Smartcontract add nullifier, update contract to last circuit

contracts/Miksi.sol

@@ -8,52 +8,58 @@ contract Miksi {
   constructor( address _verifierContractAddr) public {
     verifier = Verifier(_verifierContractAddr);
   }
-
-  mapping(uint256 => Deposit) deposits;
-
-  struct Deposit {
-    uint256 coinCode;
-    uint256 amount;
-    bool used;
-  }
+  uint256 amount = uint256(1000000000000000000);
+  uint256 root;
+  uint256[] commitments;
+  mapping(uint256 => bool) nullifiers;
 
   function deposit(
-            uint256 coinCode,
-            // uint256 amount,
-            uint256 commitment
+            uint256 _commitment,
+            uint256 _root
   ) public payable {
-    deposits[commitment] = Deposit(coinCode, msg.value, false);
+    // TODO check root state transition update with zkp
+
+    require(msg.value==amount, "value should be 1 ETH"); // this can be flexible with a wrapper with preset fixed amounts
+    commitments.push(_commitment);
+    root = _root;
   }
 
-  function getDeposit(
-            uint256 commitment
-  ) public view returns (uint256, uint256) {
-    return (
-      deposits[commitment].coinCode,
-      deposits[commitment].amount
-    );
+  function getCommitments() public view returns (uint256[] memory, uint256) {
+    return (commitments, root);
   }
 
   function withdraw(
-            uint256 commitment,
             address payable _address,
+            uint256 nullifier,
             uint[2] memory a,
             uint[2][2] memory b,
             uint[2] memory c
   ) public {
 
-    uint256[4] memory input = [
-      deposits[commitment].coinCode,
-      deposits[commitment].amount,
-      commitment,
+    uint256[5] memory input = [
+      0,
+      amount,
+      nullifier,
+      root,
       uint256(_address)
     ];
     require(verifier.verifyProof(a, b, c, input), "zkProof withdraw could not be verified");
-    // zk verification passed, proceed with the withdraw
-    require(!deposits[commitment].used, "deposit already withdrawed");
-    deposits[commitment].used = true;
-    _address.send(deposits[commitment].amount);
-    // _address.call.value(deposits[commitment].amount).gas(20317)();
+    // zk verification passed
+    require(useNullifier(nullifier), "nullifier already used");
+    // nullifier check passed
+    // proceed with the withdraw
 
+    _address.send(amount);
+    // _address.call.value(amount).gas(20317)();
+  }
+
+  function useNullifier(
+    uint256 nullifier
+  ) internal returns (bool) {
+    if (nullifiers[nullifier]) {
+      return false;
+    }
+    nullifiers[nullifier] = true;
+    return true;
   }
 }