added DEFAULT_SIGNAL_TEXT_MODE env variable

* allows to set the default text mode globally.
  The setting is only used when the 'text_mode' is not
  explicitly set in the payload.

see #671

README.md

@@ -145,3 +145,5 @@ There are a bunch of environmental variables that can be set inside the docker c
 * `SWAGGER_USE_HTTPS_AS_PREFERRED_SCHEME`: Use the HTTPS Scheme as preferred scheme in the Swagger UI.
 
 * `PORT`: Defaults to port `8080` unless this env var is set to tell it otherwise.
+
+* `DEFAULT_SIGNAL_TEXT_MODE`: Allows to set the default text mode that should be used when sending a message (supported values: `normal`, `styled`). The setting is only used in case the `text_mode` is not explicitly set in the payload of the `send` method.

src/api/api.go

@@ -437,10 +437,19 @@ func (a *Api) SendV2(c *gin.Context) {
 		return
 	}
 
+	textMode := req.TextMode
+	if textMode  == nil {
+		defaultSignalTextMode := utils.GetEnv("DEFAULT_SIGNAL_TEXT_MODE", "normal")
+		if defaultSignalTextMode == "styled" {
+			styledStr := "styled"
+			textMode = &styledStr
+		}
+	}
+
 	data, err := a.signalClient.SendV2(
 		req.Number, req.Message, req.Recipients, req.Base64Attachments, req.Sticker,
 		req.Mentions, req.QuoteTimestamp, req.QuoteAuthor, req.QuoteMessage, req.QuoteMentions,
-		req.TextMode, req.EditTimestamp, req.NotifySelf)
+		textMode, req.EditTimestamp, req.NotifySelf)
 	if err != nil {
 		switch err.(type) {
 		case *client.RateLimitErrorType: