/*
   Copyright (c) 2018 Brian Lough. All right reserved.

   UniversalTelegramBot - Library to create your own Telegram Bot using
   ESP8266 or ESP32 on Arduino IDE.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

/*
   **** Note Regarding Client Connection Keeping ****
   Client connection is established in functions that directly involve use of
   client, i.e sendGetToTelegram, sendPostToTelegram, and
   sendMultipartFormDataToTelegram. It is closed at the end of
   sendMultipartFormDataToTelegram, but not at the end of sendGetToTelegram and
   sendPostToTelegram as these may need to keep the connection alive for respose
   / response checking. Re-establishing a connection then wastes time which is
   noticeable in user experience. Due to this, it is important that connection
   be closed manually after calling sendGetToTelegram or sendPostToTelegram by
   calling closeClient(); Failure to close connection causes memory leakage and
   SSL errors
 */

#include "UniversalTelegramBot.h"

#define ZERO_COPY(STR)    ((char*)STR.c_str())
#define BOT_CMD(STR)      buildCommand(F(STR))

UniversalTelegramBot::UniversalTelegramBot(const String& token, Client &client) {
  updateToken(token);
  this->client = &client;
}

void UniversalTelegramBot::updateToken(const String& token) {
  _token = token;
}

String UniversalTelegramBot::getToken() {
  return _token;
}

String UniversalTelegramBot::buildCommand(const String& cmd) {
  String command;

  command += F("bot");
  command += _token;
  command += F("/");
  command += cmd;

  return command;
}

String UniversalTelegramBot::sendGetToTelegram(const String& command) {
  String body, headers;
  bool avail;
  
  // Connect with api.telegram.org if not already connected
  if (!client->connected()) {
    #ifdef TELEGRAM_DEBUG  
        Serial.println(F("[BOT]Connecting to server"));
    #endif
    if (!client->connect(TELEGRAM_HOST, TELEGRAM_SSL_PORT)) {
      #ifdef TELEGRAM_DEBUG  
        Serial.println(F("[BOT]Conection error"));
      #endif
    }
  }
  if (client->connected()) {

    #ifdef TELEGRAM_DEBUG  
        Serial.println("sending: " + command);
    #endif  

    client->print(F("GET /"));
    client->print(command);
    client->println(F(" HTTP/1.1"));
    client->println(F("Host:" TELEGRAM_HOST));
    client->println(F("Accept: application/json"));
    client->println(F("Cache-Control: no-cache"));
    client->println();

    readHTTPAnswer(body, headers);
  }

  return body;
}

bool UniversalTelegramBot::readHTTPAnswer(String &body, String &headers) {
  int ch_count = 0;
  long now = millis();
  bool finishedHeaders = false;
  bool currentLineIsBlank = true;
  bool responseReceived = false;

  while (millis() - now < longPoll * 1000 + waitForResponse) {
    while (client->available()) {
      char c = client->read();
      responseReceived = true;

      if (!finishedHeaders) {
        if (currentLineIsBlank && c == '\n') {
          finishedHeaders = true;
        } else {
          headers += c;
        }
      } else {
        if (ch_count < maxMessageLength) {
          body += c;
          ch_count++;
        }
      }

      if (c == '\n') currentLineIsBlank = true;
      else if (c != '\r') currentLineIsBlank = false;
    }

    if (responseReceived && ch_count > 5) { //jz
      #ifdef TELEGRAM_DEBUG  
        Serial.print(">");
        Serial.print(body);
        Serial.println("<");
      #endif
      break;
    }
  }
  return responseReceived;
}

String UniversalTelegramBot::sendPostToTelegram(const String& command, JsonObject payload) {

  String body;
  String headers;

  // Connect with api.telegram.org if not already connected
  if (!client->connected()) {
    #ifdef TELEGRAM_DEBUG  
        Serial.println(F("[BOT Client]Connecting to server"));
    #endif
    if (!client->connect(TELEGRAM_HOST, TELEGRAM_SSL_PORT)) {
      #ifdef TELEGRAM_DEBUG  
        Serial.println(F("[BOT Client]Conection error"));
      #endif
    }
  }
  if (client->connected()) {
    // POST URI
    client->print(F("POST /"));
    client->print(command);
    client->println(F(" HTTP/1.1"));
    // Host header
    client->println(F("Host:" TELEGRAM_HOST));
    // JSON content type
    client->println(F("Content-Type: application/json"));

    // Content length
    int length = measureJson(payload);
    client->print(F("Content-Length:"));
    client->println(length);
    // End of headers
    client->println();
    // POST message body
    String out;
    serializeJson(payload, out);
    
    client->println(out);
    #ifdef TELEGRAM_DEBUG
        Serial.println(String("Posting:") + out);
    #endif

    readHTTPAnswer(body, headers);
  }

  return body;
}

String UniversalTelegramBot::sendMultipartFormDataToTelegram(
    const String& command, const String& binaryPropertyName, const String& fileName,
    const String& contentType, const String& chat_id, int fileSize,
    MoreDataAvailable moreDataAvailableCallback,
    GetNextByte getNextByteCallback, 
    GetNextBuffer getNextBufferCallback,
    GetNextBufferLen getNextBufferLenCallback) {

  String body;
  String headers;
  
  const String boundary = F("------------------------b8f610217e83e29b");

  // Connect with api.telegram.org if not already connected
  if (!client->connected()) {
    #ifdef TELEGRAM_DEBUG  
        Serial.println(F("[BOT Client]Connecting to server"));
    #endif
    if (!client->connect(TELEGRAM_HOST, TELEGRAM_SSL_PORT)) {
      #ifdef TELEGRAM_DEBUG  
        Serial.println(F("[BOT Client]Conection error"));
      #endif
    }
  }
  if (client->connected()) {
    String start_request = "";
    String end_request = "";

    start_request += F("--");
    start_request += boundary;
    start_request += F("\r\ncontent-disposition: form-data; name=\"chat_id\"\r\n\r\n");
    start_request += chat_id;
    start_request += F("\r\n" "--");
    start_request += boundary;
    start_request += F("\r\ncontent-disposition: form-data; name=\"");
    start_request += binaryPropertyName;
    start_request += F("\"; filename=\"");
    start_request += fileName;
    start_request += F("\"\r\n" "Content-Type: ");
    start_request += contentType;
    start_request += F("\r\n" "\r\n");

    end_request += F("\r\n" "--");
    end_request += boundary;
    end_request += F("--" "\r\n");
    
    client->print(F("POST /"));
    client->print(buildCommand(command));
    client->println(F(" HTTP/1.1"));
    Serial.print("*")  ; delay(jzdelay); 
    
    // Host header
    client->println(F("Host: " TELEGRAM_HOST));       //jz <<<<<<<<<<<<<<<<<<<<< println !!!!!!!! >>>>>>>>>>>>>>>>>>>>
    client->println(F("User-Agent: arduino/1.0"));
    Serial.print("*")  ; delay(jzdelay);
    client->println(F("Accept: */*"));
    Serial.print("*")  ; delay(jzdelay);
    
    int contentLength = fileSize + start_request.length() + end_request.length();
    
    #ifdef TELEGRAM_DEBUG  
        Serial.println("Content-Length: " + String(contentLength));
    #endif
    client->print(F("Content-Length: "));
    client->println(String(contentLength));
    Serial.print("*")  ; delay(jzdelay);
    client->print(F("Content-Type: multipart/form-data; boundary="));
    client->println(boundary);
    //Serial.print(" --- bef ---")  ; delay(jzdelay);
    client->println();   // client->println(F"");
    //Serial.print(" --- aft ---")  ; delay(jzdelay);
    client->print(start_request);
    Serial.print("*")  ; delay(jzdelay);

    #ifdef TELEGRAM_DEBUG  
     Serial.print("Start request: " + start_request);
    #endif

    if (getNextByteCallback == nullptr) {
        while (moreDataAvailableCallback()) {
            client->write((const uint8_t *)getNextBufferCallback(), getNextBufferLenCallback());
            #ifdef TELEGRAM_DEBUG  
             Serial.println(F("Sending photo from buffer"));
            #endif
            }
    } else {
        #ifdef TELEGRAM_DEBUG  
            Serial.println(F("Sending photo by binary"));
        #endif
        //byte buffer[jzblocksize];
        int count = 0;
        char ch;
        while (moreDataAvailableCallback()) {
            buffer[count] = getNextByteCallback();
            count++;
            if (count == jzblocksize) {
                // yield();
                #ifdef TELEGRAM_DEBUG  
                    //jz Serial.println(F("Sending binary photo full buffer"));
                #endif
                client->write((const uint8_t *)buffer, jzblocksize);
                Serial.print("*")  ; delay(jzdelay);
                count = 0;
            }
        }
        
        if (count > 0) {
            #ifdef TELEGRAM_DEBUG  
                Serial.println(F("Sending binary photo remaining buffer"));
            #endif
            client->write((const uint8_t *)buffer, count);
            Serial.print("*")  ; delay(jzdelay);
        }
    }

    client->print(end_request); 
    Serial.print("*")  ; delay(jzdelay);
    
    #ifdef TELEGRAM_DEBUG  
        Serial.print("End request: " + end_request);
    #endif
    
    //Serial.print("... Done Sending.  Client.Available = ");  Serial.println(client->available());
    //delay(2000);
    //Serial.print("... 2 secs later.  Client.Available = ");  Serial.println(client->available());
    readHTTPAnswer(body, headers);
  }

  closeClient();
  return body;
}

String UniversalTelegramBot::sendMultipartFormDataToTelegramWithCaption(
    const String& command, const String& binaryPropertyName, const String& fileName,
    const String& contentType, const String& caption, const String& chat_id, int fileSize,
    MoreDataAvailable moreDataAvailableCallback,
    GetNextByte getNextByteCallback, 
    GetNextBuffer getNextBufferCallback,
    GetNextBufferLen getNextBufferLenCallback) {

  String body;
  String headers;
  
  const String boundary = F("------------------------b8f610217e83e29b");

  // Connect with api.telegram.org if not already connected
  if (!client->connected()) {
    #ifdef TELEGRAM_DEBUG  
        Serial.println(F("[BOT Client]Connecting to server"));
    #endif
    if (!client->connect(TELEGRAM_HOST, TELEGRAM_SSL_PORT)) {
      #ifdef TELEGRAM_DEBUG  
        Serial.println(F("[BOT Client]Conection error"));
      #endif
    }
  }
  if (client->connected()) {
    String start_request = "";
    String end_request = "";

    start_request += F("--");
    start_request += boundary;
    start_request += F("\r\ncontent-disposition: form-data; name=\"chat_id\"\r\n\r\n");
    start_request += chat_id;
    start_request += F("\r\n" "--");

// jz caption start
    start_request += boundary;
    start_request += F("\r\ncontent-disposition: form-data; name=\"caption\"\r\n\r\n");
    start_request += caption;
    start_request += F("\r\n" "--");
// jz caption end
    
    start_request += boundary;
    start_request += F("\r\ncontent-disposition: form-data; name=\"");
    start_request += binaryPropertyName;
    start_request += F("\"; filename=\"");
    start_request += fileName;
    start_request += F("\"\r\n" "Content-Type: ");
    start_request += contentType;
    start_request += F("\r\n" "\r\n");

    end_request += F("\r\n" "--");
    end_request += boundary;
    end_request += F("--" "\r\n");
    
    client->print(F("POST /"));
    client->print(buildCommand(command));
    client->println(F(" HTTP/1.1"));
    Serial.print("*")  ; delay(jzdelay); 
    
    // Host header
    client->println(F("Host: " TELEGRAM_HOST));       //jz <<<<<<<<<<<<<<<<<<<<< println !!!!!!!! >>>>>>>>>>>>>>>>>>>>
    client->println(F("User-Agent: arduino/1.0"));
    Serial.print("*")  ; delay(jzdelay);
    client->println(F("Accept: */*"));
    Serial.print("*")  ; delay(jzdelay);
    
    int contentLength = fileSize + start_request.length() + end_request.length();
    
    #ifdef TELEGRAM_DEBUG  
        Serial.println("Content-Length: " + String(contentLength));
    #endif
    client->print(F("Content-Length: "));
    client->println(String(contentLength));
    Serial.print("*")  ; delay(jzdelay);
    client->print(F("Content-Type: multipart/form-data; boundary="));
    client->println(boundary);
    Serial.print("*")  ; delay(jzdelay);
    client->println();    // client->println(F(""));         <--- jz 1.05 bug
    Serial.print("*")  ; delay(jzdelay);
    client->print(start_request);
    Serial.print("*")  ; delay(jzdelay);

    #ifdef TELEGRAM_DEBUG  
     Serial.print("Start request: " + start_request);
    #endif

    if (getNextByteCallback == nullptr) {
        while (moreDataAvailableCallback()) {
            client->write((const uint8_t *)getNextBufferCallback(), getNextBufferLenCallback());
            #ifdef TELEGRAM_DEBUG  
             Serial.println(F("Sending photo from buffer"));
            #endif
            }
    } else {
        #ifdef TELEGRAM_DEBUG  
            Serial.println(F("Sending photo by binary"));
        #endif
        //byte buffer[jzblocksize];
        int count = 0;
        char ch;
        while (moreDataAvailableCallback()) {
            buffer[count] = getNextByteCallback();
            count++;
            if (count == jzblocksize) {
                // yield();
                #ifdef TELEGRAM_DEBUG  
                    //jz Serial.println(F("Sending binary photo full buffer"));
                #endif
                client->write((const uint8_t *)buffer, jzblocksize);
                Serial.print("*")  ; delay(jzdelay);
                count = 0;
            }
        }
        
        if (count > 0) {
            #ifdef TELEGRAM_DEBUG  
                Serial.println(F("Sending binary photo remaining buffer"));
            #endif
            client->write((const uint8_t *)buffer, count);
            Serial.print("*")  ; delay(jzdelay);
        }
    }

    client->print(end_request); 
    Serial.print("*")  ; delay(jzdelay);
    
    #ifdef TELEGRAM_DEBUG  
        Serial.print("End request: " + end_request);
    #endif
    
    //Serial.print("... Done Sending.  Client.Available = ");  Serial.println(client->available());
    //delay(2000);
    //Serial.print("... 2 secs later.  Client.Available = ");  Serial.println(client->available());
    readHTTPAnswer(body, headers);
  }

  closeClient();
  return body;
}

bool UniversalTelegramBot::getMe() {
  String response = sendGetToTelegram(BOT_CMD("getMe")); // receive reply from telegram.org
  DynamicJsonDocument doc(maxMessageLength);
  DeserializationError error = deserializeJson(doc, ZERO_COPY(response));
  closeClient();

  if (!error) {
    if (doc.containsKey("result")) {
      name = doc["result"]["first_name"].as<String>();
      userName = doc["result"]["username"].as<String>();
      return true;
    }
  }

  return false;
}

/*********************************************************************************
 * SetMyCommands - Update the command list of the bot on the telegram server     *
 * (Argument to pass: Serialied array of BotCommand)                             *
 * CAUTION: All commands must be lower-case                                      *
 * Returns true, if the command list was updated successfully                    *
 ********************************************************************************/
bool UniversalTelegramBot::setMyCommands(const String& commandArray) {
  DynamicJsonDocument payload(maxMessageLength);
  payload["commands"] = serialized(commandArray);
  bool sent = false;
  String response = "";
  #if defined(_debug)
  Serial.println(F("sendSetMyCommands: SEND Post /setMyCommands"));
  #endif  // defined(_debug)
  unsigned long sttime = millis();

  while (millis() < sttime + 8000ul) { // loop for a while to send the message
    response = sendPostToTelegram(BOT_CMD("setMyCommands"), payload.as<JsonObject>());
    #ifdef _debug  
    Serial.println("setMyCommands response" + response);
    #endif
    sent = checkForOkResponse(response);
    if (sent) break;
  }

  closeClient();
  return sent;
}


/***************************************************************
 * GetUpdates - function to receive messages from telegram *
 * (Argument to pass: the last+1 message to read)             *
 * Returns the number of new messages           *
 ***************************************************************/
int UniversalTelegramBot::getUpdates(long offset) {

  #ifdef TELEGRAM_DEBUG  
    Serial.println(F("GET Update Messages"));
  #endif
  String command = BOT_CMD("getUpdates?offset=");
  command += offset;
  command += F("&limit=");
  command += HANDLE_MESSAGES;

  if (longPoll > 0) {
    command += F("&timeout=");
    command += String(longPoll);
  }
  String response = sendGetToTelegram(command); // receive reply from telegram.org

  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 {
    #ifdef TELEGRAM_DEBUG  
      Serial.print(F("incoming message length "));
      Serial.println(response.length());
      Serial.println(F("Creating DynamicJsonBuffer"));
    #endif

    // Parse response into Json object
    DynamicJsonDocument doc(maxMessageLength);
    DeserializationError error = deserializeJson(doc, ZERO_COPY(response));
      
    if (!error) {
      #ifdef TELEGRAM_DEBUG  
        Serial.print(F("GetUpdates parsed jsonObj: "));
        serializeJson(doc, Serial);
        Serial.println();
      #endif
      if (doc.containsKey("result")) {
        int resultArrayLength = doc["result"].size();
        if (resultArrayLength > 0) {
          int newMessageIndex = 0;
          // Step through all results
          for (int i = 0; i < resultArrayLength; i++) {
            JsonObject result = doc["result"][i];
            if (processResult(result, newMessageIndex)) newMessageIndex++;
          }
          // We will keep the client open because there may be a response to be
          // given
          return newMessageIndex;
        } else {
          #ifdef TELEGRAM_DEBUG  
            Serial.println(F("no new messages"));
          #endif
        }
      } else {
        #ifdef TELEGRAM_DEBUG  
            Serial.println(F("Response contained no 'result'"));
        #endif
      }
    } else { // Parsing failed
      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 {
        // Buffer may not be big enough, increase buffer or reduce max number of
        // messages
        #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     
      }
    }
    // Close the client as no response is to be given
    closeClient();
    return 0;
  }
}

bool UniversalTelegramBot::processResult(JsonObject result, int messageIndex) {
  int update_id = result["update_id"];
  // Check have we already dealt with this message (this shouldn't happen!)
  if (last_message_received != update_id) {
    last_message_received = update_id;
    messages[messageIndex].update_id = update_id;
    messages[messageIndex].text = F("");
    messages[messageIndex].from_id = F("");
    messages[messageIndex].from_name = F("");
    messages[messageIndex].longitude = 0;
    messages[messageIndex].latitude = 0;
    messages[messageIndex].reply_to_message_id = 0;
    messages[messageIndex].reply_to_text = F("");
    messages[messageIndex].query_id = F("");

    if (result.containsKey("message")) {
      JsonObject message = result["message"];
      messages[messageIndex].type = F("message");
      messages[messageIndex].from_id = message["from"]["id"].as<String>();
      messages[messageIndex].from_name = message["from"]["first_name"].as<String>();
      messages[messageIndex].date = message["date"].as<String>();
      messages[messageIndex].chat_id = message["chat"]["id"].as<String>();
      messages[messageIndex].chat_title = message["chat"]["title"].as<String>();
      messages[messageIndex].hasDocument = false;
      if (message.containsKey("text")) {
        messages[messageIndex].text = message["text"].as<String>();
          
      } else if (message.containsKey("location")) {
        messages[messageIndex].longitude = message["location"]["longitude"].as<float>();
        messages[messageIndex].latitude  = message["location"]["latitude"].as<float>();
      } else if (message.containsKey("document")) {
        String file_id = message["document"]["file_id"].as<String>();
        messages[messageIndex].file_caption = message["caption"].as<String>();
        messages[messageIndex].file_name = message["document"]["file_name"].as<String>();
        if (getFile(messages[messageIndex].file_path, messages[messageIndex].file_size, file_id) == true)
          messages[messageIndex].hasDocument = true;
        else
          messages[messageIndex].hasDocument = false;
      }
      if (message.containsKey("reply_to_message")) {
        messages[messageIndex].reply_to_message_id = message["reply_to_message"]["message_id"];
        // no need to check if containsKey["text"]. If it doesn't, it default to null
        messages[messageIndex].reply_to_text = message["reply_to_message"]["text"].as<String>();
      } 
    } else if (result.containsKey("channel_post")) {
      JsonObject message = result["channel_post"];
      messages[messageIndex].type = F("channel_post");
      messages[messageIndex].text = message["text"].as<String>();
      messages[messageIndex].date = message["date"].as<String>();
      messages[messageIndex].chat_id = message["chat"]["id"].as<String>();
      messages[messageIndex].chat_title = message["chat"]["title"].as<String>();

    } else if (result.containsKey("callback_query")) {
      JsonObject message = result["callback_query"];
      messages[messageIndex].type = F("callback_query");
      messages[messageIndex].from_id = message["from"]["id"].as<String>();
      messages[messageIndex].from_name = message["from"]["first_name"].as<String>();
      messages[messageIndex].text = message["data"].as<String>();
      messages[messageIndex].date = message["date"].as<String>();
      messages[messageIndex].chat_id = message["message"]["chat"]["id"].as<String>();
      messages[messageIndex].reply_to_text = message["message"]["text"].as<String>();
      messages[messageIndex].chat_title = F("");
      messages[messageIndex].query_id = message["id"].as<String>();
    } else if (result.containsKey("edited_message")) {
      JsonObject message = result["edited_message"];
      messages[messageIndex].type = F("edited_message");
      messages[messageIndex].from_id = message["from"]["id"].as<String>();
      messages[messageIndex].from_name = message["from"]["first_name"].as<String>();
      messages[messageIndex].date = message["date"].as<String>();
      messages[messageIndex].chat_id = message["chat"]["id"].as<String>();
      messages[messageIndex].chat_title = message["chat"]["title"].as<String>();

      if (message.containsKey("text")) {
        messages[messageIndex].text = message["text"].as<String>();
          
      } else if (message.containsKey("location")) {
        messages[messageIndex].longitude = message["location"]["longitude"].as<float>();
        messages[messageIndex].latitude  = message["location"]["latitude"].as<float>();
      }
    }
    return true;
  }
  return false;
}

/***********************************************************************
 * SendMessage - function to send message to telegram                  *
 * (Arguments to pass: chat_id, text to transmit and markup(optional)) *
 ***********************************************************************/
bool UniversalTelegramBot::sendSimpleMessage(const String& chat_id, const String& text,
                                             const String& parse_mode) {

  bool sent = false;
  #ifdef TELEGRAM_DEBUG  
    Serial.println(F("sendSimpleMessage: SEND Simple Message"));
  #endif
  long sttime = millis();

  if (text != "") {
    while (millis() < sttime + 8000) { // loop for a while to send the message
      String command = BOT_CMD("sendMessage?chat_id=");
      command += chat_id;
      command += F("&text=");
      command += text;
      command += F("&parse_mode=");
      command += parse_mode;
      String response = sendGetToTelegram(command);
      #ifdef TELEGRAM_DEBUG  
        Serial.println(response);
      #endif
      sent = checkForOkResponse(response);
      if (sent) break;
    }
  }
  closeClient();
  return sent;
}

bool UniversalTelegramBot::sendMessage(const String& chat_id, const String& text,
                                       const String& parse_mode) {

  DynamicJsonDocument payload(maxMessageLength);
  payload["chat_id"] = chat_id;
  payload["text"] = text;

  if (parse_mode != "")
    payload["parse_mode"] = parse_mode;

  return sendPostMessage(payload.as<JsonObject>());
}

bool UniversalTelegramBot::sendMessageWithReplyKeyboard(
    const String& chat_id, const String& text, const String& parse_mode, const String& keyboard,
    bool resize, bool oneTime, bool selective) {
    
  DynamicJsonDocument payload(maxMessageLength);
  payload["chat_id"] = chat_id;
  payload["text"] = text;

  if (parse_mode != "")
    payload["parse_mode"] = parse_mode;

  JsonObject replyMarkup = payload.createNestedObject("reply_markup");
    
  replyMarkup["keyboard"] = serialized(keyboard);

  // Telegram defaults these values to false, so to decrease the size of the
  // payload we will only send them if needed
  if (resize)
    replyMarkup["resize_keyboard"] = resize;

  if (oneTime)
    replyMarkup["one_time_keyboard"] = oneTime;

  if (selective)
    replyMarkup["selective"] = selective;

  return sendPostMessage(payload.as<JsonObject>());
}

bool UniversalTelegramBot::sendMessageWithInlineKeyboard(const String& chat_id,
                                                         const String& text,
                                                         const String& parse_mode,
                                                         const String& keyboard) {

  DynamicJsonDocument payload(maxMessageLength);
  payload["chat_id"] = chat_id;
  payload["text"] = text;

  if (parse_mode != "")
    payload["parse_mode"] = parse_mode;

  JsonObject replyMarkup = payload.createNestedObject("reply_markup");
  replyMarkup["inline_keyboard"] = serialized(keyboard);
  return sendPostMessage(payload.as<JsonObject>());
}

/***********************************************************************
 * SendPostMessage - function to send message to telegram                  *
 * (Arguments to pass: chat_id, text to transmit and markup(optional)) *
 ***********************************************************************/
bool UniversalTelegramBot::sendPostMessage(JsonObject payload) {

  bool sent = false;
  #ifdef TELEGRAM_DEBUG 
    Serial.print(F("sendPostMessage: SEND Post Message: "));
    serializeJson(payload, Serial);
    Serial.println();
  #endif 
  long sttime = millis();

  if (payload.containsKey("text")) {
    while (millis() < sttime + 8000) { // loop for a while to send the message
      String response = sendPostToTelegram(BOT_CMD("sendMessage"), payload);
      #ifdef TELEGRAM_DEBUG  
        Serial.println(response);
      #endif
      sent = checkForOkResponse(response);
      if (sent) break;
    }
  }

  closeClient();
  return sent;
}

String UniversalTelegramBot::sendPostPhoto(JsonObject payload) {

  bool sent = false;
  String response = "";
  #ifdef TELEGRAM_DEBUG  
    Serial.println(F("sendPostPhoto: SEND Post Photo"));
  #endif
  long sttime = millis();

  if (payload.containsKey("photo")) {
    while (millis() < sttime + 8000) { // loop for a while to send the message
      response = sendPostToTelegram(BOT_CMD("sendPhoto"), payload);
      #ifdef TELEGRAM_DEBUG  
        Serial.println(response);
      #endif
      sent = checkForOkResponse(response);
      if (sent) break;
      
    }
  }

  closeClient();
  return response;
}

String UniversalTelegramBot::sendPhotoByBinary(
    const String& chat_id, const String& contentType, int fileSize,
    MoreDataAvailable moreDataAvailableCallback,
    GetNextByte getNextByteCallback, GetNextBuffer getNextBufferCallback, GetNextBufferLen getNextBufferLenCallback) {

  #ifdef TELEGRAM_DEBUG  
    Serial.println(F("sendPhotoByBinary: SEND Photo"));
  #endif

  String response = sendMultipartFormDataToTelegram("sendPhoto", "photo", "img.jpg",
    contentType, chat_id, fileSize,
    moreDataAvailableCallback, getNextByteCallback, getNextBufferCallback, getNextBufferLenCallback);

  #ifdef TELEGRAM_DEBUG  
    Serial.println(response);
  #endif

  return response;
}

String UniversalTelegramBot::sendPhoto(const String& chat_id, const String& photo,
                                       const String& caption,
                                       bool disable_notification,
                                       int reply_to_message_id,
                                       const String& keyboard) {

  DynamicJsonDocument payload(maxMessageLength);
  payload["chat_id"] = chat_id;
  payload["photo"] = photo;

  if (caption.length() > 0)
      payload["caption"] = caption;

  if (disable_notification)
      payload["disable_notification"] = disable_notification;

  if (reply_to_message_id && reply_to_message_id != 0)
      payload["reply_to_message_id"] = reply_to_message_id;

  if (keyboard.length() > 0) {
    JsonObject replyMarkup = payload.createNestedObject("reply_markup");
    replyMarkup["keyboard"] = serialized(keyboard);
  }

  return sendPostPhoto(payload.as<JsonObject>());
}

bool UniversalTelegramBot::checkForOkResponse(const String& response) {
  int last_id;
  DynamicJsonDocument doc(response.length());
  deserializeJson(doc, response);

  // Save last sent message_id
  last_id = doc["result"]["message_id"];
  if (last_id > 0) last_sent_message_id = last_id;

  return doc["ok"] | false;  // default is false, but this is more explicit and clear
}

bool UniversalTelegramBot::sendChatAction(const String& chat_id, const String& text) {

  bool sent = false;
  #ifdef TELEGRAM_DEBUG  
    Serial.println(F("SEND Chat Action Message"));
  #endif
  long sttime = millis();

  if (text != "") {
    while (millis() < sttime + 8000) { // loop for a while to send the message
      String command = BOT_CMD("sendChatAction?chat_id=");
      command += chat_id;
      command += F("&action=");
      command += text;

      String response = sendGetToTelegram(command);

      #ifdef TELEGRAM_DEBUG  
        Serial.println(response);
      #endif
      sent = checkForOkResponse(response);

      if (sent) break;
      
    }
  }

  closeClient();
  return sent;
}

void UniversalTelegramBot::closeClient() {
  if (client->connected()) {
    #ifdef TELEGRAM_DEBUG  
        Serial.println(F("Closing client"));
    #endif
    client->stop();
  }
}

bool UniversalTelegramBot::getFile(String& file_path, long& file_size, const String& file_id)
{
  String command = BOT_CMD("getFile?file_id=");
  command += file_id;
  String response = sendGetToTelegram(command); // receive reply from telegram.org
  DynamicJsonDocument doc(maxMessageLength);
  DeserializationError error = deserializeJson(doc, ZERO_COPY(response));
  closeClient();

  if (!error) {
    if (doc.containsKey("result")) {
      file_path  = F("https://api.telegram.org/file/");
      file_path += buildCommand(doc["result"]["file_path"]);
      file_size = doc["result"]["file_size"].as<long>();
      return true;
    }
  }
  return false;
}

bool UniversalTelegramBot::answerCallbackQuery(const String &query_id, const String &text, bool show_alert, const String &url, int cache_time) {
  DynamicJsonDocument payload(maxMessageLength);

  payload["callback_query_id"] = query_id;
  payload["show_alert"] = show_alert;
  payload["cache_time"] = cache_time;

  if (text.length() > 0) payload["text"] = text;
  if (url.length() > 0) payload["url"] = url;

  String response = sendPostToTelegram(BOT_CMD("answerCallbackQuery"), payload.as<JsonObject>());
  #ifdef _debug  
     Serial.print(F("answerCallbackQuery response:"));
     Serial.println(response);
  #endif
  bool answer = checkForOkResponse(response);
  closeClient();
  return answer;
}