// ExampleBuildTransaction creates and signs a simple transaction using the build package.
// The build package is designed to make it easier and more intuitive to configure and sign
// a transaction.
func ExampleBuildTransaction() {
	source := "SA26PHIKZM6CXDGR472SSGUQQRYXM6S437ZNHZGRM6QA4FOPLLLFRGDX"
	tx := b.Transaction(
		b.SourceAccount{source},
		b.Sequence{1},
		b.Payment(
			b.Destination{"SBQHO2IMYKXAYJFCWGXC7YKLJD2EGDPSK3IUDHVJ6OOTTKLSCK6Z6POM"},
			b.NativeAmount{"50.0"},
		),
	)

	txe := tx.Sign(source)
	txeB64, err := txe.Base64()

	if err != nil {
		panic(err)
	}

	fmt.Printf("tx base64: %s", txeB64)
}
// ToTransactionMutator returns go-stellar-base TransactionMutator
func (op PaymentOperationBody) ToTransactionMutator() b.TransactionMutator {
	mutators := []interface{}{
		b.Destination{op.Destination},
	}

	if op.Asset.Code != "" && op.Asset.Issuer != "" {
		mutators = append(
			mutators,
			b.CreditAmount{op.Asset.Code, op.Asset.Issuer, op.Amount},
		)
	} else {
		mutators = append(
			mutators,
			b.NativeAmount{op.Amount},
		)
	}

	if op.Source != nil {
		mutators = append(mutators, b.SourceAccount{*op.Source})
	}

	return b.Payment(mutators...)
}
// ToTransactionMutator returns go-stellar-base TransactionMutator
func (op PathPaymentOperationBody) ToTransactionMutator() b.TransactionMutator {
	var path []b.Asset
	for _, pathAsset := range op.Path {
		path = append(path, pathAsset.ToBaseAsset())
	}

	mutators := []interface{}{
		b.Destination{op.Destination},
		b.PayWithPath{
			Asset:     op.SendAsset.ToBaseAsset(),
			MaxAmount: op.SendMax,
			Path:      path,
		},
	}

	if op.DestinationAsset.Code != "" && op.DestinationAsset.Issuer != "" {
		mutators = append(
			mutators,
			b.CreditAmount{
				op.DestinationAsset.Code,
				op.DestinationAsset.Issuer,
				op.DestinationAmount,
			},
		)
	} else {
		mutators = append(
			mutators,
			b.NativeAmount{op.DestinationAmount},
		)
	}

	if op.Source != nil {
		mutators = append(mutators, b.SourceAccount{*op.Source})
	}

	return b.Payment(mutators...)
}
func (rh *RequestHandler) Payment(w http.ResponseWriter, r *http.Request) {
	source := r.PostFormValue("source")
	sourceKeypair, err := keypair.Parse(source)
	if err != nil {
		log.WithFields(log.Fields{"source": source}).Print("Invalid source parameter")
		errorBadRequest(w, errorResponseString("invalid_source", "source parameter is invalid"))
		return
	}

	destination := r.PostFormValue("destination")
	destinationObject, err := rh.AddressResolver.Resolve(destination)
	if err != nil {
		log.WithFields(log.Fields{"destination": destination}).Print("Cannot resolve address")
		errorBadRequest(w, errorResponseString("invalid_destination", "Cannot resolve destination"))
		return
	}

	_, err = keypair.Parse(destinationObject.AccountId)
	if err != nil {
		log.WithFields(log.Fields{"AccountId": destinationObject.AccountId}).Print("Invalid AccountId in destination")
		errorBadRequest(w, errorResponseString("invalid_destination", "destination parameter is invalid"))
		return
	}

	amount := r.PostFormValue("amount")
	assetCode := r.PostFormValue("asset_code")
	assetIssuer := r.PostFormValue("asset_issuer")

	var operationBuilder interface{}

	if assetCode != "" && assetIssuer != "" {
		issuerKeypair, err := keypair.Parse(assetIssuer)
		if err != nil {
			log.WithFields(log.Fields{"asset_issuer": assetIssuer}).Print("Invalid asset_issuer parameter")
			errorBadRequest(w, errorResponseString("invalid_issuer", "asset_issuer parameter is invalid"))
			return
		}

		operationBuilder = b.Payment(
			b.Destination{destinationObject.AccountId},
			b.CreditAmount{assetCode, issuerKeypair.Address(), amount},
		)
	} else if assetCode == "" && assetIssuer == "" {
		mutators := []interface{}{
			b.Destination{destinationObject.AccountId},
			b.NativeAmount{amount},
		}

		// Check if destination account exist
		_, err = rh.Horizon.LoadAccount(destinationObject.AccountId)
		if err != nil {
			log.WithFields(log.Fields{"error": err}).Error("Error loading account")
			operationBuilder = b.CreateAccount(mutators...)
		} else {
			operationBuilder = b.Payment(mutators...)
		}
	} else {
		log.Print("Missing asset param.")
		errorBadRequest(w, errorResponseString("asset_missing_param", "When passing asser both params: `asset_code`, `asset_issuer` are required"))
		return
	}

	memoType := r.PostFormValue("memo_type")
	memo := r.PostFormValue("memo")

	if !(((memoType == "") && (memo == "")) || ((memoType != "") && (memo != ""))) {
		log.Print("Missing one of memo params.")
		errorBadRequest(w, errorResponseString("memo_missing_param", "When passing memo both params: `memo_type`, `memo` are required"))
		return
	}

	if destinationObject.MemoType != nil {
		if memoType != "" {
			log.Print("Memo given in request but federation returned memo fields.")
			errorBadRequest(w, errorResponseString("cannot_use_memo", "Memo given in request but federation returned memo fields"))
			return
		}

		memoType = *destinationObject.MemoType
		memo = *destinationObject.Memo
	}

	var memoMutator interface{}
	switch {
	case memoType == "":
		break
	case memoType == "id":
		id, err := strconv.ParseUint(memo, 10, 64)
		if err != nil {
			log.WithFields(log.Fields{"memo": memo}).Print("Cannot convert memo_id value to uint64")
			errorBadRequest(w, errorResponseString("cannot_convert_memo_id", "Cannot convert memo_id value"))
			return
		}
		memoMutator = b.MemoID{id}
	case memoType == "text":
		memoMutator = &b.MemoText{memo}
	default:
		log.Print("Not supported memo type: ", memoType)
		errorBadRequest(w, errorResponseString("memo_not_supported", "Not supported memo type"))
		return
	}

	accountResponse, err := rh.Horizon.LoadAccount(sourceKeypair.Address())
	if err != nil {
		log.WithFields(log.Fields{"error": err}).Error("Cannot load source account")
		errorBadRequest(w, errorResponseString("source_not_exist", "source account does not exist"))
		return
	}

	sequenceNumber, err := strconv.ParseUint(accountResponse.SequenceNumber, 10, 64)
	if err != nil {
		log.WithFields(log.Fields{"error": err}).Error("Cannot convert SequenceNumber")
		errorServerError(w)
		return
	}

	transactionMutators := []b.TransactionMutator{
		b.SourceAccount{source},
		b.Sequence{sequenceNumber + 1},
		b.Network{rh.Config.NetworkPassphrase},
		operationBuilder.(b.TransactionMutator),
	}

	if memoMutator != nil {
		transactionMutators = append(transactionMutators, memoMutator.(b.TransactionMutator))
	}

	tx := b.Transaction(transactionMutators...)

	if tx.Err != nil {
		log.WithFields(log.Fields{"err": tx.Err}).Print("Transaction builder error")
		// TODO when build.OperationBuilder interface is ready check for
		// create_account and payment errors separately
		switch {
		case tx.Err.Error() == "Asset code length is invalid":
			errorBadRequest(w, errorResponseString("asset_code_invalid", "asset_code param is invalid"))
		case strings.Contains(tx.Err.Error(), "cannot parse amount"):
			errorBadRequest(w, errorResponseString("invalid_amount", "amount is invalid"))
		default:
			log.WithFields(log.Fields{"err": tx.Err}).Print("Transaction builder error")
			errorServerError(w)
		}
		return
	}

	txe := tx.Sign(source)
	txeB64, err := txe.Base64()

	if err != nil {
		log.WithFields(log.Fields{"error": err}).Error("Cannot encode transaction envelope")
		errorServerError(w)
		return
	}

	submitResponse, err := rh.Horizon.SubmitTransaction(txeB64)
	if err != nil {
		log.WithFields(log.Fields{"error": err}).Error("Error submitting transaction")
		errorServerError(w)
		return
	}

	response, err := json.MarshalIndent(submitResponse, "", "  ")
	if err != nil {
		log.WithFields(log.Fields{"error": err}).Error("Cannot Marshal submitResponse")
		errorServerError(w)
		return
	}

	if submitResponse.Ledger != nil {
		w.Write(response)
	} else {
		errorBadRequest(w, string(response))
	}

}
// HandlerSend implements /send endpoint
func (rh *RequestHandler) HandlerSend(c web.C, w http.ResponseWriter, r *http.Request) {
	request := &compliance.SendRequest{}
	request.FromRequest(r)

	err := request.Validate()
	if err != nil {
		errorResponse := err.(*protocols.ErrorResponse)
		log.WithFields(errorResponse.LogData).Error(errorResponse.Error())
		server.Write(w, errorResponse)
		return
	}

	destinationObject, stellarToml, err := rh.FederationResolver.Resolve(request.Destination)
	if err != nil {
		log.WithFields(log.Fields{
			"destination": request.Destination,
			"err":         err,
		}).Print("Cannot resolve address")
		server.Write(w, compliance.CannotResolveDestination)
		return
	}

	if stellarToml.AuthServer == "" {
		log.Print("No AUTH_SERVER in stellar.toml")
		server.Write(w, compliance.AuthServerNotDefined)
		return
	}

	var payWithMutator *b.PayWithPath

	if request.SendMax != "" {
		// Path payment
		var sendAsset b.Asset
		if request.SendAssetCode != "" && request.SendAssetIssuer != "" {
			sendAsset = b.CreditAsset(request.SendAssetCode, request.SendAssetIssuer)
		} else if request.SendAssetCode == "" && request.SendAssetIssuer == "" {
			sendAsset = b.NativeAsset()
		} else {
			log.Print("Missing send asset param.")
			server.Write(w, protocols.MissingParameterError)
			return
		}

		payWith := b.PayWith(sendAsset, request.SendMax)

		for _, asset := range request.Path {
			if asset.Code == "" && asset.Issuer == "" {
				payWith = payWith.Through(b.NativeAsset())
			} else {
				payWith = payWith.Through(b.CreditAsset(asset.Code, asset.Issuer))
			}
		}

		payWithMutator = &payWith
	}

	mutators := []interface{}{
		b.Destination{destinationObject.AccountID},
		b.CreditAmount{
			request.AssetCode,
			request.AssetIssuer,
			request.Amount,
		},
	}

	if payWithMutator != nil {
		mutators = append(mutators, *payWithMutator)
	}

	operationMutator := b.Payment(mutators...)
	if operationMutator.Err != nil {
		log.WithFields(log.Fields{
			"err": operationMutator.Err,
		}).Error("Error creating operation")
		server.Write(w, protocols.InternalServerError)
		return
	}

	// Fetch Sender Info
	senderInfo := ""

	if rh.Config.Callbacks.FetchInfo != "" {
		fetchInfoRequest := compliance.FetchInfoRequest{Address: request.Sender}
		resp, err := rh.Client.PostForm(
			rh.Config.Callbacks.FetchInfo,
			fetchInfoRequest.ToValues(),
		)
		if err != nil {
			log.WithFields(log.Fields{
				"fetch_info": rh.Config.Callbacks.FetchInfo,
				"err":        err,
			}).Error("Error sending request to fetch_info server")
			server.Write(w, protocols.InternalServerError)
			return
		}

		defer resp.Body.Close()
		body, err := ioutil.ReadAll(resp.Body)
		if err != nil {
			log.WithFields(log.Fields{
				"fetch_info": rh.Config.Callbacks.FetchInfo,
				"err":        err,
			}).Error("Error reading fetch_info server response")
			server.Write(w, protocols.InternalServerError)
			return
		}

		if resp.StatusCode != http.StatusOK {
			log.WithFields(log.Fields{
				"fetch_info": rh.Config.Callbacks.FetchInfo,
				"status":     resp.StatusCode,
				"body":       string(body),
			}).Error("Error response from fetch_info server")
			server.Write(w, protocols.InternalServerError)
			return
		}

		senderInfo = string(body)
	}

	memoPreimage := &memo.Memo{
		Transaction: memo.Transaction{
			SenderInfo: senderInfo,
			Route:      destinationObject.Memo,
			Extra:      request.ExtraMemo,
		},
	}

	memoJSON := memoPreimage.Marshal()
	memoHashBytes := sha256.Sum256(memoJSON)
	memoMutator := &b.MemoHash{xdr.Hash(memoHashBytes)}

	transaction, err := submitter.BuildTransaction(
		request.Source,
		rh.Config.NetworkPassphrase,
		operationMutator,
		memoMutator,
	)

	var txBytes bytes.Buffer
	_, err = xdr.Marshal(&txBytes, transaction)
	if err != nil {
		log.Error("Error mashaling transaction")
		server.Write(w, protocols.InternalServerError)
		return
	}

	txBase64 := base64.StdEncoding.EncodeToString(txBytes.Bytes())

	authData := compliance.AuthData{
		Sender:   request.Sender,
		NeedInfo: rh.Config.NeedsAuth,
		Tx:       txBase64,
		Memo:     string(memoJSON),
	}

	data, err := json.Marshal(authData)
	if err != nil {
		log.Error("Error mashaling authData")
		server.Write(w, protocols.InternalServerError)
		return
	}
	sig, err := rh.SignatureSignerVerifier.Sign(rh.Config.Keys.SigningSeed, data)
	if err != nil {
		log.Error("Error signing authData")
		server.Write(w, protocols.InternalServerError)
		return
	}

	authRequest := compliance.AuthRequest{
		Data:      string(data),
		Signature: sig,
	}
	resp, err := rh.Client.PostForm(
		stellarToml.AuthServer,
		authRequest.ToValues(),
	)
	if err != nil {
		log.WithFields(log.Fields{
			"auth_server": stellarToml.AuthServer,
			"err":         err,
		}).Error("Error sending request to auth server")
		server.Write(w, protocols.InternalServerError)
		return
	}

	defer resp.Body.Close()
	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		log.Error("Error reading auth server response")
		server.Write(w, protocols.InternalServerError)
		return
	}

	if resp.StatusCode != 200 {
		log.WithFields(log.Fields{
			"status": resp.StatusCode,
			"body":   string(body),
		}).Error("Error response from auth server")
		server.Write(w, protocols.InternalServerError)
		return
	}

	var authResponse compliance.AuthResponse
	err = json.Unmarshal(body, &authResponse)
	if err != nil {
		log.WithFields(log.Fields{
			"status": resp.StatusCode,
			"body":   string(body),
		}).Error("Error unmarshalling auth response")
		server.Write(w, protocols.InternalServerError)
		return
	}

	response := compliance.SendResponse{
		AuthResponse:   authResponse,
		TransactionXdr: txBase64,
	}
	server.Write(w, &response)
}
// Payment implements /payment endpoint
func (rh *RequestHandler) Payment(w http.ResponseWriter, r *http.Request) {
	request := &bridge.PaymentRequest{}
	request.FromRequest(r)

	err := request.Validate()
	if err != nil {
		errorResponse := err.(*protocols.ErrorResponse)
		log.WithFields(errorResponse.LogData).Error(errorResponse.Error())
		server.Write(w, errorResponse)
		return
	}

	if request.Source == "" {
		request.Source = rh.Config.Accounts.BaseSeed
	}

	sourceKeypair, _ := keypair.Parse(request.Source)

	var submitResponse horizon.SubmitTransactionResponse
	var submitError error

	if request.ExtraMemo != "" && rh.Config.Compliance != "" {
		// Compliance server part
		sendRequest := request.ToComplianceSendRequest()

		resp, err := rh.Client.PostForm(
			rh.Config.Compliance+"/send",
			sendRequest.ToValues(),
		)
		if err != nil {
			log.WithFields(log.Fields{"err": err}).Error("Error sending request to compliance server")
			server.Write(w, protocols.InternalServerError)
			return
		}

		defer resp.Body.Close()
		body, err := ioutil.ReadAll(resp.Body)
		if err != nil {
			log.Error("Error reading compliance server response")
			server.Write(w, protocols.InternalServerError)
			return
		}

		if resp.StatusCode != 200 {
			log.WithFields(log.Fields{
				"status": resp.StatusCode,
				"body":   string(body),
			}).Error("Error response from compliance server")
			server.Write(w, protocols.InternalServerError)
			return
		}

		var complianceSendResponse compliance.SendResponse
		err = json.Unmarshal(body, &complianceSendResponse)
		if err != nil {
			log.Error("Error unmarshalling from compliance server")
			server.Write(w, protocols.InternalServerError)
			return
		}

		if complianceSendResponse.AuthResponse.InfoStatus == compliance.AuthStatusPending ||
			complianceSendResponse.AuthResponse.TxStatus == compliance.AuthStatusPending {
			log.WithFields(log.Fields{"response": complianceSendResponse}).Info("Compliance response pending")
			server.Write(w, bridge.NewPaymentPendingError(complianceSendResponse.AuthResponse.Pending))
			return
		}

		if complianceSendResponse.AuthResponse.InfoStatus == compliance.AuthStatusDenied ||
			complianceSendResponse.AuthResponse.TxStatus == compliance.AuthStatusDenied {
			log.WithFields(log.Fields{"response": complianceSendResponse}).Info("Compliance response denied")
			server.Write(w, bridge.PaymentDenied)
			return
		}

		var tx xdr.Transaction
		err = xdr.SafeUnmarshalBase64(complianceSendResponse.TransactionXdr, &tx)
		if err != nil {
			log.Error("Error unmarshalling transaction returned by compliance server")
			server.Write(w, protocols.InternalServerError)
			return
		}

		submitResponse, submitError = rh.TransactionSubmitter.SignAndSubmitRawTransaction(request.Source, &tx)
	} else {
		// Payment without compliance server
		destinationObject, _, err := rh.FederationResolver.Resolve(request.Destination)
		if err != nil {
			log.WithFields(log.Fields{"destination": request.Destination, "err": err}).Print("Cannot resolve address")
			server.Write(w, bridge.PaymentCannotResolveDestination)
			return
		}

		_, err = keypair.Parse(destinationObject.AccountID)
		if err != nil {
			log.WithFields(log.Fields{"AccountId": destinationObject.AccountID}).Print("Invalid AccountId in destination")
			server.Write(w, protocols.NewInvalidParameterError("destination", request.Destination))
			return
		}

		var payWithMutator *b.PayWithPath

		if request.SendMax != "" {
			// Path payment
			var sendAsset b.Asset
			if request.SendAssetCode == "" && request.SendAssetIssuer == "" {
				sendAsset = b.NativeAsset()
			} else {
				sendAsset = b.CreditAsset(request.SendAssetCode, request.SendAssetIssuer)
			}

			payWith := b.PayWith(sendAsset, request.SendMax)

			for i := 0; ; i++ {
				codeFieldName := fmt.Sprintf("path[%d][asset_code]", i)
				issuerFieldName := fmt.Sprintf("path[%d][asset_issuer]", i)

				// If the element does not exist in PostForm break the loop
				if _, exists := r.PostForm[codeFieldName]; !exists {
					break
				}

				code := r.PostFormValue(codeFieldName)
				issuer := r.PostFormValue(issuerFieldName)

				if code == "" && issuer == "" {
					payWith = payWith.Through(b.NativeAsset())
				} else {
					payWith = payWith.Through(b.CreditAsset(code, issuer))
				}
			}

			payWithMutator = &payWith
		}

		var operationBuilder interface{}

		if request.AssetCode != "" && request.AssetIssuer != "" {
			mutators := []interface{}{
				b.Destination{destinationObject.AccountID},
				b.CreditAmount{request.AssetCode, request.AssetIssuer, request.Amount},
			}

			if payWithMutator != nil {
				mutators = append(mutators, *payWithMutator)
			}

			operationBuilder = b.Payment(mutators...)
		} else {
			mutators := []interface{}{
				b.Destination{destinationObject.AccountID},
				b.NativeAmount{request.Amount},
			}

			if payWithMutator != nil {
				mutators = append(mutators, *payWithMutator)
			}

			// Check if destination account exist
			_, err = rh.Horizon.LoadAccount(destinationObject.AccountID)
			if err != nil {
				log.WithFields(log.Fields{"error": err}).Error("Error loading account")
				operationBuilder = b.CreateAccount(mutators...)
			} else {
				operationBuilder = b.Payment(mutators...)
			}
		}

		memoType := request.MemoType
		memo := request.Memo

		if destinationObject.MemoType != "" {
			if request.MemoType != "" {
				log.Print("Memo given in request but federation returned memo fields.")
				server.Write(w, bridge.PaymentCannotUseMemo)
				return
			}

			memoType = destinationObject.MemoType
			memo = destinationObject.Memo
		}

		var memoMutator interface{}
		switch {
		case memoType == "":
			break
		case memoType == "id":
			id, err := strconv.ParseUint(memo, 10, 64)
			if err != nil {
				log.WithFields(log.Fields{"memo": memo}).Print("Cannot convert memo_id value to uint64")
				server.Write(w, protocols.NewInvalidParameterError("memo", request.Memo))
				return
			}
			memoMutator = b.MemoID{id}
		case memoType == "text":
			memoMutator = &b.MemoText{memo}
		case memoType == "hash":
			memoBytes, err := hex.DecodeString(memo)
			if err != nil || len(memoBytes) != 32 {
				log.WithFields(log.Fields{"memo": memo}).Print("Cannot decode hash memo value")
				server.Write(w, protocols.NewInvalidParameterError("memo", request.Memo))
				return
			}
			var b32 [32]byte
			copy(b32[:], memoBytes[0:32])
			hash := xdr.Hash(b32)
			memoMutator = &b.MemoHash{hash}
		default:
			log.Print("Not supported memo type: ", memoType)
			server.Write(w, protocols.NewInvalidParameterError("memo", request.Memo))
			return
		}

		accountResponse, err := rh.Horizon.LoadAccount(sourceKeypair.Address())
		if err != nil {
			log.WithFields(log.Fields{"error": err}).Error("Cannot load source account")
			server.Write(w, bridge.PaymentSourceNotExist)
			return
		}

		sequenceNumber, err := strconv.ParseUint(accountResponse.SequenceNumber, 10, 64)
		if err != nil {
			log.WithFields(log.Fields{"error": err}).Error("Cannot convert SequenceNumber")
			server.Write(w, protocols.InternalServerError)
			return
		}

		transactionMutators := []b.TransactionMutator{
			b.SourceAccount{request.Source},
			b.Sequence{sequenceNumber + 1},
			b.Network{rh.Config.NetworkPassphrase},
			operationBuilder.(b.TransactionMutator),
		}

		if memoMutator != nil {
			transactionMutators = append(transactionMutators, memoMutator.(b.TransactionMutator))
		}

		tx := b.Transaction(transactionMutators...)

		if tx.Err != nil {
			log.WithFields(log.Fields{"err": tx.Err}).Print("Transaction builder error")
			// TODO when build.OperationBuilder interface is ready check for
			// create_account and payment errors separately
			switch {
			case tx.Err.Error() == "Asset code length is invalid":
				server.Write(
					w,
					protocols.NewInvalidParameterError("asset_code", request.AssetCode),
				)
			case strings.Contains(tx.Err.Error(), "cannot parse amount"):
				server.Write(
					w,
					protocols.NewInvalidParameterError("amount", request.Amount),
				)
			default:
				log.WithFields(log.Fields{"err": tx.Err}).Print("Transaction builder error")
				server.Write(w, protocols.InternalServerError)
			}
			return
		}

		txe := tx.Sign(request.Source)
		txeB64, err := txe.Base64()

		if err != nil {
			log.WithFields(log.Fields{"error": err}).Error("Cannot encode transaction envelope")
			server.Write(w, protocols.InternalServerError)
			return
		}

		submitResponse, submitError = rh.Horizon.SubmitTransaction(txeB64)
	}

	if submitError != nil {
		log.WithFields(log.Fields{"error": submitError}).Error("Error submitting transaction")
		server.Write(w, protocols.InternalServerError)
		return
	}

	errorResponse := bridge.ErrorFromHorizonResponse(submitResponse)
	if errorResponse != nil {
		log.WithFields(errorResponse.LogData).Error(errorResponse.Error())
		server.Write(w, errorResponse)
		return
	}

	// Path payment send amount
	if submitResponse.ResultXdr != nil {
		var transactionResult xdr.TransactionResult
		reader := strings.NewReader(*submitResponse.ResultXdr)
		b64r := base64.NewDecoder(base64.StdEncoding, reader)
		_, err := xdr.Unmarshal(b64r, &transactionResult)

		if err == nil && transactionResult.Result.Code == xdr.TransactionResultCodeTxSuccess {
			operationResult := (*transactionResult.Result.Results)[0]
			if operationResult.Tr.PathPaymentResult != nil {
				sendAmount := operationResult.Tr.PathPaymentResult.SendAmount()
				submitResponse.SendAmount = amount.String(sendAmount)
			}
		}
	}

	server.Write(w, &submitResponse)
}
func TestTransactionSubmitter(t *testing.T) {
	mockHorizon := new(mocks.MockHorizon)
	mockEntityManager := new(mocks.MockEntityManager)
	mocks.PredefinedTime = time.Now()

	Convey("TransactionSubmitter", t, func() {
		seed := "SDZT3EJZ7FZRYNTLOZ7VH6G5UYBFO2IO3Q5PGONMILPCZU3AL7QNZHTE"
		accountID := "GCLOMB72ODBFUGK4E2BK7VMR3RNZ5WSTMEOGNA2YUVHFR3WMH2XBAB6H"

		Convey("LoadAccount", func() {
			transactionSubmitter := NewTransactionSubmitter(
				mockHorizon,
				mockEntityManager,
				"Test SDF Network ; September 2015",
				mocks.Now,
			)

			Convey("When seed is invalid", func() {
				_, err := transactionSubmitter.LoadAccount("invalidSeed")
				assert.NotNil(t, err)
			})

			Convey("When there is a problem loading an account", func() {
				mockHorizon.On(
					"LoadAccount",
					accountID,
				).Return(
					horizon.AccountResponse{},
					errors.New("Account not found"),
				).Once()

				_, err := transactionSubmitter.LoadAccount(seed)
				assert.NotNil(t, err)
				mockHorizon.AssertExpectations(t)
			})

			Convey("Successfully loads an account", func() {
				mockHorizon.On(
					"LoadAccount",
					accountID,
				).Return(
					horizon.AccountResponse{
						AccountID:      accountID,
						SequenceNumber: "10372672437354496",
					},
					nil,
				).Once()

				account, err := transactionSubmitter.LoadAccount(seed)
				assert.Nil(t, err)
				assert.Equal(t, account.Keypair.Address(), accountID)
				assert.Equal(t, account.Seed, seed)
				assert.Equal(t, account.SequenceNumber, uint64(10372672437354496))
				mockHorizon.AssertExpectations(t)
			})
		})

		Convey("SubmitTransaction", func() {
			Convey("Submits transaction without a memo", func() {
				operation := b.Payment(
					b.Destination{"GB3W7VQ2A2IOQIS4LUFUMRC2DWXONUDH24ROLE6RS4NGUNHVSXKCABOM"},
					b.NativeAmount{"100"},
				)

				Convey("Error response from horizon", func() {
					transactionSubmitter := NewTransactionSubmitter(
						mockHorizon,
						mockEntityManager,
						"Test SDF Network ; September 2015",
						mocks.Now,
					)

					mockHorizon.On(
						"LoadAccount",
						accountID,
					).Return(
						horizon.AccountResponse{
							AccountID:      accountID,
							SequenceNumber: "10372672437354496",
						},
						nil,
					).Once()

					err := transactionSubmitter.InitAccount(seed)
					assert.Nil(t, err)

					txB64 := "AAAAAJbmB/pwwloZXCaCr9WR3Fue2lNhHGaDWKVOWO7MPq4QAAAAZAAk2eQAAAABAAAAAAAAAAAAAAABAAAAAAAAAAEAAAAAd2/WGgaQ6CJcXQtGRFodrubQZ9ci5ZPRlxpqNPWV1CAAAAAAAAAAADuaygAAAAAAAAAAAcw+rhAAAABAyFjIMIZOtstCWtZlVBDj1AhTmsk5v1i2GGY4by2b5mgZoXXGgFTB8sfbQav0LzFKCcxY8h+9xPMT2e9xznAfDw=="

					// Persist sending transaction
					mockEntityManager.On(
						"Persist",
						mock.AnythingOfType("*entities.SentTransaction"),
					).Return(nil).Once().Run(func(args mock.Arguments) {
						transaction := args.Get(0).(*entities.SentTransaction)
						assert.Equal(t, "4f885999be6ea7891052a53e496bcfb5c5a1a5bfb31923f649b028fdc74dd050", transaction.TransactionID)
						assert.Equal(t, "sending", string(transaction.Status))
						assert.Equal(t, "GCLOMB72ODBFUGK4E2BK7VMR3RNZ5WSTMEOGNA2YUVHFR3WMH2XBAB6H", transaction.Source)
						assert.Equal(t, mocks.PredefinedTime, transaction.SubmittedAt)
						assert.Equal(t, txB64, transaction.EnvelopeXdr)
					})

					// Persist failure
					mockEntityManager.On(
						"Persist",
						mock.AnythingOfType("*entities.SentTransaction"),
					).Return(nil).Once().Run(func(args mock.Arguments) {
						transaction := args.Get(0).(*entities.SentTransaction)
						assert.Equal(t, "4f885999be6ea7891052a53e496bcfb5c5a1a5bfb31923f649b028fdc74dd050", transaction.TransactionID)
						assert.Equal(t, "failure", string(transaction.Status))
						assert.Equal(t, "GCLOMB72ODBFUGK4E2BK7VMR3RNZ5WSTMEOGNA2YUVHFR3WMH2XBAB6H", transaction.Source)
						assert.Equal(t, mocks.PredefinedTime, transaction.SubmittedAt)
						assert.Equal(t, txB64, transaction.EnvelopeXdr)
					})

					mockHorizon.On("SubmitTransaction", txB64).Return(
						horizon.SubmitTransactionResponse{
							Ledger: nil,
							Extras: &horizon.SubmitTransactionResponseExtras{
								ResultXdr: "AAAAAAAAAGT/////AAAAAQAAAAAAAAAB////+wAAAAA=", // no_destination
							},
						},
						nil,
					).Once()

					_, err = transactionSubmitter.SubmitTransaction(seed, operation, nil)
					assert.Nil(t, err)
					mockHorizon.AssertExpectations(t)
				})

				Convey("Bad Sequence response from horizon", func() {
					transactionSubmitter := NewTransactionSubmitter(
						mockHorizon,
						mockEntityManager,
						"Test SDF Network ; September 2015",
						mocks.Now,
					)

					mockHorizon.On(
						"LoadAccount",
						accountID,
					).Return(
						horizon.AccountResponse{
							AccountID:      accountID,
							SequenceNumber: "10372672437354496",
						},
						nil,
					).Once()

					err := transactionSubmitter.InitAccount(seed)
					assert.Nil(t, err)

					txB64 := "AAAAAJbmB/pwwloZXCaCr9WR3Fue2lNhHGaDWKVOWO7MPq4QAAAAZAAk2eQAAAABAAAAAAAAAAAAAAABAAAAAAAAAAEAAAAAd2/WGgaQ6CJcXQtGRFodrubQZ9ci5ZPRlxpqNPWV1CAAAAAAAAAAADuaygAAAAAAAAAAAcw+rhAAAABAyFjIMIZOtstCWtZlVBDj1AhTmsk5v1i2GGY4by2b5mgZoXXGgFTB8sfbQav0LzFKCcxY8h+9xPMT2e9xznAfDw=="

					// Persist sending transaction
					mockEntityManager.On(
						"Persist",
						mock.AnythingOfType("*entities.SentTransaction"),
					).Return(nil).Once().Run(func(args mock.Arguments) {
						transaction := args.Get(0).(*entities.SentTransaction)
						assert.Equal(t, "4f885999be6ea7891052a53e496bcfb5c5a1a5bfb31923f649b028fdc74dd050", transaction.TransactionID)
						assert.Equal(t, "sending", string(transaction.Status))
						assert.Equal(t, "GCLOMB72ODBFUGK4E2BK7VMR3RNZ5WSTMEOGNA2YUVHFR3WMH2XBAB6H", transaction.Source)
						assert.Equal(t, mocks.PredefinedTime, transaction.SubmittedAt)
						assert.Equal(t, txB64, transaction.EnvelopeXdr)
					})

					// Persist failure
					mockEntityManager.On(
						"Persist",
						mock.AnythingOfType("*entities.SentTransaction"),
					).Return(nil).Once().Run(func(args mock.Arguments) {
						transaction := args.Get(0).(*entities.SentTransaction)
						assert.Equal(t, "4f885999be6ea7891052a53e496bcfb5c5a1a5bfb31923f649b028fdc74dd050", transaction.TransactionID)
						assert.Equal(t, "failure", string(transaction.Status))
						assert.Equal(t, "GCLOMB72ODBFUGK4E2BK7VMR3RNZ5WSTMEOGNA2YUVHFR3WMH2XBAB6H", transaction.Source)
						assert.Equal(t, mocks.PredefinedTime, transaction.SubmittedAt)
						assert.Equal(t, txB64, transaction.EnvelopeXdr)
					})

					mockHorizon.On("SubmitTransaction", txB64).Return(
						horizon.SubmitTransactionResponse{
							Ledger: nil,
							Extras: &horizon.SubmitTransactionResponseExtras{
								ResultXdr: "AAAAAAAAAAD////7AAAAAA==", // tx_bad_seq
							},
						},
						nil,
					).Once()

					// Updating sequence number
					mockHorizon.On(
						"LoadAccount",
						accountID,
					).Return(
						horizon.AccountResponse{
							AccountID:      accountID,
							SequenceNumber: "100",
						},
						nil,
					).Once()

					_, err = transactionSubmitter.SubmitTransaction(seed, operation, nil)
					assert.Nil(t, err)
					assert.Equal(t, uint64(100), transactionSubmitter.Accounts[seed].SequenceNumber)
					mockHorizon.AssertExpectations(t)
				})

				Convey("Successfully submits a transaction", func() {
					transactionSubmitter := NewTransactionSubmitter(
						mockHorizon,
						mockEntityManager,
						"Test SDF Network ; September 2015",
						mocks.Now,
					)

					mockHorizon.On(
						"LoadAccount",
						accountID,
					).Return(
						horizon.AccountResponse{
							AccountID:      accountID,
							SequenceNumber: "10372672437354496",
						},
						nil,
					).Once()

					err := transactionSubmitter.InitAccount(seed)
					assert.Nil(t, err)

					txB64 := "AAAAAJbmB/pwwloZXCaCr9WR3Fue2lNhHGaDWKVOWO7MPq4QAAAAZAAk2eQAAAABAAAAAAAAAAAAAAABAAAAAAAAAAEAAAAAd2/WGgaQ6CJcXQtGRFodrubQZ9ci5ZPRlxpqNPWV1CAAAAAAAAAAADuaygAAAAAAAAAAAcw+rhAAAABAyFjIMIZOtstCWtZlVBDj1AhTmsk5v1i2GGY4by2b5mgZoXXGgFTB8sfbQav0LzFKCcxY8h+9xPMT2e9xznAfDw=="

					// Persist sending transaction
					mockEntityManager.On(
						"Persist",
						mock.AnythingOfType("*entities.SentTransaction"),
					).Return(nil).Once().Run(func(args mock.Arguments) {
						transaction := args.Get(0).(*entities.SentTransaction)
						assert.Equal(t, "4f885999be6ea7891052a53e496bcfb5c5a1a5bfb31923f649b028fdc74dd050", transaction.TransactionID)
						assert.Equal(t, "sending", string(transaction.Status))
						assert.Equal(t, "GCLOMB72ODBFUGK4E2BK7VMR3RNZ5WSTMEOGNA2YUVHFR3WMH2XBAB6H", transaction.Source)
						assert.Equal(t, mocks.PredefinedTime, transaction.SubmittedAt)
						assert.Equal(t, txB64, transaction.EnvelopeXdr)
					})

					// Persist failure
					mockEntityManager.On(
						"Persist",
						mock.AnythingOfType("*entities.SentTransaction"),
					).Return(nil).Once().Run(func(args mock.Arguments) {
						transaction := args.Get(0).(*entities.SentTransaction)
						assert.Equal(t, "4f885999be6ea7891052a53e496bcfb5c5a1a5bfb31923f649b028fdc74dd050", transaction.TransactionID)
						assert.Equal(t, "success", string(transaction.Status))
						assert.Equal(t, "GCLOMB72ODBFUGK4E2BK7VMR3RNZ5WSTMEOGNA2YUVHFR3WMH2XBAB6H", transaction.Source)
						assert.Equal(t, mocks.PredefinedTime, transaction.SubmittedAt)
						assert.Equal(t, txB64, transaction.EnvelopeXdr)
					})

					ledger := uint64(1486276)
					mockHorizon.On("SubmitTransaction", txB64).Return(
						horizon.SubmitTransactionResponse{Ledger: &ledger},
						nil,
					).Once()

					response, err := transactionSubmitter.SubmitTransaction(seed, operation, nil)
					assert.Nil(t, err)
					assert.Equal(t, *response.Ledger, ledger)
					assert.Equal(t, uint64(10372672437354497), transactionSubmitter.Accounts[seed].SequenceNumber)
					mockHorizon.AssertExpectations(t)
				})
			})

			Convey("Submits transaction with a memo", func() {
				operation := b.Payment(
					b.Destination{"GB3W7VQ2A2IOQIS4LUFUMRC2DWXONUDH24ROLE6RS4NGUNHVSXKCABOM"},
					b.NativeAmount{"100"},
				)

				memo := b.MemoText{"Testing!"}

				Convey("Successfully submits a transaction", func() {
					transactionSubmitter := NewTransactionSubmitter(
						mockHorizon,
						mockEntityManager,
						"Test SDF Network ; September 2015",
						mocks.Now,
					)

					mockHorizon.On(
						"LoadAccount",
						accountID,
					).Return(
						horizon.AccountResponse{
							AccountID:      accountID,
							SequenceNumber: "10372672437354496",
						},
						nil,
					).Once()

					err := transactionSubmitter.InitAccount(seed)
					assert.Nil(t, err)

					txB64 := "AAAAAJbmB/pwwloZXCaCr9WR3Fue2lNhHGaDWKVOWO7MPq4QAAAAZAAk2eQAAAABAAAAAAAAAAEAAAAIVGVzdGluZyEAAAABAAAAAAAAAAEAAAAAd2/WGgaQ6CJcXQtGRFodrubQZ9ci5ZPRlxpqNPWV1CAAAAAAAAAAADuaygAAAAAAAAAAAcw+rhAAAABAU5ahFsd28sVKSUFcmAiEf+zSLXhf9HG/pJuQirR0s43zs7Y43vM8T3sIvJWHgwMADaZiy/D+evYWd/vS/uO8Ag=="

					// Persist sending transaction
					mockEntityManager.On(
						"Persist",
						mock.AnythingOfType("*entities.SentTransaction"),
					).Return(nil).Once().Run(func(args mock.Arguments) {
						transaction := args.Get(0).(*entities.SentTransaction)
						assert.Equal(t, "60cb3c020b0c97352cbabdf68a822b04baea61927b0f1ac31260a9f8d0150316", transaction.TransactionID)
						assert.Equal(t, "sending", string(transaction.Status))
						assert.Equal(t, "GCLOMB72ODBFUGK4E2BK7VMR3RNZ5WSTMEOGNA2YUVHFR3WMH2XBAB6H", transaction.Source)
						assert.Equal(t, mocks.PredefinedTime, transaction.SubmittedAt)
						assert.Equal(t, txB64, transaction.EnvelopeXdr)
					})

					// Persist failure
					mockEntityManager.On(
						"Persist",
						mock.AnythingOfType("*entities.SentTransaction"),
					).Return(nil).Once().Run(func(args mock.Arguments) {
						transaction := args.Get(0).(*entities.SentTransaction)
						assert.Equal(t, "60cb3c020b0c97352cbabdf68a822b04baea61927b0f1ac31260a9f8d0150316", transaction.TransactionID)
						assert.Equal(t, "success", string(transaction.Status))
						assert.Equal(t, "GCLOMB72ODBFUGK4E2BK7VMR3RNZ5WSTMEOGNA2YUVHFR3WMH2XBAB6H", transaction.Source)
						assert.Equal(t, mocks.PredefinedTime, transaction.SubmittedAt)
						assert.Equal(t, txB64, transaction.EnvelopeXdr)
					})

					ledger := uint64(1486276)
					mockHorizon.On("SubmitTransaction", txB64).Return(
						horizon.SubmitTransactionResponse{Ledger: &ledger},
						nil,
					).Once()

					response, err := transactionSubmitter.SubmitTransaction(seed, operation, memo)
					assert.Nil(t, err)
					assert.Equal(t, *response.Ledger, ledger)
					assert.Equal(t, uint64(10372672437354497), transactionSubmitter.Accounts[seed].SequenceNumber)
					mockHorizon.AssertExpectations(t)
				})
			})
		})
	})
}
func (rh *RequestHandler) Send(w http.ResponseWriter, r *http.Request) {
	destination := r.PostFormValue("destination")
	assetCode := r.PostFormValue("asset_code")
	amount := r.PostFormValue("amount")

	destinationObject, err := rh.AddressResolver.Resolve(destination)
	if err != nil {
		log.WithFields(log.Fields{"destination": destination}).Print("Cannot resolve address")
		errorBadRequest(w, errorResponseString("invalid_destination", "Cannot resolve destination"))
		return
	}

	_, err = keypair.Parse(destinationObject.AccountId)
	if err != nil {
		log.WithFields(log.Fields{"AccountId": destinationObject.AccountId}).Print("Invalid AccountId in destination")
		errorBadRequest(w, errorResponseString("invalid_destination", "destination parameter is invalid"))
		return
	}

	if !rh.isAssetAllowed(assetCode) {
		log.Print("Asset code not allowed: ", assetCode)
		errorBadRequest(w, errorResponseString("invalid_asset_code", "Given assetCode not allowed"))
		return
	}

	issuingKeypair, err := keypair.Parse(*rh.Config.Accounts.IssuingSeed)
	if err != nil {
		log.Print("Invalid issuingSeed")
		errorServerError(w)
		return
	}

	operationMutator := b.Payment(
		b.Destination{destinationObject.AccountId},
		b.CreditAmount{assetCode, issuingKeypair.Address(), amount},
	)
	if operationMutator.Err != nil {
		log.Print("Error creating operationMutator ", operationMutator.Err)
		errorServerError(w)
		return
	}

	memoType := r.PostFormValue("memo_type")
	memo := r.PostFormValue("memo")

	if !(((memoType == "") && (memo == "")) || ((memoType != "") && (memo != ""))) {
		log.Print("Missing one of memo params.")
		errorBadRequest(w, errorResponseString("memo_missing_param", "When passing memo both params: `memo_type`, `memo` are required"))
		return
	}

	if destinationObject.MemoType != nil {
		if memoType != "" {
			log.Print("Memo given in request but federation returned memo fields.")
			errorBadRequest(w, errorResponseString("cannot_use_memo", "Memo given in request but federation returned memo fields"))
			return
		}

		memoType = *destinationObject.MemoType
		memo = *destinationObject.Memo
	}

	var memoMutator interface{}
	switch {
	case memoType == "":
		break
	case memoType == "id":
		id, err := strconv.ParseUint(memo, 10, 64)
		if err != nil {
			log.WithFields(log.Fields{"memo": memo}).Print("Cannot convert memo_id value to uint64")
			errorBadRequest(w, errorResponseString("cannot_convert_memo_id", "Cannot convert memo_id value"))
			return
		}
		memoMutator = b.MemoID{id}
	case memoType == "text":
		memoMutator = b.MemoText{memo}
	default:
		log.Print("Not supported memo type: ", memoType)
		errorBadRequest(w, errorResponseString("memo_not_supported", "Not supported memo type"))
		return
	}

	submitResponse, err := rh.TransactionSubmitter.SubmitTransaction(
		*rh.Config.Accounts.IssuingSeed,
		operationMutator,
		memoMutator,
	)
	if err != nil {
		log.Print("Error submitting transaction ", err)
		errorServerError(w)
		return
	}

	if submitResponse.Errors != nil {
		var errorString string
		if submitResponse.Errors.OperationErrorCode != "" {
			switch submitResponse.Errors.OperationErrorCode {
			case "payment_malformed":
				errorString = errorResponseString(
					"payment_malformed",
					"Operation is malformed.",
				)
			case "payment_underfunded":
				errorString = errorResponseString(
					"payment_underfunded",
					"Not enough funds to send this transaction.",
				)
			case "payment_src_no_trust":
				errorString = errorResponseString(
					"payment_src_no_trust",
					"No trustline on source account.",
				)
			case "payment_src_not_authorized":
				errorString = errorResponseString(
					"payment_src_not_authorized",
					"Source not authorized to transfer.",
				)
			case "payment_no_destination":
				errorString = errorResponseString(
					"payment_no_destination",
					"Destination account does not exist.",
				)
			case "payment_no_trust":
				errorString = errorResponseString(
					"payment_no_trust",
					"Destination missing a trust line for asset.",
				)
			case "payment_not_authorized":
				errorString = errorResponseString(
					"payment_not_authorized",
					"Destination not authorized to trust asset. It needs to be allowed first by using /authorize endpoint.",
				)
			case "payment_line_full":
				errorString = errorResponseString(
					"payment_line_full",
					"Sending this payment would make a destination go above their limit.",
				)
			case "payment_no_issuer":
				errorString = errorResponseString(
					"payment_no_issuer",
					"Missing issuer on asset.",
				)
			default:
				errorServerError(w)
				return
			}
		} else if submitResponse.Errors.TransactionErrorCode != "" {
			switch submitResponse.Errors.TransactionErrorCode {
			case "transaction_bad_seq":
				errorString = errorResponseString(
					"transaction_bad_seq",
					"Bad Sequence. Please, try again.",
				)
			default:
				errorServerError(w)
				return
			}
		}

		errorBadRequest(w, errorString)
		return
	}

	json, err := json.MarshalIndent(submitResponse, "", "  ")

	if err != nil {
		errorServerError(w)
		return
	}

	w.Write(json)
}
func TestRequestHandlerSend(t *testing.T) {
	mockAddressResolverHelper := new(MockAddressResolverHelper)
	addressResolver := AddressResolver{mockAddressResolverHelper}

	mockTransactionSubmitter := new(mocks.MockTransactionSubmitter)

	IssuingSeed := "SC34WILLHVADXMP6ACPMIRA6TRAWJMVCLPFNW7S6MUMXJVLAZUC4EWHP"
	AuthorizingSeed := "SC37TBSIAYKIDQ6GTGLT2HSORLIHZQHBXVFI5P5K4Q5TSHRTRBK3UNWG"

	config := config.Config{
		Assets: []string{"USD", "EUR"},
		Accounts: &config.Accounts{
			// GD4I7AFSLZGTDL34TQLWJOM2NHLIIOEKD5RHHZUW54HERBLSIRKUOXRR
			IssuingSeed: &IssuingSeed,
			// GBQXA3ABGQGTCLEVZIUTDRWWJOQD5LSAEDZAG7GMOGD2HBLWONGUVO4I
			AuthorizingSeed: &AuthorizingSeed,
		},
	}

	issuingKeypair, err := keypair.Parse(*config.Accounts.IssuingSeed)
	if err != nil {
		panic(err)
	}

	requestHandler := RequestHandler{
		AddressResolver:      addressResolver,
		Config:               &config,
		TransactionSubmitter: mockTransactionSubmitter,
	}
	testServer := httptest.NewServer(http.HandlerFunc(requestHandler.Send))
	defer testServer.Close()

	Convey("Given send request", t, func() {
		Convey("When destination is invalid", func() {
			destination := "GD3YBOYIUVLU"
			assetCode := "USD"

			Convey("it should return error", func() {
				statusCode, response := getResponse(testServer, url.Values{"destination": {destination}, "asset_code": {assetCode}})
				responseString := strings.TrimSpace(string(response))
				assert.Equal(t, 400, statusCode)
				assert.Equal(t, errorResponseString("invalid_destination", "destination parameter is invalid"), responseString)
			})
		})

		Convey("When assetCode is invalid", func() {
			destination := "GDSIKW43UA6JTOA47WVEBCZ4MYC74M3GNKNXTVDXFHXYYTNO5GGVN632"
			assetCode := "GBP"

			Convey("it should return error", func() {
				statusCode, response := getResponse(testServer, url.Values{"destination": {destination}, "asset_code": {assetCode}})
				responseString := strings.TrimSpace(string(response))
				assert.Equal(t, 400, statusCode)
				assert.Equal(t, errorResponseString("invalid_asset_code", "Given assetCode not allowed"), responseString)
			})
		})

		Convey("When destination is a Stellar address", func() {
			params := url.Values{
				"asset_code":  {"USD"},
				"amount":      {"20"},
				"destination": {"bob*stellar.org"},
			}

			Convey("When stellar.toml does not exist", func() {
				mockAddressResolverHelper.On(
					"GetStellarToml",
					"stellar.org",
				).Return(
					StellarToml{},
					errors.New("stellar.toml response status code indicates error"),
				).Once()

				Convey("it should return error", func() {
					statusCode, response := getResponse(testServer, params)
					responseString := strings.TrimSpace(string(response))
					assert.Equal(t, 400, statusCode)
					assert.Equal(t, errorResponseString("invalid_destination", "Cannot resolve destination"), responseString)
				})
			})

			Convey("When stellar.toml does not contain FEDERATION_SERVER", func() {
				mockAddressResolverHelper.On(
					"GetStellarToml",
					"stellar.org",
				).Return(
					StellarToml{},
					nil,
				).Once()

				Convey("it should return error", func() {
					statusCode, response := getResponse(testServer, params)
					responseString := strings.TrimSpace(string(response))
					assert.Equal(t, 400, statusCode)
					assert.Equal(t, errorResponseString("invalid_destination", "Cannot resolve destination"), responseString)
				})
			})

			Convey("When GetDestination() errors", func() {
				federationServer := "http://api.example.com"
				mockAddressResolverHelper.On(
					"GetStellarToml",
					"stellar.org",
				).Return(
					StellarToml{&federationServer},
					nil,
				).Once()

				mockAddressResolverHelper.On(
					"GetDestination",
					"http://api.example.com",
					"bob*stellar.org",
				).Return(
					StellarDestination{},
					errors.New("Only HTTPS federation servers allowed"),
				).Once()

				Convey("it should return error", func() {
					statusCode, response := getResponse(testServer, params)
					responseString := strings.TrimSpace(string(response))
					assert.Equal(t, 400, statusCode)
					assert.Equal(t, errorResponseString("invalid_destination", "Cannot resolve destination"), responseString)
				})
			})

			Convey("When federation response is correct", func() {
				federationServer := "http://api.example.com"
				mockAddressResolverHelper.On(
					"GetStellarToml",
					"stellar.org",
				).Return(
					StellarToml{&federationServer},
					nil,
				).Once()

				mockAddressResolverHelper.On(
					"GetDestination",
					"http://api.example.com",
					"bob*stellar.org",
				).Return(StellarDestination{AccountId: "GDSIKW43UA6JTOA47WVEBCZ4MYC74M3GNKNXTVDXFHXYYTNO5GGVN632"}, nil).Once()

				var ledger uint64
				ledger = 1988728
				expectedSubmitResponse := horizon.SubmitTransactionResponse{&ledger, nil, nil}

				operation := b.Payment(
					b.Destination{"GDSIKW43UA6JTOA47WVEBCZ4MYC74M3GNKNXTVDXFHXYYTNO5GGVN632"},
					b.CreditAmount{
						params.Get("asset_code"),
						issuingKeypair.Address(),
						params.Get("amount"),
					},
				)

				mockTransactionSubmitter.On(
					"SubmitTransaction",
					*config.Accounts.IssuingSeed,
					operation,
					nil,
				).Return(expectedSubmitResponse, nil).Once()

				Convey("it should return success", func() {
					statusCode, response := getResponse(testServer, params)
					responseString := strings.TrimSpace(string(response))

					expectedResponse, err := json.MarshalIndent(expectedSubmitResponse, "", "  ")
					if err != nil {
						panic(err)
					}

					assert.Equal(t, 200, statusCode)
					assert.Equal(t, string(expectedResponse), responseString)
				})
			})
		})

		Convey("When destination is an accountId", func() {
			params := url.Values{
				"asset_code":  {"USD"},
				"amount":      {"20"},
				"destination": {"GDSIKW43UA6JTOA47WVEBCZ4MYC74M3GNKNXTVDXFHXYYTNO5GGVN632"},
			}

			Convey("When params are valid", func() {
				operation := b.Payment(
					b.Destination{params.Get("destination")},
					b.CreditAmount{
						params.Get("asset_code"),
						issuingKeypair.Address(),
						params.Get("amount"),
					},
				)

				Convey("transaction fails", func() {
					mockTransactionSubmitter.On(
						"SubmitTransaction",
						*config.Accounts.IssuingSeed,
						operation,
						nil,
					).Return(
						horizon.SubmitTransactionResponse{},
						errors.New("Error sending transaction"),
					).Once()

					Convey("it should return server error", func() {
						statusCode, response := getResponse(testServer, params)
						responseString := strings.TrimSpace(string(response))
						assert.Equal(t, 500, statusCode)
						assert.Equal(t, getServerErrorResponseString(), responseString)
						mockTransactionSubmitter.AssertExpectations(t)
					})
				})

				Convey("transaction succeeds (no memo)", func() {
					var ledger uint64
					ledger = 100
					expectedSubmitResponse := horizon.SubmitTransactionResponse{
						Ledger: &ledger,
					}

					mockTransactionSubmitter.On(
						"SubmitTransaction",
						*config.Accounts.IssuingSeed,
						operation,
						nil,
					).Return(expectedSubmitResponse, nil).Once()

					Convey("it should succeed", func() {
						statusCode, response := getResponse(testServer, params)
						var actualSubmitTransactionResponse horizon.SubmitTransactionResponse
						json.Unmarshal(response, &actualSubmitTransactionResponse)
						assert.Equal(t, 200, statusCode)
						assert.Equal(t, expectedSubmitResponse, actualSubmitTransactionResponse)
						mockTransactionSubmitter.AssertExpectations(t)
					})
				})

				Convey("transaction succeeds (with memo)", func() {
					params.Add("memo_type", "id")
					params.Add("memo", "123")

					var ledger uint64
					ledger = 100
					expectedSubmitResponse := horizon.SubmitTransactionResponse{
						Ledger: &ledger,
					}

					memo := b.MemoID{123}

					mockTransactionSubmitter.On(
						"SubmitTransaction",
						*config.Accounts.IssuingSeed,
						operation,
						memo,
					).Return(expectedSubmitResponse, nil).Once()

					Convey("it should succeed", func() {
						statusCode, response := getResponse(testServer, params)
						var actualSubmitTransactionResponse horizon.SubmitTransactionResponse
						json.Unmarshal(response, &actualSubmitTransactionResponse)
						assert.Equal(t, 200, statusCode)
						assert.Equal(t, expectedSubmitResponse, actualSubmitTransactionResponse)
						mockTransactionSubmitter.AssertExpectations(t)
					})
				})
			})
		})
	})
}