#include <WiFi.h>
#include <HTTPClient.h>
#include <ArduinoJson.h>
#include <BluetoothSerial.h>
#include <NTPClient.h>
#include <WiFiUdp.h>

BluetoothSerial SerialBT;

const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";
const char* serverURL = "http://your_server_url.com/post_data_endpoint";
const float R1 = 15000.0;  // Value of R1 in ohms (15K)
const float R2 = 4700.0;   // Value of R2 in ohms (4.7K)

float I = 0.0; // Initialize 'I' with a default value

// Define NTP settings
const char* ntpServer = "pool.ntp.org";
const int utcOffset = 0; // UTC offset in seconds

WiFiUDP ntpUDP;
NTPClient timeClient(ntpUDP, ntpServer, utcOffset);

void setup() {
  Serial.begin(115200);
  SerialBT.begin("ESP32_BT"); // Bluetooth device name
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");

  // Initialize the NTP client and set the time update interval (in seconds)
  timeClient.begin();
  timeClient.update();
}

void loop() {
  // Update the NTP time client
  timeClient.update();

  if (SerialBT.available()) {
    // If there's Bluetooth data available, read 'I' value
    I = SerialBT.parseFloat();
    Serial.print("Received I: ");
    Serial.println(I);
    calculateAndPost(I);
  }
}

void calculateAndPost(float I) {
  float V = I * (R1 + R2);
  Serial.print("Calculated Voltage (V): ");
  Serial.println(V);

  // Get the current timestamp from the NTP client
  String timestamp = timeClient.getFormattedTime();

  WiFiClient client;
  HTTPClient http;
  String serverResponse;

  // Create a JSON object with the provided structure, including the timestamp
  StaticJsonDocument<400> jsonDoc;
  jsonDoc["device"] = "XC015145";
  jsonDoc["gsmgateway"] = "XC015145";
  jsonDoc["timestamp"] = timestamp;
  JsonArray data = jsonDoc.createNestedArray("data");
  data.add("ANA-MACADDRESS-RTCTIMESTAMP-" + String(V, 2)); // Adjust the format as needed

  if (http.begin(client, serverURL)) {
    http.addHeader("Content-Type", "application/json");

    serializeJson(jsonDoc, client);

    int httpResponseCode = http.POST(serverResponse);

    if (httpResponseCode > 0) {
      Serial.print("HTTP Response Code: ");
      Serial.println(httpResponseCode);
      Serial.print("Server Response: ");
      Serial.println(serverResponse);
    } else {
      Serial.print("Error in HTTP POST request. Error code: ");
      Serial.println(httpResponseCode);
    }
    http.end();
  } else {
    Serial.println("Failed to connect to the server");
  }
}