#include <WiFi.h>
#include <HTTPClient.h>
#include <ArduinoJson.h>
#include <NTPClient.h>
// change next line to use with another board/shield
//#include <ESP8266WiFi.h>
//#include <WiFi.h> // for WiFi shield
//#include <WiFi101.h> // for WiFi 101 shield or MKR1000
#include <WiFiUdp.h>

long randNumber;

const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* serverUrl = "http://206.189.0.204:8080/api/v1/thermalsense";
char str[10];
#define MAX_UID 10 /* Change to whatever length you need */

WiFiUDP ntpUDP;

// By default 'pool.ntp.org' is used with 60 seconds update interval and
// no offset
NTPClient timeClient(ntpUDP,"pool.ntp.org", 3 * 3600);

const char * generateUID() {
  /* Change to allowable characters */
  const char possible[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
  static char uid[MAX_UID + 1];
  for (int p = 0, i = 0; i < MAX_UID; i++) {
    int r = random(0, strlen(possible));
    uid[p++] = possible[r];
  }
  uid[MAX_UID] = '\0';
  return uid;
}


void setup() {
  Serial.begin(115200);
  // Connect to Wi-Fi
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi..");
  }
  Serial.println("WiFi connected.");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
  //Serial.println("Connected to WiFi");
  // Perform HTTP POST

  //timeClient.setTimeOffset(10800);
  timeClient.begin();
  //postData();
  //getEpoch();
}

void loop() {
  randNumber = random(20, 35);
  Serial.println(randNumber);
  timeClient.update();
  Serial.println(timeClient.getEpochTime());
  postData();
  delay(10000);
  // The formattedDate comes with the following format:
  // 2018-05-28T16:00:13Z
  // We need to extract date and time
  //formattedDate = timeClient.getFormattedTime();
  //Serial.println(formattedDate);
}

void postData() {

  StaticJsonDocument<128> doc;

  doc["messageCode"] = generateUID();
  doc["probeID"] = "TMP002";
  doc["param"] = randNumber;
  doc["timeStamp"] = timeClient.getEpochTime();

  // serializeJson(doc, output);
  // Create JSON object
  // StaticJsonDocument<200> doc;
  // JsonObject data = doc.createNestedObject("data");
  // data["celcius"] = 25;
  // data["fahrenheit"] = 77;
  // doc["name"] = "temperature_sensor";

  // Serialize JSON to string
  String jsonStr;
  serializeJson(doc, jsonStr);
  // Send HTTP POST request
  HTTPClient http;
  http.begin(serverUrl);
  http.addHeader("Content-Type", "application/json");
  int httpResponseCode = http.POST(jsonStr);
  if (httpResponseCode > 0) {
    Serial.print("HTTP Response code: ");
    Serial.println(httpResponseCode);
    Serial.println(jsonStr);
    String response = http.getString();
    Serial.println(response);
  } else {
    Serial.print("Error in HTTP POST request: ");
    Serial.println(httpResponseCode);
  }
  http.end();
}