From 12c6d3ae22b7378280d6fed6c675281761bc092d Mon Sep 17 00:00:00 2001
From: Denis Fadeev <denis@fadeev.org>
Date: Mon, 9 Oct 2023 20:55:52 +0300
Subject: [PATCH] feat: make swap example compatible with Bitcoin (#63)

---
 omnichain/swap/contracts/Swap.sol | 39 ++++++++++++++++++++++++++++---
 omnichain/swap/package.json       |  2 +-
 omnichain/swap/tasks/interact.ts  |  9 ++++---
 omnichain/swap/yarn.lock          |  8 +++----
 4 files changed, 47 insertions(+), 11 deletions(-)

diff --git a/omnichain/swap/contracts/Swap.sol b/omnichain/swap/contracts/Swap.sol
index 56a2749a..68393a44 100644
--- a/omnichain/swap/contracts/Swap.sol
+++ b/omnichain/swap/contracts/Swap.sol
@@ -5,11 +5,15 @@ import "@zetachain/protocol-contracts/contracts/zevm/SystemContract.sol";
 import "@zetachain/protocol-contracts/contracts/zevm/interfaces/zContract.sol";
 
 import "@zetachain/toolkit/contracts/SwapHelperLib.sol";
+import "@zetachain/toolkit/contracts/BytesHelperLib.sol";
 
 contract Swap is zContract {
     error SenderNotSystemContract();
+    error WrongGasContract();
+    error NotEnoughToPayGasFee();
 
     SystemContract public immutable systemContract;
+    uint256 constant BITCOIN = 18332;
 
     constructor(address systemContractAddress) {
         systemContract = SystemContract(systemContractAddress);
@@ -24,8 +28,29 @@ contract Swap is zContract {
         if (msg.sender != address(systemContract)) {
             revert SenderNotSystemContract();
         }
-        (address targetZRC20, bytes32 recipient, uint256 minAmountOut) = abi
-            .decode(message, (address, bytes32, uint256));
+
+        uint32 targetChainID;
+        bytes memory recipient;
+        uint256 minAmountOut;
+
+        if (context.chainID == BITCOIN) {
+            targetChainID = BytesHelperLib.bytesToUint32(message, 0);
+            recipient = BytesHelperLib.bytesToBech32Bytes(message, 4);
+        } else {
+            (
+                uint32 targetChainID_,
+                bytes32 recipient_,
+                uint256 minAmountOut_
+            ) = abi.decode(message, (uint32, bytes32, uint256));
+            targetChainID = targetChainID_;
+            recipient = abi.encodePacked(recipient_);
+            minAmountOut = minAmountOut_;
+        }
+
+        address targetZRC20 = systemContract.gasCoinZRC20ByChainId(
+            targetChainID
+        );
+
         uint256 outputAmount = SwapHelperLib._doSwap(
             systemContract.wZetaContractAddress(),
             systemContract.uniswapv2FactoryAddress(),
@@ -35,6 +60,14 @@ contract Swap is zContract {
             targetZRC20,
             minAmountOut
         );
-        SwapHelperLib._doWithdrawal(targetZRC20, outputAmount, recipient);
+
+        (address gasZRC20, uint256 gasFee) = IZRC20(targetZRC20)
+            .withdrawGasFee();
+
+        if (gasZRC20 != targetZRC20) revert WrongGasContract();
+        if (gasFee >= outputAmount) revert NotEnoughToPayGasFee();
+
+        IZRC20(targetZRC20).approve(targetZRC20, gasFee);
+        IZRC20(targetZRC20).withdraw(recipient, outputAmount - gasFee);
     }
 }
diff --git a/omnichain/swap/package.json b/omnichain/swap/package.json
index bbf17fb5..cc4e7460 100644
--- a/omnichain/swap/package.json
+++ b/omnichain/swap/package.json
@@ -27,7 +27,7 @@
     "@types/node": ">=12.0.0",
     "@typescript-eslint/eslint-plugin": "^5.59.9",
     "@typescript-eslint/parser": "^5.59.9",
-    "@zetachain/toolkit": "^2.1.2",
+    "@zetachain/toolkit": "^2.2.4",
     "axios": "^1.3.6",
     "chai": "^4.2.0",
     "dotenv": "^16.0.3",
diff --git a/omnichain/swap/tasks/interact.ts b/omnichain/swap/tasks/interact.ts
index 22705099..64655a91 100644
--- a/omnichain/swap/tasks/interact.ts
+++ b/omnichain/swap/tasks/interact.ts
@@ -9,13 +9,16 @@ const main = async (args: any, hre: HardhatRuntimeEnvironment) => {
   const [signer] = await hre.ethers.getSigners();
   console.log(`🔑 Using account: ${signer.address}\n`);
 
-  const targetZRC20 = getAddress("zrc20", args.destination);
+  const targetChainID = hre.config.networks[args.destination]?.chainId;
+  if (targetChainID === undefined) {
+    throw new Error("Invalid destination network");
+  }
   const minAmountOut = BigNumber.from("0");
 
   const data = prepareData(
     args.contract,
-    ["address", "bytes32", "uint256"],
-    [targetZRC20, args.recipient, minAmountOut]
+    ["uint32", "bytes32", "uint256"],
+    [targetChainID, args.recipient, minAmountOut]
   );
   const to = getAddress("tss", hre.network.name as any);
   const value = parseEther(args.amount);
diff --git a/omnichain/swap/yarn.lock b/omnichain/swap/yarn.lock
index 4f204992..46dd45e2 100644
--- a/omnichain/swap/yarn.lock
+++ b/omnichain/swap/yarn.lock
@@ -1690,10 +1690,10 @@
   resolved "https://registry.yarnpkg.com/@zetachain/protocol-contracts/-/protocol-contracts-2.1.0.tgz#775b4eee7c85d115232dece121cbfc798fde6b63"
   integrity sha512-xmG6p8DizIk0h7Tr8Lt6UMG0ejrfRrPx0qH9ze3enwblo7W+eGP12oQ7djanYu50B0pNhh9z7xy/IYxKa9wD0Q==
 
-"@zetachain/toolkit@^2.1.2":
-  version "2.1.2"
-  resolved "https://registry.yarnpkg.com/@zetachain/toolkit/-/toolkit-2.1.2.tgz#f83b57d323eab2f54961565b8bd15279eab964e7"
-  integrity sha512-eKZDUKWCf/h5RRvQsP0rG2qB0kKaw9GvpSylZwetx8+NckhKwQi52sUisX7sjHVqjDziTSdsagkrl4HmiPJ0pQ==
+"@zetachain/toolkit@^2.2.4":
+  version "2.2.4"
+  resolved "https://registry.yarnpkg.com/@zetachain/toolkit/-/toolkit-2.2.4.tgz#4c80d160fdac1ebe9058c4f626934056476982f7"
+  integrity sha512-njh+owCjXAMe3PVvgm/5zIjErUqx87M/SciJXolAHYnbnKm85/gVwyguQu3mpHFQ5sIYBU2YN/W7HoMn6kVG1g==
   dependencies:
     "@inquirer/prompts" "^2.1.1"
     "@inquirer/select" "1.1.3"