package keeper import ( sdk "github.com/cosmos/cosmos-sdk/types" sdkerrors "github.com/cosmos/cosmos-sdk/types/errors" "github.com/kava-labs/kava/x/harvest/types" ) // Borrow funds func (k Keeper) Borrow(ctx sdk.Context, borrower sdk.AccAddress, coins sdk.Coins) error { err := k.ValidateBorrow(ctx, borrower, coins) if err != nil { return err } err = k.supplyKeeper.SendCoinsFromModuleToAccount(ctx, types.ModuleAccountName, borrower, coins) if err != nil { return err } borrow, found := k.GetBorrow(ctx, borrower) if !found { borrow = types.NewBorrow(borrower, coins) } else { borrow.Amount = borrow.Amount.Add(coins...) } k.SetBorrow(ctx, borrow) ctx.EventManager().EmitEvent( sdk.NewEvent( types.EventTypeHarvestBorrow, sdk.NewAttribute(types.AttributeKeyBorrower, borrow.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 { // 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.GetMoneyMarket(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) proprosedBorrowUSDValue = proprosedBorrowUSDValue.Add(coinUSDValue) } // Get the total borrowable USD amount at user's existing deposits deposits := k.GetDepositsByUser(ctx, borrower) if len(deposits) == 0 { return sdkerrors.Wrapf(types.ErrDepositsNotFound, "no deposits found for %s", borrower) } totalBorrowableAmount := sdk.ZeroDec() for _, deposit := range deposits { moneyMarket, ok := moneyMarketCache[deposit.Amount.Denom] // Fetch money market and store in local cache if !ok { newMoneyMarket, found := k.GetMoneyMarket(ctx, deposit.Amount.Denom) if !found { return sdkerrors.Wrapf(types.ErrMarketNotFound, "no market found for denom %s", deposit.Amount.Denom) } moneyMarketCache[deposit.Amount.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 { sdkerrors.Wrapf(types.ErrPriceNotFound, "no price found for market %s", moneyMarket.SpotMarketID) } depositUSDValue := sdk.NewDecFromInt(deposit.Amount.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.GetMoneyMarket(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 is greater than maximum valid borrow", amount) } return nil }