import type {
  NativeArtifact, NativeOperation, NativeOperationKind, NativeOperationReceipt,
  NativeProfile, NativeProfileSummary, NativeAuthStatus, NativeAuthSession, NativeClientKey, NativeAuditEvent,
} from '@typings/native';

export class NativeApiError extends Error {
  constructor(public readonly status: number, message: string) {
    super(message);
    this.name = 'NativeApiError';
  }
}

/** HttpOnly 会话 cookie 仅由服务器设置；CSRF 只放在内存，不写入浏览器存储。 */
export class NativeApi {
  private refreshing?: Promise<NativeAuthStatus>;
  private loggingOut = false;
  constructor(private csrfToken?: string) {}

  private refreshSession() {
    // 多个并行管理请求遇到过期 access cookie 时共用一次恢复，避免刷新凭据互相覆盖。
    this.refreshing ??= this.authStatus().then(status => {
      if (status.authenticated && status.csrf_token) this.csrfToken = status.csrf_token;
      return status;
    }).finally(() => { this.refreshing = undefined; });
    return this.refreshing;
  }

  private async request<T>(path: string, options: RequestInit = {}, binary = false, secrets: string[] = [], retried = false): Promise<T> {
    const attemptedCsrf = this.csrfToken;
    const controller = new AbortController();
    const abort = () => controller.abort();
    options.signal?.addEventListener('abort', abort, { once: true });
    if (options.signal?.aborted) controller.abort();
    const timer = setTimeout(abort, 30000);
    try {
      const headers = new Headers(options.headers);
      // 状态变更需要同时提交会话 cookie 和 CSRF，绝不发送管理员 bearer token。
      if (options.method && !['GET', 'HEAD', 'OPTIONS'].includes(options.method.toUpperCase())) {
        if (!this.csrfToken) throw new NativeApiError(403, '缺少会话校验信息，请刷新页面后重试');
        headers.set('X-CSRF-Token', this.csrfToken);
      }
      if (options.body && !(options.body instanceof FormData)) headers.set('Content-Type', 'application/json');
      const response = await fetch(`/api/native${path}`, {
        ...options, headers, signal: controller.signal, credentials: 'same-origin', cache: 'no-store',
      });
      // 此标记只由读取请求体之前的CSRF门禁生成；原请求尚未产生副作用，最多重试一次。
      if (response.status === 403 && response.headers.get('X-Message-Error') === 'csrf' && !retried) {
        const status = await this.authStatus(options.signal ?? undefined);
        if (!status.csrf_token) throw new NativeApiError(403, '无法取得登录校验信息，请重新打开独立应用页面');
        this.csrfToken = status.csrf_token;
        await this.ensureCsrf(options.signal ?? undefined);
        return this.request<T>(path, options, binary, secrets, true);
      }
      // 仅重试鉴权层拒绝的 401；网络失败和业务错误绝不自动重放写操作。
      if (response.status === 401 && !retried && !this.loggingOut && !['/auth/status', '/auth/login', '/auth/recover', '/auth/password'].includes(path)) {
        const status = this.csrfToken !== attemptedCsrf
          ? { authenticated: true, csrf_token: this.csrfToken } : await this.refreshSession();
        if (status.authenticated && status.csrf_token && !controller.signal.aborted) {
          this.csrfToken = status.csrf_token;
          return this.request<T>(path, options, binary, secrets, true);
        }
      }
      if (!response.ok) {
        let detail = `请求失败（HTTP ${response.status}）`;
        try {
          const body: unknown = await response.json();
          if (body && typeof body === 'object' && 'detail' in body && typeof body.detail === 'string') detail = body.detail;
        } catch { /* 错误页不一定是 JSON，保留状态码即可诊断。 */ }
        // 即使错误响应意外回显密码或 CSRF，也不在界面中展示。
        for (const secret of [this.csrfToken, attemptedCsrf, ...secrets]) {
          if (secret) detail = detail.split(secret).join('[已隐藏凭据]');
        }
        throw new NativeApiError(response.status, detail);
      }
      if (response.status === 204) return undefined as T;
      return (binary ? await response.blob() : await response.json()) as T;
    } catch (error) {
      if (error instanceof NativeApiError) throw error;
      if (controller.signal.aborted) throw new NativeApiError(0, '请求已取消或超时；操作可能已被服务器接收，请刷新历史确认');
      throw new NativeApiError(0, '网络请求失败，请检查连接并重试；操作结果以服务器记录为准');
    } finally {
      clearTimeout(timer);
      options.signal?.removeEventListener('abort', abort);
    }
  }

  async ensureCsrf(signal?: AbortSignal) {
    const probe = () => this.request<{ ready: boolean }>('/auth/csrf', { signal, headers: { 'X-CSRF-Token': this.csrfToken ?? '' } });
    try { return await probe(); }
    catch (error) {
      if (!(error instanceof NativeApiError) || error.status !== 409) throw error;
      // 多窗口或并发状态响应可使页面CSRF过时，只重取校验，不重发邮件或密码。
      const status = await this.authStatus(signal);
      this.csrfToken = status.csrf_token;
      return probe();
    }
  }
  authStatus(signal?: AbortSignal) { return this.request<NativeAuthStatus>('/auth/status', { signal }); }
  login(email: string, password: string, signal?: AbortSignal) {
    return this.request<NativeAuthSession>('/auth/login', {
      method: 'POST', body: JSON.stringify({ email, password }), signal,
    }, false, [password]);
  }
  recover(email: string, signal?: AbortSignal) {
    return this.request<{ message?: string }>('/auth/recover', {
      method: 'POST', body: JSON.stringify({ email }), signal,
    });
  }
  updatePassword(password: string, signal?: AbortSignal) {
    return this.request<{ message?: string }>('/auth/password', {
      method: 'POST', body: JSON.stringify({ password }), signal,
    }, false, [password]);
  }
  async logout() {
    // 已启动的刷新先结束，再撤销服务器会话，避免较晚的刷新响应覆盖退出 cookie。
    this.loggingOut = true;
    try { await this.refreshing; return await this.request<void>('/auth/logout', { method: 'POST' }); }
    finally { this.loggingOut = false; }
  }
  keys(profile: string, signal?: AbortSignal) {
    return this.request<{ items: NativeClientKey[] }>(`/profiles/${encodeURIComponent(profile)}/keys`, { signal });
  }
  createKey(profile: string, name: string, expiresInDays: number, signal?: AbortSignal) {
    return this.request<NativeClientKey & { key: string }>(`/profiles/${encodeURIComponent(profile)}/keys`, {
      method: 'POST', body: JSON.stringify({ name, expires_in_days: expiresInDays }), signal,
    });
  }
  revokeKey(profile: string, keyId: string, signal?: AbortSignal) {
    return this.request<unknown>(`/profiles/${encodeURIComponent(profile)}/keys/${encodeURIComponent(keyId)}`, { method: 'DELETE', signal });
  }
  audit(signal?: AbortSignal) { return this.request<{ items: NativeAuditEvent[] }>('/auth/audit', { signal }); }

  catalog(signal?: AbortSignal) { return this.request<{ items: NativeArtifact[] }>('/catalog', { signal }); }
  profiles(signal?: AbortSignal) { return this.request<{ items: NativeProfileSummary[] }>('/profiles', { signal }); }
  profile(id: string, signal?: AbortSignal) { return this.request<NativeProfile>(`/profiles/${encodeURIComponent(id)}`, { signal }); }
  createProfile(id: string, signal?: AbortSignal) {
    return this.request<NativeProfileSummary>('/profiles', { method: 'POST', body: JSON.stringify({ id }), signal });
  }
  upload(file: File, signal?: AbortSignal) {
    const body = new FormData();
    body.append('file', file);
    return this.request<NativeArtifact>('/catalog', { method: 'POST', body, signal });
  }
  download(id: string, signal?: AbortSignal) {
    return this.request<Blob>(`/catalog/${encodeURIComponent(id)}/download`, { signal }, true);
  }
  operate(id: string, kind: NativeOperationKind, body: Record<string, unknown> | undefined, key: string) {
    return this.request<NativeOperationReceipt>(`/profiles/${encodeURIComponent(id)}/${kind}`, {
      method: 'POST', body: body ? JSON.stringify(body) : undefined, headers: { 'Idempotency-Key': key },
    });
  }
  operations(profile: string, signal?: AbortSignal) {
    return this.request<{ items: NativeOperation[] }>(`/operations?profile_id=${encodeURIComponent(profile)}`, { signal });
  }
  operation(id: string, signal?: AbortSignal) {
    return this.request<NativeOperation>(`/operations/${encodeURIComponent(id)}`, { signal });
  }
  cancel(id: string) { return this.request<NativeOperation>(`/operations/${encodeURIComponent(id)}/cancel`, { method: 'POST' }); }
  call(id: string, name: string, args: Record<string, unknown>, signal?: AbortSignal) {
    return this.request<unknown>(`/profiles/${encodeURIComponent(id)}/call`, {
      method: 'POST', body: JSON.stringify({ name, arguments: args }), signal,
    });
  }
}