swap: add prototype of frontend-backend API interaction

backend/handlers/handlers.go

@@ -17,6 +17,7 @@ package handlers
 
 import (
 	"bytes"
+	"context"
 	"encoding/base64"
 	"encoding/hex"
 	"encoding/json"
@@ -49,6 +50,7 @@ import (
 	"github.com/BitBoxSwiss/bitbox-wallet-app/backend/devices/device"
 	"github.com/BitBoxSwiss/bitbox-wallet-app/backend/keystore"
 	"github.com/BitBoxSwiss/bitbox-wallet-app/backend/market"
+	"github.com/BitBoxSwiss/bitbox-wallet-app/backend/market/swapkit"
 	"github.com/BitBoxSwiss/bitbox-wallet-app/backend/rates"
 	"github.com/BitBoxSwiss/bitbox-wallet-app/backend/versioninfo"
 	utilConfig "github.com/BitBoxSwiss/bitbox-wallet-app/util/config"
@@ -247,6 +249,9 @@ func NewHandlers(
 	getAPIRouterNoError(apiRouter)("/market/vendors/{code}", handlers.getMarketVendors).Methods("GET")
 	getAPIRouterNoError(apiRouter)("/market/btcdirect-otc/supported/{code}", handlers.getMarketBtcDirectOTCSupported).Methods("GET")
 	getAPIRouterNoError(apiRouter)("/market/btcdirect/info/{action}/{code}", handlers.getMarketBtcDirectInfo).Methods("GET")
+	getAPIRouterNoError(apiRouter)("/swap/quote", handlers.getSwapkitQuote).Methods("GET")
+	getAPIRouterNoError(apiRouter)("/swap/execute", handlers.swapkitSwap).Methods("GET")
+	getAPIRouterNoError(apiRouter)("/swap/track", handlers.swapkitTrack).Methods("GET")
 	getAPIRouter(apiRouter)("/market/moonpay/buy-info/{code}", handlers.getMarketMoonpayBuyInfo).Methods("GET")
 	getAPIRouterNoError(apiRouter)("/market/pocket/api-url/{action}", handlers.getMarketPocketURL).Methods("GET")
 	getAPIRouterNoError(apiRouter)("/market/pocket/verify-address", handlers.postPocketWidgetVerifyAddress).Methods("POST")
@@ -1664,3 +1669,94 @@ func (handlers *Handlers) postConnectKeystore(r *http.Request) interface{} {
 	_, err := handlers.backend.ConnectKeystore([]byte(request.RootFingerprint))
 	return response{Success: err == nil}
 }
+
+func (handlers *Handlers) getSwapkitQuote(r *http.Request) interface{} {
+	type result struct {
+		Success bool                   `json:"success"`
+		Error   string                 `json:"error,omitempty"`
+		Quote   *swapkit.QuoteResponse `json:"quote,omitempty"`
+	}
+
+	var request swapkit.QuoteRequest
+
+	if err := json.NewDecoder(r.Body).Decode(&request); err != nil {
+		return result{Success: false, Error: err.Error()}
+	}
+
+	s := swapkit.NewClient("0722e09f-9d3f-4817-a870-069848d03ee9")
+
+	quoteResponse, err := s.Quote(context.Background(), &request)
+	if err != nil {
+		return result{
+			Success: false,
+			Error:   err.Error(),
+		}
+	}
+
+	res := result{
+		Success: quoteResponse.Error != "",
+		Error:   quoteResponse.Error, // Surface the response error to the top-level
+	}
+	if res.Success {
+		res.Quote = quoteResponse
+	}
+	return res
+}
+
+func (handlers *Handlers) swapkitSwap(r *http.Request) interface{} {
+	type result struct {
+		Success bool                  `json:"success"`
+		Error   string                `json:"error,omitempty"`
+		Swap    *swapkit.SwapResponse `json:"swap,omitempty"`
+	}
+
+	var request swapkit.SwapRequest
+
+	if err := json.NewDecoder(r.Body).Decode(&request); err != nil {
+		return result{Success: false, Error: err.Error()}
+	}
+
+	s := swapkit.NewClient("0722e09f-9d3f-4817-a870-069848d03ee9")
+	swapResponse, err := s.Swap(context.Background(), &request)
+	if err != nil {
+		return result{
+			Success: false,
+			Error:   err.Error(),
+		}
+	}
+
+	return result{
+		Success: true,
+		Swap:    swapResponse,
+	}
+
+}
+
+func (handlers *Handlers) swapkitTrack(r *http.Request) interface{} {
+	type result struct {
+		Success bool                   `json:"success"`
+		Error   string                 `json:"error,omitempty"`
+		Track   *swapkit.TrackResponse `json:"swap,omitempty"`
+	}
+
+	var request swapkit.TrackRequest
+
+	if err := json.NewDecoder(r.Body).Decode(&request); err != nil {
+		return result{Success: false, Error: err.Error()}
+	}
+
+	s := swapkit.NewClient("0722e09f-9d3f-4817-a870-069848d03ee9")
+	trackResponse, err := s.Track(context.Background(), &request)
+	if err != nil {
+		return result{
+			Success: false,
+			Error:   err.Error(),
+		}
+	}
+
+	return result{
+		Success: true,
+		Track:   trackResponse,
+	}
+
+}

backend/market/swapkit/client.go

@@ -0,0 +1,77 @@
+package swapkit
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+
+	"github.com/BitBoxSwiss/bitbox-wallet-app/util/logging"
+	"github.com/sirupsen/logrus"
+)
+
+// Client is a SwapKit client that can be used to interact with
+// SwapKit API.
+type Client struct {
+	apiKey     string
+	baseURL    string
+	httpClient *http.Client
+	log        *logrus.Entry
+}
+
+// NewClient returns a new swapkit client.
+func NewClient(apiKey string) *Client {
+	return &Client{
+		apiKey:  apiKey,
+		baseURL: "https://api.swapkit.dev",
+		httpClient: &http.Client{
+			Timeout: 20 * time.Second,
+		},
+		log: logging.Get().WithGroup("swapkit"),
+	}
+}
+
+func (c *Client) post(ctx context.Context, path string, body any, out any) error {
+	b, err := json.Marshal(body)
+	if err != nil {
+		return fmt.Errorf("marshal request: %w", err)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.baseURL+path, bytes.NewReader(b))
+	if err != nil {
+		return fmt.Errorf("create request: %w", err)
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+	if c.apiKey != "" {
+		req.Header.Set("x-api-key", c.apiKey)
+	}
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("http error: %w", err)
+	}
+	defer func() {
+		if err := resp.Body.Close(); err != nil {
+			c.log.WithError(err).Error("Error closing response body")
+		}
+	}()
+
+	bodyBytes, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return fmt.Errorf("read response: %w", err)
+	}
+
+	if resp.StatusCode >= 400 {
+		return fmt.Errorf("swapkit error %d: %s", resp.StatusCode, string(bodyBytes))
+	}
+
+	if err := json.Unmarshal(bodyBytes, out); err != nil {
+		return fmt.Errorf("decode response: %w", err)
+	}
+
+	return nil
+}

backend/market/swapkit/methods.go

@@ -0,0 +1,32 @@
+package swapkit
+
+import (
+	"context"
+)
+
+// Quote performs a SwapKit V3 quote request.
+func (c *Client) Quote(ctx context.Context, req *QuoteRequest) (*QuoteResponse, error) {
+	var resp QuoteResponse
+	if err := c.post(ctx, "/v3/quote", req, &resp); err != nil {
+		return nil, err
+	}
+	return &resp, nil
+}
+
+// Swap performs a SwapKit V3 swap request.
+func (c *Client) Swap(ctx context.Context, req *SwapRequest) (*SwapResponse, error) {
+	var resp SwapResponse
+	if err := c.post(ctx, "/v3/swap", req, &resp); err != nil {
+		return nil, err
+	}
+	return &resp, nil
+}
+
+// Track performs a SwapKit track request.
+func (c *Client) Track(ctx context.Context, req *TrackRequest) (*TrackResponse, error) {
+	var resp TrackResponse
+	if err := c.post(ctx, "/track", req, &resp); err != nil {
+		return nil, err
+	}
+	return &resp, nil
+}

backend/market/swapkit/types.go

@@ -0,0 +1,159 @@
+package swapkit
+
+import "encoding/json"
+
+// QuoteRequest represents a request to swapkit for a swap quote.
+type QuoteRequest struct {
+	SellAsset        string   `json:"sellAsset"`
+	BuyAsset         string   `json:"buyAsset"`
+	SellAmount       string   `json:"sellAmount"`
+	Providers        []string `json:"providers,omitempty"`
+	Slippage         *string  `json:"slippage,omitempty"`
+	AffiliateFee     *int     `json:"affiliateFee,omitempty"`
+	CfBoost          *bool    `json:"cfBoost,omitempty"`
+	MaxExecutionTime *int     `json:"maxExecutionTime,omitempty"`
+}
+
+// SwapRequest represents a request to swakip to execute a swap.
+type SwapRequest struct {
+	RouteID                    string `json:"routeId"`
+	SourceAddress              string `json:"sourceAddress"`
+	DestinationAddress         string `json:"destinationAddress"`
+	DisableBalanceCheck        *bool  `json:"disableBalanceCheck,omitempty"`
+	DisableEstimate            *bool  `json:"disableEstimate,omitempty"`
+	AllowSmartContractSender   *bool  `json:"allowSmartContractSender,omitempty"`
+	AllowSmartContractReceiver *bool  `json:"allowSmartContractReceiver,omitempty"`
+	DisableSecurityChecks      *bool  `json:"disableSecurityChecks,omitempty"`
+	OverrideSlippage           *bool  `json:"overrideSlippage,omitempty"`
+}
+
+// QuoteResponse contains info about swaps' quotes.
+type QuoteResponse struct {
+	QuoteID        string          `json:"quoteId"`
+	Routes         []QuoteRoute    `json:"routes"`
+	ProviderErrors []ProviderError `json:"providerErrors,omitempty"`
+	Error          string          `json:"error,omitempty"`
+}
+
+// SwapResponse is the answer provided by swapkit when asking to execute a swap.
+type SwapResponse struct {
+	RouteID                      string          `json:"routeId"`
+	Providers                    []string        `json:"providers"`
+	SellAsset                    string          `json:"sellAsset"`
+	BuyAsset                     string          `json:"buyAsset"`
+	SellAmount                   string          `json:"sellAmount"`
+	ExpectedBuyAmount            string          `json:"expectedBuyAmount"`
+	ExpectedBuyAmountMaxSlippage string          `json:"expectedBuyAmountMaxSlippage"`
+	Tx                           json.RawMessage `json:"tx"`
+	ApprovalTx                   json.RawMessage `json:"approvalTx,omitempty"`
+	TargetAddress                string          `json:"targetAddress"`
+	Memo                         string          `json:"memo,omitempty"`
+	Fees                         []Fee           `json:"fees"`
+	EstimatedTime                json.RawMessage `json:"estimatedTime,omitempty"`
+	TotalSlippageBps             int             `json:"totalSlippageBps"`
+	Legs                         json.RawMessage `json:"legs,omitempty"`
+	Warnings                     json.RawMessage `json:"warnings,omitempty"`
+	Meta                         json.RawMessage `json:"meta,omitempty"`
+	NextActions                  []NextAction    `json:"nextActions,omitempty"`
+}
+
+// QuoteRoute represent a single route to swap coins from
+// SellAsset to BuyAsset.
+type QuoteRoute struct {
+	RouteID                      string   `json:"routeId"`
+	Providers                    []string `json:"providers"`
+	SellAsset                    string   `json:"sellAsset"`
+	BuyAsset                     string   `json:"buyAsset"`
+	SellAmount                   string   `json:"sellAmount"`
+	ExpectedBuyAmount            string   `json:"expectedBuyAmount"`
+	ExpectedBuyAmountMaxSlippage string   `json:"expectedBuyAmountMaxSlippage"`
+
+	// tx object varies by chain:
+	// - EVM     → Ethers v6 transaction
+	// - UTXO    → base64 PSBT
+	Tx json.RawMessage `json:"tx"`
+
+	ApprovalTx json.RawMessage `json:"approvalTx,omitempty"`
+
+	TargetAddress    string          `json:"targetAddress"`
+	Memo             string          `json:"memo,omitempty"`
+	Fees             []Fee           `json:"fees"`
+	EstimatedTime    json.RawMessage `json:"estimatedTime,omitempty"`
+	TotalSlippageBps float64         `json:"totalSlippageBps"`
+	Legs             json.RawMessage `json:"legs,omitempty"`
+	Warnings         json.RawMessage `json:"warnings,omitempty"`
+	Meta             json.RawMessage `json:"meta,omitempty"`
+
+	NextActions []NextAction `json:"nextActions,omitempty"`
+}
+
+// Fee represents one of the possible fees for executing a swap.
+type Fee struct {
+	Type     string `json:"type"`
+	Amount   string `json:"amount"`
+	Asset    string `json:"asset"`
+	Chain    string `json:"chain"`
+	Protocol string `json:"protocol"`
+}
+
+// NextAction is provided by swap as a convenience field to suggest what
+// the next step in a swap workflow could be.
+type NextAction struct {
+	Method  string          `json:"method"`
+	URL     string          `json:"url"`
+	Payload json.RawMessage `json:"payload,omitempty"`
+}
+
+// ProviderError contains errors specific to a Provider
+// (e.g. some provided will only provide quotes for sell amounts
+// higher than a certain treshold).
+type ProviderError struct {
+	Provider  string `json:"provider"`
+	ErrorCode string `json:"errorCode"`
+	Message   string `json:"message"`
+}
+
+// TrackRequest is used to query swapkit fo track the status of a swap.
+type TrackRequest struct {
+	Hash    string `json:"hash"`
+	ChainID string `json:"chainId"`
+}
+
+// TrackResponse represents SwapKit's response for a tracked transaction
+type TrackResponse struct {
+	ChainID        string          `json:"chainId"`
+	Hash           string          `json:"hash"`
+	Block          int64           `json:"block"`
+	Type           string          `json:"type"`           // swap, token_transfer, etc.
+	Status         string          `json:"status"`         // not_started, pending, swapping, completed, refunded, failed, unknown
+	TrackingStatus string          `json:"trackingStatus"` // deprecated, status is enough
+	FromAsset      string          `json:"fromAsset"`
+	FromAmount     string          `json:"fromAmount"`
+	FromAddress    string          `json:"fromAddress"`
+	ToAsset        string          `json:"toAsset"`
+	ToAmount       string          `json:"toAmount"`
+	ToAddress      string          `json:"toAddress"`
+	FinalisedAt    int64           `json:"finalisedAt"`       // UNIX timestamp
+	Meta           json.RawMessage `json:"meta,omitempty"`    // provider, images, etc.
+	Payload        json.RawMessage `json:"payload,omitempty"` // transaction-specific info
+	Legs           []TrackLeg      `json:"legs,omitempty"`    // individual steps in transaction
+}
+
+// TrackLeg represents a step of the transaction
+type TrackLeg struct {
+	ChainID        string          `json:"chainId"`
+	Hash           string          `json:"hash"`
+	Block          int64           `json:"block"`
+	Type           string          `json:"type"`
+	Status         string          `json:"status"`
+	TrackingStatus string          `json:"trackingStatus"`
+	FromAsset      string          `json:"fromAsset"`
+	FromAmount     string          `json:"fromAmount"`
+	FromAddress    string          `json:"fromAddress"`
+	ToAsset        string          `json:"toAsset"`
+	ToAmount       string          `json:"toAmount"`
+	ToAddress      string          `json:"toAddress"`
+	FinalisedAt    int64           `json:"finalisedAt"`
+	Meta           json.RawMessage `json:"meta,omitempty"`
+	Payload        json.RawMessage `json:"payload,omitempty"`
+}