type="button"
            disabled={unnamed}
            onClick={() => setSaving(true)}
            className="btn-primary text-xs"
          >
            {t("pool.save")}
          </button>
        </div>
      )}

      {picking && (
        <PickMembersDialog
          users={users}
          group={draft.find((d) => d.key === picking)!}
          groupOf={groupNameOf}
          onClose={() => setPicking(null)}
          onDone={(ids) => {
            const d = draft.find((x) => x.key === picking)!;
            const added = ids.filter((id) => !d.userIds.includes(id));
            setDraft((ds) =>
              ds.map((x) =>
                x.key === picking
                  ? { ...x, userIds: ids }
                  : { ...x, userIds: x.userIds.filter((id) => !added.includes(id)) }
              )
            );
            setPicking(null);
          }}
        />
      )}
      {saving && (
        <SaveBoardDialog
          draft={draft}
          changed={changedGroups}
          profiles={pendingProfiles}
          removed={removed}
          profileLabel={profileLabel}
          onClose={() => setSaving(false)}
          onProgress={(d, r) => {
            setDraft(d);
            setRemoved(r);
          }}
          onDone={() => {
            toast.success(t("pool.board.saved"));
            setSaving(false);
            saved.current = true;
            onChanged();
          }}
        />
      )}
      {deleting && (
        <DeleteGroupDialog
          group={deleting}
          onClose={() => setDeleting(null)}
          onDone={() => {
            toast.success(t("pool.groups.deleted", { name: deleting.name }));
            setDeleting(null);
            onChanged();
          }}
        />
      )}
    </div>
  );
}

/** A column's Pick members: tick by role or "No group"; staged on the board. */
function PickMembersDialog({
  users,
  group,
  groupOf,
  onClose,
  onDone,
}: {
  users: ServerUserUsage[] | null;
  group: Draft;
  groupOf: (userId: number) => string | null;
  onClose: () => void;
  onDone: (ids: number[]) => void;
}) {
  const { t } = useTranslation("users");
  const [chosen, setChosen] = useState<Set<number>>(() => new Set(group.userIds));
  const name = group.name || t("pool.board.untitled");
  return (
    <ConfirmModal
      open
      title={t("pool.board.pick", { name })}
      message={t("pool.board.pickHint")}
      confirmLabel={t("pool.board.apply")}
      cancelLabel={t("common:cancel")}
      destructive={false}
      onConfirm={() => onDone([...chosen])}
      onCancel={onClose}
    >
      <div className="mt-3">
        <MemberPicker
          users={users}
          chosen={chosen}
          onChange={setChosen}
          groupOf={groupOf}
          grouped
          note={(u) => {
            const g = groupOf(u.id);
            return g && g !== group.name ? (
              <span className="ml-1.5 text-[11px] text-fg-muted">
                {t("pool.groups.inGroup", { group: g })}
              </span>
            ) : null;
          }}
        />
      </div>
    </ConfirmModal>
  );
}

/**
 * Save: the admin's password once, then every staged change in order —
 * profiles moved into the pool, new pools created, changed pools set, merged
 * pools deleted. What already went through is written back into the board, so
 * a retry after a failure never moves a profile in twice, makes a pool again
 * or deletes one twice.
 */
function SaveBoardDialog({
  draft,
  changed,
  profiles,
  removed,
  profileLabel,
  onClose,
  onProgress,
  onDone,
}: {
  draft: Draft[];
  changed: Draft[];
  /** `tool|profile:name` entries to move into the pool first. */
  profiles: string[];
  /** Saved pools merged into another, deleted last. */
  removed: Removed[];
  profileLabel: (tool: PoolTool, name: string) => string;
  onClose: () => void;
  onProgress: (d: Draft[], removed: Removed[]) => void;
  onDone: () => void;
}) {
  const { t } = useTranslation("users");
  const [current, setCurrent] = useState("");
  const [busy, setBusy] = useState(false);
  const [error, setError] = useState<string | null>(null);

  const submit = async () => {
    if (!current || busy) return;
    setBusy(true);
    setError(null);
    let work = draft.map((d) => ({
      ...d,
      userIds: [...d.userIds],
      accounts: { ...d.accounts },
    }));
    const todo = new Set(changed.map((d) => d.key));
    let gone = [...removed];
    try {
      for (const entry of profiles) {
        const [tool, ref] = entry.split("|") as [PoolTool, string];
        const profile = ref.slice(PROFILE.length);
        const r = await api.accountPool.add({ tool, name: profile, profile }, current);
        work = work.map((d) => ({
          ...d,
          accounts: {
            ...d.accounts,
            [tool]: d.accounts[tool].map((n) => (n === ref ? r.account.name : n)),
          },
        }));
      }
      for (const d of work) {
        if (!todo.has(d.key)) continue;
        let id = d.id;
        if (id === null) {
          id = (await api.accountPool.createGroup(d.name.trim(), current)).group.id;
          const made = id;
          work = work.map((x) => (x.key === d.key ? { ...x, id: made } : x));
        }
        await api.accountPool.updateGroup(
          id,
          {
            ...(d.id !== null ? { name: d.name.trim() } : {}),
            userIds: d.userIds,
            accounts: Object.fromEntries(TOOLS.map((tool) => [tool, d.accounts[tool]])),
          },
          current
        );
        todo.delete(d.key);
      }
      // Last: the merged pools' members already moved into their new pool.
      for (const r of removed) {
        await api.accountPool.deleteGroup(r.id, current);
        gone = gone.filter((x) => x.id !== r.id);
      }
      onDone();
    } catch (e) {
      onProgress(work, gone);
      setError(errorText(t, e));
    } finally {
      setBusy(false);
    }
  };

  return (
    <ConfirmModal
      open
      title={t("pool.board.saveTitle")}
      message={t("pool.board.saveHint")}
      confirmLabel={t("pool.save")}
      cancelLabel={t("common:cancel")}
      destructive={false}
      busy={busy}
      disabled={!current}
      onConfirm={() => void submit()}
      onCancel={onClose}
    >
      <ul className="mt-3 space-y-1 text-xs text-fg-secondary" data-testid="pool-board-summary">
        {profiles.map((entry) => {
          const [tool, ref] = entry.split("|") as [PoolTool, string];
          return (
            <li key={entry}>
              {t("pool.board.summaryProfile", {
                name: profileLabel(tool, ref.slice(PROFILE.length)),
              })}
            </li>
          );
        })}
        {removed.map((r) => (
          <li key={`m${r.id}`}>{t("pool.board.summaryMerge", { from: r.name, into: r.into })}</li>
        ))}
        {changed.map((d) => (
          <li key={d.key}>
            {t(d.id === null ? "pool.board.summaryNew" : "pool.board.summaryGroup", {
              name: d.name.trim(),
              count: d.userIds.length,
              accounts: TOOLS.reduce((n, tool) => n + d.accounts[tool].length, 0),
            })}
          </li>
        ))}
      </ul>
      <label className="mt-3 block">
        <span className="text-xs font-medium text-fg-secondary">{t("yourPassword")}</span>
        <input
          type="password"
          className="input mt-1 w-full text-sm"
          value={current}
          onChange={(e) => setCurrent(e.target.value)}
          onKeyDown={(e) => {
            if (isSubmitEnter(e)) {
              e.preventDefault();
              void submit();
            }
          }}
          autoComplete="current-password"
          aria-label={t("yourPassword")}
        />
        <span className="mt-0.5 block text-[11px] text-fg-muted">{t("yourPasswordHint")}</span>
      </label>
      {error && (
        <p role="alert" className="mt-2 text-xs text-status-danger">
          {error}
        </p>
      )}
    </ConfirmModal>
  );
}

function DeleteGroupDialog({
  group,
  onClose,
  onDone,
}: {
  group: PoolGroup;
  onClose: () => void;
  onDone: () => void;
}) {
  const { t } = useTranslation("users");
  const [current, setCurrent] = useState("");
  const [busy, setBusy] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const submit = async () => {
    if (!current || busy) return;
    setBusy(true);
    setError(null);
    try {
      await api.accountPool.deleteGroup(group.id, current);
      onDone();
    } catch (e) {
      setError(errorText(t, e));
    } finally {
      setBusy(false);
    }
  };
  return (
    <ConfirmModal
      open
      title={t("pool.groups.delete", { name: group.name })}
      message={t("pool.groups.deleteHint")}
      confirmLabel={t("pool.removeButton")}
      cancelLabel={t("common:cancel")}
      busy={busy}
      disabled={!current}
      onConfirm={() => void submit()}
      onCancel={onClose}
    >
      <label className="mt-3 block">
        <span className="text-xs font-medium text-fg-secondary">{t("yourPassword")}</span>
        <input
          type="password"
          className="input mt-1 w-full text-sm"
          value={current}
          onChange={(e) => setCurrent(e.target.value)}
          onKeyDown={(e) => {
            if (isSubmitEnter(e)) {
              e.preventDefault();
              void submit();
            }
          }}
          autoComplete="current-password"
          aria-label={t("yourPassword")}
        />
      </label>
      {error && (
        <p role="alert" className="mt-2 text-xs text-status-danger">
          {error}
        </p>
      )}
    </ConfirmModal>
  );
}