feat(backend): Expose and use min_confirmations filter to get utxos (#…

…2601)

# Motivation

The bitcoin API to get utxos exposes a filter for the mininum
confirmations of the transaction.

In this PR, I expose this filter in `get_all_utxos` and use it in the
`btc_select_user_utxos_fee` endpoint.

# Changes

* Add optional parameter min_confirmations to `get_all_utxos`.
* Change page for filter parameter for helper `get_utxos`.
* Call `get_all_utxos` with 6 minimum confirmations.

# Tests

We can't add integration tests for bitcoin api until pocket-ic supports
bitcoin.

src/backend/backend.did

@@ -124,6 +124,7 @@ type SelectedUtxosFeeRequest = record {
   network : BitcoinNetwork;
   amount_satoshis : nat64;
   source_address : text;
+  min_confirmations : opt nat32;
 };
 type SelectedUtxosFeeResponse = record {
   fee_satoshis : nat64;

src/backend/src/bitcoin_api.rs

@@ -11,12 +11,12 @@ use ic_cdk::api::management_canister::bitcoin::{
 async fn get_utxos(
     network: BitcoinNetwork,
     address: String,
-    maybe_next_page: Option<Vec<u8>>,
+    filter: Option<UtxoFilter>,
 ) -> Result<GetUtxosResponse, String> {
     let utxos_res = bitcoin_get_utxos(GetUtxosRequest {
         address,
         network,
-        filter: maybe_next_page.map(UtxoFilter::Page),
+        filter,
     })
     .await
     .map_err(|err| err.1)?;
@@ -25,13 +25,19 @@ async fn get_utxos(
 }
 /// Returns all the UTXOs of a specific address.
 /// API interface returns a paginated view of the utxos but we need to get them all.
-pub async fn get_all_utxos(network: BitcoinNetwork, address: String) -> Result<Vec<Utxo>, String> {
-    let mut utxos_response = get_utxos(network, address.clone(), None).await?;
+pub async fn get_all_utxos(
+    network: BitcoinNetwork,
+    address: String,
+    min_confirmations: Option<u32>,
+) -> Result<Vec<Utxo>, String> {
+    let filter = min_confirmations.map(UtxoFilter::MinConfirmations);
+    let mut utxos_response = get_utxos(network, address.clone(), filter).await?;
 
     let mut all_utxos: Vec<Utxo> = utxos_response.utxos;
     let mut next_page: Option<Vec<u8>> = utxos_response.next_page;
     while next_page.is_some() {
-        utxos_response = get_utxos(network, address.clone(), next_page).await?;
+        utxos_response =
+            get_utxos(network, address.clone(), next_page.map(UtxoFilter::Page)).await?;
         all_utxos.extend(utxos_response.utxos);
         next_page = utxos_response.next_page;
     }

src/backend/src/lib.rs

@@ -285,13 +285,23 @@ fn list_custom_tokens() -> Vec<CustomToken> {
     read_state(|s| s.custom_token.get(&stored_principal).unwrap_or_default().0)
 }
 
+const MIN_CONFIRMATIONS_ACCEPTED_BTC_TX: u32 = 6;
+
 #[update(guard = "may_read_user_data")]
 async fn btc_select_user_utxos_fee(
     params: SelectedUtxosFeeRequest,
 ) -> Result<SelectedUtxosFeeResponse, SelectedUtxosFeeError> {
-    let all_utxos = bitcoin_api::get_all_utxos(params.network, params.source_address)
-        .await
-        .map_err(|msg| SelectedUtxosFeeError::InternalError { msg })?;
+    let all_utxos = bitcoin_api::get_all_utxos(
+        params.network,
+        params.source_address,
+        Some(
+            params
+                .min_confirmations
+                .unwrap_or(MIN_CONFIRMATIONS_ACCEPTED_BTC_TX),
+        ),
+    )
+    .await
+    .map_err(|msg| SelectedUtxosFeeError::InternalError { msg })?;
 
     let median_fee_millisatoshi_per_vbyte = bitcoin_api::get_fee_per_byte(params.network)
         .await

src/backend/tests/it/bitcoin.rs

@@ -19,6 +19,8 @@ fn test_select_user_utxos_fee_returns_zero_when_user_has_insufficient_funds() {
         amount_satoshis: 100_000_000u64,
         source_address: "bcrt1qpg7udjvq7gx2fp480pgt4hnhj3qc4nhrkstc33".to_string(),
         network: BitcoinNetwork::Regtest,
+        // Until bitcoin is supported in pocket-ic it only works with 1.
+        min_confirmations: Some(1),
     };
     let response = pic_setup.update::<Result<SelectedUtxosFeeResponse, SelectedUtxosFeeError>>(
         caller,

src/declarations/backend/backend.did

@@ -124,6 +124,7 @@ type SelectedUtxosFeeRequest = record {
   network : BitcoinNetwork;
   amount_satoshis : nat64;
   source_address : text;
+  min_confirmations : opt nat32;
 };
 type SelectedUtxosFeeResponse = record {
   fee_satoshis : nat64;

src/declarations/backend/backend.did.d.ts

@@ -136,6 +136,7 @@ export interface SelectedUtxosFeeRequest {
 	network: BitcoinNetwork;
 	amount_satoshis: bigint;
 	source_address: string;
+	min_confirmations: [] | [number];
 }
 export interface SelectedUtxosFeeResponse {
 	fee_satoshis: bigint;

src/declarations/backend/backend.factory.certified.did.js

@@ -54,7 +54,8 @@ export const idlFactory = ({ IDL }) => {
 	const SelectedUtxosFeeRequest = IDL.Record({
 		network: BitcoinNetwork,
 		amount_satoshis: IDL.Nat64,
-		source_address: IDL.Text
+		source_address: IDL.Text,
+		min_confirmations: IDL.Opt(IDL.Nat32)
 	});
 	const Outpoint = IDL.Record({
 		txid: IDL.Vec(IDL.Nat8),

src/declarations/backend/backend.factory.did.js

@@ -54,7 +54,8 @@ export const idlFactory = ({ IDL }) => {
 	const SelectedUtxosFeeRequest = IDL.Record({
 		network: BitcoinNetwork,
 		amount_satoshis: IDL.Nat64,
-		source_address: IDL.Text
+		source_address: IDL.Text,
+		min_confirmations: IDL.Opt(IDL.Nat32)
 	});
 	const Outpoint = IDL.Record({
 		txid: IDL.Vec(IDL.Nat8),

src/shared/src/types.rs

@@ -170,6 +170,7 @@ pub mod bitcoin {
         pub amount_satoshis: u64,
         pub source_address: String,
         pub network: BitcoinNetwork,
+        pub min_confirmations: Option<u32>,
     }
 
     #[derive(CandidType, Deserialize, Clone, Eq, PartialEq, Debug)]