package keeper import ( "strings" sdk "github.com/cosmos/cosmos-sdk/types" sdkerrors "github.com/cosmos/cosmos-sdk/types/errors" "github.com/kava-labs/kava/x/hard/types" ) // Borrow funds func (k Keeper) Borrow(ctx sdk.Context, borrower sdk.AccAddress, coins sdk.Coins) error { // Set any new denoms' global borrow index to 1.0 for _, coin := range coins { _, foundInterestFactor := k.GetBorrowInterestFactor(ctx, coin.Denom) if !foundInterestFactor { _, foundMm := k.GetMoneyMarket(ctx, coin.Denom) if foundMm { k.SetBorrowInterestFactor(ctx, coin.Denom, sdk.OneDec()) } } } // Get current stored LTV based on stored borrows/deposits prevLtv, err := k.GetStoreLTV(ctx, borrower) if err != nil { return err } // Call incentive hook existingBorrow, hasExistingBorrow := k.GetBorrow(ctx, borrower) if hasExistingBorrow { k.BeforeBorrowModified(ctx, existingBorrow) } k.SyncSupplyInterest(ctx, borrower) k.SyncBorrowInterest(ctx, borrower) // Validate borrow amount within user and protocol limits err = k.ValidateBorrow(ctx, borrower, coins) if err != nil { return err } // Sends coins from Hard module account to user err = k.supplyKeeper.SendCoinsFromModuleToAccount(ctx, types.ModuleAccountName, borrower, coins) if err != nil { if strings.Contains(err.Error(), "insufficient account funds") { modAccCoins := k.supplyKeeper.GetModuleAccount(ctx, types.ModuleAccountName).GetCoins() for _, coin := range coins { _, isNegative := modAccCoins.SafeSub(sdk.NewCoins(coin)) if isNegative { return sdkerrors.Wrapf(types.ErrBorrowExceedsAvailableBalance, "the requested borrow amount of %s exceeds the total amount of %s%s available to borrow", coin, modAccCoins.AmountOf(coin.Denom), coin.Denom, ) } } } } interestFactors := types.BorrowInterestFactors{} currBorrow, foundBorrow := k.GetBorrow(ctx, borrower) if foundBorrow { interestFactors = currBorrow.Index } for _, coin := range coins { interestFactorValue, foundValue := k.GetBorrowInterestFactor(ctx, coin.Denom) if foundValue { interestFactors = interestFactors.SetInterestFactor(coin.Denom, interestFactorValue) } } // Calculate new borrow amount var amount sdk.Coins if foundBorrow { amount = currBorrow.Amount.Add(coins...) } else { amount = coins } // Construct the user's new/updated borrow with amount and interest factors borrow := types.NewBorrow(borrower, amount, interestFactors) // Calculate the new Loan-to-Value ratio of Deposit-to-Borrow deposit, foundDeposit := k.GetDeposit(ctx, borrower) if !foundDeposit { return types.ErrDepositNotFound } newLtv, err := k.CalculateLtv(ctx, deposit, borrow) if err != nil { return err } k.UpdateBorrowAndLtvIndex(ctx, borrow, newLtv, prevLtv) // Update total borrowed amount by newly borrowed coins. Don't add user's pending interest as // it has already been included in the total borrowed coins by the BeginBlocker. k.IncrementBorrowedCoins(ctx, coins) if !hasExistingBorrow { k.AfterBorrowCreated(ctx, borrow) } else { k.AfterBorrowModified(ctx, borrow) } ctx.EventManager().EmitEvent( sdk.NewEvent( types.EventTypeHardBorrow, sdk.NewAttribute(types.AttributeKeyBorrower, borrower.String()), sdk.NewAttribute(types.AttributeKeyBorrowCoins, coins.String()), ), ) return nil } // ValidateBorrow validates a borrow request against borrower and protocol requirements func (k Keeper) ValidateBorrow(ctx sdk.Context, borrower sdk.AccAddress, amount sdk.Coins) error { if amount.IsZero() { return types.ErrBorrowEmptyCoins } // Get the proposed borrow USD value moneyMarketCache := map[string]types.MoneyMarket{} proprosedBorrowUSDValue := sdk.ZeroDec() for _, coin := range amount { moneyMarket, ok := moneyMarketCache[coin.Denom] // Fetch money market and store in local cache if !ok { newMoneyMarket, found := k.GetMoneyMarketParam(ctx, coin.Denom) if !found { return sdkerrors.Wrapf(types.ErrMarketNotFound, "no market found for denom %s", coin.Denom) } moneyMarketCache[coin.Denom] = newMoneyMarket moneyMarket = newMoneyMarket } // Calculate this coin's USD value and add it borrow's total USD value assetPriceInfo, err := k.pricefeedKeeper.GetCurrentPrice(ctx, moneyMarket.SpotMarketID) if err != nil { return sdkerrors.Wrapf(types.ErrPriceNotFound, "no price found for market %s", moneyMarket.SpotMarketID) } coinUSDValue := sdk.NewDecFromInt(coin.Amount).Quo(sdk.NewDecFromInt(moneyMarket.ConversionFactor)).Mul(assetPriceInfo.Price) // Validate the requested borrow value for the asset against the money market's global borrow limit if moneyMarket.BorrowLimit.HasMaxLimit { var assetTotalBorrowedAmount sdk.Int totalBorrowedCoins, found := k.GetBorrowedCoins(ctx) if !found { assetTotalBorrowedAmount = sdk.ZeroInt() } else { assetTotalBorrowedAmount = totalBorrowedCoins.AmountOf(coin.Denom) } newProposedAssetTotalBorrowedAmount := sdk.NewDecFromInt(assetTotalBorrowedAmount.Add(coin.Amount)) if newProposedAssetTotalBorrowedAmount.GT(moneyMarket.BorrowLimit.MaximumLimit) { return sdkerrors.Wrapf(types.ErrGreaterThanAssetBorrowLimit, "proposed borrow would result in %s borrowed, but the maximum global asset borrow limit is %s", newProposedAssetTotalBorrowedAmount, moneyMarket.BorrowLimit.MaximumLimit) } } proprosedBorrowUSDValue = proprosedBorrowUSDValue.Add(coinUSDValue) } // Get the total borrowable USD amount at user's existing deposits deposit, found := k.GetDeposit(ctx, borrower) if !found { return sdkerrors.Wrapf(types.ErrDepositsNotFound, "no deposits found for %s", borrower) } totalBorrowableAmount := sdk.ZeroDec() for _, depCoin := range deposit.Amount { moneyMarket, ok := moneyMarketCache[depCoin.Denom] // Fetch money market and store in local cache if !ok { newMoneyMarket, found := k.GetMoneyMarketParam(ctx, depCoin.Denom) if !found { return sdkerrors.Wrapf(types.ErrMarketNotFound, "no market found for denom %s", depCoin.Denom) } moneyMarketCache[depCoin.Denom] = newMoneyMarket moneyMarket = newMoneyMarket } // Calculate the borrowable amount and add it to the user's total borrowable amount assetPriceInfo, err := k.pricefeedKeeper.GetCurrentPrice(ctx, moneyMarket.SpotMarketID) if err != nil { return sdkerrors.Wrapf(types.ErrPriceNotFound, "no price found for market %s", moneyMarket.SpotMarketID) } depositUSDValue := sdk.NewDecFromInt(depCoin.Amount).Quo(sdk.NewDecFromInt(moneyMarket.ConversionFactor)).Mul(assetPriceInfo.Price) borrowableAmountForDeposit := depositUSDValue.Mul(moneyMarket.BorrowLimit.LoanToValue) totalBorrowableAmount = totalBorrowableAmount.Add(borrowableAmountForDeposit) } // Get the total USD value of user's existing borrows existingBorrowUSDValue := sdk.ZeroDec() existingBorrow, found := k.GetBorrow(ctx, borrower) if found { for _, borrowedCoin := range existingBorrow.Amount { moneyMarket, ok := moneyMarketCache[borrowedCoin.Denom] // Fetch money market and store in local cache if !ok { newMoneyMarket, found := k.GetMoneyMarketParam(ctx, borrowedCoin.Denom) if !found { return sdkerrors.Wrapf(types.ErrMarketNotFound, "no market found for denom %s", borrowedCoin.Denom) } moneyMarketCache[borrowedCoin.Denom] = newMoneyMarket moneyMarket = newMoneyMarket } // Calculate this borrow coin's USD value and add it to the total previous borrowed USD value assetPriceInfo, err := k.pricefeedKeeper.GetCurrentPrice(ctx, moneyMarket.SpotMarketID) if err != nil { return sdkerrors.Wrapf(types.ErrPriceNotFound, "no price found for market %s", moneyMarket.SpotMarketID) } coinUSDValue := sdk.NewDecFromInt(borrowedCoin.Amount).Quo(sdk.NewDecFromInt(moneyMarket.ConversionFactor)).Mul(assetPriceInfo.Price) existingBorrowUSDValue = existingBorrowUSDValue.Add(coinUSDValue) } } // Validate that the proposed borrow's USD value is within user's borrowable limit if proprosedBorrowUSDValue.GT(totalBorrowableAmount.Sub(existingBorrowUSDValue)) { return sdkerrors.Wrapf(types.ErrInsufficientLoanToValue, "requested borrow %s exceeds the allowable amount as determined by the collateralization ratio", amount) } return nil } // IncrementBorrowedCoins increments the total amount of borrowed coins by the newCoins parameter func (k Keeper) IncrementBorrowedCoins(ctx sdk.Context, newCoins sdk.Coins) { borrowedCoins, found := k.GetBorrowedCoins(ctx) if !found { if !newCoins.Empty() { k.SetBorrowedCoins(ctx, newCoins) } } else { k.SetBorrowedCoins(ctx, borrowedCoins.Add(newCoins...)) } } // DecrementBorrowedCoins decrements the total amount of borrowed coins by the coins parameter func (k Keeper) DecrementBorrowedCoins(ctx sdk.Context, coins sdk.Coins) error { borrowedCoins, found := k.GetBorrowedCoins(ctx) if !found { return sdkerrors.Wrapf(types.ErrBorrowedCoinsNotFound, "cannot repay coins if no coins are currently borrowed") } updatedBorrowedCoins, isAnyNegative := borrowedCoins.SafeSub(coins) if isAnyNegative { return types.ErrNegativeBorrowedCoins } k.SetBorrowedCoins(ctx, updatedBorrowedCoins) return nil } // GetSyncedBorrow returns a borrow object containing current balances and indexes func (k Keeper) GetSyncedBorrow(ctx sdk.Context, borrower sdk.AccAddress) (types.Borrow, bool) { borrow, found := k.GetBorrow(ctx, borrower) if !found { return types.Borrow{}, false } return k.loadSyncedBorrow(ctx, borrow), true } // loadSyncedBorrow calculates a user's synced borrow, but does not update state func (k Keeper) loadSyncedBorrow(ctx sdk.Context, borrow types.Borrow) types.Borrow { totalNewInterest := sdk.Coins{} newBorrowIndexes := types.BorrowInterestFactors{} for _, coin := range borrow.Amount { interestFactorValue, foundInterestFactorValue := k.GetBorrowInterestFactor(ctx, coin.Denom) if foundInterestFactorValue { // Locate the interest factor by coin denom in the user's list of interest factors foundAtIndex := -1 for i := range borrow.Index { if borrow.Index[i].Denom == coin.Denom { foundAtIndex = i break } } // Calculate interest owed by user for this asset if foundAtIndex != -1 { storedAmount := sdk.NewDecFromInt(borrow.Amount.AmountOf(coin.Denom)) userLastInterestFactor := borrow.Index[foundAtIndex].Value coinInterest := (storedAmount.Quo(userLastInterestFactor).Mul(interestFactorValue)).Sub(storedAmount) totalNewInterest = totalNewInterest.Add(sdk.NewCoin(coin.Denom, coinInterest.TruncateInt())) } } borrowIndex := types.NewBorrowInterestFactor(coin.Denom, interestFactorValue) newBorrowIndexes = append(newBorrowIndexes, borrowIndex) } return types.NewBorrow(borrow.Borrower, borrow.Amount.Add(totalNewInterest...), newBorrowIndexes) }