support to post in thread (#6)

* support to post in thread

* specify thread timestamp and reply broadcast flag as context value

---------

Co-authored-by: Samuel Berthe <dev@samuel-berthe.fr>

context.go

@@ -0,0 +1,29 @@
+package slogslack
+
+import "context"
+
+type threadTimestampCtxKey struct{}
+
+// reply in thread to posts with timestamps set this
+func WithThreadTimestamp(ctx context.Context, ts string) context.Context {
+	return context.WithValue(ctx, threadTimestampCtxKey{}, ts)
+}
+
+func ContextThreadTimestamp(ctx context.Context) string {
+	if v, ok := ctx.Value(threadTimestampCtxKey{}).(string); ok {
+		return v
+	}
+	return ""
+}
+
+type replyBroadcastCtxKey struct{}
+
+// broadcast to channel when replies to thread if set
+func WithReplyBroadcast(ctx context.Context) context.Context {
+	return context.WithValue(ctx, replyBroadcastCtxKey{}, true)
+}
+
+func ContextReplyBroadcast(ctx context.Context) bool {
+	_, ok := ctx.Value(replyBroadcastCtxKey{}).(bool)
+	return ok
+}

handler.go

@@ -92,6 +92,13 @@ func (h *SlackHandler) Handle(ctx context.Context, record slog.Record) error {
 		message.IconURL = h.option.IconURL
 	}
 
+	if ts := ContextThreadTimestamp(ctx); ts != "" {
+		message.ThreadTimestamp = ts
+		if ContextReplyBroadcast(ctx) {
+			message.ReplyBroadcast = true
+		}
+	}
+
 	go func() {
 		_ = h.postMessage(ctx, message)
 	}()
@@ -123,6 +130,20 @@ func (h *SlackHandler) postMessage(ctx context.Context, message *slack.WebhookMe
 		return slack.PostWebhookContext(ctx, h.option.WebhookURL, message)
 	}
 
+	options := []slack.MsgOption{
+		slack.MsgOptionText(message.Text, true),
+		slack.MsgOptionAttachments(message.Attachments...),
+		slack.MsgOptionUsername(message.Username),
+		slack.MsgOptionIconURL(message.IconURL),
+		slack.MsgOptionIconEmoji(message.IconEmoji),
+	}
+	if message.ThreadTimestamp != "" {
+		options = append(options, slack.MsgOptionTS(message.ThreadTimestamp))
+	}
+	if message.ReplyBroadcast {
+		options = append(options, slack.MsgOptionBroadcast())
+	}
+
 	_, _, err := slack.
 		New(h.option.BotToken).
 		PostMessageContext(