Issue 43 - Need to account for already repaid amount in liquidations

packages/contracts/contracts/LenderCommitmentForwarder/extensions/LenderCommitmentGroup/LenderCommitmentGroup_Smart.sol

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
+
 // Contracts
 import "@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol";
 import "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol";
@@ -434,8 +435,14 @@ contract LenderCommitmentGroup_Smart is
     {
 
          int256 poolTotalEstimatedValueSigned = int256(totalPrincipalTokensCommitted) 
+         //+ int256( totalPrincipalTokensRepaid )   //cant really incorporate because needs totalPrincipalTokensLended to help balance it 
+
          + int256(totalInterestCollected)  + int256(tokenDifferenceFromLiquidations) 
-         - int256(totalPrincipalTokensWithdrawn);
+         - int256( totalPrincipalTokensWithdrawn )
+         //- int256( totalPrincipalTokensLended )  //amount borrowed -- should not be incorporated as it does not really affect net value 
+         ;
+
+
 
         //if the poolTotalEstimatedValue_ is less than 0, we treat it as 0.  
         poolTotalEstimatedValue_ = poolTotalEstimatedValueSigned > int256(0)
@@ -661,7 +668,11 @@ contract LenderCommitmentGroup_Smart is
 
         //use original principal amount as amountDue
 
-        uint256 amountDue = _getAmountOwedForBid(_bidId);
+        uint256 loanTotalPrincipalAmount = _getLoanTotalPrincipalAmount(_bidId);  //only used for the auction delta amount 
+
+        (uint256 principalDue,uint256 interestDue) = _getAmountOwedForBid(_bidId);  //this is the base amount that must be repaid by the liquidator
+
+      //  uint256 principalAmountAlreadyRepaid = loanTotalPrincipalAmount - principalDue;
 
 
         uint256 loanDefaultedTimeStamp = ITellerV2(TELLER_V2)
@@ -673,10 +684,11 @@ contract LenderCommitmentGroup_Smart is
         );
 
         int256 minAmountDifference = getMinimumAmountDifferenceToCloseDefaultedLoan(
-                amountDue,
+                loanTotalPrincipalAmount,
                 loanDefaultedOrUnpausedAtTimeStamp
             );
 
+
         require(
             _tokenAmountDifference >= minAmountDifference,
             "Insufficient tokenAmountDifference"
@@ -687,7 +699,8 @@ contract LenderCommitmentGroup_Smart is
             //this is used when the collateral value is higher than the principal (rare)
             //the loan will be completely made whole and our contract gets extra funds too
             uint256 tokensToTakeFromSender = abs(minAmountDifference);
-
+
+
 
            uint256 liquidationProtocolFee = Math.mulDiv( 
                 tokensToTakeFromSender , 
@@ -699,18 +712,22 @@ contract LenderCommitmentGroup_Smart is
             IERC20(principalToken).safeTransferFrom(
                 msg.sender,
                 address(this),
-                amountDue + tokensToTakeFromSender - liquidationProtocolFee
+                principalDue + tokensToTakeFromSender - liquidationProtocolFee
             ); 
 
             address protocolFeeRecipient = ITellerV2(address(TELLER_V2)).getProtocolFeeRecipient();
 
-              IERC20(principalToken).safeTransferFrom(
-                msg.sender,
-                address(protocolFeeRecipient),
-                 liquidationProtocolFee
-            );
+            if (liquidationProtocolFee > 0) {
+                IERC20(principalToken).safeTransferFrom(
+                    msg.sender,
+                    address(protocolFeeRecipient),
+                    liquidationProtocolFee
+                );
+            }
+
+            totalPrincipalTokensRepaid += principalDue;
 
-            totalPrincipalTokensRepaid += amountDue;
+         //   tokenDifferenceFromLiquidations += int256(principalAmountAlreadyRepaid); //this helps us more correctly calculate the shortfall
             tokenDifferenceFromLiquidations += int256(tokensToTakeFromSender - liquidationProtocolFee );
 
 
@@ -719,33 +736,56 @@ contract LenderCommitmentGroup_Smart is
 
             uint256 tokensToGiveToSender = abs(minAmountDifference);
 
-
-            IERC20(principalToken).safeTransferFrom(
-                msg.sender,
-                address(this),
-                amountDue - tokensToGiveToSender  
-            );
+
+
+               //dont stipend/refund more than principalDue base 
+            if (tokensToGiveToSender > principalDue) {
+                tokensToGiveToSender = principalDue;
+            }
+
+            uint256 netAmountDue =   principalDue - tokensToGiveToSender ;
+
 
-            totalPrincipalTokensRepaid += amountDue;
+            if (netAmountDue > 0) {
+                IERC20(principalToken).safeTransferFrom(
+                    msg.sender,
+                    address(this),
+                    netAmountDue //principalDue - tokensToGiveToSender  
+                );
+            }
+
+            totalPrincipalTokensRepaid += principalDue;
 
             //this will make tokenDifference go more negative
-            tokenDifferenceFromLiquidations -= int256(tokensToGiveToSender);
+
+            //this is the shortfall 
+          //  tokenDifferenceFromLiquidations += int256(principalAmountAlreadyRepaid);//this helps us more correctly calculate the shortfall
+            // tokenDifferenceFromLiquidations -= int256(tokensToGiveToSender);
+
+           //  uint256 shortfallNet = principalDue < tokensToGiveToSender ? tokensToGiveToSender - principalDue  : 0;
+
+              tokenDifferenceFromLiquidations -= int256(tokensToGiveToSender);
+
 
 
         }
 
+        //this will effectively 'forfeit' tokens from this contract equal to ... the amount (principal) that has not been repaid ! principalDue
+
+
         //this will give collateral to the caller
         ITellerV2(TELLER_V2).lenderCloseLoanWithRecipient(_bidId, msg.sender);
 
 
          emit DefaultedLoanLiquidated(
             _bidId,
             msg.sender,
-            amountDue, 
+            principalDue, 
             _tokenAmountDifference
         );
     }
 
+
 
     function getLastUnpausedAt() 
     public view 
@@ -766,18 +806,29 @@ contract LenderCommitmentGroup_Smart is
         lastUnpausedAt =  block.timestamp;
     }
 
+     function _getLoanTotalPrincipalAmount(uint256 _bidId )
+        internal
+        view
+        virtual
+        returns (uint256 principalAmount)
+    {
+        (,,,, principalAmount, , ,  )
+           = ITellerV2(TELLER_V2).getLoanSummary(_bidId);
+
+
+    }
+
 
 
     function _getAmountOwedForBid(uint256 _bidId )
         internal
         view
         virtual
-        returns (uint256 amountDue)
+        returns (uint256 principal,uint256 interest)
     {
-        (,,,, amountDue, , ,  )
-         = ITellerV2(TELLER_V2).getLoanSummary(_bidId);
+        Payment memory owed = ITellerV2(TELLER_V2).calculateAmountOwed(_bidId, block.timestamp );
 
-
+        return (owed.principal, owed.interest) ;
     }
 
 
@@ -966,7 +1017,11 @@ contract LenderCommitmentGroup_Smart is
         public
         view
         returns (uint256)
-    {
+    {   
+        if (totalPrincipalTokensRepaid > totalPrincipalTokensLended) {
+            return 0;
+        }
+
         return totalPrincipalTokensLended - totalPrincipalTokensRepaid;
     }
 

packages/contracts/contracts/mock/TellerV2SolMock.sol

@@ -193,6 +193,8 @@ ILoanRepaymentCallbacks
         );
     }
 
+
+
     /*
      * @notice Calculates the minimum payment amount due for a loan.
      * @param _bidId The id of the loan bid to get the payment amount for.

packages/contracts/tests/SmartCommitmentForwarder/LenderCommitmentGroup_Smart_Liquidations_Tests.sol

@@ -236,7 +236,8 @@ contract LenderCommitmentGroup_Smart_Test is Testable {
         uint256 bidId = 0;
 
 
-       lenderCommitmentGroupSmart.set_mockAmountOwedForBid(amountOwed); 
+       lenderCommitmentGroupSmart.set_mockLoanTotalPrincipalAmount(amountOwed); 
+       lenderCommitmentGroupSmart.set_mockAmountOwedForBid(amountOwed, 0); 
 
 
 
@@ -291,7 +292,8 @@ contract LenderCommitmentGroup_Smart_Test is Testable {
 
      _tellerV2.setMockProtocolFeeRecipient( address(lenderCommitmentGroupSmart)  );
 
-       lenderCommitmentGroupSmart.set_mockAmountOwedForBid(amountOwed); 
+       lenderCommitmentGroupSmart.set_mockLoanTotalPrincipalAmount(amountOwed); 
+       lenderCommitmentGroupSmart.set_mockAmountOwedForBid(amountOwed, 0); 
 
 
         //time has advanced enough to now have a 50 percent discount s
@@ -347,7 +349,9 @@ function test_liquidateDefaultedLoanWithIncentive_increments_amount_repaid_A() p
       lenderCommitmentGroupSmart.set_totalPrincipalTokensCommitted(originalTotalPrincipalTokensCommitted);
 
 
-       lenderCommitmentGroupSmart.set_mockAmountOwedForBid(amountOwed); 
+       lenderCommitmentGroupSmart.set_mockLoanTotalPrincipalAmount(amountOwed); 
+       lenderCommitmentGroupSmart.set_mockAmountOwedForBid(amountOwed, 0); 
+
        _tellerV2.setMockProtocolFeeRecipient( address(lenderCommitmentGroupSmart)  );
 
 
@@ -420,8 +424,8 @@ function test_liquidateDefaultedLoanWithIncentive_increments_amount_repaid_A() p
        _tellerV2.setMockOwner( address(lenderCommitmentGroupSmart)  );
        _tellerV2.setMockProtocolFeeRecipient( address(lenderCommitmentGroupSmart)  );
 
-       lenderCommitmentGroupSmart.set_mockAmountOwedForBid(amountOwed); 
-
+       lenderCommitmentGroupSmart.set_mockLoanTotalPrincipalAmount(amountOwed); 
+       lenderCommitmentGroupSmart.set_mockAmountOwedForBid(amountOwed, 0); 
 
         //time has advanced enough to now have a 50 percent discount s
          vm.warp(1000);   //loanDefaultedTimeStamp ?

packages/contracts/tests/SmartCommitmentForwarder/LenderCommitmentGroup_Smart_Override.sol

@@ -16,7 +16,10 @@ contract LenderCommitmentGroup_Smart_Override is LenderCommitmentGroup_Smart {
     uint256 mockSharesExchangeRate;
     int256 mockMinimumAmountDifferenceToCloseDefaultedLoan;
 
-    uint256 mockAmountOwed;
+    uint256 mockLoanTotalPrincipalAmount;
+
+    uint256 mockAmountOwedPrincipal;
+    uint256 mockAmountOwedInterest;
 
     address mockToken0;
     address mockToken1;
@@ -71,16 +74,28 @@ contract LenderCommitmentGroup_Smart_Override is LenderCommitmentGroup_Smart {
     }
 
     function _getAmountOwedForBid(uint256 _bidId )
-     internal override view returns (uint256){
-        return mockAmountOwed;
+     internal override view returns (uint256, uint256){
+        return (mockAmountOwedPrincipal,mockAmountOwedInterest );
 
      }
 
-    function set_mockAmountOwedForBid(uint256 _amt) public {
-        mockAmountOwed = _amt;
+    function set_mockAmountOwedForBid(uint256 _principal,uint256 _interest) public {
+        mockAmountOwedPrincipal = _principal;
+        mockAmountOwedInterest = _interest;
     }
 
 
+
+     function _getLoanTotalPrincipalAmount(uint256 _bidId )
+     internal override view returns (uint256){
+        return mockLoanTotalPrincipalAmount;
+
+     }
+    function set_mockLoanTotalPrincipalAmount(uint256 _principal) public {
+        mockLoanTotalPrincipalAmount = _principal;
+
+    }
+
     function set_totalPrincipalTokensRepaid(uint256 _mockAmt) public {
         totalPrincipalTokensRepaid = _mockAmt;
     }