laconicd/x/auction/keeper/keeper.go

659 lines
21 KiB
Go

package keeper
import (
"encoding/hex"
"encoding/json"
"fmt"
"time"
"github.com/cerc-io/laconicd/x/auction/types"
"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"
auth "github.com/cosmos/cosmos-sdk/x/auth/keeper"
bank "github.com/cosmos/cosmos-sdk/x/bank/keeper"
params "github.com/cosmos/cosmos-sdk/x/params/types"
wnsUtils "github.com/cerc-io/laconicd/utils"
)
// CompletedAuctionDeleteTimeout => Completed auctions are deleted after this timeout (after reveals end time).
const CompletedAuctionDeleteTimeout = time.Hour * 24
// PrefixIDToAuctionIndex is the prefix for Id -> Auction index in the KVStore.
// Note: This is the primary index in the system.
// Note: Golang doesn't support const arrays.
var PrefixIDToAuctionIndex = []byte{0x00}
// prefixOwnerToAuctionsIndex is the prefix for the Owner -> [Auction] index in the KVStore.
var prefixOwnerToAuctionsIndex = []byte{0x01}
// PrefixAuctionBidsIndex is the prefix for the (auction, bidder) -> Bid index in the KVStore.
var PrefixAuctionBidsIndex = []byte{0x02}
// PrefixBidderToAuctionsIndex is the prefix for the Bidder -> [Auction] index in the KVStore.
var PrefixBidderToAuctionsIndex = []byte{0x03}
// Keeper maintains the link to storage and exposes getter/setter methods for the various parts of the state machine
type Keeper struct {
accountKeeper auth.AccountKeeper
bankKeeper bank.Keeper
// Track auction usage in other cosmos-sdk modules (more like a usage tracker).
usageKeepers []types.AuctionUsageKeeper
storeKey storetypes.StoreKey // Unexposed key to access store from sdk.Context
cdc codec.BinaryCodec // The wire codec for binary encoding/decoding.
paramSubspace params.Subspace
}
// AuctionClientKeeper is the subset of functionality exposed to other modules.
type AuctionClientKeeper interface {
HasAuction(ctx sdk.Context, id string) bool
GetAuction(ctx sdk.Context, id string) types.Auction
MatchAuctions(ctx sdk.Context, matchFn func(*types.Auction) bool) []*types.Auction
}
// NewKeeper creates new instances of the auction Keeper
func NewKeeper(accountKeeper auth.AccountKeeper, bankKeeper bank.Keeper, storeKey storetypes.StoreKey, cdc codec.BinaryCodec, ps params.Subspace) Keeper {
if !ps.HasKeyTable() {
ps = ps.WithKeyTable(types.ParamKeyTable())
}
return Keeper{
accountKeeper: accountKeeper,
bankKeeper: bankKeeper,
storeKey: storeKey,
cdc: cdc,
paramSubspace: ps,
}
}
func (k *Keeper) SetUsageKeepers(usageKeepers []types.AuctionUsageKeeper) {
k.usageKeepers = usageKeepers
}
func (k Keeper) GetUsageKeepers() []types.AuctionUsageKeeper {
return k.usageKeepers
}
// Generates Auction Id -> Auction index key.
func GetAuctionIndexKey(id string) []byte {
return append(PrefixIDToAuctionIndex, []byte(id)...)
}
// Generates Owner -> Auctions index key.
func GetOwnerToAuctionsIndexKey(owner string, auctionID string) []byte {
return append(append(prefixOwnerToAuctionsIndex, []byte(owner)...), []byte(auctionID)...)
}
func GetBidderToAuctionsIndexKey(bidder string, auctionID string) []byte {
return append(append(PrefixBidderToAuctionsIndex, []byte(bidder)...), []byte(auctionID)...)
}
func GetBidIndexKey(auctionID string, bidder string) []byte {
return append(GetAuctionBidsIndexPrefix(auctionID), []byte(bidder)...)
}
func GetAuctionBidsIndexPrefix(auctionID string) []byte {
return append(append(PrefixAuctionBidsIndex, []byte(auctionID)...))
}
// SaveAuction - saves a auction to the store.
func (k Keeper) SaveAuction(ctx sdk.Context, auction *types.Auction) {
store := ctx.KVStore(k.storeKey)
// Auction Id -> Auction index.
store.Set(GetAuctionIndexKey(auction.Id), k.cdc.MustMarshal(auction))
// Owner -> [Auction] index.
store.Set(GetOwnerToAuctionsIndexKey(auction.OwnerAddress, auction.Id), []byte{})
// Notify interested parties.
for _, keeper := range k.usageKeepers {
keeper.OnAuction(ctx, auction.Id)
}
}
func (k Keeper) SaveBid(ctx sdk.Context, bid *types.Bid) {
store := ctx.KVStore(k.storeKey)
store.Set(GetBidIndexKey(bid.AuctionId, bid.BidderAddress), k.cdc.MustMarshal(bid))
store.Set(GetBidderToAuctionsIndexKey(bid.BidderAddress, bid.AuctionId), []byte{})
// Notify interested parties.
for _, keeper := range k.usageKeepers {
keeper.OnAuctionBid(ctx, bid.AuctionId, bid.BidderAddress)
}
}
func (k Keeper) DeleteBid(ctx sdk.Context, bid types.Bid) {
store := ctx.KVStore(k.storeKey)
store.Delete(GetBidIndexKey(bid.AuctionId, bid.BidderAddress))
store.Delete(GetOwnerToAuctionsIndexKey(bid.BidderAddress, bid.AuctionId))
}
// HasAuction - checks if a auction by the given Id exists.
func (k Keeper) HasAuction(ctx sdk.Context, id string) bool {
store := ctx.KVStore(k.storeKey)
return store.Has(GetAuctionIndexKey(id))
}
func (k Keeper) HasBid(ctx sdk.Context, id string, bidder string) bool {
store := ctx.KVStore(k.storeKey)
return store.Has(GetBidIndexKey(id, bidder))
}
// DeleteAuction - deletes the auction.
func (k Keeper) DeleteAuction(ctx sdk.Context, auction types.Auction) {
// Delete all bids first.
bids := k.GetBids(ctx, auction.Id)
for _, bid := range bids {
k.DeleteBid(ctx, *bid)
}
// Delete the auction itself.
store := ctx.KVStore(k.storeKey)
store.Delete(GetAuctionIndexKey(auction.Id))
store.Delete(GetOwnerToAuctionsIndexKey(auction.OwnerAddress, auction.Id))
}
// GetAuction - gets a record from the store.
func (k Keeper) GetAuction(ctx sdk.Context, id string) *types.Auction {
store := ctx.KVStore(k.storeKey)
auctionKey := GetAuctionIndexKey(id)
if !store.Has(auctionKey) {
return nil
}
bz := store.Get(auctionKey)
var obj types.Auction
k.cdc.MustUnmarshal(bz, &obj)
return &obj
}
// GetBids gets the auction bids.
func (k Keeper) GetBids(ctx sdk.Context, id string) []*types.Bid {
store := ctx.KVStore(k.storeKey)
bids := []*types.Bid{}
itr := sdk.KVStorePrefixIterator(store, GetAuctionBidsIndexPrefix(id))
defer itr.Close()
for ; itr.Valid(); itr.Next() {
bz := store.Get(itr.Key())
if bz != nil {
var obj types.Bid
k.cdc.MustUnmarshal(bz, &obj)
bids = append(bids, &obj)
}
}
return bids
}
func (k Keeper) GetBid(ctx sdk.Context, id string, bidder string) types.Bid {
store := ctx.KVStore(k.storeKey)
bz := store.Get(GetBidIndexKey(id, bidder))
var obj types.Bid
k.cdc.MustUnmarshal(bz, &obj)
return obj
}
// ListAuctions - get all auctions.
func (k Keeper) ListAuctions(ctx sdk.Context) []types.Auction {
var auctions []types.Auction
store := ctx.KVStore(k.storeKey)
itr := sdk.KVStorePrefixIterator(store, PrefixIDToAuctionIndex)
defer itr.Close()
for ; itr.Valid(); itr.Next() {
bz := store.Get(itr.Key())
if bz != nil {
var obj types.Auction
k.cdc.MustUnmarshal(bz, &obj)
auctions = append(auctions, obj)
}
}
return auctions
}
// QueryAuctionsByOwner - query auctions by owner.
func (k Keeper) QueryAuctionsByOwner(ctx sdk.Context, ownerAddress string) []types.Auction {
auctions := []types.Auction{}
ownerPrefix := append(prefixOwnerToAuctionsIndex, []byte(ownerAddress)...)
store := ctx.KVStore(k.storeKey)
itr := sdk.KVStorePrefixIterator(store, ownerPrefix)
defer itr.Close()
for ; itr.Valid(); itr.Next() {
auctionID := itr.Key()[len(ownerPrefix):]
bz := store.Get(append(PrefixIDToAuctionIndex, auctionID...))
if bz != nil {
var obj types.Auction
k.cdc.MustUnmarshal(bz, &obj)
auctions = append(auctions, obj)
}
}
return auctions
}
// QueryAuctionsByBidder - query auctions by bidder
func (k Keeper) QueryAuctionsByBidder(ctx sdk.Context, bidderAddress string) []types.Auction {
auctions := []types.Auction{}
bidderPrefix := append(PrefixBidderToAuctionsIndex, []byte(bidderAddress)...)
store := ctx.KVStore(k.storeKey)
itr := sdk.KVStorePrefixIterator(store, []byte(bidderPrefix))
defer itr.Close()
for ; itr.Valid(); itr.Next() {
auctionID := itr.Key()[len(bidderPrefix):]
bz := store.Get(append(PrefixIDToAuctionIndex, auctionID...))
if bz != nil {
var obj types.Auction
k.cdc.MustUnmarshal(bz, &obj)
auctions = append(auctions, obj)
}
}
return auctions
}
// MatchAuctions - get all matching auctions.
func (k Keeper) MatchAuctions(ctx sdk.Context, matchFn func(*types.Auction) bool) []*types.Auction {
var auctions []*types.Auction
store := ctx.KVStore(k.storeKey)
itr := sdk.KVStorePrefixIterator(store, PrefixIDToAuctionIndex)
defer itr.Close()
for ; itr.Valid(); itr.Next() {
bz := store.Get(itr.Key())
if bz != nil {
var obj types.Auction
k.cdc.MustUnmarshal(bz, &obj)
if matchFn(&obj) {
auctions = append(auctions, &obj)
}
}
}
return auctions
}
// CreateAuction creates a new auction.
func (k Keeper) CreateAuction(ctx sdk.Context, msg types.MsgCreateAuction) (*types.Auction, error) {
// Might be called from another module directly, always validate.
err := msg.ValidateBasic()
if err != nil {
return nil, err
}
signerAddress, err := sdk.AccAddressFromBech32(msg.Signer)
if err != nil {
return nil, err
}
// Generate auction Id.
account := k.accountKeeper.GetAccount(ctx, signerAddress)
if account == nil {
return nil, sdkerrors.Wrap(sdkerrors.ErrInvalidAddress, "Account not found.")
}
auctionID := types.AuctionID{
Address: signerAddress,
AccNum: account.GetAccountNumber(),
Sequence: account.GetSequence(),
}.Generate()
// Compute timestamps.
now := ctx.BlockTime()
commitsEndTime := now.Add(time.Duration(msg.CommitsDuration))
revealsEndTime := now.Add(time.Duration(msg.CommitsDuration + msg.RevealsDuration))
auction := types.Auction{
Id: auctionID,
Status: types.AuctionStatusCommitPhase,
OwnerAddress: signerAddress.String(),
CreateTime: now,
CommitsEndTime: commitsEndTime,
RevealsEndTime: revealsEndTime,
CommitFee: msg.CommitFee,
RevealFee: msg.RevealFee,
MinimumBid: msg.MinimumBid,
}
// Save auction in store.
k.SaveAuction(ctx, &auction)
return &auction, nil
}
func (k Keeper) CommitBid(ctx sdk.Context, msg types.MsgCommitBid) (*types.Bid, error) {
if !k.HasAuction(ctx, msg.AuctionId) {
return nil, sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "Auction not found.")
}
auction := k.GetAuction(ctx, msg.AuctionId)
if auction.Status != types.AuctionStatusCommitPhase {
return nil, sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "Auction is not in commit phase.")
}
signerAddress, err := sdk.AccAddressFromBech32(msg.Signer)
if err != nil {
return nil, err
}
// Take auction fees from account.
totalFee := auction.CommitFee.Add(auction.RevealFee)
sdkErr := k.bankKeeper.SendCoinsFromAccountToModule(ctx, signerAddress, types.ModuleName, sdk.NewCoins(totalFee))
if sdkErr != nil {
return nil, sdkErr
}
// Check if an old bid already exists, if so, return old bids auction fee (update bid scenario).
bidder := signerAddress.String()
if k.HasBid(ctx, msg.AuctionId, bidder) {
oldBid := k.GetBid(ctx, msg.AuctionId, bidder)
oldTotalFee := oldBid.CommitFee.Add(oldBid.RevealFee)
sdkErr := k.bankKeeper.SendCoinsFromModuleToAccount(ctx, types.ModuleName, signerAddress, sdk.NewCoins(oldTotalFee))
if sdkErr != nil {
return nil, sdkErr
}
}
// Save new bid.
bid := types.Bid{
AuctionId: msg.AuctionId,
BidderAddress: bidder,
Status: types.BidStatusCommitted,
CommitHash: msg.CommitHash,
CommitTime: ctx.BlockTime(),
CommitFee: auction.CommitFee,
RevealFee: auction.RevealFee,
}
k.SaveBid(ctx, &bid)
return &bid, nil
}
// RevealBid reeals a bid comitted earlier.
func (k Keeper) RevealBid(ctx sdk.Context, msg types.MsgRevealBid) (*types.Auction, error) {
if !k.HasAuction(ctx, msg.AuctionId) {
return nil, sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "Auction not found.")
}
auction := k.GetAuction(ctx, msg.AuctionId)
if auction.Status != types.AuctionStatusRevealPhase {
return nil, sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "Auction is not in reveal phase.")
}
signerAddress, err := sdk.AccAddressFromBech32(msg.Signer)
if err != nil {
return nil, err
}
if !k.HasBid(ctx, msg.AuctionId, signerAddress.String()) {
return nil, sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "Bid not found.")
}
bid := k.GetBid(ctx, auction.Id, signerAddress.String())
if bid.Status != types.BidStatusCommitted {
return nil, sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "Bid not in committed state.")
}
revealBytes, err := hex.DecodeString(msg.Reveal)
if err != nil {
return nil, sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "Invalid reveal string.")
}
cid, err := wnsUtils.CIDFromJSONBytes(revealBytes)
if err != nil {
return nil, sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "Invalid reveal JSON.")
}
if bid.CommitHash != cid {
return nil, sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "Commit hash mismatch.")
}
var reveal map[string]interface{}
err = json.Unmarshal(revealBytes, &reveal)
if err != nil {
return nil, sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "Reveal JSON unmarshal error.")
}
chainID, err := wnsUtils.GetAttributeAsString(reveal, "chainId")
if err != nil || chainID != ctx.ChainID() {
return nil, sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "Invalid reveal chainID.")
}
auctionID, err := wnsUtils.GetAttributeAsString(reveal, "auctionId")
if err != nil || auctionID != msg.AuctionId {
return nil, sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "Invalid reveal auction Id.")
}
bidderAddress, err := wnsUtils.GetAttributeAsString(reveal, "bidderAddress")
if err != nil {
return nil, sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "Invalid reveal bid address.")
}
if bidderAddress != signerAddress.String() {
return nil, sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "Reveal bid address mismatch.")
}
bidAmountStr, err := wnsUtils.GetAttributeAsString(reveal, "bidAmount")
if err != nil {
return nil, sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "Invalid reveal bid amount.")
}
bidAmount, err := sdk.ParseCoinNormalized(bidAmountStr)
if err != nil {
return nil, sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "Invalid reveal bid amount.")
}
if bidAmount.IsLT(auction.MinimumBid) {
return nil, sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "Bid is lower than minimum bid.")
}
// Lock bid amount.
sdkErr := k.bankKeeper.SendCoinsFromAccountToModule(ctx, signerAddress, types.ModuleName, sdk.NewCoins(bidAmount))
if sdkErr != nil {
return nil, sdkErr
}
// Update bid.
bid.BidAmount = bidAmount
bid.RevealTime = ctx.BlockTime()
bid.Status = types.BidStatusRevealed
k.SaveBid(ctx, &bid)
return auction, nil
}
// GetAuctionModuleBalances gets the auction module account(s) balances.
func (k Keeper) GetAuctionModuleBalances(ctx sdk.Context) sdk.Coins {
moduleAddress := k.accountKeeper.GetModuleAddress(types.ModuleName)
balances := k.bankKeeper.GetAllBalances(ctx, moduleAddress)
return balances
}
func (k Keeper) EndBlockerProcessAuctions(ctx sdk.Context) {
// Transition auction state (commit, reveal, expired, completed).
k.processAuctionPhases(ctx)
// Delete stale auctions.
k.deleteCompletedAuctions(ctx)
}
func (k Keeper) processAuctionPhases(ctx sdk.Context) {
auctions := k.MatchAuctions(ctx, func(_ *types.Auction) bool {
return true
})
for _, auction := range auctions {
// Commit -> Reveal state.
if auction.Status == types.AuctionStatusCommitPhase && ctx.BlockTime().After(auction.CommitsEndTime) {
auction.Status = types.AuctionStatusRevealPhase
k.SaveAuction(ctx, auction)
ctx.Logger().Info(fmt.Sprintf("Moved auction %s to reveal phase.", auction.Id))
}
// Reveal -> Expired state.
if auction.Status == types.AuctionStatusRevealPhase && ctx.BlockTime().After(auction.RevealsEndTime) {
auction.Status = types.AuctionStatusExpired
k.SaveAuction(ctx, auction)
ctx.Logger().Info(fmt.Sprintf("Moved auction %s to expired state.", auction.Id))
}
// If auction has expired, pick a winner from revealed bids.
if auction.Status == types.AuctionStatusExpired {
k.pickAuctionWinner(ctx, auction)
}
}
}
// Delete completed stale auctions.
func (k Keeper) deleteCompletedAuctions(ctx sdk.Context) {
auctions := k.MatchAuctions(ctx, func(auction *types.Auction) bool {
deleteTime := auction.RevealsEndTime.Add(CompletedAuctionDeleteTimeout)
return auction.Status == types.AuctionStatusCompleted && ctx.BlockTime().After(deleteTime)
})
for _, auction := range auctions {
ctx.Logger().Info(fmt.Sprintf("Deleting completed auction %s after timeout.", auction.Id))
k.DeleteAuction(ctx, *auction)
}
}
func (k Keeper) pickAuctionWinner(ctx sdk.Context, auction *types.Auction) {
ctx.Logger().Info(fmt.Sprintf("Picking auction %s winner.", auction.Id))
var highestBid *types.Bid
var secondHighestBid *types.Bid
bids := k.GetBids(ctx, auction.Id)
for _, bid := range bids {
ctx.Logger().Info(fmt.Sprintf("Processing bid %s %s", bid.BidderAddress, bid.BidAmount.String()))
// Only consider revealed bids.
if bid.Status != types.BidStatusRevealed {
ctx.Logger().Info(fmt.Sprintf("Ignoring unrevealed bid %s %s", bid.BidderAddress, bid.BidAmount.String()))
continue
}
// Init highest bid.
if highestBid == nil {
highestBid = bid
ctx.Logger().Info(fmt.Sprintf("Initializing 1st bid %s %s", bid.BidderAddress, bid.BidAmount.String()))
continue
}
if highestBid.BidAmount.IsLT(bid.BidAmount) {
ctx.Logger().Info(fmt.Sprintf("New highest bid %s %s", bid.BidderAddress, bid.BidAmount.String()))
secondHighestBid = highestBid
highestBid = bid
ctx.Logger().Info(fmt.Sprintf("Updated 1st bid %s %s", highestBid.BidderAddress, highestBid.BidAmount.String()))
ctx.Logger().Info(fmt.Sprintf("Updated 2nd bid %s %s", secondHighestBid.BidderAddress, secondHighestBid.BidAmount.String()))
} else if secondHighestBid == nil || secondHighestBid.BidAmount.IsLT(bid.BidAmount) {
ctx.Logger().Info(fmt.Sprintf("New 2nd highest bid %s %s", bid.BidderAddress, bid.BidAmount.String()))
secondHighestBid = bid
ctx.Logger().Info(fmt.Sprintf("Updated 2nd bid %s %s", secondHighestBid.BidderAddress, secondHighestBid.BidAmount.String()))
} else {
ctx.Logger().Info(fmt.Sprintf("Ignoring bid as it doesn't affect 1st/2nd price %s %s", bid.BidderAddress, bid.BidAmount.String()))
}
}
// Highest bid is the winner, but pays second highest bid price.
auction.Status = types.AuctionStatusCompleted
if highestBid != nil {
auction.WinnerAddress = highestBid.BidderAddress
auction.WinningBid = highestBid.BidAmount
// Winner pays 2nd price, if a 2nd price exists.
auction.WinningPrice = highestBid.BidAmount
if secondHighestBid != nil {
auction.WinningPrice = secondHighestBid.BidAmount
}
ctx.Logger().Info(fmt.Sprintf("Auction %s winner %s.", auction.Id, auction.WinnerAddress))
ctx.Logger().Info(fmt.Sprintf("Auction %s winner bid %s.", auction.Id, auction.WinningBid.String()))
ctx.Logger().Info(fmt.Sprintf("Auction %s winner price %s.", auction.Id, auction.WinningPrice.String()))
} else {
ctx.Logger().Info(fmt.Sprintf("Auction %s has no valid revealed bids (no winner).", auction.Id))
}
k.SaveAuction(ctx, auction)
for _, bid := range bids {
bidderAddress, err := sdk.AccAddressFromBech32(bid.BidderAddress)
if err != nil {
ctx.Logger().Error(fmt.Sprintf("Invalid bidderAddress address. %v", err))
panic("Invalid bidder address.")
}
if bid.Status == types.BidStatusRevealed {
// Send reveal fee back to bidders that've revealed the bid.
sdkErr := k.bankKeeper.SendCoinsFromModuleToAccount(ctx, types.ModuleName, bidderAddress, sdk.NewCoins(bid.RevealFee))
if sdkErr != nil {
ctx.Logger().Error(fmt.Sprintf("Auction error returning reveal fee: %v", sdkErr))
panic(sdkErr)
}
}
// Send back locked bid amount to all bidders.
sdkErr := k.bankKeeper.SendCoinsFromModuleToAccount(ctx, types.ModuleName, bidderAddress, sdk.NewCoins(bid.BidAmount))
if sdkErr != nil {
ctx.Logger().Error(fmt.Sprintf("Auction error returning bid amount: %v", sdkErr))
panic(sdkErr)
}
}
// Process winner account (if nobody bids, there won't be a winner).
if auction.WinnerAddress != "" {
winnerAddress, err := sdk.AccAddressFromBech32(auction.WinnerAddress)
if err != nil {
ctx.Logger().Error(fmt.Sprintf("Invalid winner address. %v", err))
panic("Invalid winner address.")
}
// Take 2nd price from winner.
sdkErr := k.bankKeeper.SendCoinsFromAccountToModule(ctx, winnerAddress, types.ModuleName, sdk.NewCoins(auction.WinningPrice))
if sdkErr != nil {
ctx.Logger().Error(fmt.Sprintf("Auction error taking funds from winner: %v", sdkErr))
panic(sdkErr)
}
// Burn anything over the min. bid amount.
amountToBurn := auction.WinningPrice.Sub(auction.MinimumBid)
if amountToBurn.IsNegative() {
ctx.Logger().Error(fmt.Sprintf("Auction coins to burn cannot be negative."))
panic("Auction coins to burn cannot be negative.")
}
// Use auction burn module account instead of actually burning coins to better keep track of supply.
sdkErr = k.bankKeeper.SendCoinsFromModuleToModule(ctx, types.ModuleName, types.AuctionBurnModuleAccountName, sdk.NewCoins(amountToBurn))
if sdkErr != nil {
ctx.Logger().Error(fmt.Sprintf("Auction error burning coins: %v", sdkErr))
panic(sdkErr)
}
}
// Notify other modules (hook).
ctx.Logger().Info(fmt.Sprintf("Auction %s notifying %d modules.", auction.Id, len(k.usageKeepers)))
for _, keeper := range k.usageKeepers {
ctx.Logger().Info(fmt.Sprintf("Auction %s notifying module %s.", auction.Id, keeper.ModuleName()))
keeper.OnAuctionWinnerSelected(ctx, auction.Id)
}
}