service backend

api/fx/oracle/client/client.go

@@ -0,0 +1,252 @@
+package client
+
+import (
+	"context"
+	"crypto/tls"
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+
+	fxv1 "github.com/tech/sendico/pkg/proto/common/fx/v1"
+	moneyv1 "github.com/tech/sendico/pkg/proto/common/money/v1"
+	tracev1 "github.com/tech/sendico/pkg/proto/common/trace/v1"
+	oraclev1 "github.com/tech/sendico/pkg/proto/oracle/v1"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/credentials/insecure"
+)
+
+// Client exposes typed helpers around the oracle gRPC API.
+type Client interface {
+	LatestRate(ctx context.Context, req LatestRateParams) (*RateSnapshot, error)
+	GetQuote(ctx context.Context, req GetQuoteParams) (*Quote, error)
+	Close() error
+}
+
+// RequestMeta carries optional multi-tenant context for oracle calls.
+type RequestMeta struct {
+	TenantRef       string
+	OrganizationRef string
+	Trace           *tracev1.TraceContext
+}
+
+type LatestRateParams struct {
+	Meta     RequestMeta
+	Pair     *fxv1.CurrencyPair
+	Provider string
+}
+
+type RateSnapshot struct {
+	Pair      *fxv1.CurrencyPair
+	Mid       string
+	Bid       string
+	Ask       string
+	SpreadBps string
+	Provider  string
+	RateRef   string
+	AsOf      time.Time
+}
+
+type GetQuoteParams struct {
+	Meta              RequestMeta
+	Pair              *fxv1.CurrencyPair
+	Side              fxv1.Side
+	BaseAmount        *moneyv1.Money
+	QuoteAmount       *moneyv1.Money
+	Firm              bool
+	TTL               time.Duration
+	PreferredProvider string
+	MaxAge            time.Duration
+}
+
+type Quote struct {
+	QuoteRef    string
+	Pair        *fxv1.CurrencyPair
+	Side        fxv1.Side
+	Price       string
+	BaseAmount  *moneyv1.Money
+	QuoteAmount *moneyv1.Money
+	ExpiresAt   time.Time
+	Provider    string
+	RateRef     string
+	Firm        bool
+}
+
+type grpcOracleClient interface {
+	GetQuote(ctx context.Context, in *oraclev1.GetQuoteRequest, opts ...grpc.CallOption) (*oraclev1.GetQuoteResponse, error)
+	LatestRate(ctx context.Context, in *oraclev1.LatestRateRequest, opts ...grpc.CallOption) (*oraclev1.LatestRateResponse, error)
+}
+
+type oracleClient struct {
+	cfg    Config
+	conn   *grpc.ClientConn
+	client grpcOracleClient
+}
+
+// New dials the oracle endpoint and returns a ready client.
+func New(ctx context.Context, cfg Config, opts ...grpc.DialOption) (Client, error) {
+	cfg.setDefaults()
+	if strings.TrimSpace(cfg.Address) == "" {
+		return nil, errors.New("oracle: address is required")
+	}
+
+	dialCtx, cancel := context.WithTimeout(ctx, cfg.DialTimeout)
+	defer cancel()
+
+	dialOpts := make([]grpc.DialOption, 0, len(opts)+1)
+	dialOpts = append(dialOpts, opts...)
+
+	if cfg.Insecure {
+		dialOpts = append(dialOpts, grpc.WithTransportCredentials(insecure.NewCredentials()))
+	} else {
+		dialOpts = append(dialOpts, grpc.WithTransportCredentials(credentials.NewTLS(&tls.Config{})))
+	}
+
+	conn, err := grpc.DialContext(dialCtx, cfg.Address, dialOpts...)
+	if err != nil {
+		return nil, fmt.Errorf("oracle: dial %s: %w", cfg.Address, err)
+	}
+
+	return &oracleClient{
+		cfg:    cfg,
+		conn:   conn,
+		client: oraclev1.NewOracleClient(conn),
+	}, nil
+}
+
+// NewWithClient injects a pre-built oracle client (useful for tests).
+func NewWithClient(cfg Config, oc grpcOracleClient) Client {
+	cfg.setDefaults()
+	return &oracleClient{
+		cfg:    cfg,
+		client: oc,
+	}
+}
+
+func (c *oracleClient) Close() error {
+	if c.conn != nil {
+		return c.conn.Close()
+	}
+	return nil
+}
+
+func (c *oracleClient) LatestRate(ctx context.Context, req LatestRateParams) (*RateSnapshot, error) {
+	if req.Pair == nil {
+		return nil, errors.New("oracle: pair is required")
+	}
+
+	callCtx, cancel := c.callContext(ctx)
+	defer cancel()
+
+	resp, err := c.client.LatestRate(callCtx, &oraclev1.LatestRateRequest{
+		Meta:     toProtoMeta(req.Meta),
+		Pair:     req.Pair,
+		Provider: req.Provider,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("oracle: latest rate: %w", err)
+	}
+	if resp.GetRate() == nil {
+		return nil, errors.New("oracle: latest rate: empty payload")
+	}
+	return fromProtoRate(resp.GetRate()), nil
+}
+
+func (c *oracleClient) GetQuote(ctx context.Context, req GetQuoteParams) (*Quote, error) {
+	if req.Pair == nil {
+		return nil, errors.New("oracle: pair is required")
+	}
+	if req.Side == fxv1.Side_SIDE_UNSPECIFIED {
+		return nil, errors.New("oracle: side is required")
+	}
+
+	baseSupplied := req.BaseAmount != nil
+	quoteSupplied := req.QuoteAmount != nil
+	if baseSupplied == quoteSupplied {
+		return nil, errors.New("oracle: exactly one of base_amount or quote_amount must be set")
+	}
+
+	callCtx, cancel := c.callContext(ctx)
+	defer cancel()
+
+	protoReq := &oraclev1.GetQuoteRequest{
+		Meta:              toProtoMeta(req.Meta),
+		Pair:              req.Pair,
+		Side:              req.Side,
+		Firm:              req.Firm,
+		PreferredProvider: req.PreferredProvider,
+	}
+	if req.TTL > 0 {
+		protoReq.TtlMs = req.TTL.Milliseconds()
+	}
+	if req.MaxAge > 0 {
+		protoReq.MaxAgeMs = int32(req.MaxAge.Milliseconds())
+	}
+	if baseSupplied {
+		protoReq.AmountInput = &oraclev1.GetQuoteRequest_BaseAmount{BaseAmount: req.BaseAmount}
+	} else {
+		protoReq.AmountInput = &oraclev1.GetQuoteRequest_QuoteAmount{QuoteAmount: req.QuoteAmount}
+	}
+
+	resp, err := c.client.GetQuote(callCtx, protoReq)
+	if err != nil {
+		return nil, fmt.Errorf("oracle: get quote: %w", err)
+	}
+	if resp.GetQuote() == nil {
+		return nil, errors.New("oracle: get quote: empty payload")
+	}
+	return fromProtoQuote(resp.GetQuote()), nil
+}
+
+func (c *oracleClient) callContext(ctx context.Context) (context.Context, context.CancelFunc) {
+	if _, ok := ctx.Deadline(); ok {
+		return context.WithCancel(ctx)
+	}
+	return context.WithTimeout(ctx, c.cfg.CallTimeout)
+}
+
+func toProtoMeta(meta RequestMeta) *oraclev1.RequestMeta {
+	if meta.TenantRef == "" && meta.OrganizationRef == "" && meta.Trace == nil {
+		return nil
+	}
+	return &oraclev1.RequestMeta{
+		TenantRef:       meta.TenantRef,
+		OrganizationRef: meta.OrganizationRef,
+		Trace:           meta.Trace,
+	}
+}
+
+func fromProtoRate(rate *oraclev1.RateSnapshot) *RateSnapshot {
+	if rate == nil {
+		return nil
+	}
+	return &RateSnapshot{
+		Pair:      rate.Pair,
+		Mid:       rate.GetMid().GetValue(),
+		Bid:       rate.GetBid().GetValue(),
+		Ask:       rate.GetAsk().GetValue(),
+		SpreadBps: rate.GetSpreadBps().GetValue(),
+		Provider:  rate.GetProvider(),
+		RateRef:   rate.GetRateRef(),
+		AsOf:      time.UnixMilli(rate.GetAsofUnixMs()),
+	}
+}
+
+func fromProtoQuote(quote *oraclev1.Quote) *Quote {
+	if quote == nil {
+		return nil
+	}
+	return &Quote{
+		QuoteRef:    quote.GetQuoteRef(),
+		Pair:        quote.Pair,
+		Side:        quote.GetSide(),
+		Price:       quote.GetPrice().GetValue(),
+		BaseAmount:  quote.BaseAmount,
+		QuoteAmount: quote.QuoteAmount,
+		ExpiresAt:   time.UnixMilli(quote.GetExpiresAtUnixMs()),
+		Provider:    quote.GetProvider(),
+		RateRef:     quote.GetRateRef(),
+		Firm:        quote.GetFirm(),
+	}
+}