From 5f51079458e703d39047eba7c6f310d3f447c40f Mon Sep 17 00:00:00 2001
From: Rigidity <me@rigidnetwork.com>
Date: Wed, 4 Sep 2024 12:59:17 -0400
Subject: [PATCH] Allow multiple outputs in send_xch

---
 index.d.ts    | 12 ++++++++----
 src/lib.rs    | 27 ++++++++++++++++++++-------
 src/wallet.rs | 17 +++++++++++------
 3 files changed, 39 insertions(+), 17 deletions(-)

diff --git a/index.d.ts b/index.d.ts
index 2ad21eb..a34611c 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -186,16 +186,20 @@ export interface UnspentCoinsResponse {
  * @returns {Vec<Coin>} Array of selected coins.
  */
 export declare function selectCoins(allCoins: Array<Coin>, totalAmount: bigint): Array<Coin>
+/** An output puzzle hash and amount. */
+export interface Output {
+  puzzleHash: Buffer
+  amount: bigint
+}
 /**
- * Sends XCH to a given puzzle hash.
+ * Sends XCH to a given set of puzzle hashes.
  *
  * @param {Buffer} syntheticKey - The synthetic key used by the wallet.
  * @param {Vec<Coin>} selectedCoins - Coins to be spent, as retured by `select_coins`.
- * @param {Buffer} puzzleHash - The puzzle hash to send to.
- * @param {BigInt} amount - The amount to use for the created coin.
+ * @param {Vec<Output>} outputs - The output amounts to create.
  * @param {BigInt} fee - The fee to use for the transaction.
  */
-export declare function sendXch(syntheticKey: Buffer, selectedCoins: Array<Coin>, puzzleHash: Buffer, amount: bigint, fee: bigint): Array<CoinSpend>
+export declare function sendXch(syntheticKey: Buffer, selectedCoins: Array<Coin>, outputs: Array<Output>, fee: bigint): Array<CoinSpend>
 /**
  * Adds an offset to a launcher id to make it deterministically unique from the original.
  *
diff --git a/src/lib.rs b/src/lib.rs
index c46df9d..83c42f6 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -726,29 +726,42 @@ pub fn select_coins(all_coins: Vec<Coin>, total_amount: BigInt) -> napi::Result<
         .collect::<Result<Vec<Coin>>>()
 }
 
-/// Sends XCH to a given puzzle hash.
+/// An output puzzle hash and amount.
+#[napi(object)]
+pub struct Output {
+    pub puzzle_hash: Buffer,
+    pub amount: BigInt,
+}
+
+/// Sends XCH to a given set of puzzle hashes.
 ///
 /// @param {Buffer} syntheticKey - The synthetic key used by the wallet.
 /// @param {Vec<Coin>} selectedCoins - Coins to be spent, as retured by `select_coins`.
-/// @param {Buffer} puzzleHash - The puzzle hash to send to.
-/// @param {BigInt} amount - The amount to use for the created coin.
+/// @param {Vec<Output>} outputs - The output amounts to create.
 /// @param {BigInt} fee - The fee to use for the transaction.
 #[napi]
 pub fn send_xch(
     synthetic_key: Buffer,
     selected_coins: Vec<Coin>,
-    puzzle_hash: Buffer,
-    amount: BigInt,
+    outputs: Vec<Output>,
     fee: BigInt,
 ) -> napi::Result<Vec<CoinSpend>> {
+    let mut items = Vec::new();
+
+    for output in outputs {
+        items.push((
+            RustBytes32::from_js(output.puzzle_hash)?,
+            u64::from_js(output.amount)?,
+        ));
+    }
+
     let coin_spends = wallet::send_xch(
         RustPublicKey::from_js(synthetic_key)?,
         &selected_coins
             .into_iter()
             .map(RustCoin::from_js)
             .collect::<Result<Vec<RustCoin>>>()?,
-        RustBytes32::from_js(puzzle_hash)?,
-        u64::from_js(amount)?,
+        &items,
         u64::from_js(fee)?,
     )
     .map_err(js::err)?;
diff --git a/src/wallet.rs b/src/wallet.rs
index 82a2748..007566c 100644
--- a/src/wallet.rs
+++ b/src/wallet.rs
@@ -193,20 +193,25 @@ fn spend_coins_together(
 pub fn send_xch(
     synthetic_key: PublicKey,
     coins: &[Coin],
-    puzzle_hash: Bytes32,
-    amount: u64,
+    outputs: &[(Bytes32, u64)],
     fee: u64,
 ) -> Result<Vec<CoinSpend>, WalletError> {
     let mut ctx = SpendContext::new();
 
+    let mut conditions = Conditions::new().reserve_fee(fee);
+    let mut total_amount = fee;
+
+    for output in outputs {
+        conditions = conditions.create_coin(output.0, output.1, Vec::new());
+        total_amount += output.1;
+    }
+
     spend_coins_together(
         &mut ctx,
         synthetic_key,
         coins,
-        Conditions::new()
-            .create_coin(puzzle_hash, amount, Vec::new())
-            .reserve_fee(fee),
-        (amount + fee).try_into().unwrap(),
+        conditions,
+        total_amount.try_into().unwrap(),
         StandardArgs::curry_tree_hash(synthetic_key).into(),
     )?;