package simulation import ( "fmt" "math/rand" "github.com/cosmos/cosmos-sdk/baseapp" "github.com/cosmos/cosmos-sdk/codec" "github.com/cosmos/cosmos-sdk/simapp/helpers" sdk "github.com/cosmos/cosmos-sdk/types" "github.com/cosmos/cosmos-sdk/x/simulation" appparams "github.com/kava-labs/kava/app/params" "github.com/kava-labs/kava/x/cdp/keeper" "github.com/kava-labs/kava/x/cdp/types" ) // Simulation operation weights constants const ( OpWeightMsgCdp = "op_weight_msg_cdp" ) // WeightedOperations returns all the operations from the module with their respective weights func WeightedOperations( appParams simulation.AppParams, cdc *codec.Codec, ak types.AccountKeeper, k keeper.Keeper, pfk types.PricefeedKeeper, ) simulation.WeightedOperations { var weightMsgCdp int appParams.GetOrGenerate(cdc, OpWeightMsgCdp, &weightMsgCdp, nil, func(_ *rand.Rand) { weightMsgCdp = appparams.DefaultWeightMsgCdp }, ) return simulation.WeightedOperations{ simulation.NewWeightedOperation( weightMsgCdp, SimulateMsgCdp(ak, k, pfk), ), } } // SimulateMsgCdp generates a MsgCreateCdp or MsgDepositCdp with random values. func SimulateMsgCdp(ak types.AccountKeeper, k keeper.Keeper, pfk types.PricefeedKeeper) simulation.Operation { return func( r *rand.Rand, app *baseapp.BaseApp, ctx sdk.Context, accs []simulation.Account, chainID string, ) (simulation.OperationMsg, []simulation.FutureOperation, error) { simAccount, _ := simulation.RandomAcc(r, accs) acc := ak.GetAccount(ctx, simAccount.Address) if acc == nil { return simulation.NoOpMsg(types.ModuleName), nil, nil } coins := acc.GetCoins() collateralParams := k.GetParams(ctx).CollateralParams if len(collateralParams) == 0 { return simulation.NoOpMsg(types.ModuleName), nil, nil } randCollateralParam := collateralParams[r.Intn(len(collateralParams))] debtParam, _ := k.GetDebtParam(ctx, randCollateralParam.DebtLimit.Denom) if coins.AmountOf(randCollateralParam.Denom).IsZero() { return simulation.NoOpMsg(types.ModuleName), nil, nil } price, err := pfk.GetCurrentPrice(ctx, randCollateralParam.SpotMarketID) if err != nil { return simulation.NoOpMsg(types.ModuleName), nil, nil // pricefeed going down is an expected event } // convert the price to the same units as the debt param priceShifted := ShiftDec(price.Price, debtParam.ConversionFactor) spendableCoins := acc.SpendableCoins(ctx.BlockTime()) fees, err := simulation.RandomFees(r, ctx, spendableCoins) if err != nil { return simulation.NoOpMsg(types.ModuleName), nil, err } spendableCoins = spendableCoins.Sub(fees) existingCDP, found := k.GetCdpByOwnerAndCollateralType(ctx, acc.GetAddress(), randCollateralParam.Type) if !found { // calculate the minimum amount of collateral that is needed to create a cdp with the debt floor amount of debt and the minimum liquidation ratio // (debtFloor * liquidationRatio)/priceShifted minCollateralDeposit := (sdk.NewDecFromInt(debtParam.DebtFloor).Mul(randCollateralParam.LiquidationRatio)).Quo(priceShifted) // convert to proper collateral units minCollateralDeposit = ShiftDec(minCollateralDeposit, randCollateralParam.ConversionFactor) // convert to integer and always round up minCollateralDepositRounded := minCollateralDeposit.TruncateInt().Add(sdk.OneInt()) if spendableCoins.AmountOf(randCollateralParam.Denom).LT(minCollateralDepositRounded) { // account doesn't have enough funds to open a cdp for the min debt amount return simulation.NewOperationMsgBasic(types.ModuleName, "no-operation", "insufficient funds to open cdp", false, nil), nil, nil } // set the max collateral deposit to the amount of coins in the account maxCollateralDeposit := spendableCoins.AmountOf(randCollateralParam.Denom) // randomly select a collateral deposit amount collateralDeposit := sdk.NewInt(int64(simulation.RandIntBetween(r, int(minCollateralDepositRounded.Int64()), int(maxCollateralDeposit.Int64())))) // calculate how much the randomly selected deposit is worth collateralDepositValue := ShiftDec(sdk.NewDecFromInt(collateralDeposit), randCollateralParam.ConversionFactor.Neg()).Mul(priceShifted) // calculate the max amount of debt that could be drawn for the chosen deposit maxDebtDraw := collateralDepositValue.Quo(randCollateralParam.LiquidationRatio).TruncateInt() // check that the debt limit hasn't been reached availableAssetDebt := randCollateralParam.DebtLimit.Amount.Sub(k.GetTotalPrincipal(ctx, randCollateralParam.Type, debtParam.Denom)) if availableAssetDebt.LTE(debtParam.DebtFloor) { // debt limit has been reached return simulation.NewOperationMsgBasic(types.ModuleName, "no-operation", "debt limit reached, cannot open cdp", false, nil), nil, nil } // ensure that the debt draw does not exceed the debt limit maxDebtDraw = sdk.MinInt(maxDebtDraw, availableAssetDebt) // randomly select a debt draw amount debtDraw := sdk.NewInt(int64(simulation.RandIntBetween(r, int(debtParam.DebtFloor.Int64()), int(maxDebtDraw.Int64())))) msg := types.NewMsgCreateCDP(acc.GetAddress(), sdk.NewCoin(randCollateralParam.Denom, collateralDeposit), sdk.NewCoin(debtParam.Denom, debtDraw), randCollateralParam.Type) tx := helpers.GenTx( []sdk.Msg{msg}, fees, helpers.DefaultGenTxGas, chainID, []uint64{acc.GetAccountNumber()}, []uint64{acc.GetSequence()}, simAccount.PrivKey, ) _, _, err := app.Deliver(tx) if err != nil { // to aid debugging, add the stack trace to the comment field of the returned opMsg return simulation.NewOperationMsg(msg, false, fmt.Sprintf("%+v", err)), nil, err } return simulation.NewOperationMsg(msg, true, ""), nil, nil } // a cdp already exists, deposit to it, draw debt from it, or repay debt to it // close 25% of the time if canClose(spendableCoins, existingCDP, debtParam.Denom) && shouldClose(r) { repaymentAmount := spendableCoins.AmountOf(debtParam.Denom) msg := types.NewMsgRepayDebt(acc.GetAddress(), randCollateralParam.Type, sdk.NewCoin(debtParam.Denom, repaymentAmount)) tx := helpers.GenTx( []sdk.Msg{msg}, fees, helpers.DefaultGenTxGas, chainID, []uint64{acc.GetAccountNumber()}, []uint64{acc.GetSequence()}, simAccount.PrivKey, ) _, _, err := app.Deliver(tx) if err != nil { return simulation.NewOperationMsg(msg, false, fmt.Sprintf("%+v", err)), nil, err } return simulation.NewOperationMsg(msg, true, ""), nil, nil } // deposit 25% of the time if hasCoins(spendableCoins, randCollateralParam.Denom) && shouldDeposit(r) { randDepositAmount := sdk.NewInt(int64(simulation.RandIntBetween(r, 1, int(spendableCoins.AmountOf(randCollateralParam.Denom).Int64())))) msg := types.NewMsgDeposit(acc.GetAddress(), acc.GetAddress(), sdk.NewCoin(randCollateralParam.Denom, randDepositAmount), randCollateralParam.Type) tx := helpers.GenTx( []sdk.Msg{msg}, fees, helpers.DefaultGenTxGas, chainID, []uint64{acc.GetAccountNumber()}, []uint64{acc.GetSequence()}, simAccount.PrivKey, ) _, _, err := app.Deliver(tx) if err != nil { return simulation.NewOperationMsg(msg, false, fmt.Sprintf("%+v", err)), nil, err } return simulation.NewOperationMsg(msg, true, ""), nil, nil } // draw debt 25% of the time if shouldDraw(r) { collateralShifted := ShiftDec(sdk.NewDecFromInt(existingCDP.Collateral.Amount), randCollateralParam.ConversionFactor.Neg()) collateralValue := collateralShifted.Mul(priceShifted) newFeesAccumulated := k.CalculateFees(ctx, existingCDP.Principal, sdk.NewInt(ctx.BlockTime().Unix()-existingCDP.FeesUpdated.Unix()), randCollateralParam.Type).Amount totalFees := existingCDP.AccumulatedFees.Amount.Add(newFeesAccumulated) // given the current collateral value, calculate how much debt we could add while maintaining a valid liquidation ratio debt := existingCDP.Principal.Amount.Add(totalFees) maxTotalDebt := collateralValue.Quo(randCollateralParam.LiquidationRatio) maxDebt := (maxTotalDebt.Sub(sdk.NewDecFromInt(debt))).Mul(sdk.MustNewDecFromStr("0.95")).TruncateInt() if maxDebt.LTE(sdk.OneInt()) { // debt in cdp is maxed out return simulation.NewOperationMsgBasic(types.ModuleName, "no-operation", "cdp debt maxed out, cannot draw more debt", false, nil), nil, nil } // check if the debt limit has been reached availableAssetDebt := randCollateralParam.DebtLimit.Amount.Sub(k.GetTotalPrincipal(ctx, randCollateralParam.Type, debtParam.Denom)) if availableAssetDebt.LTE(sdk.OneInt()) { // debt limit has been reached return simulation.NewOperationMsgBasic(types.ModuleName, "no-operation", "debt limit reached, cannot draw more debt", false, nil), nil, nil } maxDraw := sdk.MinInt(maxDebt, availableAssetDebt) randDrawAmount := sdk.NewInt(int64(simulation.RandIntBetween(r, 1, int(maxDraw.Int64())))) msg := types.NewMsgDrawDebt(acc.GetAddress(), randCollateralParam.Type, sdk.NewCoin(debtParam.Denom, randDrawAmount)) tx := helpers.GenTx( []sdk.Msg{msg}, fees, helpers.DefaultGenTxGas, chainID, []uint64{acc.GetAccountNumber()}, []uint64{acc.GetSequence()}, simAccount.PrivKey, ) _, _, err := app.Deliver(tx) if err != nil { return simulation.NewOperationMsg(msg, false, fmt.Sprintf("%+v", err)), nil, err } return simulation.NewOperationMsg(msg, true, ""), nil, nil } // repay debt 25% of the time if hasCoins(spendableCoins, debtParam.Denom) { debt := existingCDP.Principal.Amount payableDebt := debt.Sub(debtParam.DebtFloor) if payableDebt.IsZero() { return simulation.NewOperationMsgBasic(types.ModuleName, "no-operation", "cannot make partial repayment, cdp at debt floor", false, nil), nil, nil } maxRepay := sdk.MinInt( spendableCoins.AmountOf(debtParam.Denom), payableDebt, ) var randRepayAmount sdk.Int if maxRepay.Equal(sdk.OneInt()) { randRepayAmount = sdk.OneInt() } else { randRepayAmount = sdk.NewInt(int64(simulation.RandIntBetween(r, 1, int(maxRepay.Int64())))) } msg := types.NewMsgRepayDebt(acc.GetAddress(), randCollateralParam.Type, sdk.NewCoin(debtParam.Denom, randRepayAmount)) tx := helpers.GenTx( []sdk.Msg{msg}, fees, helpers.DefaultGenTxGas, chainID, []uint64{acc.GetAccountNumber()}, []uint64{acc.GetSequence()}, simAccount.PrivKey, ) _, _, err := app.Deliver(tx) if err != nil { return simulation.NewOperationMsg(msg, false, fmt.Sprintf("%+v", err)), nil, err } return simulation.NewOperationMsg(msg, true, ""), nil, nil } return simulation.NoOpMsg(types.ModuleName), nil, nil } } func shouldDraw(r *rand.Rand) bool { threshold := 50 value := simulation.RandIntBetween(r, 1, 100) return value > threshold } func shouldDeposit(r *rand.Rand) bool { threshold := 66 value := simulation.RandIntBetween(r, 1, 100) return value > threshold } func hasCoins(spendableCoins sdk.Coins, denom string) bool { return spendableCoins.AmountOf(denom).IsPositive() } func shouldClose(r *rand.Rand) bool { threshold := 75 value := simulation.RandIntBetween(r, 1, 100) return value > threshold } func canClose(spendableCoins sdk.Coins, c types.CDP, denom string) bool { repaymentAmount := c.Principal.Add(c.AccumulatedFees).Amount return spendableCoins.AmountOf(denom).GTE(repaymentAmount) }