Function pullAndReconstruct

src/core/sync.ts:88–193

(
  walletAddress: string,
  passphrase: string,
  dbPath: string
)

 * Used when setting up a new device.
 */
export async function pullAndReconstruct(
  walletAddress: string,
  passphrase: string,
  dbPath: string
): Promise<{ factCount: number; version: number }> {
  // Step 1: Fetch identity to get salt
  const identity = await fetchIdentity(walletAddress, MAX_PULL_IDENTITY_BYTES);
  if (!identity) {
    throw new Error(
      "No identity found on Arweave for this wallet. " +
        "Make sure you ran `sharedcontext init` on another device and pushed the identity."
    );
  }

  // Step 2: Derive key from passphrase + salt
  const key = deriveKey(passphrase, identity.salt);

  // Step 3: Verify we can decrypt the private key (validates passphrase)
  try {
    decrypt(identity.encryptedPrivateKey, key);
  } catch {
    throw new Error("Wrong passphrase. Decryption failed.");
  }

  // Step 4: Query all shards
  const allShards = await queryShards(walletAddress);
  const dataShards = allShards.filter(
    (s) => s.type === "delta" || s.type === "snapshot"
  );

  if (dataShards.length === 0) {
    // No shards yet, just set up empty db
    const db = openDatabase(dbPath);
    setMeta(db, "current_version", "0");
    setMeta(db, "wallet_address", walletAddress);
    db.close();
    return { factCount: 0, version: 0 };
  }

  // Step 5: Find the latest snapshot (if any) and only fetch shards after it
  const latestSnapshot = findLatestSnapshot(dataShards);
  const shardsToFetch = latestSnapshot
    ? dataShards.filter((s) => s.version >= latestSnapshot.version)
    : dataShards;

  // Step 6: Download and process shards
  const decryptedShards: Shard[] = [];
  for (const shardInfo of shardsToFetch) {
    try {
      const encrypted = await downloadShard(
        shardInfo.txId,
        MAX_PULL_DATA_SHARD_BYTES
      );

      // Signature is mandatory for all data shards.
      if (!shardInfo.signature) {
        console.warn(
          `Skipping shard v${shardInfo.version}: missing signature.`