Add Bitcoin support to Relay swapper

Cargo.toml

@@ -114,6 +114,7 @@ sui-types = { package = "sui-sdk-types", version = "0.2.2", features = [
     "serde",
 ] }
 k256 = { version = "0.13.4", features = ["ecdsa", "sha256"] }
+bitcoin = { version = "0.32", default-features = false, features = ["std"] }
 
 uniffi = { version = "0.31.0" }
 regex = { version = "1.12.3" }

crates/gem_aptos/src/signer/chain_signer.rs

@@ -226,7 +226,7 @@ fn gas_unit_price(input: &TransactionLoadInput) -> Result<u64, SignerError> {
 
 fn resolve_max_gas_amount(input: &TransactionLoadInput) -> u64 {
     if let TransactionInputType::Swap(_, _, swap_data) = &input.input_type
-        && let Some(limit) = &swap_data.data.gas_limit
+        && let Some(limit) = &swap_data.data.limit
         && let Ok(parsed) = limit.parse::<u64>()
     {
         return parsed;

crates/gem_bitcoin/Cargo.toml

@@ -7,7 +7,7 @@ publish = false
 [features]
 default = []
 rpc = ["dep:chain_traits", "dep:gem_client"]
-signer = ["dep:signer", "dep:gem_hash", "dep:hex"]
+signer = ["dep:signer", "dep:gem_hash", "dep:hex", "dep:bitcoin"]
 reqwest = ["gem_client/reqwest"]
 chain_integration_tests = ["rpc", "reqwest", "settings/testkit"]
 
@@ -28,6 +28,7 @@ serde_serializers = { path = "../serde_serializers", features = ["bigint"] }
 signer = { path = "../signer", optional = true }
 gem_hash = { path = "../gem_hash", optional = true }
 hex = { workspace = true, optional = true }
+bitcoin = { workspace = true, optional = true }
 
 [dev-dependencies]
 tokio = { workspace = true, features = ["macros", "rt"] }

crates/gem_bitcoin/src/provider/preload.rs

@@ -7,7 +7,9 @@ use std::error::Error;
 
 use gem_client::Client;
 use primitives::{
-    BitcoinChain, FeePriority, FeeRate, GasPriceType, TransactionInputType, TransactionLoadData, TransactionLoadInput, TransactionLoadMetadata, TransactionPreloadInput, UTXO,
+    BitcoinChain, FeePriority, FeeRate, GasPriceType, SwapProvider, TransactionFee, TransactionInputType, TransactionLoadData, TransactionLoadInput, TransactionLoadMetadata,
+    TransactionPreloadInput, UTXO,
+    swap::SwapQuoteDataType,
 };
 
 use crate::models::Address;
@@ -32,10 +34,11 @@ impl<C: Client> ChainTransactionLoad for BitcoinClient<C> {
     }
 
     async fn get_transaction_load(&self, input: TransactionLoadInput) -> Result<TransactionLoadData, Box<dyn Error + Sync + Send>> {
-        Ok(TransactionLoadData {
-            fee: input.default_fee(),
-            metadata: input.metadata,
-        })
+        let fee = match swap_provider_fee(&input) {
+            Some(result) => result?,
+            None => input.default_fee(),
+        };
+        Ok(TransactionLoadData { fee, metadata: input.metadata })
     }
 
     async fn get_transaction_fee_rates(&self, _input_type: TransactionInputType) -> Result<Vec<FeeRate>, Box<dyn Error + Sync + Send>> {
@@ -64,6 +67,19 @@ impl<C: Client> BitcoinClient<C> {
     }
 }
 
+fn swap_provider_fee(input: &TransactionLoadInput) -> Option<Result<TransactionFee, &'static str>> {
+    let swap_data = input.input_type.get_swap_data().ok()?;
+    if swap_data.data.data_type != SwapQuoteDataType::Contract {
+        return None;
+    }
+    let provider = swap_data.quote.provider_data.provider;
+    if !matches!(provider, SwapProvider::Relay) {
+        return None;
+    }
+    let limit = swap_data.data.limit.as_deref()?;
+    Some(limit.parse::<BigInt>().map(TransactionFee::new_from_fee).map_err(|_| "invalid swap fee"))
+}
+
 fn calculate_fee_rate(fee_sat_per_kb: &str, minimum_byte_fee: u32) -> Result<BigInt, Box<dyn Error + Sync + Send>> {
     let rate = BigNumberFormatter::value_from_amount(fee_sat_per_kb, 8)?.parse::<f64>()? / 1000.0;
     let minimum_byte_fee = minimum_byte_fee as f64;