XO Integration Part II

package-lock.json

@@ -8185,9 +8185,9 @@
       }
     },
     "node_modules/idb": {
-      "version": "8.0.1",
-      "resolved": "https://registry.npmjs.org/idb/-/idb-8.0.1.tgz",
-      "integrity": "sha512-EkBCzUZSdhJV8PxMSbeEV//xguVKZu9hZZulM+2gHXI0t2hGVU3eYE6/XnH77DS6FM2FY8wl17aDcu9vXpvLWQ==",
+      "version": "8.0.3",
+      "resolved": "https://registry.npmjs.org/idb/-/idb-8.0.3.tgz",
+      "integrity": "sha512-LtwtVyVYO5BqRvcsKuB2iUMnHwPVByPCXFXOpuU96IZPPoPN6xjOGxZQ74pgSVVLQWtUOYgyeL4GE98BY5D3wg==",
       "license": "ISC"
     },
     "node_modules/ieee754": {
@@ -14750,7 +14750,7 @@
         "@electrum-cash/protocol": "2.1.0-development.8075178089",
         "@xocash/primitives": "*",
         "better-sqlite3": "^11.8.1",
-        "idb": "^8.0.0",
+        "idb": "8.0.3",
         "msgpackr": "^1.11.2",
         "zod": "^3.24.2"
       },

packages/primitives/src/block-header.ts

@@ -88,6 +88,31 @@ export class BlockHeader {
     return new this(bytes);
   }
 
+  static generateRandom(timestampUnix?: number): BlockHeader {
+    // Create buffer for the 80-byte header
+    const header = new Uint8Array(80);
+
+    // Fill with random bytes
+    crypto.getRandomValues(header);
+
+    // Optional: Set specific version if needed
+    // First 4 bytes is version (little-endian)
+    const version = 1;
+    header[0] = version & 0xff;
+    header[1] = (version >> 8) & 0xff;
+    header[2] = (version >> 16) & 0xff;
+    header[3] = (version >> 24) & 0xff;
+
+    // Optional: Set realistic timestamp (current time)
+    const timestamp = timestampUnix || Math.floor(Date.now() / 1000);
+    header[68] = timestamp & 0xff;
+    header[69] = (timestamp >> 8) & 0xff;
+    header[70] = (timestamp >> 16) & 0xff;
+    header[71] = (timestamp >> 24) & 0xff;
+
+    return this.fromBytes(header);
+  }
+
   /**
    * Checks whether the given BlochHeader is of a valid structure.
    *

packages/stack/package.json

@@ -36,7 +36,7 @@
     "@electrum-cash/protocol": "2.1.0-development.8075178089",
     "@xocash/primitives": "*",
     "better-sqlite3": "^11.8.1",
-    "idb": "^8.0.0",
+    "idb": "8.0.3",
     "msgpackr": "^1.11.2",
     "zod": "^3.24.2"
   },

packages/stack/src/blockchain/base-blockchain.ts

@@ -7,7 +7,7 @@ import {
   type BlockchainUnsubscribeCallback,
 } from './types.js';
 
-import { Transaction } from '@xocash/primitives';
+import { BlockHeader, Transaction, TransactionHash } from '@xocash/primitives';
 
 export type BlockchainEvents = {
   isConnectedUpdated: boolean;
@@ -80,6 +80,15 @@ export abstract class BaseBlockchain<
     address: string,
   ): Promise<BlockchainTransactions>;
 
+  /**
+   * Retrieves the Block Header at the given height.
+   *
+   * @param {number} blockHeight - The block height of the header to retrieve
+   * @returns {Promise<BlockHeader>} A promise that resolves with the Block Header
+   * @throws {Error} If the block number is invalid or the query fails
+   */
+  abstract fetchBlockHeader(blockHeight: number): Promise<BlockHeader>;
+
   /**
    * Retrieves detailed information about a specific transaction.
    *
@@ -196,15 +205,29 @@ export abstract class BaseBlockchain<
       tx = Transaction.from(tx);
     }
 
-    const txHash = tx.toHashHex();
+    // Then wait for either resolution or timeout
+    return this.waitForTransactionHash(tx.toHash(), timeoutMs);
+  }
+
+  async waitForTransactionHash(
+    txHash: TransactionHash | Uint8Array | string,
+    timeoutMs = 10_000,
+  ) {
+    // Cast the transaction hash.
+    if (!(txHash instanceof TransactionHash)) {
+      txHash = TransactionHash.from(txHash);
+    }
 
     // First, subscribe to the transaction
     let unsubscribeCallback: () => void;
-    const subscriptionPromise = this.subscribeTransaction(txHash, () => {
-      if (unsubscribeCallback) {
-        unsubscribeCallback();
-      }
-    });
+    const subscriptionPromise = this.subscribeTransaction(
+      txHash.toHex(),
+      () => {
+        if (unsubscribeCallback) {
+          unsubscribeCallback();
+        }
+      },
+    );
 
     // Then create the wait promise without an async executor
     const waitForTxPromise = new Promise<void>((resolve, reject) => {
@@ -218,7 +241,7 @@ export abstract class BaseBlockchain<
       // Create a subscribe function so that we get notified when transaction is seen by network
       unsubscribeCallback = () => {
         clearTimeout(timeout);
-        this.unsubscribeTransaction(txHash, unsubscribeCallback);
+        this.unsubscribeTransaction(txHash.toHex(), unsubscribeCallback);
         resolve();
       };
     });

packages/stack/src/blockchain/blockchain-electrum.ts

@@ -9,6 +9,7 @@ import { type BaseStore, StoreInMemory } from '../storage/index.js';
 
 import {
   Address,
+  BlockHeader,
   ExtMap,
   Outpoint,
   Transaction,
@@ -24,6 +25,7 @@ import {
   type TransactionSubscribeNotification,
   initializeElectrumClient,
   broadcastTransaction,
+  fetchBlockHeaderFromBlockHeight,
   fetchUnspentTransactionOutputs,
   fetchHistory,
   fetchTransaction,
@@ -278,7 +280,7 @@ export class BlockchainElectrum extends BaseBlockchain<
       return Transaction.fromHex(txHex).toRaw();
     });
 
-    // Decode the hex into our transaction primitive.
+    // Decode the raw data into our transaction primitive.
     const transaction = Transaction.fromRaw(transactionRaw);
 
     // Return the transaction hex.
@@ -318,6 +320,32 @@ export class BlockchainElectrum extends BaseBlockchain<
     return transactionsIndexed;
   }
 
+  async fetchBlockHeader(blockHeight: number) {
+    // Wait for connection to be established before attempting to subscribe.
+    // TODO: Consider doing this at a higher level.
+    if (!this.isConnected) {
+      await this.waitFor('isConnectedUpdated', (isConnected) => isConnected);
+    }
+
+    // Define the cache key.
+    const cacheKey = `blockHeader.${blockHeight}`;
+
+    // Attempt to get the transaction history from the cache or fetch them if not available.
+    const blockHeaderRaw = await this.store.getOrSet(cacheKey, async () => {
+      const headerHex = await fetchBlockHeaderFromBlockHeight(
+        this.electrumClient,
+        blockHeight,
+      );
+      return BlockHeader.fromHex(headerHex).toRaw();
+    });
+
+    // Decode the raw data into our Block Header primitive.
+    const blockHeader = BlockHeader.fromRaw(blockHeaderRaw);
+
+    // Return the block header.
+    return blockHeader;
+  }
+
   async broadcastTransaction(
     tx: Transaction | Uint8Array | string,
     opts: BroadcastOpts = { timeoutMs: 10_000, waitUntilSeen: true },

packages/stack/src/blockchain/blockchain-inmemory.ts

@@ -9,6 +9,7 @@ import {
 
 import {
   Address,
+  BlockHeader,
   ExtMap,
   Outpoint,
   Transaction,
@@ -30,6 +31,7 @@ export class BlockchainInMemory extends BaseBlockchain {
     return blockchain as InstanceType<T>;
   }
 
+  private blockHeaders: Array<BlockHeader>;
   private transactions: BlockchainTransactions;
   private addressSubscriptions: Map<string, Set<BlockchainCallback>>;
   private transactionSubscriptions: Map<string, Set<BlockchainCallback>>;
@@ -40,6 +42,7 @@ export class BlockchainInMemory extends BaseBlockchain {
     this.transactions = new ExtMap<BlockchainTransaction>();
     this.addressSubscriptions = new Map();
     this.transactionSubscriptions = new Map();
+    this.blockHeaders = [];
   }
 
   async start() {}
@@ -89,6 +92,17 @@ export class BlockchainInMemory extends BaseBlockchain {
     });
   }
 
+  async fetchBlockHeader(blockHeight: number) {
+    const blockHeader = this.blockHeaders[blockHeight];
+
+    if (!blockHeader) {
+      throw new Error(`No block available for height ${blockHeight}`);
+    }
+
+    // Return the block header.
+    return blockHeader;
+  }
+
   async broadcastTransaction(
     tx: Transaction | Uint8Array | string,
     opts: { skipValidation: boolean } = { skipValidation: false },
@@ -326,6 +340,14 @@ export class BlockchainInMemory extends BaseBlockchain {
   }
 
   async mineBlock(outputs: Array<Output>): Promise<void> {
+    // Create a block header from the current timestamp.
+    const newBlockHeader = BlockHeader.generateRandom(
+      Math.floor(Date.now() / 1000),
+    );
+
+    // Add it to our list of block headers.
+    this.blockHeaders.push(newBlockHeader);
+
     // Create a transaction that pays to our subscribed address.
     const transaction = Transaction.fromRaw({
       version: 2,

packages/stack/src/storage/activities.ts

@@ -25,10 +25,18 @@ export interface Activity {
 // Define the snapshot structure
 export type SnapshotByType = {
   [type: string]: {
-    [id: string]: Activity;
+    [entityId: string]: Activity;
   };
 };
 
+export type ActivitiesIndexedByKey<T extends Activity = Activity> = {
+  [entityId: string]: T;
+};
+
+export type ActivitiesIndexedByEntityId<T extends Activity = Activity> = {
+  [key: string]: T;
+};
+
 // Policy type definition
 export type PolicyFunction = (
   existingActivity: Activity | undefined,
@@ -36,6 +44,7 @@ export type PolicyFunction = (
 ) => Activity;
 
 export type ActivitiesEvents = {
+  snapshotUpdated: undefined;
   [key: `updated:${string}`]: { activity: Activity };
 };
 
@@ -172,12 +181,17 @@ export class Activities extends EventEmitter<ActivitiesEvents> {
   /**
    * Get all activities of a specific type
    */
-  public getByType<T extends Activity>(type: T['key']): T[] {
-    const activities = this.snapshot[type];
+  public getByKey<T extends Activity>(
+    key: T['key'],
+  ): ActivitiesIndexedByKey<T> {
+    const activities = this.snapshot[key];
     if (!activities) {
-      return [];
+      return {};
     }
-    return Object.values(activities) as T[];
+
+    // NOTE: We want to return a new object, not a reference to our current object.
+    //       But we only need to "clone" the first level as each activity itself is immutable.
+    return { ...activities } as ActivitiesIndexedByKey<T>;
   }
 
   /**
@@ -227,6 +241,9 @@ export class Activities extends EventEmitter<ActivitiesEvents> {
 
       // Emit the updated activity.
       this.emit(`updated:${activity.key}`, { activity });
+
+      // Emit an event indicating our snapshot has been updated.
+      this.emit('snapshotUpdated', undefined);
     } else if (storeKey !== this.storeKeyMap.get(snapshotKey)) {
       // If we kept the existing activity, delete the new activity from the store
       // await this.store.set(storeKey, null);
@@ -261,6 +278,8 @@ export class Activities extends EventEmitter<ActivitiesEvents> {
       await this.processActivity(storeKey, activity);
     }
 
+    this.emit('snapshotUpdated', undefined);
+
     return this.snapshot;
   }
 

packages/stack/src/storage/base-store.ts

@@ -6,6 +6,7 @@ export type StorageOpts = {
 };
 
 export type StoreEvents = {
+  [key: `set:${string}`]: any;
   set: { key: string; value: any };
   delete: { key: string };
   clear: undefined;

packages/stack/src/storage/store-localstorage.ts

@@ -26,6 +26,10 @@ export class StorageLocalStorage extends BaseStorage {
     const stores = new Set<string>();
 
     // Iterate through localStorage to find all stores with our dbName prefix
+    // NOTE: I think this was me (Jim) just being stupid.
+    //       We don't want to do this - we want to over-ride "on" to emit on first subscription.
+    //       And then call super.on?
+    /*
     for (let i = 0; i < localStorage.length; i++) {
       const key = localStorage.key(i);
       if (key && key.startsWith(prefix)) {
@@ -35,6 +39,7 @@ export class StorageLocalStorage extends BaseStorage {
         }
       }
     }
+    */
 
     return Array.from(stores);
   }
@@ -171,7 +176,15 @@ export class StoreLocalStorage extends BaseStore {
     encryption?: Encrypter,
     parentStorage?: StorageLocalStorage,
   ) {
-    return new this(dbName, storeName, encryption, parentStorage);
+    const store = new this(dbName, storeName, encryption, parentStorage);
+
+    // Emit events for all entries.
+    const allEntries = await store.all();
+    Object.entries(allEntries).forEach(([key, value]) =>
+      store.emit(`set:${key}`, value),
+    );
+
+    return store;
   }
 
   async all<T>() {
@@ -235,6 +248,7 @@ export class StoreLocalStorage extends BaseStore {
     // LocalStorage can only store strings, so we convert the binary data
     localStorage.setItem(fullKey, encryptedValue);
     this.emit('set', { key, value });
+    this.emit(`set:${key}`, value);
   }
 
   async delete(key: string) {

packages/stack/src/wallet/activities.ts

@@ -24,6 +24,11 @@ export interface WalletDescription extends Activity {
   value: string;
 }
 
+export interface WalletCurrency extends Activity {
+  key: 'WalletCurrency';
+  value: string;
+}
+
 export interface WalletHDAddressGap extends Activity {
   key: 'WalletHDAddressGap';
   value: number;

packages/stack/src/wallet/base-wallet.ts

@@ -173,5 +173,5 @@ export abstract class BaseWallet<
    */
   abstract sendTransaction(
     template: Partial<TransactionTemplate>,
-  ): Promise<void>;
+  ): Promise<Uint8Array>;
 }

packages/stack/src/wallet/wallet-hd.ts

@@ -372,6 +372,9 @@ export class WalletHD extends BaseWallet {
 
     // Broadcast the transaction to the blockchain.
     await this.blockchain.broadcastTransaction(generatedTxBytes);
+
+    // Return the transaction.
+    return generatedTxBytes;
   }
 
   async deriveWallets(

packages/stack/src/wallet/wallet-p2pkh.ts

@@ -414,6 +414,9 @@ export class WalletP2PKH extends BaseWallet {
 
     // Broadcast the transaction to the blockchain.
     await this.blockchain.broadcastTransaction(generatedTxBytes);
+
+    // Return the transaction.
+    return generatedTxBytes;
   }
 
   private async onAddressNotification(