#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <WiFi.h>       // Include the WiFi library for ESP32
#include <HTTPClient.h> // Include the HTTPClient library for HTTP requests

LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C address 0x27, 16 columns and 2 rows

const int batteryPin = 34; // Connect the battery to pin 34 (analog pin)
const int tempPin = 35;    // Connect the temperature sensor to pin 35 (analog pin)

// Blynk credentials
#define BLYNK_TEMPLATE_ID "TMPL34IoYx_BG"
#define BLYNK_TEMPLATE_NAME "EV Sample1"
#define BLYNK_AUTH_TOKEN "iiY7TaV4ikjwwUV8-lUqK9J3XNj8h0Z8"

char ssid[] = "Wokwi-GUEST";  // Enter the Wokwi Guest WiFi SSID
char pass[] = ""; // Wokwi Guest network does not require a password
const char* blynkServer = "http://blynk.cloud"; // Blynk cloud server

void setup() {
  lcd.init();      // Initialize the LCD
  lcd.backlight(); // Turn on backlight
  lcd.clear();     // Clear the screen
  
  Serial.begin(9600); // Initialize serial communication
  delay(1000); // Wait for Serial Monitor to initialize
  
  Serial.println("Initializing...");
  
  // Connect to WiFi
  WiFi.begin(ssid, pass);
  
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  
  Serial.println("Connected to WiFi");
  lcd.setCursor(0, 0);
  lcd.print("WiFi connected!");
  delay(2000); // Display the message for 2 seconds
  lcd.clear();
}

void loop() {
  float voltage = readBatteryVoltage();      // Read the battery voltage
  int batteryPercentage = calculateBatteryPercentage(voltage); // Calculate battery percentage
  float temperature = readTemperature();     // Read the temperature
  
  // Print readings to LCD
  lcd.setCursor(0, 0); 
  lcd.print("Battery: ");
  lcd.print(batteryPercentage);
  lcd.print("%");

  lcd.setCursor(0, 1);
  lcd.print("Temp: ");
  lcd.print(temperature);
  lcd.print("C");
  
  // Print readings to Serial Monitor
  Serial.print("Battery Percentage: ");
  Serial.print(batteryPercentage);
  Serial.print("% | Temperature: ");
  Serial.print(temperature);
  Serial.println("C");

  // Send data to Blynk using HTTP
  sendToBlynk(batteryPercentage, temperature);
  
  delay(1000); // Wait for 1 second before taking next readings
}

void sendToBlynk(int batteryPercentage, float temperature) {
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;

    // Construct the Blynk API URLs
    String url1 = String(blynkServer) + "/auth/" + BLYNK_AUTH_TOKEN + "/update/V1?value=" + String(batteryPercentage);
    String url2 = String(blynkServer) + "/auth/" + BLYNK_AUTH_TOKEN + "/update/V2?value=" + String(temperature);

    // Send the battery percentage to Blynk
    http.begin(url1.c_str());
    int httpResponseCode1 = http.GET();
    if (httpResponseCode1 > 0) {
      Serial.println("Battery percentage sent to Blynk");
    } else {
      Serial.print("Error sending battery percentage: ");
      Serial.println(httpResponseCode1);
    }
    http.end();

    // Send the temperature to Blynk
    http.begin(url2.c_str());
    int httpResponseCode2 = http.GET();
    if (httpResponseCode2 > 0) {
      Serial.println("Temperature sent to Blynk");
    } else {
      Serial.print("Error sending temperature: ");
      Serial.println(httpResponseCode2);
    }
    http.end();
  } else {
    Serial.println("WiFi not connected");
  }
}

float readBatteryVoltage() {
  // Simulate battery voltage reading
  float voltage = random(36, 42) / 10.0; // Simulate voltage between 3.6V and 4.2V
  return voltage;
}

int calculateBatteryPercentage(float voltage) {
  float minVoltage = 3.6; // Minimum voltage of the battery
  float maxVoltage = 4.2; // Maximum voltage of the battery

  // Calculate battery percentage based on the voltage
  int batteryPercentage = map(voltage * 100, minVoltage * 100, maxVoltage * 100, 0, 100); // map function needs integer values, hence multiplied by 100
  batteryPercentage = constrain(batteryPercentage, 0, 100); // Limit the percentage to 0-100

  return batteryPercentage;
}

float readTemperature() {
  // Simulate temperature reading
  float temperature = random(200, 400) / 10.0; // Simulate temperature between 20°C and 40°C
  return temperature;
}