Function buildDownloadFileTask

packages/core/src/sync/sync-files.ts:991–1019

(
  backend: ISyncBackend,
  info: BookInfo,
  setBookSyncStatus: (id: string, status: "local" | "remote") => Promise<void>,
)

}

function buildDownloadFileTask(
  backend: ISyncBackend,
  info: BookInfo,
  setBookSyncStatus: (id: string, status: "local" | "remote") => Promise<void>,
): FileTask {
  const bookTitle = info.book.title || "未知书籍";
  return {
    label: bookTitle,
    run: async (onProgress) => {
      const taskStart = Date.now();
      try {
        console.log(`[Sync] 📥 Downloading book: ${bookTitle} ← ${info.remoteFilePath}`);
        const bytes = await downloadRemoteFileToPath(
          backend,
          info.remoteFilePath,
          info.localFilePath,
          onProgress,
        );
        await setBookSyncStatus(info.book.id, "local");
        const size = bytes === null ? "" : ` (${(bytes / 1024 / 1024).toFixed(2)} MB)`;
        console.log(`[Sync] ✓ Downloaded "${bookTitle}"${size} in ${Date.now() - taskStart}ms`);
        return true;
      } catch (e) {
        console.log(`[Sync] ✗ Failed to download "${bookTitle}": ${e}`);
        return false;
      }
    },
  };
}

function buildUploadCoverTask(backend: ISyncBackend, info: BookInfo): FileTask {
  const bookTitle = info.book.title || "未知书籍";