add custom envelope types with json codecs.

envelopes.go

@@ -0,0 +1,190 @@
+package nostr
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/mailru/easyjson"
+	jwriter "github.com/mailru/easyjson/jwriter"
+	"github.com/tidwall/gjson"
+)
+
+type EventEnvelope struct {
+	SubscriptionID *string
+	Event
+}
+
+func (v *EventEnvelope) UnmarshalJSON(data []byte) error {
+	r := gjson.ParseBytes(data)
+	arr := r.Array()
+	switch len(arr) {
+	case 2:
+		return easyjson.Unmarshal([]byte(arr[1].Raw), &v.Event)
+	case 3:
+		v.SubscriptionID = &arr[1].Str
+		return easyjson.Unmarshal([]byte(arr[2].Raw), &v.Event)
+	default:
+		return fmt.Errorf("failed to decode EVENT envelope")
+	}
+}
+
+func (v EventEnvelope) MarshalJSON() ([]byte, error) {
+	w := jwriter.Writer{}
+	w.RawString(`["EVENT",`)
+	if v.SubscriptionID != nil {
+		w.RawString(`"` + *v.SubscriptionID + `",`)
+	}
+	v.MarshalEasyJSON(&w)
+	w.RawString(`]`)
+	return w.BuildBytes()
+}
+
+type ReqEnvelope struct {
+	SubscriptionID string
+	Filters
+}
+
+func (v *ReqEnvelope) UnmarshalJSON(data []byte) error {
+	r := gjson.ParseBytes(data)
+	arr := r.Array()
+	if len(arr) < 3 {
+		return fmt.Errorf("failed to decode REQ envelope: missing filters")
+	}
+	v.SubscriptionID = arr[1].Str
+	v.Filters = make(Filters, len(arr)-2)
+	f := 0
+	for i := 2; i < len(arr); i++ {
+		if err := easyjson.Unmarshal([]byte(arr[i].Raw), &v.Filters[f]); err != nil {
+			return fmt.Errorf("%w -- on filter %d", err, f)
+		}
+		f++
+	}
+
+	return nil
+}
+
+func (v ReqEnvelope) MarshalJSON() ([]byte, error) {
+	w := jwriter.Writer{}
+	w.RawString(`["REQ",`)
+	w.RawString(`"` + v.SubscriptionID + `"`)
+	for _, filter := range v.Filters {
+		w.RawString(`,`)
+		filter.MarshalEasyJSON(&w)
+	}
+	w.RawString(`]`)
+	return w.BuildBytes()
+}
+
+type NoticeEnvelope string
+
+func (v *NoticeEnvelope) UnmarshalJSON(data []byte) error {
+	r := gjson.ParseBytes(data)
+	arr := r.Array()
+	switch len(arr) {
+	case 2:
+		*v = NoticeEnvelope(arr[1].Str)
+		return nil
+	default:
+		return fmt.Errorf("failed to decode NOTICE envelope")
+	}
+}
+
+func (v NoticeEnvelope) MarshalJSON() ([]byte, error) {
+	w := jwriter.Writer{}
+	w.RawString(`["NOTICE",`)
+	w.Raw(json.Marshal(string(v)))
+	w.RawString(`]`)
+	return w.BuildBytes()
+}
+
+type EOSEEnvelope string
+
+func (v *EOSEEnvelope) UnmarshalJSON(data []byte) error {
+	r := gjson.ParseBytes(data)
+	arr := r.Array()
+	switch len(arr) {
+	case 2:
+		*v = EOSEEnvelope(arr[1].Str)
+		return nil
+	default:
+		return fmt.Errorf("failed to decode EOSE envelope")
+	}
+}
+
+func (v EOSEEnvelope) MarshalJSON() ([]byte, error) {
+	w := jwriter.Writer{}
+	w.RawString(`["EOSE",`)
+	w.Raw(json.Marshal(string(v)))
+	w.RawString(`]`)
+	return w.BuildBytes()
+}
+
+type OKEnvelope struct {
+	EventID string
+	OK      bool
+	Reason  *string
+}
+
+func (v *OKEnvelope) UnmarshalJSON(data []byte) error {
+	r := gjson.ParseBytes(data)
+	arr := r.Array()
+	if len(arr) < 3 {
+		return fmt.Errorf("failed to decode OK envelope: missing fields")
+	}
+	v.EventID = arr[1].Str
+	v.OK = arr[2].Raw == "true"
+
+	if len(arr) > 3 {
+		v.Reason = &arr[3].Str
+	}
+
+	return nil
+}
+
+func (v OKEnvelope) MarshalJSON() ([]byte, error) {
+	w := jwriter.Writer{}
+	w.RawString(`["OK",`)
+	w.RawString(`"` + v.EventID + `",`)
+	ok := "false"
+	if v.OK {
+		ok = "true"
+	}
+	w.RawString(ok)
+	if v.Reason != nil {
+		w.RawString(`,`)
+		w.Raw(json.Marshal(v.Reason))
+	}
+	w.RawString(`]`)
+	return w.BuildBytes()
+}
+
+type AuthEnvelope struct {
+	Challenge *string
+	Event     Event
+}
+
+func (v *AuthEnvelope) UnmarshalJSON(data []byte) error {
+	r := gjson.ParseBytes(data)
+	arr := r.Array()
+	if len(arr) < 2 {
+		return fmt.Errorf("failed to decode Auth envelope: missing fields")
+	}
+	if arr[1].IsObject() {
+		return easyjson.Unmarshal([]byte(arr[1].Raw), &v.Event)
+	} else {
+		v.Challenge = &arr[1].Str
+	}
+	return nil
+}
+
+func (v AuthEnvelope) MarshalJSON() ([]byte, error) {
+	w := jwriter.Writer{}
+	w.RawString(`["AUTH",`)
+	if v.Challenge != nil {
+		w.Raw(json.Marshal(*v.Challenge))
+	} else {
+		v.Event.MarshalEasyJSON(&w)
+	}
+	w.RawString(`]`)
+	return w.BuildBytes()
+}