chore: implement required FungibleTokenPacketData v3 interface methods

modules/apps/transfer/types/v3/packet.go

@@ -0,0 +1,124 @@
+package v3
+
+import (
+	"encoding/json"
+	"errors"
+	"strings"
+
+	errorsmod "cosmossdk.io/errors"
+	sdkmath "cosmossdk.io/math"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+
+	"github.com/cosmos/ibc-go/v8/modules/apps/transfer/types"
+	ibcerrors "github.com/cosmos/ibc-go/v8/modules/core/errors"
+	ibcexported "github.com/cosmos/ibc-go/v8/modules/core/exported"
+)
+
+var (
+	_ ibcexported.PacketData         = (*FungibleTokenPacketData)(nil)
+	_ ibcexported.PacketDataProvider = (*FungibleTokenPacketData)(nil)
+)
+
+// NewFungibleTokenPacketData constructs a new NewFungibleTokenPacketData instance
+func NewFungibleTokenPacketData(
+	tokens []*Token,
+	sender, receiver string,
+	memo string,
+) FungibleTokenPacketData {
+	return FungibleTokenPacketData{
+		Tokens:   tokens,
+		Sender:   sender,
+		Receiver: receiver,
+		Memo:     memo,
+	}
+}
+
+// ValidateBasic is used for validating the token transfer.
+// NOTE: The addresses formats are not validated as the sender and recipient can have different
+// formats defined by their corresponding chains that are not known to IBC.
+func (ftpd FungibleTokenPacketData) ValidateBasic() error {
+	if strings.TrimSpace(ftpd.Sender) == "" {
+		return errorsmod.Wrap(ibcerrors.ErrInvalidAddress, "sender address cannot be blank")
+	}
+
+	if strings.TrimSpace(ftpd.Receiver) == "" {
+		return errorsmod.Wrap(ibcerrors.ErrInvalidAddress, "receiver address cannot be blank")
+	}
+
+	if len(ftpd.Tokens) == 0 {
+		return errorsmod.Wrap(types.ErrInvalidAmount, "tokens cannot be empty")
+	}
+
+	for _, token := range ftpd.Tokens {
+		amount, ok := sdkmath.NewIntFromString(token.Amount)
+		if !ok {
+			return errorsmod.Wrapf(types.ErrInvalidAmount, "unable to parse transfer amount (%s) into math.Int", token.Amount)
+		}
+
+		if !amount.IsPositive() {
+			return errorsmod.Wrapf(types.ErrInvalidAmount, "amount must be strictly positive: got %d", amount)
+		}
+
+		// TODO: check denom validation here: should use ValidatePrefixedDenom? potentially linked to: https://github.com/cosmos/ibc-go/issues/6124
+		if err := sdk.ValidateDenom(token.Denom); err != nil {
+			return errorsmod.Wrap(types.ErrInvalidDenomForTransfer, err.Error())
+		}
+	}
+
+	if len(ftpd.Memo) > types.MaximumMemoLength {
+		return errorsmod.Wrapf(types.ErrInvalidMemo, "memo must not exceed %d bytes", types.MaximumMemoLength)
+	}
+
+	return nil
+}
+
+func (t *Token) GetFullDenomPath() string {
+	if len(t.Trace) == 0 {
+		return t.Denom
+	}
+	return strings.Join(t.Trace, "/") + "/" + t.Denom
+}
+
+// GetBytes is a helper for serialising
+func (ftpd FungibleTokenPacketData) GetBytes() []byte {
+	bz, err := json.Marshal(&ftpd)
+	if err != nil {
+		panic(errors.New("cannot marshal v3 FungibleTokenPacketData into bytes"))
+	}
+
+	return bz
+}
+
+// GetCustomPacketData interprets the memo field of the packet data as a JSON object
+// and returns the value associated with the given key.
+// If the key is missing or the memo is not properly formatted, then nil is returned.
+func (ftpd FungibleTokenPacketData) GetCustomPacketData(key string) interface{} {
+	if len(ftpd.Memo) == 0 {
+		return nil
+	}
+
+	jsonObject := make(map[string]interface{})
+	err := json.Unmarshal([]byte(ftpd.Memo), &jsonObject)
+	if err != nil {
+		return nil
+	}
+
+	memoData, found := jsonObject[key]
+	if !found {
+		return nil
+	}
+
+	return memoData
+}
+
+// GetPacketSender returns the sender address embedded in the packet data.
+//
+// NOTE:
+//   - The sender address is set by the module which requested the packet to be sent,
+//     and this module may not have validated the sender address by a signature check.
+//   - The sender address must only be used by modules on the sending chain.
+//   - sourcePortID is not used in this implementation.
+func (ftpd FungibleTokenPacketData) GetPacketSender(sourcePortID string) string {
+	return ftpd.Sender
+}