void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
}

/*
  WriteMultipleFields
  
  Description: Writes values to fields 1,2,3,4 and status in a single ThingSpeak update every 20 seconds over secured HTTPS connection.
  
  Hardware: ESP8266 based boards
  
  !!! IMPORTANT - Modify the secrets.h file for this project with your network connection and ThingSpeak channel details. !!!
  
  Note:
  - Requires ESP8266WiFi library, WiFiClientSecure library and ESP8622 board add-on. See https://github.com/esp8266/Arduino for details.
  - Select the target hardware from the Tools->Board menu
  - This example is written for a network using WPA encryption. For WEP or WPA, change the WiFi.begin() call accordingly.
  
  ThingSpeak ( https://www.thingspeak.com ) is an analytic IoT platform service that allows you to aggregate, visualize, and 
  analyze live data streams in the cloud. Visit https://www.thingspeak.com to sign up for a free account and create a channel.  
  
  Documentation for the ThingSpeak Communication Library for Arduino is in the README.md folder where the library was installed.
  See https://www.mathworks.com/help/thingspeak/index.html for the full ThingSpeak documentation.
  
  For licensing information, see the accompanying license file.
  
  Copyright 2020, The MathWorks, Inc.
*/

#define SECRET_SSID "WOKWI-GUEST" // For HTTPS SSL connection
#define  SECRET_PASS ""// For HTTPS SSL connection
#define  SECRET_CH_ID  2477274 // For HTTPS SSL connection
#define   SECRET_WRITE_APIKEY "GMTBA7M6F1AQSDW3
" // For HTTPS SSL connection


#include <WiFi.h>
#include <WiFiClientSecure.h>
#include "secrets.h"
#include "ThingSpeak.h" // always include thingspeak header file after other header files and custom macros

char ssid[] = SECRET_SSID;   // your network SSID (name) 
char pass[] = SECRET_PASS;   // your network password
int keyIndex = 0;            // your network key Index number (needed only for WEP)
WiFiClientSecure  client;

unsigned long myChannelNumber = SECRET_CH_ID;
const char * myWriteAPIKey = SECRET_WRITE_APIKEY;

// Initialize our values
int number1 = 0;
int number2 = random(0,100);
int number3 = random(0,100);
int number4 = random(0,100);
String myStatus = "";

// Fingerprint check, make sure that the certificate has not expired.
const char * fingerprint = NULL; // use SECRET_SHA1_FINGERPRINT for fingerprint check
void setup() {
  Serial.begin(115200);  // Initialize serial
  while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo native USB port only
  }
  
  WiFi.mode(WIFI_STA); 

  if(fingerprint!=NULL){
    client.setFingerprint(fingerprint);
  }
  else{
    client.setInsecure(); // To perform a simple SSL Encryption
  }
  
  ThingSpeak.begin(client);  // Initialize ThingSpeak
}

void loop() {

  // Connect or reconnect to WiFi
  if(WiFi.status() != WL_CONNECTED){
    Serial.print("Attempting to connect to SSID: ");
    Serial.println(SECRET_SSID);
    while(WiFi.status() != WL_CONNECTED){
      WiFi.begin(ssid, pass);  // Connect to WPA/WPA2 network. Change this line if using open or WEP network
      Serial.print(".");
      delay(5000);     
    } 
    Serial.println("\nConnected.");
  }

  // set the fields with the values
  ThingSpeak.setField(1, number1);
  ThingSpeak.setField(2, number2);
  ThingSpeak.setField(3, number3);
  ThingSpeak.setField(4, number4);

  // figure out the status message
  if(number1 > number2){
    myStatus = String("field1 is greater than field2"); 
  }
  else if(number1 < number2){
    myStatus = String("field1 is less than field2");
  }
  else{
    myStatus = String("field1 equals field2");
  }
  
  // set the status
  ThingSpeak.setStatus(myStatus);
  
  // write to the ThingSpeak channel
  int x = ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
  if(x == 200){
    Serial.println("Channel update successful.");
  }
  else{
    Serial.println("Problem updating channel. HTTP error code " + String(x));
  }
  
  // change the values
  number1++;
  if(number1 > 99){
    number1 = 0;
  }
  number2 = random(0,100);
  number3 = random(0,100);
  number4 = random(0,100);
  
  delay(20000); // Wait 20 seconds to update the channel again
}