0g-chain/x/hard/keeper/withdraw.go
2021-02-03 23:23:03 +01:00

93 lines
2.6 KiB
Go

package keeper
import (
sdk "github.com/cosmos/cosmos-sdk/types"
sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
"github.com/kava-labs/kava/x/hard/types"
)
// Withdraw returns some or all of a deposit back to original depositor
func (k Keeper) Withdraw(ctx sdk.Context, depositor sdk.AccAddress, coins sdk.Coins) error {
// Get current stored LTV based on stored borrows/deposits
prevLtv, err := k.GetStoreLTV(ctx, depositor)
if err != nil {
return err
}
deposit, found := k.GetDeposit(ctx, depositor)
if !found {
return sdkerrors.Wrapf(types.ErrDepositNotFound, "no deposit found for %s", depositor)
}
// Call incentive hook
k.BeforeDepositModified(ctx, deposit)
k.SyncBorrowInterest(ctx, depositor)
k.SyncSupplyInterest(ctx, depositor)
amount, err := k.CalculateWithdrawAmount(deposit.Amount, coins)
if err != nil {
return err
}
borrow, found := k.GetBorrow(ctx, depositor)
if !found {
borrow = types.Borrow{}
}
proposedDeposit := types.NewDeposit(deposit.Depositor, deposit.Amount.Sub(amount), types.SupplyInterestFactors{})
valid, err := k.IsWithinValidLtvRange(ctx, proposedDeposit, borrow)
if err != nil {
return err
}
if !valid {
return sdkerrors.Wrapf(types.ErrInvalidWithdrawAmount, "proposed withdraw outside loan-to-value range")
}
err = k.supplyKeeper.SendCoinsFromModuleToAccount(ctx, types.ModuleAccountName, depositor, amount)
if err != nil {
return err
}
deposit.Amount = deposit.Amount.Sub(amount)
newLtv, err := k.CalculateLtv(ctx, deposit, borrow)
if err != nil {
return err
}
k.UpdateDepositAndLtvIndex(ctx, deposit, newLtv, prevLtv)
// Update total supplied amount
k.DecrementSuppliedCoins(ctx, amount)
// Call incentive hook
k.AfterDepositModified(ctx, deposit)
ctx.EventManager().EmitEvent(
sdk.NewEvent(
types.EventTypeHardWithdrawal,
sdk.NewAttribute(sdk.AttributeKeyAmount, amount.String()),
sdk.NewAttribute(types.AttributeKeyDepositor, depositor.String()),
),
)
return nil
}
// CalculateWithdrawAmount enables full withdraw of deposited coins by adjusting withdraw amount
// to equal total deposit amount if the requested withdraw amount > current deposit amount
func (k Keeper) CalculateWithdrawAmount(available sdk.Coins, request sdk.Coins) (sdk.Coins, error) {
result := sdk.Coins{}
if !request.DenomsSubsetOf(available) {
return result, types.ErrInvalidWithdrawDenom
}
for _, coin := range request {
if coin.Amount.GT(available.AmountOf(coin.Denom)) {
result = append(result, sdk.NewCoin(coin.Denom, available.AmountOf(coin.Denom)))
} else {
result = append(result, coin)
}
}
return result, nil
}