// ---- Module-level non-reactive holders ----
// 这些变量不放在 store 里 (避免 React 重渲 + 跨切片共享单例)。
// 每一个切片在 helpers.ts 顶层导入它们，确保所有 slice 看到的同一份。

import type {
  ActiveEditSession,
  ScriptItem,
  WorkspaceBoundApi,
} from "~/services/api";

import { toast } from "sonner";

// 缓存的会话类型（多 iframe 共存方案）
type CachedSession = {
  session: ActiveEditSession;
  jupyterUrl: string;
  lastActiveTime: number;
};

export type PythonEditorBuffer = {
  initialContent: string | null;
  content: string | null;
  dirty: boolean;
  saving: boolean;
  initial: boolean;
  loadError: string | null;
};

// 模块级可变 holder（非响应式，避免 React 重渲）
export const sessionCache = new Map<string, CachedSession>();
let _selectedId: string | null = null;
let _editSession: ActiveEditSession | null = null;
let _editorOpening = false;
let _editorOpenRequest = 0;
let _api: WorkspaceBoundApi | null = null;
let _previewController: AbortController | null = null;
let _previewRequest = 0;
let _pythonEditorOpeningIds = new Set<string>();
let _scriptCountSeq = 0;
// 当前登录用户 id —— 与 `_api` 一样由 layout 在 render body 绑定。
// 用于：(1) `loadScripts`/`loadOwnerGroup` 区分"我"与他人；
// (2) `toggleExpanded` 判定展开真实目录时是否需要 loadChildren（他人的
// 目录全靠脚本路径推断，不调 listWorkspaceDirectories）。
let _currentUserId: string | null = null;
// 当前工作区 id —— listWorkspaceMembers 不像 listScripts 那样把 workspaceId
// 烤进 bound api，需要显式传入，故由 layout 绑定。
let _workspaceId: string | null = null;

export const bindScriptWorkspaceApi = (api: WorkspaceBoundApi | null) => {
  _api = api;
};

export const bindScriptWorkspaceUser = (userId: string | null) => {
  _currentUserId = userId;
};

export const bindScriptWorkspaceId = (workspaceId: string | null) => {
  _workspaceId = workspaceId;
};

// `loadedScriptPaths` / `loadedChildPaths` 的 key 命名空间：
// `${owner_user_id}:${parent_path}`，让"我"与他人的同名子目录缓存互不串扰。
// owner 缺省时回退当前用户，再回退字面量 "me"（仅作占位 key，不会发到后端）。
export function ownerCacheKey(
  ownerUserId: string | undefined,
  path: string,
): string {
  const owner = ownerUserId ?? _currentUserId ?? "me";
  return `${owner}:${path}`;
}

export const getSessionCache = () => sessionCache;
export const clearSessionCache = () => {
  sessionCache.clear();
};

// handle ref 给 Sidebar 用，避免订阅 store
export const editSessionHandle: { current: ActiveEditSession | null } = {
  current: null,
};

// ---- 跨切片共享的内部 getters (供切片实现使用) ----

export function getApi(): WorkspaceBoundApi | null {
  return _api;
}

export function getCurrentUserId(): string | null {
  return _currentUserId;
}

export function getWorkspaceId(): string | null {
  return _workspaceId;
}

export function getSelectedId(): string | null {
  return _selectedId;
}

export function setSelectedId(value: string | null): void {
  _selectedId = value;
}

export function getEditSession(): ActiveEditSession | null {
  return _editSession;
}

export function getEditorOpening(): boolean {
  return _editorOpening;
}

export function setEditorOpening(value: boolean): void {
  _editorOpening = value;
}

export function getEditorOpenRequest(): number {
  return _editorOpenRequest;
}

export function bumpEditorOpenRequest(): number {
  _editorOpenRequest += 1;
  return _editorOpenRequest;
}

export function getPreviewController(): AbortController | null {
  return _previewController;
}

export function setPreviewController(value: AbortController | null): void {
  _previewController = value;
}

export function bumpPreviewRequest(): number {
  _previewRequest += 1;
  return _previewRequest;
}

export function getPreviewRequest(): number {
  return _previewRequest;
}

export function getPythonEditorOpeningIds(): Set<string> {
  return _pythonEditorOpeningIds;
}

export function bumpScriptCountSeq(): number {
  _scriptCountSeq += 1;
  return _scriptCountSeq;
}

export function getScriptCountSeq(): number {
  return _scriptCountSeq;
}

// ---- 工具函数 (原模块级 helper, 不依赖 set/get) ----

export function requireApi(): WorkspaceBoundApi {
  if (!_api) {
    throw new Error("script workspace API 未绑定");
  }
  return _api;
}

export function ownedScriptPath(item: ScriptItem) {
  return item.relative_path
    .replaceAll("\\", "/")
    .split("/")
    .slice(2)
    .join("/");
}

export function pushToast(
  tone: "success" | "error" | "info",
  message: string,
): void {
  if (tone === "error") toast.error(message);
  else if (tone === "info") toast.info(message);
  else toast.success(message);
}

export async function sha256Hex(
  buffer: ArrayBuffer,
): Promise<string | null> {
  // `crypto.subtle` 仅在 secure context（HTTPS / localhost）下可用；不可用时
  // 跳过 hash 计算，让后端走非校验路径。
  if (typeof crypto === "undefined" || !crypto.subtle?.digest) {
    return null;
  }
  const digest = await crypto.subtle.digest("SHA-256", buffer);
  return Array.from(new Uint8Array(digest))
    .map((byte) => byte.toString(16).padStart(2, "0"))
    .join("");
}

// ---- setEditSessionState (跨切片 helper, 原 store 闭包内 function) ----
//
// 必须在每个使用它的 slice 里手动传 `set`,因为 store 不再是单 closure。
// 内部更新模块级 `_editSession` + `editSessionHandle.current`,再 `set` 切片 state。
export function applyEditSessionState(
  set: (partial: {
    editSession: ActiveEditSession | null;
    embeddedJupyterUrl: string | null;
  }) => void,
  next: ActiveEditSession | null,
  nextJupyterUrl: string | null,
): void {
  _editSession = next;
  editSessionHandle.current = next;
  set({
    editSession: next,
    embeddedJupyterUrl: next ? nextJupyterUrl : null,
  });
}

// ---- 模块级 reset (供 useScriptWorkspaceStore.reset 调用) ----
//
// 同步模块级可变状态 + abort preview controller;不写响应式 state(state 由根 reset 处理)。
export function resetModuleState(): void {
  if (_previewController) {
    _previewController.abort();
    _previewController = null;
  }
  _previewRequest += 1;
  _selectedId = null;
  _editSession = null;
  editSessionHandle.current = null;
  sessionCache.clear();
  _pythonEditorOpeningIds.clear();
}