#include <WiFi.h>


#include <Wire.h>              // Include Wire library for I2C communication
#include <LiquidCrystal_I2C.h> // Include the LiquidCrystal I2C library


#include <TimeLib.h>  // Include the Time library

#include <time.h>


#include <ESP32Time.h>


/* WiFi credentials */
#define WIFI_SSID "LAPSPOT"
#define WIFI_PASSWORD "qwertyuiop"


#define NTP_SERVER "asia.pool.ntp.org"
#define NTP_OFFSET 14400
#define NTP_DAYLIGHT_OFFSET 0

ESP32Time timeClient(NTP_OFFSET);


unsigned long sendDataPrevMillis = 0, timeUpdatePrevMillis = 0, updatePrevMillis = 0;

#define LCD_ADDRESS 0x27 // I2C address of the LCD

#define LCD_COLUMNS 16
#define LCD_ROWS 2

// Define the LCD display
LiquidCrystal_I2C lcd(LCD_ADDRESS, LCD_COLUMNS, LCD_ROWS);



void initWifi(bool reconnect = false)
{

  // LCD: Display the connection status
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Connecting WiFi");
  Serial.println("Connecting to WiFi");

  while (WiFi.status() != WL_CONNECTED)
  {
  }

  // LCD: Display the IP address
  lcd.clear();
  lcd.setCursor(0, 0);
  if (reconnect)
  {
    char buf[64];
    sprintf(buf, "Reconnected to Wi-Fi. IP: %s", WiFi.localIP().toString().c_str());
    
    lcd.print("WiFi Reconnected");
    Serial.println("WiFi Reconnected");
    Serial.println("Reconnected to Wi-Fi");
  }
  else
  {
    char buf[64];
    sprintf(buf, "Connected to Wi-Fi. IP: %s", WiFi.localIP().toString().c_str());

    lcd.print("WiFi Connected");
    Serial.println("WiFi Connected");
    Serial.println("Connected to Wi-Fi");
  }

  lcd.setCursor(0, 1);
  lcd.print(WiFi.localIP().toString());
  delay(500);
}


void initTime(bool reconnect = false)
{
  if (reconnect)
  {
    configTime(NTP_OFFSET, NTP_DAYLIGHT_OFFSET, NTP_SERVER);
    struct tm timeinfo;
    if (!getLocalTime(&timeinfo))
      timeClient.setTimeStruct(timeinfo);

    return;
  }

  while (true)
  {
    lcd.clear();
    lcd.setCursor(0, 0);

    configTime(NTP_OFFSET, NTP_DAYLIGHT_OFFSET, NTP_SERVER);
    struct tm timeinfo;
    if (!getLocalTime(&timeinfo))
    {
      timeClient.setTimeStruct(timeinfo);
      lcd.print("NTP Time Error");
      lcd.setCursor(0, 1);
      lcd.print("retrying...");
      Serial.println("NTP time error");
      delay(500);
      continue;
    }

    timeUpdatePrevMillis = millis();

    // Get the current time from RTC
    String time_buf = timeClient.getTime("%m/%d %H:%M:%S");

   
    lcd.print("Current Time:");
    lcd.setCursor(0, 1);
    lcd.print(time_buf.c_str());
    Serial.printf("Current Time: %s\n", time_buf.c_str());
    delay(500);
    return; 
  }
}

TaskHandle_t uploadDataTask;

void uploadData(void *parameter)
{
  while (true)
  {

    // Update the time every 1 minute
    if (millis() - timeUpdatePrevMillis > 60000 && WiFi.status() == WL_CONNECTED)
    {
      timeUpdatePrevMillis = millis();
      initTime(true);

      Serial.println("Time updated");
    }

    if (millis() - sendDataPrevMillis > 2000)
    {
      sendDataPrevMillis = millis();

      if (random(0,1))
      {
        lcd.setCursor(14, 1);
        lcd.write(0x06);

        Serial.println("Data sent to Firebase\n");
      }
      else
      {
        lcd.setCursor(14, 1);
        // add a cross mark
        lcd.write(0x07);

        Serial.println("Failed to send data to Firebase. Retrying...\n");
      }
    }
  }
}

void setup()
{
  // Initialize serial port
  Serial.begin(115200);
  
  // Initialize LCD
  lcd.init();
  lcd.backlight();

  // Initialize Wi-Fi
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);

  // Connect to Wi-Fi
  initWifi();

  // Initialize Time
  initTime();


  Serial.println("Setup done");

  xTaskCreatePinnedToCore(uploadData, "Task1", 10000, NULL, 0, &uploadDataTask, 0);
  lcd.clear();
}

void loop()
{
  // Send data to Firebase every 1 second
  if (millis() - updatePrevMillis > 500)
  {
    updatePrevMillis = millis();

    // Read the AC voltage value
    float acVoltage = zmpt.getVoltageAC(AC_FREQUENCY);
    int acCurrent = analogRead(AC_PIN);

    float calibrationFactor = 0.005;

    float current = (acCurrent - 512) * calibrationFactor;
    float power = acVoltage * current;

    char power_buf[32];
    String time_buf = timeClient.getTime("%m/%d %H:%M:%S");
    sprintf(power_buf, "%.2fV %.2fA %.2fW", acVoltage, current);

    Serial.println(power_buf);
    Serial.println(time_buf.c_str());
    Serial.println(timeClient.getEpoch());

    // LCD: Display the current time and power consumption
    lcd.setCursor(0, 0);
    lcd.print(power_buf);
    lcd.setCursor(0, 1);
    lcd.print(time_buf.c_str());

  } 
}