BuildPayForData

service/state/core_access.go

@@ -3,7 +3,6 @@ package state
 import (
 	"context"
 	"fmt"
-
 	sdk_tx "github.com/cosmos/cosmos-sdk/types/tx"
 	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
 	"google.golang.org/grpc"
@@ -103,3 +102,14 @@ func (ca *CoreAccessor) SubmitTxWithBroadcastMode(
 	}
 	return txResp.TxResponse, nil
 }
+
+func (ca *CoreAccessor) KeyringSigner() *apptypes.KeyringSigner {
+	return ca.signer
+}
+
+func (ca *CoreAccessor) Conn() (*grpc.ClientConn, error) {
+	if ca.coreConn == nil {
+		return nil, fmt.Errorf("no running gRPC connection")
+	}
+	return ca.coreConn, nil
+}

service/state/interface.go

@@ -2,6 +2,10 @@ package state
 
 import (
 	"context"
+
+	"google.golang.org/grpc"
+
+	apptypes "github.com/celestiaorg/celestia-app/x/payment/types"
 )
 
 // Accessor represents the behaviors necessary for a user to
@@ -12,6 +16,13 @@ type Accessor interface {
 	Start(context.Context) error
 	// Stop stops the state Accessor.
 	Stop(context.Context) error
+
+	// KeyringSigner returns the KeyringSigner used by the Accessor.
+	KeyringSigner() *apptypes.KeyringSigner
+	// Conn returns a gRPC connection to node that serves state-related
+	// requests.
+	Conn() (*grpc.ClientConn, error)
+
 	// Balance retrieves the Celestia coin balance
 	// for the node's account/signer.
 	Balance(ctx context.Context) (*Balance, error)

service/state/pfd.go

@@ -0,0 +1,78 @@
+package state
+
+import (
+	"context"
+	"github.com/cosmos/cosmos-sdk/x/auth/signing"
+
+	apptypes "github.com/celestiaorg/celestia-app/x/payment/types"
+	"github.com/celestiaorg/nmt/namespace"
+)
+
+var (
+	gasLim = uint64(200000)
+)
+
+type PayForData = apptypes.MsgWirePayForMessage
+
+// SubmitPayForData builds, signs and submits a PayForData message.
+func (s *Service) SubmitPayForData(ctx context.Context, nID namespace.ID, message []byte) (*TxResponse, error) {
+	pfd, err := s.BuildPayForData(ctx, nID, message)
+	if err != nil {
+		return nil, err
+	}
+	signed, err := s.SignPayForData(pfd, apptypes.SetGasLimit(gasLim))
+	if err != nil {
+		return nil, err
+	}
+
+	signer := s.accessor.KeyringSigner()
+	rawTx, err := signer.EncodeTx(signed)
+	if err != nil {
+		return nil, err
+	}
+
+	return s.accessor.SubmitTx(ctx, rawTx)
+}
+
+// BuildPayForData builds a PayForData message.
+func (s *Service) BuildPayForData(ctx context.Context, nID namespace.ID, message []byte) (*PayForData, error) {
+	// create the raw WirePayForMessage transaction
+	wpfmMsg, err := apptypes.NewWirePayForMessage(nID, message, 16, 32, 64, 128)
+	if err != nil {
+		return nil, err
+	}
+
+	// get signer and conn info
+	signer := s.accessor.KeyringSigner()
+	conn, err := s.accessor.Conn()
+	if err != nil {
+		return nil, err
+	}
+
+	// query for account information necessary to sign a valid tx
+	err = signer.QueryAccountNumber(ctx, conn)
+	if err != nil {
+		return nil, err
+	}
+
+	// generate the signatures for each `MsgPayForMessage` using the `KeyringSigner`,
+	// then set the gas limit for the tx
+	gasLimOption := apptypes.SetGasLimit(gasLim)
+	err = wpfmMsg.SignShareCommitments(signer, gasLimOption)
+	if err != nil {
+		return nil, err
+	}
+
+	return wpfmMsg, nil
+}
+
+// SignPayForData signs the given PayForData message.
+func (s *Service) SignPayForData(pfd *PayForData, gasLimOption apptypes.TxBuilderOption) (signing.Tx, error) {
+	signer := s.accessor.KeyringSigner()
+	// Build and sign the final `WirePayForMessage` tx that now contains the signatures
+	// for potential `MsgPayForMessage`s
+	return signer.BuildSignedTx(
+		gasLimOption(signer.NewTxBuilder()),
+		pfd,
+	)
+}