Remove fees (borrow and redeem) and SP logic for LQTY and front ends

contracts/src/BoldToken.sol

@@ -46,6 +46,8 @@ contract BoldToken is CheckContract, IBoldToken {
 
  mapping (address => uint256) private _nonces;
 
+ uint256 public deploymentStartTime;
+
  // User data for Bold token
  mapping (address => uint256) private _balances;
  mapping (address => mapping (address => uint256)) private _allowances; 
@@ -88,6 +90,8 @@ contract BoldToken is CheckContract, IBoldToken {
  _HASHED_VERSION = hashedVersion;
  _CACHED_CHAIN_ID = _chainID();
  _CACHED_DOMAIN_SEPARATOR = _buildDomainSeparator(_TYPE_HASH, hashedName, hashedVersion);
+
+ deploymentStartTime = block.timestamp;
  }
 
  // --- Functions for intra-Liquity calls ---

contracts/src/BorrowerOperations.sol

@@ -165,8 +165,7 @@ contract BorrowerOperations is LiquityBase, Ownable, CheckContract, IBorrowerOpe
  vars.netDebt = _boldAmount;
 
  if (!isRecoveryMode) {
- vars.BoldFee = _triggerBorrowingFee(contractsCache.troveManager, contractsCache.boldToken, _boldAmount, _maxFeePercentage);
- vars.netDebt = vars.netDebt + vars.BoldFee;
+ // TODO: implement interest rate charges
  }
  _requireAtLeastMinNetDebt(vars.netDebt);
 
@@ -271,8 +270,7 @@ contract BorrowerOperations is LiquityBase, Ownable, CheckContract, IBorrowerOpe
 
  // If the adjustment incorporates a debt increase and system is in Normal Mode, then trigger a borrowing fee
  if (_isDebtIncrease && !isRecoveryMode) { 
- vars.BoldFee = _triggerBorrowingFee(contractsCache.troveManager, contractsCache.boldToken, _boldChange, _maxFeePercentage);
- vars.netDebtChange = vars.netDebtChange + vars.BoldFee; // The raw debt change includes the fee
+ // TODO: implement interest rate charges
  }
 
  vars.debt = contractsCache.troveManager.getTroveDebt(_borrower);
@@ -358,19 +356,6 @@ contract BorrowerOperations is LiquityBase, Ownable, CheckContract, IBorrowerOpe
 
  // --- Helper functions ---
 
- function _triggerBorrowingFee(ITroveManager _troveManager, IBoldToken _boldToken, uint _boldAmount, uint _maxFeePercentage) internal returns (uint) {
- _troveManager.decayBaseRateFromBorrowing(); // decay the baseRate state variable
- uint BoldFee = _troveManager.getBorrowingFee(_boldAmount);
-
- _requireUserAcceptsFee(BoldFee, _boldAmount, _maxFeePercentage);
-
- // Send fee to LQTY staking contract
- lqtyStaking.increaseF_bold(BoldFee);
- _boldToken.mint(lqtyStakingAddress, BoldFee);
-
- return BoldFee;
- }
-
  function _getUSDValue(uint _coll, uint _price) internal pure returns (uint) {
  uint usdValue = _price * _coll / DECIMAL_PRECISION;
 

contracts/src/Interfaces/IBoldToken.sol

@@ -6,6 +6,8 @@ import "../Dependencies/IERC20.sol";
 import "../Dependencies/IERC2612.sol";
 
 interface IBoldToken is IERC20, IERC2612 { 
+ function deploymentStartTime() external view returns (uint256);
+
  function mint(address _account, uint256 _amount) external;
 
  function burn(address _account, uint256 _amount) external;

contracts/src/Interfaces/IStabilityPool.sol

@@ -27,18 +27,7 @@ import "./ITroveManager.sol";
  * Please see the implementation spec in the proof document, which closely follows on from the compounded deposit / ETH gain derivations:
  * https://github.com/liquity/liquity/blob/master/papers/Scalable_Reward_Distribution_with_Compounding_Stakes.pdf
  *
- * --- LQTY ISSUANCE TO STABILITY POOL DEPOSITORS ---
- *
- * An LQTY issuance event occurs at every deposit operation, and every liquidation.
- *
- * Each deposit is tagged with the address of the front end through which it was made.
- *
- * All deposits earn a share of the issued LQTY in proportion to the deposit as a share of total deposits. The LQTY earned
- * by a given deposit, is split between the depositor and the front end through which the deposit was made, based on the front end's kickbackRate.
- *
- * Please see the system Readme for an overview:
- * https://github.com/liquity/dev/blob/main/README.md#lqty-issuance-to-stability-providers
- */
+*/
 interface IStabilityPool is ILiquityBase {
  function borrowerOperations() external view returns (IBorrowerOperations);
  function boldToken() external view returns (IBoldToken);
@@ -54,64 +43,34 @@ interface IStabilityPool is ILiquityBase {
  address _activePoolAddress,
  address _boldTokenAddress,
  address _sortedTrovesAddress,
- address _priceFeedAddress,
- address _communityIssuanceAddress
+ address _priceFeedAddress
  ) external;
-
- /*
- * Initial checks:
- * - Frontend is registered or zero address
- * - Sender is not a registered frontend
- * - _amount is not zero
- * ---
- * - Triggers a LQTY issuance, based on time passed since the last issuance. The LQTY issuance is shared between *all* depositors and front ends
- * - Tags the deposit with the provided front end tag param, if it's a new deposit
- * - Sends depositor's accumulated gains (LQTY, ETH) to depositor
- * - Sends the tagged front end's accumulated LQTY gains to the tagged front end
- * - Increases deposit and tagged front end's stake, and takes new snapshots for each.
- */
- function provideToSP(uint _amount, address _frontEndTag) external;
-
- /*
- * Initial checks:
- * - _amount is zero or there are no under collateralized troves left in the system
- * - User has a non zero deposit
- * ---
- * - Triggers a LQTY issuance, based on time passed since the last issuance. The LQTY issuance is shared between *all* depositors and front ends
- * - Removes the deposit's front end tag if it is a full withdrawal
- * - Sends all depositor's accumulated gains (LQTY, ETH) to depositor
- * - Sends the tagged front end's accumulated LQTY gains to the tagged front end
- * - Decreases deposit and tagged front end's stake, and takes new snapshots for each.
- *
- * If _amount > userDeposit, the user withdraws all of their compounded deposit.
- */
+
+ /* provideToSP():
+ * - Calculates depositor's ETH gain
+ * - Calculates the compounded deposit
+ * - Increases deposit, and takes new snapshots of accumulators P and S
+ * - Sends depositor's accumulated ETH gains to depositor
+ */
+ function provideToSP(uint _amount) external;
+
+
+ /* withdrawFromSP():
+ * - Calculates depositor's ETH gain
+ * - Calculates the compounded deposit
+ * - Sends the requested BOLD withdrawal to depositor 
+ * - (If _amount > userDeposit, the user withdraws all of their compounded deposit)
+ * - Decreases deposit by withdrawn amount and takes new snapshots of accumulators P and S
+ */
  function withdrawFromSP(uint _amount) external;
 
- /*
- * Initial checks:
- * - User has a non zero deposit
- * - User has an open trove
- * - User has some ETH gain
- * ---
- * - Triggers a LQTY issuance, based on time passed since the last issuance. The LQTY issuance is shared between *all* depositors and front ends
- * - Sends all depositor's LQTY gain to depositor
- * - Sends all tagged front end's LQTY gain to the tagged front end
- * - Transfers the depositor's entire ETH gain from the Stability Pool to the caller's trove
- * - Leaves their compounded deposit in the Stability Pool
- * - Updates snapshots for deposit and tagged front end stake
- */
+ /* withdrawETHGainToTrove():
+ * - Transfers the depositor's entire ETH gain from the Stability Pool to the caller's trove
+ * - Leaves their compounded deposit in the Stability Pool
+ * - Takes new snapshots of accumulators P and S 
+ */
  function withdrawETHGainToTrove(address _upperHint, address _lowerHint) external;
 
- /*
- * Initial checks:
- * - Frontend (sender) not already registered
- * - User (sender) has no deposit
- * - _kickbackRate is in the range [0, 100%]
- * ---
- * Front end makes a one-time selection of kickback rate upon registering
- */
- function registerFrontEnd(uint _kickbackRate) external;
-
  /*
  * Initial checks:
  * - Caller is TroveManager
@@ -138,31 +97,11 @@ interface IStabilityPool is ILiquityBase {
  */
  function getDepositorETHGain(address _depositor) external view returns (uint);
 
- /*
- * Calculate the LQTY gain earned by a deposit since its last snapshots were taken.
- * If not tagged with a front end, the depositor gets a 100% cut of what their deposit earned.
- * Otherwise, their cut of the deposit's earnings is equal to the kickbackRate, set by the front end through
- * which they made their deposit.
- */
- function getDepositorLQTYGain(address _depositor) external view returns (uint);
-
- /*
- * Return the LQTY gain earned by the front end.
- */
- function getFrontEndLQTYGain(address _frontEnd) external view returns (uint);
-
  /*
  * Return the user's compounded deposit.
  */
  function getCompoundedBoldDeposit(address _depositor) external view returns (uint);
 
- /*
- * Return the front end's compounded stake.
- *
- * The front end's compounded stake is equal to the sum of its depositors' compounded deposits.
- */
- function getCompoundedFrontEndStake(address _frontEnd) external view returns (uint);
-
  /*
  * Fallback function
  * Only callable by Active Pool, it just accounts for ETH received

contracts/src/Interfaces/ITroveManager.sol

@@ -33,6 +33,8 @@ interface ITroveManager is ILiquityBase {
  function sortedTroves() external view returns(ISortedTroves);
  function borrowerOperationsAddress() external view returns (address);
 
+ function BOOTSTRAP_PERIOD() external view returns (uint256);
+
  function getTroveOwnersCount() external view returns (uint);
 
  function getTroveFromTroveOwnersArray(uint _index) external view returns (address);