Emit CW721 token owner before transfer

x/wasm/keeper/keeper.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/binary"
+	"encoding/json"
 	"fmt"
 	"math"
 	"path/filepath"
@@ -371,6 +372,7 @@ func (k Keeper) execute(ctx sdk.Context, contractAddress sdk.AccAddress, caller
 	// prepare querier
 	querier := k.newQueryHandler(ctx, contractAddress)
 	gas := k.runtimeGasForContract(ctx)
+	k.emitCW721OwnerBeforeTransferIfApplicable(ctx, contractAddress, msg)
 	res, gasUsed, execErr := k.wasmVM.Execute(codeInfo.CodeHash, env, info, msg, prefixStore, cosmwasmAPI, querier, k.gasMeter(ctx), gas, costJSONDeserialization)
 	k.consumeRuntimeGas(ctx, gasUsed)
 	if execErr != nil {
@@ -1072,6 +1074,53 @@ func (k Keeper) newQueryHandler(ctx sdk.Context, contractAddress sdk.AccAddress)
 	return NewQueryHandler(ctx, k.wasmVMQueryHandler, contractAddress, k.gasRegister)
 }
 
+func (k Keeper) emitCW721OwnerBeforeTransferIfApplicable(ctx sdk.Context, contractAddress sdk.AccAddress, msg []byte) {
+	parsedMsg := map[string]json.RawMessage{}
+	if err := json.Unmarshal(msg, &parsedMsg); err != nil {
+		return
+	}
+	subMsg, ok := parsedMsg["transfer_nft"]
+	if !ok {
+		subMsg, ok = parsedMsg["send_nft"]
+	}
+	if !ok {
+		subMsg, ok = parsedMsg["burn"]
+	}
+	if !ok {
+		return
+	}
+	parsedSubMsg := map[string]json.RawMessage{}
+	if err := json.Unmarshal(subMsg, &parsedSubMsg); err != nil {
+		return
+	}
+	if tokenBz, ok := parsedSubMsg["token_id"]; ok && len(tokenBz) > 2 {
+		tokenID := string(tokenBz[1 : len(tokenBz)-1])
+		ownerQuery := map[string]interface{}{"owner_of": map[string]string{
+			"token_id": tokenID,
+		}}
+		ownerQueryBz, err := json.Marshal(ownerQuery)
+		if err != nil {
+			return
+		}
+		resBz, err := k.QuerySmart(ctx.WithGasMeter(sdk.NewInfiniteGasMeterWithMultiplier(ctx)), contractAddress, ownerQueryBz)
+		if err != nil {
+			return
+		}
+		res := map[string]json.RawMessage{}
+		if err := json.Unmarshal(resBz, &res); err != nil {
+			return
+		}
+		if ownerBz, ok := res["owner"]; ok && len(ownerBz) > 2 {
+			ctx.EventManager().EmitEvent(sdk.NewEvent(
+				types.EventTypeCW721PreTransferOwner,
+				sdk.NewAttribute(types.AttributeKeyContractAddr, contractAddress.String()),
+				sdk.NewAttribute(types.AttributeKeyTokenId, tokenID),
+				sdk.NewAttribute(types.AttributeKeyOwner, string(ownerBz[1:len(ownerBz)-1])),
+			))
+		}
+	}
+}
+
 // MultipliedGasMeter wraps the GasMeter from context and multiplies all reads by out defined multiplier
 type MultipliedGasMeter struct {
 	originalMeter sdk.GasMeter

x/wasm/types/events.go

@@ -6,15 +6,16 @@ const (
 	// CustomContractEventPrefix contracts can create custom events. To not mix them with other system events they got the `wasm-` prefix.
 	CustomContractEventPrefix = "wasm-"
 
-	EventTypeStoreCode         = "store_code"
-	EventTypeInstantiate       = "instantiate"
-	EventTypeExecute           = "execute"
-	EventTypeMigrate           = "migrate"
-	EventTypePinCode           = "pin_code"
-	EventTypeUnpinCode         = "unpin_code"
-	EventTypeSudo              = "sudo"
-	EventTypeReply             = "reply"
-	EventTypeGovContractResult = "gov_contract_result"
+	EventTypeStoreCode             = "store_code"
+	EventTypeInstantiate           = "instantiate"
+	EventTypeExecute               = "execute"
+	EventTypeMigrate               = "migrate"
+	EventTypePinCode               = "pin_code"
+	EventTypeUnpinCode             = "unpin_code"
+	EventTypeSudo                  = "sudo"
+	EventTypeReply                 = "reply"
+	EventTypeGovContractResult     = "gov_contract_result"
+	EventTypeCW721PreTransferOwner = "cw721_pretransfer_owner"
 )
 
 // event attributes returned from contract execution
@@ -25,4 +26,6 @@ const (
 	AttributeKeyCodeID        = "code_id"
 	AttributeKeyResultDataHex = "result"
 	AttributeKeyFeature       = "feature"
+	AttributeKeyTokenId       = "token_id"
+	AttributeKeyOwner         = "owner"
 )