From 50d1706a067383ad68cd0b227b7b5b339f1157cb Mon Sep 17 00:00:00 2001
From: Christian Hesse <mail@eworm.de>
Date: Wed, 2 Jun 2021 22:53:43 +0200
Subject: global-functions: make Telegram notifications a module

---
 global-functions.d/notification-telegram | 162 +++++++++++++++++++++++++++++++
 1 file changed, 162 insertions(+)
 create mode 100644 global-functions.d/notification-telegram

(limited to 'global-functions.d/notification-telegram')

diff --git a/global-functions.d/notification-telegram b/global-functions.d/notification-telegram
new file mode 100644
index 0000000..1509a2e
--- /dev/null
+++ b/global-functions.d/notification-telegram
@@ -0,0 +1,162 @@
+#!rsc by RouterOS
+# RouterOS script: global-functions.d/notification-telegram
+# Copyright (c) 2013-2021 Christian Hesse <mail@eworm.de>
+# https://git.eworm.de/cgit/routeros-scripts/about/COPYING.md
+
+:global FlushTelegramQueue;
+:global NotificationFunctions;
+:global SendTelegram;
+:global SendTelegram2;
+
+# flush telegram queue
+:set FlushTelegramQueue do={
+  :global TelegramQueue;
+
+  :global LogPrintExit2;
+
+  :local AllDone true;
+  :local QueueLen [ :len $TelegramQueue ];
+
+  :if ([ :len [ / system scheduler find where name="FlushTelegramQueue" ] ] > 0 && $QueueLen = 0) do={
+    $LogPrintExit2 warning $0 ("Flushing Telegram messages from scheduler, but queue is empty.") false;
+  }
+
+  :foreach Id,Message in=$TelegramQueue do={
+    :if ([ :typeof $Message ] = "array" ) do={
+      :do {
+        / tool fetch check-certificate=yes-without-crl output=none http-method=post \
+          ("https://api.telegram.org/bot" . ($Message->"tokenid") . "/sendMessage") \
+          http-data=("chat_id=" . ($Message->"chatid") . \
+          "&disable_notification=" . ($Message->"silent") . \
+          "&disable_web_page_preview=true&parse_mode=" . ($Message->"parsemode") . \
+          "&text=" . ($Message->"text")) as-value;
+        :set ($TelegramQueue->$Id);
+      } on-error={
+        $LogPrintExit2 debug $0 ("Sending queued Telegram message failed.") false;
+        :set AllDone false;
+      }
+    }
+  }
+
+  :if ($AllDone = true && $QueueLen = [ :len $TelegramQueue ]) do={
+    / system scheduler remove [ find where name="FlushTelegramQueue" ];
+    :set TelegramQueue;
+  }
+}
+
+# send notification via telegram - expects one array argument
+:set ($NotificationFunctions->"telegram") do={
+  :local Notification $1;
+
+  :global Identity;
+  :global TelegramChatId;
+  :global TelegramChatIdOverride;
+  :global TelegramFixedWidthFont;
+  :global TelegramQueue;
+  :global TelegramTokenId;
+  :global TelegramTokenIdOverride;
+
+  :global CertificateAvailable;
+  :global CharacterReplace;
+  :global EitherOr;
+  :global IfThenElse;
+  :global LogPrintExit2;
+  :global SymbolForNotification;
+  :global UrlEncode;
+
+  :local EscapeMD do={
+    :global TelegramFixedWidthFont;
+
+    :global CharacterReplace;
+    :global IfThenElse;
+
+    :if ($TelegramFixedWidthFont != true) do={
+      :return ($1 . [ $IfThenElse ($2 = "body") "\n" "" ]);
+    }
+
+    :local Return $1;
+    :local Chars {
+      "body"={ "\\"; "`" };
+      "hint"={ "_"; "*"; "["; "]"; "("; ")"; "~"; "`"; ">";
+               "#"; "+"; "-"; "="; "|"; "{"; "}"; "."; "!" };
+    }
+    :foreach Char in=($Chars->$2) do={
+      :set Return [ $CharacterReplace $Return $Char ("\\" . $Char) ];
+    }
+
+    :if ($2 = "body") do={
+      :return ("```\n" . $Return . "\n```");
+    }
+
+    :return $Return;
+  }
+
+  :local ChatId [ $EitherOr ($TelegramChatIdOverride->($Notification->"origin")) $TelegramChatId ];
+  :local TokenId [ $EitherOr ($TelegramTokenIdOverride->($Notification->"origin")) $TelegramTokenId ];
+
+  :if ([ :len $TokenId ] = 0 || [ :len $ChatId ] = 0) do={
+    :return false;
+  }
+
+  :local Truncated false;
+  :local LenLink [ :len ($Notification->"link") ];
+  :local Text ("[" . $Identity . "] " . ($Notification->"subject") . "\n\n" . ($Notification->"message"));
+  :local LenText [ :len $Text ];
+  :if ($LenText > (3968 - $LenLink)) do={
+    :set Text [ $EscapeMD ([ :pick $Text 0 (3840 - $LenLink) ] . "...") "body" ];
+    :set Truncated true;
+  } else={
+    :set Text [ $EscapeMD $Text "body" ];
+  }
+  :if ($LenLink > 0) do={
+    :set Text ($Text . "\n" . [ $SymbolForNotification "link" ] . [ $EscapeMD ($Notification->"link") "hint" ]);
+  }
+  :if ($Truncated = true) do={
+    :set Text ($Text . "\n" . [ $SymbolForNotification "scissors" ] . \
+      [ $EscapeMD ("The Telegram message was too long and has been truncated, cut off " . \
+      (($LenText - [ :len $Text ]) * 100 / $LenText) . "%!") "hint" ]);
+  }
+  :set Text [ $UrlEncode $Text ];
+  :local ParseMode [ $IfThenElse ($TelegramFixedWidthFont = true) "MarkdownV2" "" ];
+
+  :do {
+    :if ([ $CertificateAvailable "Go Daddy Secure Certificate Authority - G2" ] = false) do={
+      $LogPrintExit2 warning $0 ("Downloading required certificate failed.") true;
+    }
+    / tool fetch check-certificate=yes-without-crl output=none http-method=post \
+      ("https://api.telegram.org/bot" . $TokenId . "/sendMessage") \
+      http-data=("chat_id=" . $ChatId . "&disable_notification=" . ($Notification->"silent") . \
+      "&disable_web_page_preview=true&parse_mode=" . $ParseMode . "&text=" . $Text) as-value;
+  } on-error={
+    $LogPrintExit2 info $0 ("Failed sending telegram notification! Queuing...") false;
+
+    :if ([ :typeof $TelegramQueue ] = "nothing") do={
+      :set TelegramQueue [ :toarray "" ];
+    }
+    :set Text ($Text . [ $UrlEncode ("\n" . [ $SymbolForNotification "alarm-clock" ] . \
+      [ $EscapeMD ("This message was queued since " . [ / system clock get date ] . \
+      " " . [ / system clock get time ] . " and may be obsolete.") "hint" ]) ]);
+    :set ($TelegramQueue->[ :len $TelegramQueue ]) { chatid=$ChatId; tokenid=$TokenId;
+      parsemode=$ParseMode; text=$Text; silent=($Notification->"silent") };
+    :if ([ :len [ / system scheduler find where name="FlushTelegramQueue" ] ] = 0) do={
+      / system scheduler add name=FlushTelegramQueue interval=1m start-time=startup \
+        on-event=":global FlushTelegramQueue; \$FlushTelegramQueue;";
+    }
+  }
+}
+
+# send notification via telegram - expects at lease two string arguments
+:set SendTelegram do={
+  :global SendTelegram2;
+
+  $SendTelegram2 ({ subject=$1; message=$2; link=$3; silent=$4 });
+}
+
+# send notification via telegram - expects one array argument
+:set SendTelegram2 do={
+  :local Notification $1;
+
+  :global NotificationFunctions;
+
+  ($NotificationFunctions->"telegram") ("\$NotificationFunctions->\"telegram\"") $Notification;
+}
-- 
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