get post ID from context

cmd/apollo-worker-notifications/main.go

@@ -460,7 +460,7 @@ func payloadFromMessage(acct *data.Account, msg *reddit.MessageData, badgeCount
 		break
 	case (msg.Kind == "t1" && msg.Type == "comment_reply"):
 		title := fmt.Sprintf(`%s in “%s”`, msg.Author, postTitle)
-		_, postID := reddit.SplitID(msg.ParentID)
+		postID := reddit.PostIDFromContext(msg.Context)
 		payload = payload.
 			AlertTitle(title).
 			Category("inbox-comment-reply").

internal/reddit/client.go

@@ -6,6 +6,7 @@ import (
 	"io/ioutil"
 	"net/http"
 	"net/http/httptrace"
+	"regexp"
 	"strings"
 	"time"
 
@@ -34,6 +35,21 @@ func SplitID(id string) (string, string) {
 	return "", ""
 }
 
+func PostIDFromContext(context string) string {
+	exps := []*regexp.Regexp{
+		regexp.MustCompile(`\/r\/[^\/]*\/comments\/([^\/]*)\/.*`),
+	}
+
+	for _, exp := range exps {
+		matches := exp.FindStringSubmatch(context)
+		if len(matches) != 2 {
+			continue
+		}
+		return matches[1]
+	}
+	return ""
+}
+
 func NewClient(id, secret string, statsd *statsd.Client) *Client {
 	tracer := &httptrace.ClientTrace{
 		GotConn: func(info httptrace.GotConnInfo) {