XO wallet integration

packages/stack/src/blockchain/index.ts

@@ -3,3 +3,4 @@ export * from './blockchain-electrum.js';
 export * from './blockchain-inmemory.js';
 export * from './traits.js';
 export * from './types.js';
+export * from './utils.js';

packages/stack/src/blockchain/utils.ts

@@ -0,0 +1,54 @@
+// TODO: If we end up with several utilities, we might want to consider a refactor:
+//       1. Convert BlockchainTransactions into a class with a sort function.
+//       2. Have WalletTransactions extends from BlockchainTransactions.
+
+import { type BlockchainTransactions } from './types.js';
+
+export function sortTransactions(
+  transactions: BlockchainTransactions,
+  order: 'ASC' | 'DESC',
+): BlockchainTransactions {
+  return transactions.sort((a, b) => {
+    // Name the outcomes, or I'll go insane.
+    const aFirst = order === 'DESC' ? -1 : 1;
+    const bFirst = order === 'DESC' ? 1 : -1;
+
+    // Sort by mempool, then blockheight, then dependency.
+    // height = 0 -- mempool
+    // height > 0 -- confirmed
+    // height < 0 -- mempool with dependencies
+
+    // If a is dependant on a tx in the mempool, while b is in the mempool or confirmed, sort a before b.
+    if (a.height <= -1 && b.height >= 0) {
+      return aFirst;
+    }
+
+    // If b is dependant on a tx in the mempool, while a is in the mempool or confirmed, sort b before a.
+    if (b.height <= -1 && a.height >= 0) {
+      return bFirst;
+    }
+
+    // If a is in the mempool, while b is confirmed, sort a before b.
+    if (a.height <= 0 && b.height > 0) {
+      return aFirst;
+    }
+
+    // If b is in the mempool, while a is confirmed, sort b before a.
+    if (b.height <= 0 && a.height > 0) {
+      return bFirst;
+    }
+
+    // If a has a higher blockheight than b, sort a before b.
+    if (a.height > b.height) {
+      return aFirst;
+    }
+
+    // If b has a higher blockheight than a, sort b before a.
+    if (b.height > a.height) {
+      return bFirst;
+    }
+
+    // There was no criteria to sort by, so return 0.
+    return 0;
+  });
+}