From dfa318b8c0944f7755152ef491050881f10e3a26 Mon Sep 17 00:00:00 2001
From: chris <leosameric@gmail.com>
Date: Wed, 13 Nov 2024 15:46:27 +1000
Subject: [PATCH] feat: Layerzero airdrop native gas

---
 .../src/layerZero/index.ts                    | 30 ++++++++++++++-----
 .../src/layerZero/types/index.ts              |  4 +++
 2 files changed, 26 insertions(+), 8 deletions(-)

diff --git a/packages/canonical-bridge-sdk/src/layerZero/index.ts b/packages/canonical-bridge-sdk/src/layerZero/index.ts
index a441c588..b0e5eff1 100644
--- a/packages/canonical-bridge-sdk/src/layerZero/index.ts
+++ b/packages/canonical-bridge-sdk/src/layerZero/index.ts
@@ -33,13 +33,22 @@ export class LayerZero {
     walletClient,
     gasAmount = 200000n,
     version = 1,
+    airDropGas = 0n,
+    dstAddress = '0x',
   }: ISendCakeTokenInput): Promise<Hash> {
     try {
       const address32Bytes = pad(userAddress, { size: 32 });
-      const adapterParams = encodePacked(
-        ['uint16', 'uint256'],
-        [version, gasAmount]
-      );
+      /* version 1 - send token
+       * version 2 - send token and air drop native gas on destination chain
+       * https://docs.layerzero.network/v1/developers/evm/evm-guides/advanced/relayer-adapter-parameters#airdrop
+       */
+      const adapterParams =
+        version === 1
+          ? encodePacked(['uint16', 'uint256'], [version, gasAmount])
+          : encodePacked(
+              ['uint16', 'uint', 'uint', 'address'],
+              [2, gasAmount, airDropGas, dstAddress]
+            );
       const fees = await publicClient.readContract({
         address: bridgeAddress,
         abi: CAKE_PROXY_OFT_ABI,
@@ -109,13 +118,18 @@ export class LayerZero {
     publicClient,
     gasAmount = 200000n,
     version = 1,
+    airDropGas = 0n,
+    dstAddress = '0x',
   }: IGetEstimateFeeInput) {
     try {
       const address32Bytes = pad(userAddress, { size: 32 });
-      const adapterParams = encodePacked(
-        ['uint16', 'uint256'],
-        [version, gasAmount]
-      );
+      const adapterParams =
+        version === 1
+          ? encodePacked(['uint16', 'uint256'], [version, gasAmount])
+          : encodePacked(
+              ['uint16', 'uint', 'uint', 'address'],
+              [2, gasAmount, airDropGas, dstAddress]
+            );
       const fees = await publicClient.readContract({
         address: bridgeAddress,
         abi: CAKE_PROXY_OFT_ABI,
diff --git a/packages/canonical-bridge-sdk/src/layerZero/types/index.ts b/packages/canonical-bridge-sdk/src/layerZero/types/index.ts
index de081be1..915e3672 100644
--- a/packages/canonical-bridge-sdk/src/layerZero/types/index.ts
+++ b/packages/canonical-bridge-sdk/src/layerZero/types/index.ts
@@ -11,6 +11,8 @@ export interface ISendCakeTokenInput {
   version?: number;
   publicClient: PublicClient;
   walletClient: WalletClient;
+  dstAddress?: `0x${string}`;
+  airDropGas?: bigint;
 }
 
 export interface IGetEstimateFeeInput {
@@ -21,6 +23,8 @@ export interface IGetEstimateFeeInput {
   gasAmount?: bigint;
   version?: number;
   publicClient: PublicClient;
+  dstAddress?: `0x${string}`;
+  airDropGas?: bigint;
 }
 
 export interface LayerZeroToken {