mqtt_util.hpp

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#include <ArduinoJson.h>
#include <string>
#include "SDReader.hpp"
 
void process_command(string command, string message){
 
    if(command == "get_time_range"){
        // convert message to json structure
        StaticJsonDocument<256> doc;
        deserializeJson(doc, message);
 
        int page_size;
        JsonArray topic_filter_ja = {};
        string time_range;
 
        if(!doc.containsKey("page_size")){
            if(USB_DEBUG) Serial.println("[ERROR] MQTT command \'get_time_range\' missing key \'page_size\' so using default size of 20");
            page_size = 20;
 
        }else{
            page_size = doc["page_size"]; 
        }
 
        if(!doc.containsKey("time_range")){
            if(USB_DEBUG) Serial.println("[ERROR] MQTT command \'get_time_range\' missing key \'time_range\' so quitting");
            return;
 
        }else{
            time_range = doc["time_range"].as<string>();
        }
 
        if(!doc.containsKey("topic_filter")){
            if(USB_DEBUG) Serial.println("[ERROR] MQTT command \'get_time_range\' missing key \'topic_filter\' so using default \"\"");
            topic_filter_ja.add("");
        }else{
            topic_filter_ja = doc["topic_filter"];
        }
 
        // empty topic filter vector
        vector<string> topic_filter_v = {};
 
        // convert topic filter jason array to vector
        for(JsonVariant n : topic_filter_ja){
            topic_filter_v.push_back(n.as<string>());
        }
 
        // parse time range string for epochs
        int ampersand_pos = time_range.find("&");
        string epoch = time_range.substr(0, ampersand_pos);
        string terminus = time_range.substr(ampersand_pos+1);
 
        TimeStamp* ep = NULL;
        TimeStamp* term = NULL;
 
        // convert strings to TimeStamp objects
        if(epoch.find("T") != string::npos){
            ep = new TimeStamp(epoch);
        }else{
            ep = new TimeStamp(stoi(epoch));
        }
 
        if(terminus.find("T") != string::npos){
            term = new TimeStamp(terminus);
        }else{
            term = new TimeStamp(stoi(terminus));
        }
 
 
 
        Serial.println("[DEBUG] pulling data range");
        /*
        if(USB_DEBUG){
            Serial.print("[DEBUG] process command has ");
            double perc = ESP.getFreeHeap();
            Serial.print(perc);
            Serial.println(" free bytes");
        }
        */
        // read data from files and upload via MQTT
        SDReader sdr;
        sdr.read_entry_range_from_files(
                *ep, 
                *term, 
                topic_filter_v,
                page_size);
 
    }else{
 
        if(USB_DEBUG) {
            Serial.print("[DEBUG] unkown command \'");
            Serial.print(command.c_str());
            Serial.println("\'");
        }
 
    }
 
    if(USB_DEBUG) Serial.println("[DEBUG] finished processing MQTT command");
}
 
 
void callback(char* topic, byte* message, unsigned int length){
    std::string msg_str;
    for(int i = 0; i < length; i++){
        msg_str += (char)message[i];
    }
 
    Serial.printf("[MQTT] Received \'%s\'|\'%s\'\n", topic, msg_str.c_str());
 
    // TODO: check if something needs to be done when receiving MQTT packets
    // parse command
    string topic_s = topic;
    int mac_id_pos = topic_s.find("/", 15);
    string command = topic_s.substr(14, mac_id_pos - 14);
   
    // parse mac id
    string mac_id = topic_s.substr(mac_id_pos + 1);
 
    // check if MAC is match before processing command
    if(WiFi.macAddress().c_str() == mac_id){
        process_command(command, msg_str);
    }
 
    
}