feat: add stickers

internal/service/chat_service_test.go

@@ -2459,3 +2459,153 @@ func TestSend_ReplyCarriesItsQuoteImmediately(t *testing.T) {
 		t.Error("a retried reply lost its quote")
 	}
 }
+
+// grantSticker gives a user a reward the way sādhana does, returning its key.
+func grantSticker(t *testing.T, pg *repository.Postgres, userID, key string) string {
+	t.Helper()
+	ctx := context.Background()
+	var rewardID string
+	if err := pg.Pool.QueryRow(ctx, `
+		INSERT INTO sadhna_rewards (key, name, image_url)
+		VALUES ($1, $2, 'https://example.invalid/art.png')
+		ON CONFLICT (key) DO UPDATE SET name = EXCLUDED.name
+		RETURNING id`, key, "Sticker "+key).Scan(&rewardID); err != nil {
+		t.Fatalf("create reward: %v", err)
+	}
+	t.Cleanup(func() {
+		_, _ = pg.Pool.Exec(ctx, `DELETE FROM sadhna_rewards WHERE id = $1`, rewardID)
+	})
+	if userID != "" {
+		// milestone is unique per user; a large random-ish one avoids clashing
+		// with any real streak rows.
+		if _, err := pg.Pool.Exec(ctx, `
+			INSERT INTO sadhna_reward_grants (user_id, reward_id, milestone)
+			VALUES ($1, $2, $3) ON CONFLICT DO NOTHING`,
+			userID, rewardID, 900000+len(key)); err != nil {
+			t.Fatalf("grant reward: %v", err)
+		}
+	}
+	return key
+}
+
+func stickerAttachment(t *testing.T, msgs []model.Message) *model.Attachment {
+	t.Helper()
+	for i := range msgs {
+		for j := range msgs[i].Attachments {
+			if msgs[i].Attachments[j].Kind == model.AttachmentSticker {
+				return &msgs[i].Attachments[j]
+			}
+		}
+	}
+	return nil
+}
+
+// A sticker key is not a capability: sending one you never earned must fail,
+// or the whole catalog is available to anyone who can guess a key.
+func TestStickers_OnlySendWhatYouOwn(t *testing.T) {
+	svc, _, pg := testChatService(t)
+	ctx := context.Background()
+	a, b := chatUser(t, pg, "A"), chatUser(t, pg, "B")
+	conv, err := svc.OpenDM(ctx, a, b)
+	if err != nil {
+		t.Fatal(err)
+	}
+	cleanupConv(t, pg, conv.ID)
+
+	mine := grantSticker(t, pg, a, "sticker_owned_"+a[:8])
+	// Exists in the catalog, granted to nobody.
+	unearned := grantSticker(t, pg, "", "sticker_unearned_"+a[:8])
+
+	if _, err := svc.Send(ctx, a, conv.ID, SendRequest{StickerKey: &mine}); err != nil {
+		t.Fatalf("sending an earned sticker: %v", err)
+	}
+	msgs, _ := svc.Messages(ctx, a, conv.ID, 0, 10)
+	att := stickerAttachment(t, msgs)
+	if att == nil {
+		t.Fatal("an earned sticker did not attach")
+	}
+	if att.ImageURL == nil || *att.ImageURL == "" || att.EntityID == nil || *att.EntityID != mine {
+		t.Errorf("attachment = %+v, want the artwork and its key", att)
+	}
+
+	// Not earned, not saved: the message sends, but carries no sticker.
+	if _, err := svc.Send(ctx, a, conv.ID, SendRequest{
+		Body: "trying", StickerKey: &unearned,
+	}); err != nil {
+		t.Fatal(err)
+	}
+	msgs, _ = svc.Messages(ctx, a, conv.ID, 0, 10)
+	for i := range msgs {
+		for j := range msgs[i].Attachments {
+			if att := msgs[i].Attachments[j]; att.Kind == model.AttachmentSticker &&
+				att.EntityID != nil && *att.EntityID == unearned {
+				t.Error("a sticker the sender never earned was attached")
+			}
+		}
+	}
+}
+
+// Saving is how a sticker spreads — but only from a message actually sent to
+// you, in a thread you are actually in.
+func TestStickers_SaveFromChat(t *testing.T) {
+	svc, _, pg := testChatService(t)
+	ctx := context.Background()
+	a, b, outsider := chatUser(t, pg, "A"), chatUser(t, pg, "B"), chatUser(t, pg, "C")
+	conv, err := svc.OpenDM(ctx, a, b)
+	if err != nil {
+		t.Fatal(err)
+	}
+	cleanupConv(t, pg, conv.ID)
+
+	key := grantSticker(t, pg, a, "sticker_shared_"+a[:8])
+	sent, err := svc.Send(ctx, a, conv.ID, SendRequest{StickerKey: &key})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// B has not earned it, so it isn't in their drawer yet.
+	before, _ := svc.Stickers(ctx, b)
+	for _, s := range before {
+		if s.Key == key {
+			t.Fatal("B has the sticker before saving it")
+		}
+	}
+
+	if err := svc.SaveSticker(ctx, b, sent.ID, key); err != nil {
+		t.Fatalf("saving a sticker sent to you: %v", err)
+	}
+	after, _ := svc.Stickers(ctx, b)
+	var found *model.Sticker
+	for i := range after {
+		if after[i].Key == key {
+			found = &after[i]
+		}
+	}
+	if found == nil {
+		t.Fatal("saved sticker is not in B's drawer")
+	}
+	if !found.Saved {
+		t.Error("a sticker from a chat should be marked as saved, not earned")
+	}
+	// B can now send it themselves.
+	if _, err := svc.Send(ctx, b, conv.ID, SendRequest{StickerKey: &key}); err != nil {
+		t.Errorf("B should be able to send a saved sticker: %v", err)
+	}
+	// Saving twice is harmless.
+	if err := svc.SaveSticker(ctx, b, sent.ID, key); err != nil {
+		t.Errorf("second save should be idempotent: %v", err)
+	}
+
+	// Someone outside the thread cannot save from it, even knowing both ids.
+	if err := svc.SaveSticker(ctx, outsider, sent.ID, key); !errors.Is(err, repository.ErrStickerNotOwned) {
+		t.Errorf("outsider save: err = %v, want ErrStickerNotOwned", err)
+	}
+
+	// The sender's own drawer still reports it as earned, not saved.
+	mine, _ := svc.Stickers(ctx, a)
+	for _, s := range mine {
+		if s.Key == key && s.Saved {
+			t.Error("an earned sticker is being reported as saved")
+		}
+	}
+}