feat: Add source and destination portal ERC20s, and a minting and bur…

…ning mechanism

src/Portal.sol → src/DestinationPortal.sol

@@ -4,16 +4,15 @@ pragma solidity 0.8.24;
 import { OFT } from "@layerzerolabs/oft-evm/contracts/OFT.sol";
 import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
 
-contract MyOFT is OFT {
+contract DestinationPortal is OFT {
     uint8 private constant DECIMALS = 6;
 
     constructor(
-        string memory _name,
-        string memory _symbol,
-        address _lzEndpoint
+        address _lzEndpoint,
+        address _globalOwner
     )
-        OFT(_name, _symbol, _lzEndpoint, _delegate)
-        Ownable(msg.sender)
+        OFT("Portal", "PORTAL", _lzEndpoint, _globalOwner)
+        Ownable(_globalOwner)
     { }
 
     function decimals() public pure override returns (uint8) {

src/MultiAssetVault.sol

@@ -9,22 +9,23 @@ import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.s
 import { IAssetRegistry } from "./interfaces/IAssetRegistry.sol";
 import { IMultiAssetVault } from "./interfaces/IMultiAssetVault.sol";
 
-import { IPortal } from "./interfaces/IPortal.sol";
 import { IPythOracle } from "./interfaces/IPythOracle.sol";
+import { ISourcePortal } from "./interfaces/ISourcePortal.sol";
 
 contract MultiAssetVault is IMultiAssetVault {
     using SafeERC20 for IERC20;
 
     IAssetRegistry private immutable i_assetRegistry;
     IPythOracle private immutable i_pythOracle;
-    IPortal private immutable i_portal;
+    ISourcePortal private immutable i_sourcePortal;
     mapping(address user => mapping(address asset => Position position)) private s_positions;
 
-    constructor(address _assetRegistry, address _pythOracle) {
+    constructor(address _assetRegistry, address _pythOracle, address _sourcePortal) {
         if (_assetRegistry == address(0) || _pythOracle == address(0)) revert MultiAssetVault__AddressZero();
 
         i_assetRegistry = IAssetRegistry(_assetRegistry);
         i_pythOracle = IPythOracle(_pythOracle);
+        i_sourcePortal = ISourcePortal(_sourcePortal);
     }
 
     function depositCollateral(address _asset, uint256 _amount, address _for) external {
@@ -55,9 +56,33 @@ contract MultiAssetVault is IMultiAssetVault {
         emit AmountWithdrawn(msg.sender, _asset, _amount, _to);
     }
 
-    function mint() external { }
+    function mint(address _asset, uint256 _amount, address _to) external {
+        _revertIfAssetNotWhitelisted(_asset);
+        if (_amount == 0) revert MultiAssetVault__AmountZero();
+        if (_to == address(0)) revert MultiAssetVault__AddressZero();
+
+        Position memory position = s_positions[msg.sender][_asset];
+        position.amountMinted += _amount;
+        s_positions[msg.sender][_asset] = position;
+
+        if (!_isPositionHealthy(_asset, position)) revert MultiAssetVault__MinimumCollateralisationRatioBreached();
+        i_sourcePortal.mint(_to, _amount);
+
+        emit PortalMinted(msg.sender, _asset, _amount, _to);
+    }
 
-    function burn() external { }
+    function burn(address _asset, uint256 _amount) external {
+        _revertIfAssetNotWhitelisted(_asset);
+        if (_amount == 0) revert MultiAssetVault__AmountZero();
+
+        Position memory position = s_positions[msg.sender][_asset];
+        position.amountMinted -= _amount;
+        s_positions[msg.sender][_asset] = position;
+
+        i_sourcePortal.burn(msg.sender, _amount);
+
+        emit PortalBurned(msg.sender, _asset, _amount);
+    }
 
     function _revertIfAssetNotWhitelisted(address _asset) internal view {
         if (!i_assetRegistry.isAssetWhitelisted(_asset)) revert MultiAssetVault__AssetNotWhitelisted(_asset);
@@ -75,7 +100,7 @@ contract MultiAssetVault is IMultiAssetVault {
     function _getCollateralisationRatio(address _asset, Position memory _position) internal view returns (uint256) {
         if (_position.amountMinted == 0) return type(uint256).max;
         return _getDepositedAmountValueInUsd(_asset, _position.amountDeposited)
-            * 10 ** IERC20Metadata(address(i_portal)).decimals() / _position.amountMinted;
+            * 10 ** IERC20Metadata(address(i_sourcePortal)).decimals() / _position.amountMinted;
     }
 
     function _getDepositedAmountValueInUsd(address _asset, uint256 _depositedAmount) internal view returns (uint256) {

src/SourcePortal.sol

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.24;
+
+import { OFT } from "@layerzerolabs/oft-evm/contracts/OFT.sol";
+import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
+
+import { ISourcePortal } from "./interfaces/ISourcePortal.sol";
+
+contract SourcePortal is OFT, ISourcePortal {
+    uint8 private constant DECIMALS = 6;
+
+    address private immutable i_multiAssetVault;
+
+    modifier onlyMultiAssetVault() {
+        if (msg.sender != i_multiAssetVault) revert SourcePortal__NotMultiAssetVault(msg.sender, i_multiAssetVault);
+        _;
+    }
+
+    constructor(
+        address _lzEndpoint,
+        address _globalOwner,
+        address _multiAssetVault
+    )
+        OFT("Portal", "PORTAL", _lzEndpoint, _globalOwner)
+        Ownable(_globalOwner)
+    {
+        i_multiAssetVault = _multiAssetVault;
+    }
+
+    function mint(address _to, uint256 _amount) external onlyMultiAssetVault {
+        _mint(_to, _amount);
+    }
+
+    function burn(address _to, uint256 _amount) external onlyMultiAssetVault {
+        _burn(_to, _amount);
+    }
+
+    function decimals() public pure override returns (uint8) {
+        return DECIMALS;
+    }
+}

src/interfaces/IMultiAssetVault.sol

@@ -9,6 +9,8 @@ interface IMultiAssetVault {
 
     event AmountDeposited(address by, address indexed asset, uint256 indexed amount, address indexed onBehalfOf);
     event AmountWithdrawn(address indexed by, address indexed asset, uint256 indexed amount, address to);
+    event PortalMinted(address indexed by, address indexed asset, uint256 indexed amount, address to);
+    event PortalBurned(address indexed by, address indexed asset, uint256 indexed amount);
 
     error MultiAssetVault__AddressZero();
     error MultiAssetVault__AssetNotWhitelisted(address asset);

src/interfaces/ISourcePortal.sol

@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.24;
+
+interface ISourcePortal {
+    error SourcePortal__NotMultiAssetVault(address caller, address multiAssetVault);
+
+    function mint(address _to, uint256 _amount) external;
+
+    function burn(address _to, uint256 _amount) external;
+}