first commit

internal/nostr/profile.go

@@ -0,0 +1,81 @@
+package nostr
+
+import (
+	"context"
+	"encoding/json"
+	"time"
+
+	gn "github.com/nbd-wtf/go-nostr"
+)
+
+// Metadata mirrors the kind:0 profile JSON. We accept both snake_case
+// (`display_name`, NIP-24) and the deprecated camelCase `displayName` since
+// some clients still publish only the latter. `Username` is also deprecated
+// but appears in older profiles; per NIP-24 it should be ignored in favor of
+// `Name`, but we surface it as a last-resort fallback.
+type Metadata struct {
+	Name           string `json:"name"`
+	DisplayName    string `json:"display_name"`
+	DisplayNameAlt string `json:"displayName"`
+	Username       string `json:"username"`
+	NIP05          string `json:"nip05"`
+	About          string `json:"about"`
+	Picture        string `json:"picture"`
+}
+
+// ParseMetadata decodes a kind:0 content payload.
+func ParseMetadata(content string) (*Metadata, error) {
+	var md Metadata
+	if err := json.Unmarshal([]byte(content), &md); err != nil {
+		return nil, err
+	}
+	return &md, nil
+}
+
+// FetchMetadata pulls the most recent kind:0 event for a hex pubkey across the pool.
+// Each relay may return multiple replacement events; we keep the one with the
+// highest CreatedAt across every relay reached before timeout.
+func FetchMetadata(ctx context.Context, p *Pool, hexpk string) (*Metadata, error) {
+	filter := gn.Filter{
+		Kinds:   []int{0},
+		Authors: []string{hexpk},
+		Limit:   100,
+	}
+
+	var newest *gn.Event
+	for _, url := range p.URLs() {
+		r, err := p.Connect(ctx, url)
+		if err != nil {
+			continue
+		}
+		subCtx, cancel := context.WithTimeout(ctx, 8*time.Second)
+		sub, err := r.Subscribe(subCtx, gn.Filters{filter})
+		if err != nil {
+			cancel()
+			continue
+		}
+	loop:
+		for {
+			select {
+			case ev, ok := <-sub.Events:
+				if !ok {
+					break loop
+				}
+				if newest == nil || ev.CreatedAt > newest.CreatedAt {
+					newest = ev
+				}
+			case <-sub.EndOfStoredEvents:
+				break loop
+			case <-subCtx.Done():
+				break loop
+			}
+		}
+		sub.Unsub()
+		cancel()
+	}
+
+	if newest == nil {
+		return nil, nil
+	}
+	return ParseMetadata(newest.Content)
+}