Google Sheet as Remote Config for Microcontrollers

#include <ESP8266WiFi.h>
#include <map>
#include <string>
#include "NetworkClient.h"

class Config {
   private:
    std::map<String, String> configCache;
    const String sheetId = "1OzhdDoPW-slnVct42AsFLe2zNJJrFReHDz5Gv6hccsA"; // you can get this ID from your share url
    const String sheetName = "config"; // this is sheet's name 

   public:
    /**
    * To return corresponding value for the given key. If not found, will return the defVal
    */
    String getConfig(String key, String defval) {
        // check if config cache is empty
        if (configCache.empty()) {
            loadConfig();
        }

        std::map<String, String>::const_iterator it = configCache.find(key);
        if (it == configCache.end()) {
            return defval;
        } else {
            return it->second;
        }
    }

    void loadConfig() {
        Serial.println("Loading configs...");
        HTTPClient request;
        NetworkClient client;
        if (request.begin(*client.httpClient,"https://docs.google.com/spreadsheets/d/"+ sheetId + "/gviz/tq?tqx=out:csv&sheet=" + sheetName)) {
            int responseCode = request.GET();
            Serial.println("Response code: " + String(responseCode));
            if (responseCode > 0) {
                String payload = request.getString();
                // Parse the payload and populate the data map

                int startPos = 0;
                int endPos = payload.indexOf('\n');
                bool isLastItem = false;
                while (endPos != -1) {
                    Serial.println("---------------");

                    String line = payload.substring(startPos, endPos);

                    int commaPos = line.indexOf(',');
                    if (commaPos != -1) {
                        String key = line.substring(1, commaPos - 1);
                        key.replace("\"", "");
                        String value =
                            line.substring(commaPos + 2, line.length() - 1);
                        value.replace("\"", "");

                        configCache[key] = value;
                    }
                    startPos = endPos + 1;
                    endPos = payload.indexOf('\n', startPos);
                    if (isLastItem) {
                        break;
                    }

                    if (endPos == -1) {
                        endPos = payload.length();
                        isLastItem = true;
                    }
                }

                Serial.println("Config loaded successfully!");
            }
        }
        request.end();
        Serial.println("Config load finished");
        
    }

    /**
    * To return all config key-value as one string (for logging)
    */
    String allConfigs() {
        String str = "";
        for (std::map<String, String>::iterator it = configCache.begin();
             it != configCache.end(); ++it) {
            str += it->first + "=" + it->second + ";";
        }
        return str;
    }

    void refreshConfigs() {
        Serial.println("Refreshing configs...");
        configCache.clear();
        configCache = std::map<String, String>();
        loadConfig();
    }
};
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#include <Arduino.h>
#include <WiFi.cpp>
#include <map>
#include <string>
#include <Config.cpp>

WiFiConnection wifi;
Config config;

void setup() {
  Serial.begin(115200); 
  wifi.connectToWifi();
  config.loadConfig();
}


void loop() {
  ...
  bool isServoEnabled = config.getConfig("servo_enabled", "FALSE") == "TRUE";
  int distanceThreshold = config.getConfig("distance_threshold_in_cm", "10").toInt()

  if(distanceCm < distanceThreshold) {
    if(isServoEnabled) {
      servo.write(config.getConfig("servo_on_bird", "90").toInt());
    }
    ...
  } else {
    if(isServoEnabled) {
      servo.write(config.getConfig("servo_on_watch", "0").toInt());
    }
    ...
  }
  
  ...

  if(millis() - lastHeartbeatSentAt > config.getConfig("heartbeat_interval_in_sec", "60").toInt() * 1000.0) {
    ...
    config.refreshConfigs();
  }
  
  delay(config.getConfig("main_delay_in_ms", "1000").toInt());
}
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