#!rsc by RouterOS
# RouterOS script: telegram-chat
# Copyright (c) 2023 Christian Hesse <mail@eworm.de>
# https://git.eworm.de/cgit/routeros-scripts/about/COPYING.md
#
# use Telegram to chat with your Router and send commands
# https://git.eworm.de/cgit/routeros-scripts/about/doc/telegram-chat.md

:local 0 "telegram-chat";
:global GlobalFunctionsReady;
:while ($GlobalFunctionsReady != true) do={ :delay 500ms; }

:global Identity;
:global TelegramChatActive;
:global TelegramChatGroups;
:global TelegramChatId;
:global TelegramChatIdsTrusted;
:global TelegramChatOffset;
:global TelegramTokenId;

:global CertificateAvailable;
:global EscapeForRegEx;
:global GetRandom20CharAlNum;
:global IfThenElse;
:global LogPrintExit2;
:global MkDir;
:global ScriptLock;
:global SendTelegram2;
:global SymbolForNotification;
:global ValidateSyntax;
:global WaitForFile;
:global WaitFullyConnected;

$ScriptLock $0;

$WaitFullyConnected;

:if ([ :typeof $TelegramChatOffset ] != "num") do={
  :set TelegramChatOffset 0;
}

:if ([ $CertificateAvailable "Go Daddy Secure Certificate Authority - G2" ] = false) do={
  $LogPrintExit2 warning $0 ("Downloading required certificate failed.") true;
}

:local JsonGetKey do={
  :local Array [ :toarray $1 ];
  :local Key   [ :tostr $2 ];

  :for I from=0 to=([ :len $Array ] - 1) do={
    :if (($Array->$I) = $Key) do={
      :if ($Array->($I + 1) = ":") do={
        :return ($Array->($I + 2));
      }
      :return [ :pick ($Array->($I + 1)) 1 [ :len ($Array->($I + 1)) ] ];
    }
  }

  :return false;
}

:local Data;
:do {
  :set Data ([ /tool/fetch check-certificate=yes-without-crl output=user \
    ("https://api.telegram.org/bot" . $TelegramTokenId . "/getUpdates?offset=" . \
    $TelegramChatOffset . "&allowed_updates=%5B%22message%22%5D") as-value ]->"data");
  :set Data [ :pick $Data ([ :find $Data "[" ] + 1) ([ :len $Data ] - 2) ];
} on-error={
  $LogPrintExit2 info $0 ("Failed getting updates from Telegram.") true;
}

:foreach Update in=[ :toarray $Data ] do={
  :local UpdateID [ $JsonGetKey $Update "update_id" ];
  :if ($UpdateID >= $TelegramChatOffset) do={
    :set TelegramChatOffset ($UpdateID + 1);
    :local Trusted false;
    :local Message [ $JsonGetKey $Update "message" ];
    :local From [ $JsonGetKey $Message "from" ];
    :local FromID [ $JsonGetKey $From "id" ];
    :local FromUserName [ $JsonGetKey $From "username" ];
    :foreach IdsTrusted in=($TelegramChatId, $TelegramChatIdsTrusted) do={
      :if ($FromID = $IdsTrusted || $FromUserName = $IdsTrusted) do={
        :set Trusted true;
      }
    }

    :if ($Trusted = true) do={
      :local Text [ $JsonGetKey $Message "text" ];
      :if ([ :pick $Text 0 1 ] = "!") do={
        :if ($Text ~ ("^! *(" . [ $EscapeForRegEx $Identity ] . "|@" . $TelegramChatGroups . ")\$")) do={
          :set TelegramChatActive true;
        } else={
          :set TelegramChatActive false;
        }
        $LogPrintExit2 info $0 ("Now " . [ $IfThenElse $TelegramChatActive "active" "passive" ] . "!") false;
      } else={
        :if ($TelegramChatActive = true && [ :len $Text ] > 0) do={
          :if ([ $ValidateSyntax $Text ] = true) do={
            :local File ("tmpfs/telegram-chat/" . [ $GetRandom20CharAlNum 6 ]);
            $MkDir "tmpfs/telegram-chat";
            $LogPrintExit2 info $0 ("Running command: " . $Text) false;
            :exec script=($Text . "; :execute script=\":put\" file=" . $File . ".done") file=$File;
            :if ([ $WaitForFile ($File . ".done.txt") 200 ] = false) do={
              $LogPrintExit2 warning $0 ("Command did not finish, possibly still running.") false;
            }
            :local Content [ /file/get ($File . ".txt") content ];
            $SendTelegram2 ({ origin=$0; silent=false; \
              subject=([ $SymbolForNotification "speech-balloon" ] . "Telegram Chat"); \
              message=("Command:\n" . $Text . "\n\nOutput:\n" . $Content) });
            /file/remove "tmpfs/telegram-chat";
          } else={
            $LogPrintExit2 warning $0 ("The command failed syntax validation: " . $Text) false;
          }
        }
      }
    } else={
      $LogPrintExit2 warning $0 ("Received a message from untrusted contact '" . $FromUserName . "' (ID " . $FromID . ")!") false;
    }
  }
}