Class LANBackend

packages/core/src/sync/lan-backend.ts:36–160

 * This is a client-side implementation that connects to a LAN server.
 */
export class LANBackend implements ISyncBackend {
  readonly type = "lan" as const;
  private serverUrl: string;
  private pairCode: string;
  private deviceName: string;
  private abortController: AbortController | null = null;

  constructor(serverUrl: string, pairCode: string, deviceName: string) {
    this.serverUrl = serverUrl.replace(/\/+$/, "");
    this.pairCode = pairCode;
    this.deviceName = deviceName;
  }

  private getFetchFn() {
    const platform = getPlatformService();
    return platform.fetch ? platform.fetch.bind(platform) : globalThis.fetch.bind(globalThis);
  }

  async testConnection(): Promise<boolean> {
    try {
      const fetchFn = this.getFetchFn();
      const response = await fetchFn(`${this.serverUrl}/ping`, {
        method: "GET",
        headers: {
          "X-Pair-Code": this.pairCode,
        },
      });
      return response.ok;
    } catch {
      return false;
    }
  }

  async ensureDirectories(): Promise<void> {
    // No-op for LAN - server handles this
  }

  async put(_path: string, _data: Uint8Array): Promise<void> {
    throw new Error("LAN backend does not support upload (receive-only)");
  }

  async get(path: string): Promise<Uint8Array> {
    const fetchFn = this.getFetchFn();
    const response = await fetchFn(`${this.serverUrl}/file${path}`, {
      method: "GET",
      headers: {
        "X-Pair-Code": this.pairCode,
      },
    });

    if (!response.ok) {
      throw new Error(`LAN GET failed for ${path}: ${response.status}`);
    }

    const buffer = await response.arrayBuffer();
    return new Uint8Array(buffer);
  }