add-event.go

package relayer

import (
	"context"
	"fmt"
	"regexp"

	"github.com/fiatjaf/eventstore"
	"github.com/nbd-wtf/go-nostr"
)

var nip20prefixmatcher = regexp.MustCompile(`^\w+: `)

// AddEvent has a business rule to add an event to the relayer
func AddEvent(ctx context.Context, relay Relay, evt *nostr.Event) (accepted bool, message string) {
	if evt == nil {
		return false, ""
	}

	store := relay.Storage(ctx)
	advancedSaver, _ := store.(AdvancedSaver)

	if ok, msg := relay.AcceptEvent(ctx, evt); !ok {
		if msg == "" {
			msg = "blocked: event blocked by relay"
		}
		return false, msg
	}

	if nostr.IsEphemeralKind(evt.Kind) {
		// do not store ephemeral events
	} else {
		if advancedSaver != nil {
			advancedSaver.BeforeSave(ctx, evt)
		}

		if saveErr := saveEvent(ctx, store, evt); saveErr != nil {
			switch saveErr {
			case eventstore.ErrDupEvent:
				return true, ""
			default:
				errmsg := saveErr.Error()
				if nip20prefixmatcher.MatchString(errmsg) {
					return false, errmsg
				} else {
					return false, fmt.Sprintf("error: failed to save (%s)", errmsg)
				}
			}
		}

		if advancedSaver != nil {
			advancedSaver.AfterSave(evt)
		}
	}

	if srv, ok := getServer(ctx); ok {
		srv.notifyListeners(evt)
	} else {
		BroadcastEvent(evt)
	}

	return true, ""
}

func saveEvent(ctx context.Context, store eventstore.Store, evt *nostr.Event) error {
	if nostr.IsRegularKind(evt.Kind) {
		return store.SaveEvent(ctx, evt)
	}

	return store.ReplaceEvent(ctx, evt)
}