remote_avatar: add UseLocalAvatar

bridge/config/config.go

@@ -138,6 +138,7 @@ type Protocol struct {
 	Topic                  string     // zulip
 	URL                    string     // mattermost, slack // DEPRECATED
 	UseAPI                 bool       // mattermost, slack
+	UseLocalAvatar         []string   // discord
 	UseSASL                bool       // IRC
 	UseTLS                 bool       // IRC
 	UseDiscriminator       bool       // discord

bridge/discord/discord.go

@@ -381,6 +381,19 @@ func (b *Bdiscord) webhookSend(msg *config.Message, webhookID, token string) (*d
 		err error
 	)
 
+	// If avatar is unset, maybe we need to set the local avatar
+	if msg.Avatar == "" {
+		for _, val := range b.GetStringSlice("UseLocalAvatar") {
+			if msg.Protocol != val {
+				continue
+			}
+			if avatar, ok := b.findAvatar(msg); ok {
+				msg.Avatar = avatar
+			}
+			break
+		}
+	}
+
 	// WebhookParams can have either `Content` or `File`.
 
 	// We can't send empty messages.
@@ -430,3 +443,11 @@ func (b *Bdiscord) webhookSend(msg *config.Message, webhookID, token string) (*d
 	}
 	return res, err
 }
+
+func (b *Bdiscord) findAvatar(m *config.Message) (string, bool) {
+	member, err := b.getGuildMemberByNick(m.Username)
+	if err != nil {
+		return "", false
+	}
+	return member.User.AvatarURL(""), true
+}