Fix from RobertGnz about issue with too long messages (#275)

.gitignore

@@ -32,3 +32,4 @@
 .gcc-flags.json
 .pio/
 .vscode/
+descript.ion

README.md

@@ -8,10 +8,6 @@ An Arduino IDE library for using Telegram Bot API. It's designed to be used with
 
 Join the [Arduino Telegram Library Group Chat](https://t.me/arduino_telegram_library) if you have any questions/feedback or would just like to be kept up to date with the library's progress.
 
-## Help support what I do!
-
-I have created a lot of different Arduino libraries that I hope people can make use of. [If you enjoy my work, please consider becoming a Github sponsor!](https://github.com/sponsors/witnessmenow/)
-
 ## Introduction
 
 This library provides an interface for [Telegram Bot API](https://core.telegram.org/bots/api).
@@ -24,6 +20,12 @@ Each library only supported a single type of Arduino and had different features
 
 ![alt text](https://imgs.xkcd.com/comics/standards.png "standards")
 
+Finally I have forked this library, which is since years no more under development, from witnessmenow and I have implemented the fix of [issue #275](https://github.com/witnessmenow/Universal-Arduino-Telegram-Bot/issues/275) by glorious developer [RobertGnz](https://github.com/RobertGnz) (Thank you!).
+
+Furhter I have implemented a new API-Call deleteMessage (see UniversalTelegramBot::deleteMessage in the src), to easier ban a chat_id if some flooding attack would happen.
+
+There is still much work to do: the strings in the library will crash the ESP8266 after a while of running, because of memory issues, see: [Taming Arduino Strings -- How to Avoid Memory Issues](https://www.instructables.com/Taming-Arduino-Strings-How-to-Avoid-Memory-Issues/). J-Rios has already done good work here with his [fork](https://github.com/J-Rios/Universal-Arduino-Telegram-Bot) but it is back in commits (compared to witnessmenow's repo) a lot. Maybe it is possible to use some special string library, e.g. [SafeString](https://www.forward.com.au/pfod/ArduinoProgramming/SafeString/index.html). At the moment I do [daily reset](https://www.forward.com.au/pfod/ArduinoProgramming/ArduinoStrings/index.html#reboot) to avoid memory issues.
+
 ## Installing
 
 The downloaded code can be included as a new library into the IDE selecting the menu:

src/UniversalTelegramBot.cpp

@@ -37,6 +37,8 @@
 
 #define ZERO_COPY(STR)    ((char*)STR.c_str())
 #define BOT_CMD(STR)      buildCommand(F(STR))
+// fcw: 2022-07-13: DEBUG
+// #define TELEGRAM_DEBUG
 
 UniversalTelegramBot::UniversalTelegramBot(const String& token, Client &client) {
   updateToken(token);
@@ -368,14 +370,45 @@ int UniversalTelegramBot::getUpdates(long offset) {
   }
   String response = sendGetToTelegram(command); // receive reply from telegram.org
 
+// fcw: 2022-07-13: Bug bei zu grossen Nachrichten, die werden immer wieder abgerufen und blockieren die Abfrage
+// so gemacht mit einer 1500 Zeichen grossen Nachricht von Cat (5306541440), danach ging es nicht mehr.
+// RobertGnz hat dazu schon einen issue geoeffnet, siehe:
+// https://github.com/witnessmenow/Universal-Arduino-Telegram-Bot/issues/275
+// Aenderungen sind mit // Robert und // End Robert gerahmt (hier und weiter unten noch eine Zeile).
+// Nach der Aenderung von Robert ging es wieder.
+// Siehe auch: https://github.com/witnessmenow/Universal-Arduino-Telegram-Bot/issues/266#issuecomment-985013894
+
+// Robert:
+// If deserializeJson happen to endup with an error for instance update too big for
+// the buffer, then last_message_received will not be updated.
+// Subsequent calls to getUpdates uses last_message_received + 1 for the offset value.
+// But as last_message_received was not updated we will allways read the same message.
+// Here we try to find the update_id and store it to update last_message_received if necessary.
+  char * pt1; char * pt2; long candidate;
+  candidate = -1;
+  pt1 = strstr_P( response.c_str(), (const char *) F("update_id"));
+  if ( pt1 != NULL ) {
+    pt1 = strstr_P( pt1, (const char *) F(":"));
+    if ( pt1 != NULL ) {
+      pt1++;
+      pt2 = strstr_P( pt1, (const char *) F(","));
+      if ( pt2 != NULL ) {
+        if ( pt2 - pt1 < 12 ) { // for safety 
+          sscanf( pt1, "%ld", &candidate );
+        }
+      }
+    }
+  }
+// End Robert
   if (response == "") {
     #ifdef TELEGRAM_DEBUG  
         Serial.println(F("Received empty string in response!"));
     #endif
     // close the client as there's nothing to do with an empty string
     closeClient();
     return 0;
-  } else {
+  } 
+  else {
     #ifdef TELEGRAM_DEBUG  
       Serial.print(F("incoming message length "));
       Serial.println(response.length());
@@ -386,11 +419,12 @@ int UniversalTelegramBot::getUpdates(long offset) {
     DynamicJsonDocument doc(maxMessageLength);
     DeserializationError error = deserializeJson(doc, ZERO_COPY(response));
 
-    if (!error) {
+// fcw: 2022-09-28: Hack. Nicht, wenn response zu lang (maxResponseLength in der Header Z135)
+    if ((!error) && (response.length() < maxResponseLength)) {
       #ifdef TELEGRAM_DEBUG  
         Serial.print(F("GetUpdates parsed jsonObj: "));
         serializeJson(doc, Serial);
-        Serial.println();
+        Serial.println();        
       #endif
       if (doc.containsKey("result")) {
         int resultArrayLength = doc["result"].size();
@@ -415,20 +449,35 @@ int UniversalTelegramBot::getUpdates(long offset) {
         #endif
       }
     } else { // Parsing failed
-      if (response.length() < 2) { // Too short a message. Maybe a connection issue
-        #ifdef TELEGRAM_DEBUG  
+		// fcw: fuer Seriellen Debug 
+		if (response.length() >= maxResponseLength) {
+    	#ifdef TELEGRAM_DEBUG  
+	        Serial.print(F("Received too long string in response! response.length(): "));
+	        Serial.println(response.length());
+	        Serial.print(F("last_message_received: "));
+	        Serial.println(last_message_received);        
+	        Serial.print(F("candidate: "));
+	        Serial.println(candidate);          
+    	#endif
+    	}
+        // Robert: try to update last_message_received 
+	    if ( candidate != -1 ) last_message_received = candidate;	  	  
+	    // End Robert
+
+        if (response.length() < 2) { // Too short a message. Maybe a connection issue
+          #ifdef TELEGRAM_DEBUG  
             Serial.println(F("Parsing error: Message too short"));
-        #endif
-      } else {
+          #endif
+        } else {
         // Buffer may not be big enough, increase buffer or reduce max number of
         // messages
-        #ifdef TELEGRAM_DEBUG 
+          #ifdef TELEGRAM_DEBUG 
             Serial.print(F("Failed to parse update, the message could be too "
                            "big for the buffer. Error code: "));
             Serial.println(error.c_str()); // debug print of parsing error
-        #endif     
+          #endif     
+        }
       }
-    }
     // Close the client as no response is to be given
     closeClient();
     return 0;
@@ -817,3 +866,29 @@ bool UniversalTelegramBot::answerCallbackQuery(const String &query_id, const Str
   closeClient();
   return answer;
 }
+
+// fcw: 2022-09-19: um Nachrichten zu loeschen, kopiert und angepasst von sendSimpleMessage(...)
+bool UniversalTelegramBot::deleteMessage(const String& chat_id, int message_id) {
+  bool sent = false;
+  #ifdef TELEGRAM_DEBUG  
+    Serial.println(F("deleteMessage: DELETE Message"));
+  #endif
+  unsigned long sttime = millis();
+
+  if (chat_id != "" && message_id != 0) {
+    while (millis() - sttime < 8000ul) { // loop for a while to send the message
+      String command = BOT_CMD("deleteMessage?chat_id=");
+      command += chat_id;
+      command += F("&message_id=");
+      command += String(message_id);
+      String response = sendGetToTelegram(command);
+      #ifdef TELEGRAM_DEBUG  
+        Serial.println(response);
+      #endif
+      sent = checkForOkResponse(response);
+      if (sent) break;
+    }
+  }
+  closeClient();
+  return sent;
+}

src/UniversalTelegramBot.h

@@ -22,7 +22,8 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 #ifndef UniversalTelegramBot_h
 #define UniversalTelegramBot_h
 
-//#define TELEGRAM_DEBUG 1
+// fcw: hier wird der Bibliotheks Debug-Schalter gesetzt (entkommentiert fuer seriellen DEBUG)
+// #define TELEGRAM_DEBUG 1
 #define ARDUINOJSON_DECODE_UNICODE 1
 #define ARDUINOJSON_USE_LONG_LONG 1
 #include <Arduino.h>
@@ -86,6 +87,8 @@ class UniversalTelegramBot {
 
   bool sendSimpleMessage(const String& chat_id, const String& text, const String& parse_mode);
   bool sendMessage(const String& chat_id, const String& text, const String& parse_mode = "", int message_id = 0);
+// fcw: 2022-09-19: Nachrichten loeschen...
+  bool deleteMessage(const String& chat_id, int message_id);
   bool sendMessageWithReplyKeyboard(const String& chat_id, const String& text,
                                     const String& parse_mode, const String& keyboard,
                                     bool resize = false, bool oneTime = false,
@@ -126,7 +129,10 @@ class UniversalTelegramBot {
   unsigned int waitForResponse = 1500;
   int _lastError;
   int last_sent_message_id = 0;
+// fcw: 2022-09-27: wenn maxMessageLength kleiner geht es aber nicht mehr.
   int maxMessageLength = 1500;
+// fcw: Antwort Laenge beschraenken, damit Flooding nicht auch noch zurueck gesendet wird. Laenge der Antwort: siehe response.length() Achtung: ohne Inhalt (text) ist die Laenge schon 356 gross. Maximaler Befehl (/open_with_supercode...) ist 391 Zeichen insgesamt
+unsigned int maxResponseLength = 400;
 
 private:
   // JsonObject * parseUpdates(String response);