feat: Add a basic constructor for Wallet

Author: 110CodingP

src/wallet/mod.rs

@@ -312,6 +312,49 @@ impl std::error::Error for ApplyBlockError {}
 /// A `CanonicalTx` managed by a `Wallet`.
 pub type WalletTx<'a> = CanonicalTx<'a, Arc<Transaction>, ConfirmationBlockTime>;
 
+impl<K> Wallet<K>
+where
+    K: Clone + fmt::Debug + Ord,
+{
+    /// Construct a new [`Wallet`] with the given `keyring`.
+    ///
+    /// Note: The network must be either the mainnet or one of the test networks. Also default value
+    /// of lookahead is used with no spk_cache.
+    pub fn new(mut keyring: KeyRing<K>) -> Self {
+        let network = keyring.network;
+
+        let genesis_hash = bitcoin::constants::genesis_block(network).block_hash();
+        let (chain, chain_changeset) = LocalChain::from_genesis_hash(genesis_hash);
+
+        let keyring_changeset = keyring.initial_changeset();
+
+        let mut index = KeychainTxOutIndex::new(DEFAULT_LOOKAHEAD, false);
+        let descriptors = core::mem::take(&mut keyring.descriptors);
+        for (keychain, desc) in descriptors {
+            let _inserted = index
+                .insert_descriptor(keychain, desc)
+                .expect("err: failed to insert descriptor");
+            assert!(_inserted);
+        }
+
+        let tx_graph = KeychainTxGraph::new(index);
+
+        let stage = ChangeSet {
+            keyring: keyring_changeset,
+            local_chain: chain_changeset,
+            tx_graph: bdk_chain::tx_graph::ChangeSet::default(),
+            indexer: bdk_chain::keychain_txout::ChangeSet::default(),
+        };
+
+        Self {
+            keyring,
+            chain,
+            tx_graph,
+            stage,
+        }
+    }
+}
+
 // impl Wallet {
 //     /// Build a new single descriptor [`Wallet`].
 //     ///