// Student Name: Muhammad Afeeq Zhikri Bin Zamzuri
// Student ID: 52224122134

#include <WiFi.h>
#include <HTTPClient.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <OneWire.h>
#include <DallasTemperature.h>
#include "EmonLib.h"
#include "ThingSpeak.h"

#define SCREEN_WIDTH 128 // OLED width, in pixels
#define SCREEN_HEIGHT 64 // OLED height, in pixels

// OLED display object connected to I2C
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire);

// WiFi credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// ThingSpeak API information
const char* server = "https://api.thingspeak.com";
const char* apiKey = "CDJEFTTGRAFUMV67"; // Replace with your ThingSpeak Write API Key
const char* myChannelNumber = "2810704";  // Replace with your ThingSpeak Channel Number

const int voltagePin = 35;  // Analog input pin for voltage measurement
const int currentPin = 34;  // Analog input pin for current measurement
const int redLedPin = 4;    // Digital output pin for red LED
const int greenLedPin = 5;  // Digital output pin for green LED

// Temperature sensor pins and objects
#define ONE_WIRE_BUS 15 // Pin connected to the temperature sensor
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature tempSensor(&oneWire);

EnergyMonitor currentSensor;

float voltage, current, power, powerConsumption, temperature, costOfElectricity;
unsigned long previousMillis = 0; // Variable to store the time of the last update
unsigned long totalMillis = 0;    // Variable to store the total elapsed time

// Electricity rate per kWh in Ringgit Malaysia
float electricityRate = 0.57; // Example rate of RM 0.57 per kWh

void setup() {
  Serial.begin(115200);
  
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;);
  }
  delay(500);
  display.clearDisplay();
  display.setTextColor(WHITE);

  WiFi.begin(ssid, password);
  Serial.print("Connecting to WiFi");
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected!");

  pinMode(voltagePin, INPUT);
  pinMode(currentPin, INPUT);
  pinMode(redLedPin, OUTPUT); // Set red LED pin as output
  pinMode(greenLedPin, OUTPUT); // Set green LED pin as output

  // Initialize temperature sensor
  tempSensor.begin();
}

void sendDataToThingSpeak() {
  // Read raw analog values
  int rawVoltage = analogRead(voltagePin);
  int rawCurrent = analogRead(currentPin);

  // Convert raw values to physical quantities
  voltage = (rawVoltage / 4095.0) * 230;  // Assuming 230V reference
  float currentVoltage = (rawCurrent / 4095.0) * 5; // Assuming 5V reference
  const float sensorSensitivity = 0.1; // Sensor sensitivity in V/A (adjust according to datasheet)
  current = currentVoltage / sensorSensitivity; // Calculate current in Amperes
  power = voltage * current; // Calculate power in Watts
  
  // Calculate elapsed time since last update
  unsigned long currentMillis = millis();
  unsigned long elapsedTime = currentMillis - previousMillis;
  previousMillis = currentMillis;
  totalMillis += elapsedTime;

  // Calculate power consumption
  float elapsedTimeHours = totalMillis / 3600000.0; // Convert milliseconds to hours
  powerConsumption = (power / 1000.0) * elapsedTimeHours; // Convert power to kWh and multiply by elapsed time
  costOfElectricity = powerConsumption * electricityRate; // Multiply by electricity rate

  // Read temperature from sensor
  tempSensor.requestTemperatures();
  temperature = tempSensor.getTempCByIndex(0); // Assuming only one sensor connected

  // Send data to ThingSpeak
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    String url = String(server) + "/update?api_key=" + apiKey +
                 "&field1=" + String(voltage, 2) +
                 "&field2=" + String(current, 2) +
                 "&field3=" + String(powerConsumption, 2) +
                 "&field4=" + String(temperature, 2) +
                 "&field5=" + String(costOfElectricity, 2);
    http.begin(url);
    int httpCode = http.GET();

    if (httpCode > 0) {
      Serial.println("Data sent to ThingSpeak successfully!");
    } else {
      Serial.print("Error sending data: ");
      Serial.println(http.errorToString(httpCode).c_str());
    }

    http.end();
  } else {
    Serial.println("WiFi not connected! Unable to send data.");
  }
}

void loop() {
  // Send data to ThingSpeak every 10 seconds
  static unsigned long lastSendTime = 0;
  if (millis() - lastSendTime >= 10000) {
    sendDataToThingSpeak();
    lastSendTime = millis();
  }

  // Display values on the OLED
  display.clearDisplay(); // Clear display before drawing new values
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(0, 0);
  display.print("Voltage (V): ");
  display.println(voltage, 2);

  display.setCursor(0, 16);
  display.print("Current (A): ");
  display.println(current, 2);

  display.setCursor(0, 32);
  display.print("Power/H: ");
  display.println(powerConsumption, 2);

  display.setCursor(0, 48);
  display.print("Temperature: ");
  display.println(temperature, 2);
  display.println("°C");

  display.setCursor(0, 64);
  display.print("Cost: RM ");
  display.println(costOfElectricity, 2);

  display.display();
}