sdk taking shape.

sdk/cache/interface.go

@@ -0,0 +1,10 @@
+package cache
+
+import "time"
+
+type Cache32[V any] interface {
+	Get(k string) (v V, ok bool)
+	Delete(k string)
+	Set(k string, v V) bool
+	SetWithTTL(k string, v V, d time.Duration) bool
+}

sdk/cache/memory/cache.go

@@ -0,0 +1,48 @@
+package cache_memory
+
+import (
+	"encoding/binary"
+	"encoding/hex"
+	"time"
+
+	"github.com/dgraph-io/ristretto"
+)
+
+type RistrettoCache[V any] struct {
+	Cache *ristretto.Cache[string, V]
+}
+
+func New32[V any](max int64) *RistrettoCache[V] {
+	cache, _ := ristretto.NewCache(&ristretto.Config[string, V]{
+		NumCounters: max * 10,
+		MaxCost:     max,
+		BufferItems: 64,
+		KeyToHash:   func(key string) (uint64, uint64) { return h32(key), 0 },
+	})
+	return &RistrettoCache[V]{Cache: cache}
+}
+
+func (s RistrettoCache[V]) Get(k string) (v V, ok bool) { return s.Cache.Get(k) }
+func (s RistrettoCache[V]) Delete(k string)             { s.Cache.Del(k) }
+func (s RistrettoCache[V]) Set(k string, v V) bool      { return s.Cache.Set(k, v, 1) }
+func (s RistrettoCache[V]) SetWithTTL(k string, v V, d time.Duration) bool {
+	return s.Cache.SetWithTTL(k, v, 1, d)
+}
+
+func h32(key string) uint64 {
+	// we get an event id or pubkey as hex,
+	// so just extract the last 8 bytes from it and turn them into a uint64
+	return shortUint64(key)
+}
+
+func shortUint64(idOrPubkey string) uint64 {
+	length := len(idOrPubkey)
+	if length < 8 {
+		return 0
+	}
+	b, err := hex.DecodeString(idOrPubkey[length-8:])
+	if err != nil {
+		return 0
+	}
+	return uint64(binary.BigEndian.Uint32(b))
+}

sdk/follows.go

@@ -0,0 +1,7 @@
+package sdk
+
+type Follow struct {
+	Pubkey  string
+	Relay   string
+	Petname string
+}

sdk/init.go

@@ -0,0 +1,41 @@
+package sdk
+
+import (
+	"context"
+	"time"
+
+	"github.com/nbd-wtf/go-nostr"
+	"github.com/nbd-wtf/go-nostr/sdk/cache"
+)
+
+type System struct {
+	relaysCache     cache.Cache32[[]Relay]
+	followsCache    cache.Cache32[[]Follow]
+	metadataCache   cache.Cache32[*ProfileMetadata]
+	pool            *nostr.SimplePool
+	metadataRelays  []string
+	relayListRelays []string
+}
+
+func (sys System) FetchRelaysForPubkey(ctx context.Context, pubkey string) []Relay {
+	if v, ok := sys.relaysCache.Get(pubkey); ok {
+		return v
+	}
+
+	ctx, cancel := context.WithTimeout(ctx, time.Second*5)
+	defer cancel()
+	res := FetchRelaysForPubkey(ctx, sys.pool, pubkey, sys.relayListRelays...)
+	sys.relaysCache.SetWithTTL(pubkey, res, time.Hour*6)
+	return res
+}
+
+func (sys System) FetchOutboxRelaysForPubkey(ctx context.Context, pubkey string) []string {
+	relays := sys.FetchRelaysForPubkey(ctx, pubkey)
+	result := make([]string, 0, len(relays))
+	for _, relay := range relays {
+		if relay.Outbox {
+			result = append(result, relay.URL)
+		}
+	}
+	return result
+}

sdk/metadata.go

@@ -0,0 +1,50 @@
+package sdk
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+
+	"github.com/nbd-wtf/go-nostr"
+	"github.com/nbd-wtf/go-nostr/nip19"
+)
+
+type ProfileMetadata struct {
+	pubkey string
+
+	Name        string `json:"name,omitempty"`
+	DisplayName string `json:"display_name,omitempty"`
+	About       string `json:"about,omitempty"`
+	Website     string `json:"website,omitempty"`
+	Picture     string `json:"picture,omitempty"`
+	Banner      string `json:"banner,omitempty"`
+	NIP05       string `json:"nip05,omitempty"`
+	LUD16       string `json:"lud16,omitempty"`
+}
+
+func (p ProfileMetadata) Npub() string {
+	v, _ := nip19.EncodePublicKey(p.pubkey)
+	return v
+}
+
+func (p ProfileMetadata) Nprofile(ctx context.Context, sys *System, nrelays int) string {
+	v, _ := nip19.EncodeProfile(p.pubkey, sys.FetchOutboxRelaysForPubkey(ctx, p.pubkey))
+	return v
+}
+
+func ParseMetadata(event *nostr.Event) (*ProfileMetadata, error) {
+	if event.Kind != 0 {
+		return nil, fmt.Errorf("event %s is kind %d, not 0", event.ID, event.Kind)
+	}
+
+	var meta ProfileMetadata
+	if err := json.Unmarshal([]byte(event.Content), &meta); err != nil {
+		cont := event.Content
+		if len(cont) > 100 {
+			cont = cont[0:99]
+		}
+		return nil, fmt.Errorf("failed to parse metadata (%s) from event %s: %w", cont, event.ID, err)
+	}
+
+	return &meta, nil
+}

sdk/relays.go

@@ -13,18 +13,13 @@ type Relay struct {
 	Outbox bool
 }
 
-func FetchRelaysForPubkey(ctx context.Context, pool *nostr.SimplePool, pubkey string, extraRelays ...string) []Relay {
+func FetchOutboxRelaysForPubkey(ctx context.Context, pool *nostr.SimplePool, pubkey string, n int) {
+}
+
+func FetchRelaysForPubkey(ctx context.Context, pool *nostr.SimplePool, pubkey string, relays ...string) []Relay {
 	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 
-	relays := append(extraRelays,
-		"wss://nostr-pub.wellorder.net",
-		"wss://relay.damus.io",
-		"wss://nos.lol",
-		"wss://nostr.mom",
-		"wss://relay.nostr.bg",
-	)
-
 	ch := pool.SubManyEose(ctx, relays, nostr.Filters{
 		{
 			Kinds: []int{