sdk: FetchNutZapInfo() using the same flow as FetchProfileMetadata().

sdk/zap.go

@@ -11,10 +11,20 @@ import (
 	"fiatjaf.com/nostr"
 	"fiatjaf.com/nostr/nip60"
 	"fiatjaf.com/nostr/nip60/client"
+	"fiatjaf.com/nostr/nip61"
 	"github.com/btcsuite/btcd/btcec/v2"
 	"github.com/tidwall/gjson"
 )
 
+// NutZapInfo represents user nut zap information from kind 10019 events.
+// contains both the raw event and parsed info fields.
+type NutZapInfo struct {
+	PubKey nostr.PubKey `json:"-"` // must always be set otherwise things will break
+	Event  *nostr.Event `json:"-"` // may be empty if a nut zap info event wasn't found
+
+	nip61.Info
+}
+
 // FetchZapProvider fetches the zap provider public key for a given user from their profile metadata.
 // It uses a cache to avoid repeated fetches. If no zap provider is set in the profile, returns an empty PubKey.
 func (sys *System) FetchZapProvider(ctx context.Context, pk nostr.PubKey) nostr.PubKey {
@@ -52,6 +62,84 @@ func (sys *System) FetchZapProvider(ctx context.Context, pk nostr.PubKey) nostr.
 	return nostr.ZeroPK
 }
 
+// FetchNutZapInfo fetches nut zap info for a given user from the local cache, or from the local store,
+// or, failing these, from the target user's defined outbox relays -- then caches the result.
+// always returns a NutZapInfo, even if no info was found (in which case only the PubKey field is set).
+func (sys *System) FetchNutZapInfo(ctx context.Context, pubkey nostr.PubKey) NutZapInfo {
+	if v, ok := sys.NutZapInfoCache.Get(pubkey); ok {
+		return v
+	}
+
+	for evt := range sys.Store.QueryEvents(nostr.Filter{Kinds: []nostr.Kind{10019}, Authors: []nostr.PubKey{pubkey}}, 1) {
+		// ok, we found something locally
+		nzi, err := ParseNutZapInfo(evt)
+		if err != nil {
+			break
+		}
+
+		// but if we haven't tried fetching from the network recently we should do it
+		lastFetchKey := makeLastFetchKey(10019, pubkey)
+		lastFetchData, _ := sys.KVStore.Get(lastFetchKey)
+		if lastFetchData == nil || nostr.Now()-decodeTimestamp(lastFetchData) > 7*24*60*60 {
+			newNZI := sys.tryFetchNutZapInfoFromNetwork(ctx, pubkey)
+			if newNZI != nil && newNZI.Event.CreatedAt > nzi.Event.CreatedAt {
+				nzi = *newNZI
+			}
+
+			// even if we didn't find anything register this because we tried
+			// (and we still have the previous event in our local store)
+			sys.KVStore.Set(lastFetchKey, encodeTimestamp(nostr.Now()))
+		}
+
+		// and finally save this to cache
+		sys.NutZapInfoCache.SetWithTTL(pubkey, nzi, time.Hour*6)
+
+		return nzi
+	}
+
+	var nzi NutZapInfo
+	nzi.PubKey = pubkey
+	if newNZI := sys.tryFetchNutZapInfoFromNetwork(ctx, pubkey); newNZI != nil {
+		nzi = *newNZI
+
+		// we'll only save this if we got something which means we found at least one event
+		lastFetchKey := makeLastFetchKey(10019, pubkey)
+		sys.KVStore.Set(lastFetchKey, encodeTimestamp(nostr.Now()))
+	}
+
+	// save cache even if we didn't get anything
+	sys.NutZapInfoCache.SetWithTTL(pubkey, nzi, time.Hour*6)
+
+	return nzi
+}
+
+func (sys *System) tryFetchNutZapInfoFromNetwork(ctx context.Context, pubkey nostr.PubKey) *NutZapInfo {
+	evt, err := sys.replaceableLoaders[kind_10019].Load(ctx, pubkey)
+	if err != nil {
+		return nil
+	}
+
+	nzi, err := ParseNutZapInfo(evt)
+	if err != nil {
+		return nil
+	}
+
+	sys.Publisher.Publish(ctx, evt)
+	sys.NutZapInfoCache.SetWithTTL(pubkey, nzi, time.Hour*6)
+	return &nzi
+}
+
+// ParseNutZapInfo parses a kind 10019 event into a NutZapInfo struct.
+// returns an error if the event is not kind 10019 or if parsing fails.
+func ParseNutZapInfo(event nostr.Event) (nzi NutZapInfo, err error) {
+	err = nzi.Info.ParseEvent(event)
+
+	nzi.PubKey = event.PubKey
+	nzi.Event = &event
+
+	return nzi, err
+}
+
 // FetchMintKeys fetches the active keyset from the given mint URL and parses the keys.
 // It uses a cache to avoid repeated fetches.
 func (sys *System) FetchMintKeys(ctx context.Context, mintURL string) (map[uint64]*btcec.PublicKey, error) {