fix: fix message segmentation in Telegram's markdown parse mode (close …

…#88)

channel/telegram.go

@@ -45,7 +45,7 @@ func SendTelegramMessage(message *model.Message, user *model.User, channel_ *mod
  // we have reach the end, must be valid
  nextIdx = len(text)
  } else {
- nextIdx = getNearestValidSplit(text, nextIdx)
+ nextIdx = getNearestValidSplit(text, nextIdx, messageRequest.ParseMode)
  }
  messageRequest.Text = text[idx:nextIdx]
  idx = nextIdx
@@ -70,7 +70,15 @@ func SendTelegramMessage(message *model.Message, user *model.User, channel_ *mod
  return nil
 }
 
-func getNearestValidSplit(s string, idx int) int {
+func getNearestValidSplit(s string, idx int, mode string) int {
+ if mode == "markdown" {
+ return getMarkdownNearestValidSplit(s, idx)
+ } else {
+ return getPlainTextNearestValidSplit(s, idx)
+ }
+}
+
+func getPlainTextNearestValidSplit(s string, idx int) int {
  if idx >= len(s) {
  return idx
  }
@@ -81,6 +89,22 @@ func getNearestValidSplit(s string, idx int) int {
  if isStartByte {
  return idx
  } else {
- return getNearestValidSplit(s, idx-1)
+ return getPlainTextNearestValidSplit(s, idx-1)
+ }
+}
+
+func getMarkdownNearestValidSplit(s string, idx int) int {
+ if idx >= len(s) {
+ return idx
+ }
+ if idx == 0 {
+ return 0
+ }
+ for i := idx; i >= 0; i-- {
+ if s[i] == '\n' {
+ return i + 1
+ }
  }
+ // unable to find a '\n'
+ return idx
 }