payment rails

api/server/interface/api/srequest/endpoint_union.go

@@ -0,0 +1,211 @@
+package srequest
+
+import (
+	"encoding/json"
+
+	"github.com/tech/sendico/pkg/merrors"
+)
+
+type EndpointType string
+
+const (
+	EndpointTypeLedger        EndpointType = "ledger"
+	EndpointTypeManagedWallet EndpointType = "managed_wallet"
+	EndpointTypeExternalChain EndpointType = "external_chain"
+	EndpointTypeCard          EndpointType = "card"
+)
+
+// Endpoint is a discriminated union for payment endpoints.
+type Endpoint struct {
+	Type     EndpointType      `json:"type"`
+	Data     json.RawMessage   `json:"data"`
+	Metadata map[string]string `json:"metadata,omitempty"`
+}
+
+func newEndpoint(kind EndpointType, payload interface{}, metadata map[string]string) (Endpoint, error) {
+	data, err := json.Marshal(payload)
+	if err != nil {
+		return Endpoint{}, merrors.Internal("marshal endpoint payload failed")
+	}
+	return Endpoint{
+		Type:     kind,
+		Data:     data,
+		Metadata: cloneStringMap(metadata),
+	}, nil
+}
+
+func (e Endpoint) decodePayload(expected EndpointType, dst interface{}) error {
+	if e.Type == "" {
+		return merrors.InvalidArgument("endpoint type is required")
+	}
+	if e.Type != expected {
+		return merrors.InvalidArgument("expected endpoint type " + string(expected) + ", got " + string(e.Type))
+	}
+	if len(e.Data) == 0 {
+		return merrors.InvalidArgument("endpoint data is required for type " + string(expected))
+	}
+	if err := json.Unmarshal(e.Data, dst); err != nil {
+		return merrors.InvalidArgument("decode " + string(expected) + " endpoint: " + err.Error())
+	}
+	return nil
+}
+
+func (e *Endpoint) UnmarshalJSON(data []byte) error {
+	var envelope struct {
+		Type     EndpointType      `json:"type"`
+		Data     json.RawMessage   `json:"data"`
+		Metadata map[string]string `json:"metadata"`
+	}
+	if err := json.Unmarshal(data, &envelope); err == nil {
+		if envelope.Type != "" || len(envelope.Data) > 0 {
+			if envelope.Type == "" {
+				return merrors.InvalidArgument("endpoint type is required")
+			}
+			*e = Endpoint{
+				Type:     envelope.Type,
+				Data:     envelope.Data,
+				Metadata: cloneStringMap(envelope.Metadata),
+			}
+			return nil
+		}
+	}
+
+	var legacy LegacyPaymentEndpoint
+	if err := json.Unmarshal(data, &legacy); err != nil {
+		return err
+	}
+	endpoint, err := LegacyPaymentEndpointToEndpointDTO(&legacy)
+	if err != nil {
+		return err
+	}
+	if endpoint == nil {
+		return merrors.InvalidArgument("endpoint payload is empty")
+	}
+	*e = *endpoint
+	return nil
+}
+
+func NewLedgerEndpointDTO(payload LedgerEndpoint, metadata map[string]string) (Endpoint, error) {
+	return newEndpoint(EndpointTypeLedger, payload, metadata)
+}
+
+func NewManagedWalletEndpointDTO(payload ManagedWalletEndpoint, metadata map[string]string) (Endpoint, error) {
+	return newEndpoint(EndpointTypeManagedWallet, payload, metadata)
+}
+
+func NewExternalChainEndpointDTO(payload ExternalChainEndpoint, metadata map[string]string) (Endpoint, error) {
+	return newEndpoint(EndpointTypeExternalChain, payload, metadata)
+}
+
+func NewCardEndpointDTO(payload CardEndpoint, metadata map[string]string) (Endpoint, error) {
+	return newEndpoint(EndpointTypeCard, payload, metadata)
+}
+
+func (e Endpoint) DecodeLedger() (LedgerEndpoint, error) {
+	var payload LedgerEndpoint
+	return payload, e.decodePayload(EndpointTypeLedger, &payload)
+}
+
+func (e Endpoint) DecodeManagedWallet() (ManagedWalletEndpoint, error) {
+	var payload ManagedWalletEndpoint
+	return payload, e.decodePayload(EndpointTypeManagedWallet, &payload)
+}
+
+func (e Endpoint) DecodeExternalChain() (ExternalChainEndpoint, error) {
+	var payload ExternalChainEndpoint
+	return payload, e.decodePayload(EndpointTypeExternalChain, &payload)
+}
+
+func (e Endpoint) DecodeCard() (CardEndpoint, error) {
+	var payload CardEndpoint
+	return payload, e.decodePayload(EndpointTypeCard, &payload)
+}
+
+func LegacyPaymentEndpointToEndpointDTO(old *LegacyPaymentEndpoint) (*Endpoint, error) {
+	if old == nil {
+		return nil, nil
+	}
+
+	count := 0
+	var endpoint Endpoint
+	var err error
+
+	if old.Ledger != nil {
+		count++
+		endpoint, err = NewLedgerEndpointDTO(*old.Ledger, old.Metadata)
+	}
+	if old.ManagedWallet != nil {
+		count++
+		endpoint, err = NewManagedWalletEndpointDTO(*old.ManagedWallet, old.Metadata)
+	}
+	if old.ExternalChain != nil {
+		count++
+		endpoint, err = NewExternalChainEndpointDTO(*old.ExternalChain, old.Metadata)
+	}
+	if old.Card != nil {
+		count++
+		endpoint, err = NewCardEndpointDTO(*old.Card, old.Metadata)
+	}
+
+	if err != nil {
+		return nil, err
+	}
+	if count == 0 {
+		return nil, merrors.InvalidArgument("exactly one endpoint must be set")
+	}
+	if count > 1 {
+		return nil, merrors.InvalidArgument("only one endpoint can be set")
+	}
+	return &endpoint, nil
+}
+
+func EndpointDTOToLegacyPaymentEndpoint(new *Endpoint) (*LegacyPaymentEndpoint, error) {
+	if new == nil {
+		return nil, nil
+	}
+
+	legacy := &LegacyPaymentEndpoint{
+		Metadata: cloneStringMap(new.Metadata),
+	}
+
+	switch new.Type {
+	case EndpointTypeLedger:
+		payload, err := new.DecodeLedger()
+		if err != nil {
+			return nil, err
+		}
+		legacy.Ledger = &payload
+	case EndpointTypeManagedWallet:
+		payload, err := new.DecodeManagedWallet()
+		if err != nil {
+			return nil, err
+		}
+		legacy.ManagedWallet = &payload
+	case EndpointTypeExternalChain:
+		payload, err := new.DecodeExternalChain()
+		if err != nil {
+			return nil, err
+		}
+		legacy.ExternalChain = &payload
+	case EndpointTypeCard:
+		payload, err := new.DecodeCard()
+		if err != nil {
+			return nil, err
+		}
+		legacy.Card = &payload
+	default:
+		return nil, merrors.InvalidArgument("unsupported endpoint type: " + string(new.Type))
+	}
+	return legacy, nil
+}
+
+func cloneStringMap(src map[string]string) map[string]string {
+	if len(src) == 0 {
+		return nil
+	}
+	dst := make(map[string]string, len(src))
+	for k, v := range src {
+		dst[k] = v
+	}
+	return dst
+}