TLC pre-requisites

protocol/contracts/common/CommonEventsAndErrors.sol

@@ -2,19 +2,12 @@ pragma solidity ^0.8.17;
 // SPDX-License-Identifier: AGPL-3.0-or-later
 // Temple (common/CommonEventsAndErrors.sol)
 
-// @todo check which ones we've used.
-
 /// @notice A collection of common errors thrown within the Temple contracts
 library CommonEventsAndErrors {
     error InsufficientBalance(address token, uint256 required, uint256 balance);
-    error InvalidToken(address token);
     error InvalidParam();
     error InvalidAddress(address addr);
-    error InvalidAmount(address token, uint256 amount);
     error InvalidAccess();
     error ExpectedNonZero();
-    error Slippage(uint256 minAmountExpected, uint256 acutalAmount);
-    error IsPaused();
-    error UnknownExecuteError(bytes returndata);
     event TokenRecovered(address indexed to, address indexed token, uint256 amount);
 }

protocol/contracts/interfaces/v2/ITreasuryReservesVault.sol

@@ -30,10 +30,11 @@ interface ITreasuryReservesVault is ITempleElevatedAccess {
     event StrategyShutdown(address indexed strategy, uint256 stablesRecovered, uint256 debtBurned);
     event BaseStrategySet(address indexed baseStrategy);
 
-    event Borrow(address indexed strategy, uint256 stablesAmount);
-    event Repay(address indexed strategy, uint256 stablesAmount);
+    event Borrow(address indexed strategy, address indexed recipient, uint256 stablesAmount);
+    event Repay(address indexed strategy, address indexed from, uint256 stablesAmount);
     event RealisedGain(address indexed strategy, uint256 amount);
     event RealisedLoss(address indexed strategy, uint256 amount);
+    event TreasuryPriceIndexSet(uint256 oldTpi, uint256 newTpi);
 
     error NotEnabled();
     error AlreadyEnabled();
@@ -113,6 +114,22 @@ interface ITreasuryReservesVault is ITempleElevatedAccess {
      */
     function setBaseStrategy(address _baseStrategy) external;
 
+    /**
+     * @notice The Treasury Price Index, used within strategies.
+     */
+    function treasuryPriceIndex() external view returns (uint256);
+
+    /**
+     * @notice The decimal precision of 'tpi'/Temple Price index
+     * @dev Decimal precision for 'tpi', 9880 == $0.988, precision = 4
+     */
+    function TPI_DECIMALS() external view returns (uint256);
+
+    /**
+     * @notice Set the Treasury Price Index (TPI)
+     */
+    function setTreasuryPriceIndex(uint256 value) external;
+
     /**
      * API version to help with future integrations/migrations
      */
@@ -151,21 +168,30 @@ interface ITreasuryReservesVault is ITempleElevatedAccess {
     );
 
     /**
-     * @notice The total available stables, both as a balance in this contract and
-     * any available to withdraw from the baseStrategy
+     * @notice The current max debt ceiling that a strategy is allowed to borrow up to.
      */
-    function totalAvailableStables() external view returns (uint256);
+    function strategyDebtCeiling(address strategy) external view returns (uint256);
 
     /**
-     * @notice The current dUSD debt of this strategy
+     * @notice The total available stables, both as a balance in this contract and
+     * any available to withdraw from the baseStrategy
      */
-    function currentStrategyDebt(address strategy) external view returns (uint256);
+    function totalAvailableStables() external view returns (uint256);
 
     /**
-     * @notice How much a given strategy is free to borrow
-     * @dev availableToBorrow = max(debtCeiling - debtBalance, 0);
+     * @notice A strategy's current amount borrowed, and how much remaining is free to borrow
+     * @dev The remaining amount free to borrow is bound by:
+     *   1/ How much stables is globally available (in this contract + in the base strategy)
+     *   2/ The amount each individual strategy is whitelisted to borrow.
+     * @return currentDebt The current debt position for the strategy, 
+     * @return availableToBorrow The remaining amount which the strategy can borrow
+     * @return debtCeiling The debt ceiling of the stratgy
      */
-    function availableToBorrow(address strategy) external view returns (uint256);
+    function strategyBorrowPosition(address strategy) external view returns (
+        uint256 currentDebt, 
+        uint256 availableToBorrow,
+        uint256 debtCeiling
+    );
 
     /**
      * Pause all strategy borrow and repays
@@ -209,26 +235,26 @@ interface ITreasuryReservesVault is ITempleElevatedAccess {
      * @dev This will revert if the strategy requests more stables than it's able to borrow.
      * `dUSD` will be minted 1:1 for the amount of stables borrowed
      */
-    function borrow(uint256 borrowAmount) external;
+    function borrow(uint256 borrowAmount, address recipient) external;
 
     /**
      * @notice A strategy calls to request the most funding it can.
      * @dev This will revert if the strategy requests more stables than it's able to borrow.
      * `dUSD` will be minted 1:1 for the amount of stables borrowed
      */
-    function borrowMax() external returns (uint256);
+    function borrowMax(address recipient) external returns (uint256);
 
     /**
      * @notice A strategy calls to paydown it's debt
      * This will pull the stables, and will burn the equivalent amount of dUSD from the strategy.
      */
-    function repay(uint256 repayAmount) external;
+    function repay(uint256 repayAmount, address strategy) external;
 
     /**
      * @notice A strategy calls to paydown all of it's debt
      * This will pull the stables for the entire dUSD balance of the strategy, and burn the dUSD.
      */
-    function repayAll() external returns (uint256 amountRepaid);
+    function repayAll(address strategy) external returns (uint256 amountRepaid);
 
     /**
      * @notice The second step in a two-phase shutdown. A strategy (automated) or executor (manual) calls

protocol/contracts/interfaces/v2/strategies/ITempleStrategy.sol

@@ -94,12 +94,19 @@ interface ITempleStrategy is ITempleElevatedAccess {
     function currentDebt() external view returns (uint256);
 
     /**
-     * @notice How much this strategy is free to borrow from the Treasury Reserves Vault
-     * @dev This is bound by:
-     *   1/ How much stables is globally available (in the TRV + in the TRV base strategy)
-     *   2/ The amount this individual strategy is whitelisted to borrow.
-     */
-    function availableToBorrow() external view returns (uint256);
+     * @notice A strategy's current amount borrowed from the TRV, and how much remaining is free to borrow
+     * @dev The remaining amount free to borrow is bound by:
+     *   1/ How much stables is globally available (in this contract + in the base strategy)
+     *   2/ The amount each individual strategy is whitelisted to borrow.
+     * @return currentDebt The current debt position for the strategy, 
+     * @return availableToBorrow The remaining amount which the strategy can borrow
+     * @return debtCeiling The debt ceiling of the stratgy
+     */
+    function trvBorrowPosition() external view returns (
+        uint256 currentDebt, 
+        uint256 availableToBorrow,
+        uint256 debtCeiling
+    );
 
     /**
      * @notice The Strategy Executor may set manual updates to asset balances

protocol/contracts/v2/TempleDebtToken.sol

@@ -8,7 +8,7 @@ import { mulDiv } from "@prb/math/src/Common.sol";
 
 import { ITempleDebtToken } from "contracts/interfaces/v2/ITempleDebtToken.sol";
 import { CommonEventsAndErrors } from "contracts/common/CommonEventsAndErrors.sol";
-import { CompoundedInterest } from "contracts/interestRate/CompoundedInterest.sol";
+import { CompoundedInterest } from "contracts/v2/interestRate/CompoundedInterest.sol";
 import { TempleElevatedAccess } from "contracts/v2/access/TempleElevatedAccess.sol";
 
 /**
@@ -25,7 +25,7 @@ import { TempleElevatedAccess } from "contracts/v2/access/TempleElevatedAccess.s
  *         (eg DAI's DSR at 1% APR). 
  *      It is implemented using a share based implementation such that this base rate can be updated for all debtors
  *   3/ 'risk premium' interest, where the interest rate is set per borrower.
- *         This represents a governance set premium for that individual borrower depending on its purpose. 
+ *         This represents a premium for that individual borrower depending on its purpose. 
  *         For example a higher risk / higher return borrower would have a higher risk premium.
  *
  * On a repayment, the interest accruing at the higher rate is paid down first. When there is no more `base rate` or
@@ -55,7 +55,7 @@ contract TempleDebtToken is ITempleDebtToken, TempleElevatedAccess {
     uint8 public constant override decimals = 18;
 
     /**
-     * @notice The current (base rate) interest common for all users. This can be updated by governance
+     * @notice The current (base rate) interest common for all users. This can be updated by the DAO
      * @dev 1e18 format, where 0.01e18 = 1%
      */
     uint256 public override baseRate;
@@ -113,7 +113,7 @@ contract TempleDebtToken is ITempleDebtToken, TempleElevatedAccess {
     }
 
     /**
-     * @notice Governance can add an address which is able to mint or burn debt
+     * @notice Add an address which is able to mint or burn debt
      * positions on behalf of users.
      */
     function addMinter(address account) external override onlyElevatedAccess {
@@ -122,7 +122,7 @@ contract TempleDebtToken is ITempleDebtToken, TempleElevatedAccess {
     }
 
     /**
-     * @notice Governance can remove an address which is able to mint or burn debt
+     * @notice Remove an address which is able to mint or burn debt
      * positions on behalf of users.
      */
     function removeMinter(address account) external override onlyElevatedAccess {
@@ -138,7 +138,7 @@ contract TempleDebtToken is ITempleDebtToken, TempleElevatedAccess {
     }
 
     /**
-     * @notice Governance can update the continuously compounding (base) interest rate of all debtors, from this block onwards.
+     * @notice Update the continuously compounding (base) interest rate of all debtors, from this block onwards.
      */
     function setBaseInterestRate(uint256 _rate) external override onlyElevatedAccess {
         _checkpointBase(_compoundedBaseInterest());
@@ -147,7 +147,7 @@ contract TempleDebtToken is ITempleDebtToken, TempleElevatedAccess {
     }
 
     /**
-     * @notice Governance can update the continuously compounding (risk premium) interest rate for a given debtor, from this block onwards
+     * @notice Update the continuously compounding (risk premium) interest rate for a given debtor, from this block onwards
      */
     function setRiskPremiumInterestRate(address _debtor, uint256 _rate) external override onlyElevatedAccess {
         Debtor storage debtor = debtors[_debtor];