From 93c91f3b3611c84049f4575545b308695a2733e8 Mon Sep 17 00:00:00 2001
From: boreq <boreq@0x46.net>
Date: Fri, 3 Nov 2023 10:18:22 +0900
Subject: [PATCH] Change tweet format to include an nevent link

---
 service/domain/event.go                |  9 +++++++
 service/domain/event_test.go           | 34 ++++++++++++++++++++++++++
 service/domain/tweet_generator.go      |  8 +++---
 service/domain/tweet_generator_test.go |  9 ++++---
 4 files changed, 52 insertions(+), 8 deletions(-)
 create mode 100644 service/domain/event_test.go

diff --git a/service/domain/event.go b/service/domain/event.go
index c943233..ba27160 100644
--- a/service/domain/event.go
+++ b/service/domain/event.go
@@ -6,6 +6,7 @@ import (
 
 	"github.com/boreq/errors"
 	"github.com/nbd-wtf/go-nostr"
+	"github.com/nbd-wtf/go-nostr/nip19"
 	"github.com/planetary-social/nos-crossposting-service/internal"
 )
 
@@ -128,6 +129,14 @@ func (e Event) MarshalJSON() ([]byte, error) {
 	return e.libevent.MarshalJSON()
 }
 
+func (e Event) Nevent() string {
+	nevent, err := nip19.EncodeEvent(e.id.Hex(), nil, e.pubKey.Hex())
+	if err != nil {
+		panic(err)
+	}
+	return nevent
+}
+
 func (e Event) Raw() []byte {
 	j, err := e.libevent.MarshalJSON()
 	if err != nil {
diff --git a/service/domain/event_test.go b/service/domain/event_test.go
new file mode 100644
index 0000000..8646294
--- /dev/null
+++ b/service/domain/event_test.go
@@ -0,0 +1,34 @@
+package domain_test
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/nbd-wtf/go-nostr"
+	"github.com/nbd-wtf/go-nostr/nip19"
+	"github.com/planetary-social/nos-crossposting-service/internal/fixtures"
+	"github.com/planetary-social/nos-crossposting-service/service/domain"
+	"github.com/stretchr/testify/require"
+)
+
+func TestEvent_Nevent(t *testing.T) {
+	_, sk := fixtures.SomeKeyPair()
+
+	libevent := nostr.Event{
+		Kind:    domain.EventKindNote.Int(),
+		Content: "Note text.",
+	}
+	err := libevent.Sign(sk)
+	require.NoError(t, err)
+
+	event, err := domain.NewEvent(libevent)
+	require.NoError(t, err)
+	require.Greater(t, len(event.Nevent()), 0)
+	require.True(t, strings.HasPrefix(event.Nevent(), "nevent"))
+
+	_, v, err := nip19.Decode(event.Nevent())
+	require.NoError(t, err)
+	readNevent := v.(nostr.EventPointer)
+	require.Equal(t, event.Id().Hex(), readNevent.ID)
+	require.Equal(t, event.PublicKey().Hex(), readNevent.Author)
+}
diff --git a/service/domain/tweet_generator.go b/service/domain/tweet_generator.go
index b83a59a..89bb501 100644
--- a/service/domain/tweet_generator.go
+++ b/service/domain/tweet_generator.go
@@ -40,8 +40,6 @@ func (g *TweetGenerator) Generate(event Event) ([]Tweet, error) {
 
 func (g *TweetGenerator) createText(event Event) string {
 	var builder strings.Builder
-	builder.WriteString(fmt.Sprintf("Nostr note made by %s:\n", g.njumpLinkPublicKey(event.PublicKey())))
-	builder.WriteString("\n")
 
 	if utf8.RuneCountInString(event.Content()) <= noteContentMaxLengthInRunes {
 		builder.WriteString(event.Content())
@@ -57,9 +55,11 @@ func (g *TweetGenerator) createText(event Event) string {
 		builder.WriteString("...")
 	}
 
+	builder.WriteString(fmt.Sprintf("\n\n%s", g.njumpLinkEvent(event)))
+
 	return builder.String()
 }
 
-func (g *TweetGenerator) njumpLinkPublicKey(publicKey PublicKey) string {
-	return fmt.Sprintf("https://njump.me/%s", publicKey.Npub())
+func (g *TweetGenerator) njumpLinkEvent(event Event) string {
+	return fmt.Sprintf("https://njump.me/%s", event.Nevent())
 }
diff --git a/service/domain/tweet_generator_test.go b/service/domain/tweet_generator_test.go
index bcf0c93..fee7e9e 100644
--- a/service/domain/tweet_generator_test.go
+++ b/service/domain/tweet_generator_test.go
@@ -45,7 +45,7 @@ func TestTweetGenerator(t *testing.T) {
 		t.Run(testCase.Name, func(t *testing.T) {
 			libevent := testCase.Event
 
-			authorPublicKey, authorPrivateKey := fixtures.SomeKeyPair()
+			_, authorPrivateKey := fixtures.SomeKeyPair()
 
 			err := libevent.Sign(authorPrivateKey)
 			require.NoError(t, err)
@@ -62,9 +62,10 @@ func TestTweetGenerator(t *testing.T) {
 					[]domain.Tweet{
 						domain.NewTweet(
 							fmt.Sprintf(
-								"Nostr note made by https://njump.me/%s:\n\n%s",
-								authorPublicKey.Npub(),
-								event.Content(),
+								`Some text.
+
+https://njump.me/%s`,
+								event.Nevent(),
 							),
 						),
 					},