implement nip60 events.

nip60/wallet.go

@@ -0,0 +1,176 @@
+package nip60
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"strconv"
+
+	"github.com/nbd-wtf/go-nostr"
+)
+
+type Wallet struct {
+	Identifier  string
+	Description string
+	Name        string
+	PrivateKey  string
+	Relays      []string
+	Mints       []string
+	Tokens      []Token
+	History     []HistoryEntry
+
+	temporaryBalance uint32
+}
+
+func (w Wallet) Balance() uint32 {
+	var sum uint32
+	for _, token := range w.Tokens {
+		sum += token.Amount()
+	}
+	return sum
+}
+
+func (w Wallet) ToPublishableEvents(ctx context.Context, kr nostr.Keyer, skipExisting bool) ([]nostr.Event, error) {
+	evt := nostr.Event{
+		CreatedAt: nostr.Now(),
+		Kind:      37375,
+		Tags:      make(nostr.Tags, 0, 7),
+	}
+
+	pk, err := kr.GetPublicKey(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	evt.Content, err = kr.Encrypt(
+		ctx,
+		fmt.Sprintf(`[["balance","%d","sat"],["privkey","%s"]]`, w.Balance(), w.PrivateKey),
+		pk,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	evt.Tags = append(evt.Tags,
+		nostr.Tag{"d", w.Identifier},
+		nostr.Tag{"unit", "sat"},
+	)
+	if w.Name != "" {
+		evt.Tags = append(evt.Tags, nostr.Tag{"name", w.Name})
+	}
+	if w.Description != "" {
+		evt.Tags = append(evt.Tags, nostr.Tag{"description", w.Description})
+	}
+	for _, relay := range w.Relays {
+		evt.Tags = append(evt.Tags, nostr.Tag{"relay", relay})
+	}
+
+	err = kr.SignEvent(ctx, &evt)
+	if err != nil {
+		return nil, err
+	}
+
+	events := make([]nostr.Event, 0, 1+len(w.Tokens))
+	events = append(events, evt)
+
+	for _, t := range w.Tokens {
+		var evt nostr.Event
+
+		if t.event != nil {
+			if skipExisting {
+				continue
+			}
+			evt = *t.event
+		} else {
+			err := t.toEvent(ctx, kr, w.Identifier, &evt)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		events = append(events, evt)
+	}
+
+	for _, h := range w.History {
+		var evt nostr.Event
+
+		if h.event != nil {
+			if skipExisting {
+				continue
+			}
+			evt = *h.event
+		} else {
+			err := h.toEvent(ctx, kr, w.Identifier, &evt)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		events = append(events, evt)
+	}
+
+	return events, nil
+}
+
+func (w *Wallet) parse(ctx context.Context, kr nostr.Keyer, evt *nostr.Event) error {
+	w.Tokens = make([]Token, 0, 128)
+	w.History = make([]HistoryEntry, 0, 128)
+
+	pk, err := kr.GetPublicKey(ctx)
+	if err != nil {
+		return err
+	}
+
+	jsonb, err := kr.Decrypt(ctx, evt.Content, pk)
+	if err != nil {
+		return err
+	}
+	var tags nostr.Tags
+	if len(jsonb) > 0 {
+		tags = make(nostr.Tags, 0, 7)
+		if err := json.Unmarshal([]byte(jsonb), &tags); err != nil {
+			return err
+		}
+		tags = append(tags, evt.Tags...)
+	}
+
+	essential := 0
+	for _, tag := range tags {
+		if len(tag) < 2 {
+			continue
+		}
+		switch tag[0] {
+		case "d":
+			w.Identifier = tag[1]
+		case "name":
+			w.Name = tag[1]
+		case "description":
+			w.Description = tag[1]
+		case "unit":
+			essential++
+			if tag[1] != "sat" {
+				return fmt.Errorf("only 'sat' wallets are supported")
+			}
+		case "relay":
+			w.Relays = append(w.Relays, tag[1])
+		case "mint":
+			w.Mints = append(w.Mints, tag[1])
+		case "privkey":
+			w.PrivateKey = tag[1]
+		case "balance":
+			if len(tag) < 3 {
+				return fmt.Errorf("'balance' tag must have at least 3 items")
+			}
+			if tag[2] != "sat" {
+				return fmt.Errorf("only 'sat' wallets are supported")
+			}
+			v, err := strconv.ParseUint(tag[1], 10, 32)
+			if err != nil {
+				return fmt.Errorf("invalid 'balance' %s: %w", tag[1], err)
+			}
+			w.temporaryBalance = uint32(v)
+		}
+	}
+
+	return nil
+}