forked from umee-network/umee
/
keeper.go
434 lines (368 loc) · 15.6 KB
/
keeper.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
package keeper
import (
"fmt"
"github.com/cosmos/cosmos-sdk/codec"
storetypes "github.com/cosmos/cosmos-sdk/store/types"
sdk "github.com/cosmos/cosmos-sdk/types"
sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
paramtypes "github.com/cosmos/cosmos-sdk/x/params/types"
"github.com/tendermint/tendermint/libs/log"
"github.com/mokitanetwork/katana/x/leverage/types"
)
type Keeper struct {
cdc codec.Codec
storeKey storetypes.StoreKey
paramSpace paramtypes.Subspace
hooks types.Hooks
bankKeeper types.BankKeeper
oracleKeeper types.OracleKeeper
authority string // the gov module account
liquidatorQueryEnabled bool
}
func NewKeeper(
cdc codec.Codec,
storeKey storetypes.StoreKey,
paramSpace paramtypes.Subspace,
bk types.BankKeeper,
ok types.OracleKeeper,
authority string,
enableLiquidatorQuery bool,
) (Keeper, error) {
// set KeyTable if it has not already been set
if !paramSpace.HasKeyTable() {
paramSpace = paramSpace.WithKeyTable(types.ParamKeyTable())
}
return Keeper{
cdc: cdc,
storeKey: storeKey,
paramSpace: paramSpace,
bankKeeper: bk,
oracleKeeper: ok,
authority: authority,
liquidatorQueryEnabled: enableLiquidatorQuery,
}, nil
}
func (k Keeper) Logger(ctx sdk.Context) log.Logger {
return ctx.Logger().With("module", fmt.Sprintf("x/%s", types.ModuleName))
}
// SetHooks sets the module's hooks. Note, hooks can only be set once.
func (k *Keeper) SetHooks(h types.Hooks) *Keeper {
if k.hooks != nil {
panic("leverage hooks already set")
}
k.hooks = h
return k
}
// ModuleBalance returns the amount of a given token held in the x/leverage module account
func (k Keeper) ModuleBalance(ctx sdk.Context, denom string) sdk.Coin {
amount := k.bankKeeper.SpendableCoins(ctx, authtypes.NewModuleAddress(types.ModuleName)).AmountOf(denom)
return sdk.NewCoin(denom, amount)
}
// Supply attempts to deposit assets into the leverage module account in
// exchange for uTokens. If asset type is invalid or account balance is
// insufficient, we return an error. Returns the amount of uTokens minted.
func (k Keeper) Supply(ctx sdk.Context, supplierAddr sdk.AccAddress, coin sdk.Coin) (sdk.Coin, error) {
if err := k.validateSupply(ctx, coin); err != nil {
return sdk.Coin{}, err
}
token, err := k.GetTokenSettings(ctx, coin.Denom)
if err != nil {
return sdk.Coin{}, err
}
total, err := k.GetTotalSupply(ctx, coin.Denom)
if err != nil {
return sdk.Coin{}, err
}
if token.MaxSupply.IsPositive() && total.Add(coin).Amount.GTE(token.MaxSupply) {
return sdk.Coin{}, types.ErrMaxSupply.Wrapf("attempted: %s, current supply: %s, max supply: %s",
coin, total.Amount, token.MaxSupply)
}
// determine uToken amount to mint
uToken, err := k.ExchangeToken(ctx, coin)
if err != nil {
return sdk.Coin{}, err
}
// send token balance to leverage module account
err = k.bankKeeper.SendCoinsFromAccountToModule(ctx, supplierAddr, types.ModuleName, sdk.NewCoins(coin))
if err != nil {
return sdk.Coin{}, err
}
// mint uToken and set new total uToken supply
uTokens := sdk.NewCoins(uToken)
if err = k.bankKeeper.MintCoins(ctx, types.ModuleName, uTokens); err != nil {
return sdk.Coin{}, err
}
if err = k.setUTokenSupply(ctx, k.GetUTokenSupply(ctx, uToken.Denom).Add(uToken)); err != nil {
return sdk.Coin{}, err
}
// The uTokens are sent to supplier address
if err = k.bankKeeper.SendCoinsFromModuleToAccount(ctx, types.ModuleName, supplierAddr, uTokens); err != nil {
return sdk.Coin{}, err
}
return uToken, nil
}
// Withdraw attempts to redeem uTokens from the leverage module in exchange for base tokens.
// If there are not enough uTokens in balance, Withdraw will attempt to withdraw uToken collateral
// to make up the difference (as long as borrow limit allows). If the uToken denom is invalid or
// balances are insufficient to withdraw the full amount requested, returns an error.
// Returns the amount of base tokens received.
func (k Keeper) Withdraw(ctx sdk.Context, supplierAddr sdk.AccAddress, uToken sdk.Coin) (sdk.Coin, error) {
if err := validateUToken(uToken); err != nil {
return sdk.Coin{}, err
}
// calculate base asset amount to withdraw
token, err := k.ExchangeUToken(ctx, uToken)
if err != nil {
return sdk.Coin{}, err
}
// Ensure module account has sufficient unreserved tokens to withdraw
availableAmount := k.AvailableLiquidity(ctx, token.Denom)
if token.Amount.GT(availableAmount) {
return sdk.Coin{}, sdkerrors.Wrap(types.ErrLendingPoolInsufficient, token.String())
}
// Withdraw will first attempt to use any uTokens in the supplier's wallet
amountFromWallet := sdk.MinInt(k.bankKeeper.SpendableCoins(ctx, supplierAddr).AmountOf(uToken.Denom), uToken.Amount)
// Any additional uTokens must come from the supplier's collateral
amountFromCollateral := uToken.Amount.Sub(amountFromWallet)
if amountFromCollateral.IsPositive() {
// Calculate current borrowed value
borrowed := k.GetBorrowerBorrows(ctx, supplierAddr)
borrowedValue, err := k.TotalTokenValue(ctx, borrowed)
if err != nil {
return sdk.Coin{}, err
}
// Check for sufficient collateral
collateral := k.GetBorrowerCollateral(ctx, supplierAddr)
collateralAmount := collateral.AmountOf(uToken.Denom)
if collateral.AmountOf(uToken.Denom).LT(amountFromCollateral) {
return sdk.Coin{}, types.ErrInsufficientBalance.Wrapf(
"%s uToken balance + %s from collateral is less than %s to withdraw",
amountFromWallet, collateralAmount, uToken)
}
// Calculate what borrow limit will be AFTER this withdrawal
collateralToWithdraw := sdk.NewCoin(uToken.Denom, amountFromCollateral)
newBorrowLimit, err := k.CalculateBorrowLimit(ctx, collateral.Sub(collateralToWithdraw))
if err != nil {
return sdk.Coin{}, err
}
// Return error if borrow limit would drop below borrowed value
if borrowedValue.GT(newBorrowLimit) {
return sdk.Coin{}, types.ErrUndercollaterized.Wrapf(
"withdraw would decrease borrow limit to %s, below the current borrowed value %s", newBorrowLimit, borrowedValue)
}
// reduce the supplier's collateral by amountFromCollateral
newCollateral := sdk.NewCoin(uToken.Denom, collateralAmount.Sub(amountFromCollateral))
if err = k.setCollateral(ctx, supplierAddr, newCollateral); err != nil {
return sdk.Coin{}, err
}
}
// transfer amountFromWallet uTokens to the module account
uTokens := sdk.NewCoins(sdk.NewCoin(uToken.Denom, amountFromWallet))
if err = k.bankKeeper.SendCoinsFromAccountToModule(ctx, supplierAddr, types.ModuleName, uTokens); err != nil {
return sdk.Coin{}, err
}
// send the base assets to supplier
tokens := sdk.NewCoins(token)
if err = k.bankKeeper.SendCoinsFromModuleToAccount(ctx, types.ModuleName, supplierAddr, tokens); err != nil {
return sdk.Coin{}, err
}
// burn the uTokens and set the new total uToken supply
if err = k.bankKeeper.BurnCoins(ctx, types.ModuleName, sdk.NewCoins(uToken)); err != nil {
return sdk.Coin{}, err
}
if err = k.setUTokenSupply(ctx, k.GetUTokenSupply(ctx, uToken.Denom).Sub(uToken)); err != nil {
return sdk.Coin{}, err
}
// check MinCollateralLiquidity is still satisfied after the transaction
if err = k.checkCollateralLiquidity(ctx, token.Denom); err != nil {
return sdk.Coin{}, err
}
return token, nil
}
// Borrow attempts to borrow tokens from the leverage module account using
// collateral uTokens. If asset type is invalid, collateral is insufficient,
// or module balance is insufficient, we return an error.
func (k Keeper) Borrow(ctx sdk.Context, borrowerAddr sdk.AccAddress, borrow sdk.Coin) error {
if err := k.validateBorrow(ctx, borrow); err != nil {
return err
}
// Ensure module account has sufficient unreserved tokens to loan out
availableAmount := k.AvailableLiquidity(ctx, borrow.Denom)
if borrow.Amount.GT(availableAmount) {
return types.ErrLendingPoolInsufficient.Wrap(borrow.String())
}
// Determine amount of all tokens currently borrowed
borrowed := k.GetBorrowerBorrows(ctx, borrowerAddr)
// Calculate current borrow limit
collateral := k.GetBorrowerCollateral(ctx, borrowerAddr)
borrowLimit, err := k.CalculateBorrowLimit(ctx, collateral)
if err != nil {
return err
}
// Calculate borrowed value will be AFTER this borrow
newBorrowedValue, err := k.TotalTokenValue(ctx, borrowed.Add(borrow))
if err != nil {
return err
}
// Return error if borrowed value would exceed borrow limit
if newBorrowedValue.GT(borrowLimit) {
return types.ErrUndercollaterized.Wrapf("new borrowed value would be %s with borrow limit %s",
newBorrowedValue, borrowLimit)
}
loanTokens := sdk.NewCoins(borrow)
if err := k.bankKeeper.SendCoinsFromModuleToAccount(ctx, types.ModuleName, borrowerAddr, loanTokens); err != nil {
return err
}
// Determine the total amount of denom borrowed (previously borrowed + newly borrowed)
newBorrow := borrowed.AmountOf(borrow.Denom).Add(borrow.Amount)
if err := k.setBorrow(ctx, borrowerAddr, sdk.NewCoin(borrow.Denom, newBorrow)); err != nil {
return err
}
// Check MaxSupplyUtilization after transaction
token, err := k.GetTokenSettings(ctx, borrow.Denom)
if err != nil {
return err
}
utilization := k.SupplyUtilization(ctx, borrow.Denom)
if utilization.GT(token.MaxSupplyUtilization) {
return types.ErrMaxSupplyUtilization.Wrap(utilization.String())
}
// check MinCollateralLiquidity is still satisfied after the transaction
return k.checkCollateralLiquidity(ctx, borrow.Denom)
}
// Repay attempts to repay a borrow position. If asset type is invalid, account balance
// is insufficient, or borrower has no borrows in payment denom to repay, we return an error.
// Additionally, if the amount provided is greater than the full repayment amount, only the
// necessary amount is transferred. Because amount repaid may be less than the repayment attempted,
// Repay returns the actual amount repaid.
func (k Keeper) Repay(ctx sdk.Context, borrowerAddr sdk.AccAddress, payment sdk.Coin) (sdk.Coin, error) {
if err := validateBaseToken(payment); err != nil {
return sdk.Coin{}, err
}
// determine amount of selected denom currently owed
owed := k.GetBorrow(ctx, borrowerAddr, payment.Denom)
if owed.IsZero() {
return sdk.Coin{}, types.ErrDenomNotBorrowed.Wrap(payment.Denom)
}
// prevent overpaying
payment.Amount = sdk.MinInt(owed.Amount, payment.Amount)
// send payment to leverage module account
if err := k.repayBorrow(ctx, borrowerAddr, borrowerAddr, payment); err != nil {
return sdk.Coin{}, err
}
return payment, nil
}
// Collateralize enables selected uTokens for use as collateral by a single borrower.
func (k Keeper) Collateralize(ctx sdk.Context, borrowerAddr sdk.AccAddress, uToken sdk.Coin) error {
if err := k.validateCollateralize(ctx, uToken); err != nil {
return err
}
currentCollateral := k.GetCollateral(ctx, borrowerAddr, uToken.Denom)
if err := k.setCollateral(ctx, borrowerAddr, currentCollateral.Add(uToken)); err != nil {
return err
}
err := k.bankKeeper.SendCoinsFromAccountToModule(ctx, borrowerAddr, types.ModuleName, sdk.NewCoins(uToken))
if err != nil {
return err
}
if err := k.checkCollateralLiquidity(ctx, types.ToTokenDenom(uToken.Denom)); err != nil {
return err
}
return k.checkCollateralShare(ctx, uToken.Denom)
}
// Decollateralize disables selected uTokens for use as collateral by a single borrower.
func (k Keeper) Decollateralize(ctx sdk.Context, borrowerAddr sdk.AccAddress, uToken sdk.Coin) error {
if err := validateUToken(uToken); err != nil {
return err
}
// Detect where sufficient collateral exists to disable
collateral := k.GetBorrowerCollateral(ctx, borrowerAddr)
if collateral.AmountOf(uToken.Denom).LT(uToken.Amount) {
return types.ErrInsufficientCollateral
}
// Determine what borrow limit would be AFTER disabling this denom as collateral
newBorrowLimit, err := k.CalculateBorrowLimit(ctx, collateral.Sub(uToken))
if err != nil {
return err
}
// Determine currently borrowed value
borrowed := k.GetBorrowerBorrows(ctx, borrowerAddr)
borrowedValue, err := k.TotalTokenValue(ctx, borrowed)
if err != nil {
return err
}
// Return error if borrow limit would drop below borrowed value
if newBorrowLimit.LT(borrowedValue) {
return types.ErrUndercollaterized.Wrap("new borrow limit: " + newBorrowLimit.String())
}
// Disabling uTokens as collateral withdraws any stored collateral of the denom in question
// from the module account and returns it to the user
newCollateralAmount := collateral.AmountOf(uToken.Denom).Sub(uToken.Amount)
if err := k.setCollateral(ctx, borrowerAddr, sdk.NewCoin(uToken.Denom, newCollateralAmount)); err != nil {
return err
}
return k.bankKeeper.SendCoinsFromModuleToAccount(ctx, types.ModuleName, borrowerAddr, sdk.NewCoins(uToken))
}
// Liquidate attempts to repay one of an eligible borrower's borrows (in part or in full) in exchange for
// some of the borrower's uToken collateral or associated base tokens. If the borrower is not over their
// liquidation limit, or the repayment or reward denominations are invalid, an error is returned. If the
// attempted repayment is greater than the amount owed or the maximum that can be repaid due to parameters
// or available balances, then a partial liquidation, equal to the maximum valid amount, is performed.
// Because partial liquidation is possible and exchange rates vary, Liquidate returns the actual amount of
// tokens repaid, collateral liquidated, and base tokens or uTokens rewarded.
func (k Keeper) Liquidate(
ctx sdk.Context, liquidatorAddr, borrowerAddr sdk.AccAddress, requestedRepay sdk.Coin, rewardDenom string,
) (repaid sdk.Coin, liquidated sdk.Coin, reward sdk.Coin, err error) {
if err := k.validateAcceptedAsset(ctx, requestedRepay); err != nil {
return sdk.Coin{}, sdk.Coin{}, sdk.Coin{}, err
}
// detect if the user selected a base token reward instead of a uToken
directLiquidation := !types.HasUTokenPrefix(rewardDenom)
if !directLiquidation {
// convert rewardDenom to base token
rewardDenom = types.ToTokenDenom(rewardDenom)
}
// ensure that base reward is a registered token
if err := k.validateAcceptedDenom(ctx, rewardDenom); err != nil {
return sdk.Coin{}, sdk.Coin{}, sdk.Coin{}, err
}
tokenRepay, uTokenLiquidate, tokenReward, err := k.getLiquidationAmounts(
ctx,
liquidatorAddr,
borrowerAddr,
requestedRepay,
rewardDenom,
directLiquidation,
)
if err != nil {
return sdk.Coin{}, sdk.Coin{}, sdk.Coin{}, err
}
if tokenRepay.IsZero() {
// Zero repay amount returned from liquidation computation means the target was eligible for liquidation
// but the proposed reward and repayment would have zero effect.
return sdk.Coin{}, sdk.Coin{}, sdk.Coin{}, types.ErrLiquidationRepayZero
}
// repay some of the borrower's debt using the liquidator's balance
if err = k.repayBorrow(ctx, liquidatorAddr, borrowerAddr, tokenRepay); err != nil {
return sdk.Coin{}, sdk.Coin{}, sdk.Coin{}, err
}
if directLiquidation {
err = k.liquidateCollateral(ctx, borrowerAddr, liquidatorAddr, uTokenLiquidate, tokenReward)
} else {
// send uTokens from borrower collateral to liquidator's account
err = k.decollateralize(ctx, borrowerAddr, liquidatorAddr, uTokenLiquidate)
}
if err != nil {
return sdk.Coin{}, sdk.Coin{}, sdk.Coin{}, err
}
// if borrower's collateral has reached zero, mark any remaining borrows as bad debt
if err := k.checkBadDebt(ctx, borrowerAddr); err != nil {
return sdk.Coin{}, sdk.Coin{}, sdk.Coin{}, err
}
// the last return value is the liquidator's selected reward
if directLiquidation {
return tokenRepay, uTokenLiquidate, tokenReward, nil
}
return tokenRepay, uTokenLiquidate, uTokenLiquidate, nil
}