prepareInit

primitivefinance · May 6, 2024 · 9a995d9 · 9a995d9
1 parent add319e
commit 9a995d9
Show file tree

Hide file tree

Showing 2 changed files with 27 additions and 4 deletions.
diff --git a/src/RMM.sol b/src/RMM.sol
@@ -117,6 +117,21 @@ contract RMM is ERC20 {
 
     receive() external payable {}
 
+    function prepareInit(uint256 priceX, uint256 amountX, uint256 strike_, uint256 sigma_, uint256 maturity_)
+        public
+        view
+        returns (uint256 totalLiquidity_)
+    {
+        uint256 tau_ = computeTauWadYears(maturity_ - block.timestamp);
+        uint256 initialLiquidity =
+            computeLGivenX({reserveX_: amountX, S: priceX, strike_: strike_, sigma_: sigma_, tau_: tau_});
+
+        console2.log("initialLiquidity", initialLiquidity);
+        uint256 amountY =
+            solveY({reserveX_: amountX, liquidity: initialLiquidity, strike_: strike_, sigma_: sigma_, tau_: tau_});
+        totalLiquidity_ = solveL(initialLiquidity, reserveX, amountY, strike_, sigma_, tau_, tau_);
+    }
+
     /// todo: need a way to compute initial liquidity based on price user input!
     /// @dev Initializes the pool with an implied price via the desired reserves, liquidity, and parameters.
     function init(
@@ -324,7 +339,7 @@ contract RMM is ERC20 {
         view
         returns (uint256 deltaXWad, uint256 deltaYWad, uint256 lptBurned)
     {
-        uint liquidity = totalLiquidity;
+        uint256 liquidity = totalLiquidity;
         deltaXWad = deltaLiquidity.mulDivDown(reserveX, liquidity);
         deltaYWad = deltaLiquidity.mulDivDown(reserveY, liquidity);
         lptBurned = deltaLiquidity.mulDivUp(totalSupply, liquidity);
@@ -338,7 +353,7 @@ contract RMM is ERC20 {
         lock
         returns (uint256 deltaX, uint256 deltaY)
     {
-        (uint256 deltaXWad, uint256 deltaYWad, uint lptBurned) = prepareDeallocate(deltaLiquidity);
+        (uint256 deltaXWad, uint256 deltaYWad, uint256 lptBurned) = prepareDeallocate(deltaLiquidity);
         (deltaX, deltaY) = (downscaleDown(deltaXWad, scalar(tokenX)), downscaleDown(deltaYWad, scalar(tokenY)));
 
         if (minDeltaXOut > deltaX) {

diff --git a/test/RMM.t.sol b/test/RMM.t.sol
@@ -482,12 +482,20 @@ contract RMMTest is Test {
         tokenX.approve(address(subject()), basicParams.reserveX);
         tokenY.approve(address(subject()), basicParams.reserveY);
 
+        uint256 totalLiquidity = subject().prepareInit({
+            priceX: 1 ether,
+            amountX: basicParams.reserveX,
+            strike_: basicParams.strike,
+            sigma_: basicParams.sigma,
+            maturity_: basicParams.maturity
+        });
+
         subject().init(
             address(tokenX),
             address(tokenY),
             basicParams.reserveX,
             basicParams.reserveY,
-            basicParams.totalLiquidity,
+            totalLiquidity,
             basicParams.strike,
             basicParams.sigma,
             basicParams.fee,
@@ -499,7 +507,7 @@ contract RMMTest is Test {
         assertEq(subject().tokenY(), address(tokenY), "Token Y address is not correct.");
         assertEq(subject().reserveX(), basicParams.reserveX, "Reserve X is not correct.");
         assertEq(subject().reserveY(), basicParams.reserveY, "Reserve Y is not correct.");
-        assertEq(subject().totalLiquidity(), basicParams.totalLiquidity, "Total liquidity is not correct.");
+        assertEq(subject().totalLiquidity(), totalLiquidity, "Total liquidity is not correct.");
         assertEq(subject().strike(), basicParams.strike, "Strike is not correct.");
         assertEq(subject().sigma(), basicParams.sigma, "Sigma is not correct.");
         assertEq(subject().fee(), basicParams.fee, "Fee is not correct.");