feat: added delegateFirstStakeCredential method to TxBuilder

Author: AngelCastilloB

packages/tx-construction/src/tx-builder/TxBuilder.ts

@@ -103,6 +103,8 @@ export class GenericTxBuilder implements TxBuilder {
   #logger: Logger;
   #handleProvider?: HandleProvider;
   #handleResolutions: HandleResolution[];
+  #delegateFirstStakeCredConfig: Cardano.PoolId | null | undefined = undefined;
+
   #customizeCb: CustomizeCb;
 
   constructor(dependencies: TxBuilderDependencies) {
@@ -153,6 +155,11 @@ export class GenericTxBuilder implements TxBuilder {
     });
   }
 
+  delegateFirstStakeCredential(poolId: Cardano.PoolId | null): TxBuilder {
+    this.#delegateFirstStakeCredConfig = poolId;
+    return this;
+  }
+
   delegatePortfolio(portfolio: Cardano.Cip17DelegationPortfolio | null): TxBuilder {
     if (!this.#dependencies.bip32Account) throw new Error('BIP32 account is required to delegate portfolio.');
 
@@ -212,7 +219,7 @@ export class GenericTxBuilder implements TxBuilder {
           try {
             const rewardAccountsWithWeights = this.#dependencies.bip32Account
               ? await this.#delegatePortfolio()
-              : new Map();
+              : await this.#delegateFirstStakeCredential();
 
             await this.#validateOutputs();
             // Take a snapshot of returned properties,
@@ -346,6 +353,63 @@ export class GenericTxBuilder implements TxBuilder {
     }
   }
 
+  async #delegateFirstStakeCredential(): Promise<RewardAccountsAndWeights> {
+    const rewardAccountsWithWeights: RewardAccountsAndWeights = new Map();
+    if (this.#delegateFirstStakeCredConfig === undefined) {
+      // Delegation was not configured by user
+      return Promise.resolve(rewardAccountsWithWeights);
+    }
+
+    const rewardAccounts = await this.#dependencies.txBuilderProviders.rewardAccounts();
+
+    if (!rewardAccounts?.length) {
+      // This shouldn't happen
+      throw new Error('Could not find any rewardAccount.');
+    }
+
+    const rewardAccount = rewardAccounts[0];
+
+    this.partialTxBody = { ...this.partialTxBody, certificates: [] };
+
+    const stakeCredential = Cardano.Address.fromBech32(rewardAccount.address).asReward()?.getPaymentCredential();
+
+    if (!stakeCredential) {
+      // This shouldn't happen
+      throw new Error(`Invalid credential ${stakeCredential}.`);
+    }
+
+    if (this.#delegateFirstStakeCredConfig === null) {
+      // Deregister scenario
+      if (rewardAccount.credentialStatus === Cardano.StakeCredentialStatus.Unregistered) {
+        this.#logger.warn('Stake key not registered.', rewardAccount.address, rewardAccount.credentialStatus);
+      } else {
+        this.partialTxBody.certificates!.push({
+          __typename: Cardano.CertificateType.StakeDeregistration,
+          stakeCredential
+        });
+      }
+    } else {
+      // Register and delegate scenario
+      if (rewardAccount.credentialStatus !== Cardano.StakeCredentialStatus.Unregistered) {
+        this.#logger.debug('Stake key already registered', rewardAccount.address, rewardAccount.credentialStatus);
+      } else {
+        this.partialTxBody.certificates!.push({
+          __typename: Cardano.CertificateType.StakeRegistration,
+          stakeCredential
+        });
+      }
+
+      rewardAccountsWithWeights.set(rewardAccount.address, 1);
+      this.partialTxBody.certificates!.push({
+        __typename: Cardano.CertificateType.StakeDelegation,
+        poolId: this.#delegateFirstStakeCredConfig,
+        stakeCredential
+      });
+    }
+
+    return rewardAccountsWithWeights;
+  }
+
   async #delegatePortfolio(): Promise<RewardAccountsAndWeights> {
     const rewardAccountsWithWeights: RewardAccountsAndWeights = new Map();
     if (!this.#requestedPortfolio) {

packages/tx-construction/src/tx-builder/types.ts

@@ -206,6 +206,14 @@ export interface TxBuilder {
    * @returns {OutputBuilder} {@link OutputBuilder} util for building transaction outputs.
    */
   buildOutput(txOut?: PartialTxOut): OutputBuilder;
+
+  /**
+   * Delegates the first stake credential controlled by the wallet.
+   *
+   * @param poolId The pool to delegate to, or null if the stake credential should be de-registered.
+   */
+  delegateFirstStakeCredential(poolId: Cardano.PoolId | null): TxBuilder;
+
   /**
    * Configures the transaction to include all the certificates needed to delegate to the pools from the portfolio.
    *

packages/web-extension/src/observableWallet/util.ts

@@ -54,6 +54,10 @@ export const txBuilderProperties: RemoteApiProperties<Omit<TxBuilder, 'customize
     getApiProperties: () => outputBuilderProperties,
     propType: RemoteApiPropertyType.ApiFactory
   },
+  delegateFirstStakeCredential: {
+    getApiProperties: () => txBuilderProperties,
+    propType: RemoteApiPropertyType.ApiFactory
+  },
   delegatePortfolio: {
     getApiProperties: () => txBuilderProperties,
     propType: RemoteApiPropertyType.ApiFactory