/*
ANKIT PATRAS TOPNO
IoT & Robotics - Projects 
Krutanic July 2024

1. Design an IoT System to perform following tasks

> Interface ESP32 with DHT11 Sensor to read temperature and Humidity. 
> Print this data on LCD screen 
> Send this data to ThingSpeak cloud 
> Create 2 Lamps indicator on cloud and turn on the lamps if the sensed 
valued crosses a threshold level.

*/

#include <WiFi.h> //Wifi library
#include <HTTPClient.h> //HTTP library

const char* ssid = "Wokwi-GUEST"; //wifi name
const char* password = ""; //wifi password (here, it is an open network)

String talkbacks_id = "52717"; //talkback ID
String command_id =    "44779177"; //command ID
String talkbacks_api = "PBV1XSJMEW6CY29J"; //talkback API key
String command_string=""; //empty command

void GETcommand()
{
        HTTPClient http;    

        Serial.print("[HTTP] begin...\n");
        //"http://api.thingspeak.com/talkbacks/35233/commands/16599915.json?api_key=0E1160BEX9CSNU6V"
        String url = "http://api.thingspeak.com/talkbacks/";
               url += talkbacks_id;  
               url += "/commands/";
               url += command_id;
               url += ".json?api_key=";
               url += talkbacks_api;
        http.begin(url); //HTTP

        Serial.print("[HTTP] GET...\n");
        
        // start connection and send HTTP header
        int httpCode = http.GET();

        // httpCode will be negative on error
        
        if(httpCode > 0) {
            // HTTP header has been send and Server response header has been handled
            Serial.printf("[HTTP] GET... code: %d\n", httpCode);

            // file found at server
                     if(httpCode == HTTP_CODE_OK) {
                String payload = http.getString();
                Serial.println(payload);
                int index_start = payload.indexOf("command_string\":\"") + 17;
                int index_stop = payload.indexOf("\",\"position");
                command_string = payload.substring(index_start, index_stop);
                Serial.println(command_string);            
            }
   
        } 
        else 
        {
            Serial.printf("[HTTP] GET... failed, error: %s\n", http.errorToString(httpCode).c_str());
        }

        http.end();
       
    delay(1000);
}

void connectWifi (const char* ssid, const char* password)
{
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi..");
  }
  Serial.println("Connected to WiFi");
}

void setup() {
  Serial.begin(115200);

  // Connect to Wi-Fi
  connectWifi(ssid, password);
  pinMode(2, OUTPUT);
  pinMode(4, OUTPUT);


}


// I = V/R
// 20mA = 3.3/R

void loop() {
        GETcommand();
        if(command_string == "HI") //here, "HI" is the reset condition
            {
              digitalWrite(2, LOW);//turn off the LED
              digitalWrite(4, LOW);//turn off the ERROR LED
            }
        else if(command_string == "LEDON")
            {
              digitalWrite(4, HIGH);// turn on red LED (i.e. alert)
              digitalWrite(2, LOW);//turn off the green LED (i.e. normal)
            }
        else 
            {
              digitalWrite(2, HIGH);// turn OFF red LED
              digitalWrite(4, LOW);//turn ON green LED
            }
            delay(1000);
}