#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <WiFi.h> // Include the Wi-Fi library
#include <EEPROM.h>

// Set the LCD address to 0x27 for a 20 chars and 4 line display
LiquidCrystal_I2C lcd(0x27, 20, 4);

// WiFi credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const int wifiTimeout = 6; // Adjust the timeout as needed

// NTP Server
const char* ntpServer = "pool.ntp.org";
const long gmtOffset_sec = 3600;
const int daylightOffset_sec = 3600;

// Define EEPROM addresses for storing last tank event times
#define EEPROM_ADDR_LAST_TANK_FULL 0
#define EEPROM_ADDR_LAST_TANK_EMPTY 4

// Global variables for last tank event times
long lastTankFullTime = 0;
long lastTankEmptyTime = 0;
bool updateTime = false; // Flag to update time

// Pin connected to the potentiometer and LEDs
const int potPin = 34;
const int ledPin1 = 2;
const int ledPin2 = 0;

bool ledState = false; // Variable to alternate LED states

void setup() {
  // Initialize LCD
  lcd.init();
  lcd.backlight();

  // Display initial information
  lcd.setCursor(0, 0);
  lcd.print("Water Level: --%");

  // Initialize LED pins
  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
  
  // Initialize Serial
  Serial.begin(9600);

  // Set time using ESP8266WiFi library
  configTime(gmtOffset_sec, daylightOffset_sec, ntpServer);

  // Attempt WiFi connection
  Serial.print("Connecting to WiFi");
  WiFi.begin(ssid, password, wifiTimeout);
  while (WiFi.status() != WL_CONNECTED) {
    delay(100);
    Serial.print(".");
  }
  Serial.println(" Connected!");

  // Read last tank event times from EEPROM
  readLastTankEventTimesFromEEPROM();
}

void loop() {
  // Get current time
  time_t now = time(nullptr);

  // Read potentiometer value and update water level
  int potValue = analogRead(potPin);
  int waterLevel = map(potValue, 0, 4095, 0, 100);

  // Update time if necessary
  if (updateTime || waterLevel == 100 || waterLevel < 50) {
    updateTime = false;
    now = time(nullptr); // Update time
  }

  // Control LED based on water level
  controlLED(waterLevel);

  // Display water level and LED status
  displayWaterLevel(waterLevel);
  displayLEDStatus();

  // Check for tank events
  checkTankEvents(waterLevel);

  // Refresh screen every 20 seconds
  static unsigned long lastRefresh = 0;
  if (millis() - lastRefresh >= 20000) {
    lastRefresh = millis();
    updateTime = true; // Flag to update time
  }

  // Delay for stability
  delay(1000);
}

void displayWaterLevel(int level) {
  lcd.setCursor(0, 1);
  lcd.print("Water Level: ");
  lcd.print(level);
  lcd.print("%  ");
}

void displayLEDStatus() {
  lcd.setCursor(0, 2);
  lcd.print("LED Status: ");
  if (ledState) {
    lcd.print("On   ");
  } else {
    lcd.print("Off  ");
  }
}

void checkTankEvents(int level) {
  if (level == 100 && lastTankFullTime == 0) {
    lastTankFullTime = time(nullptr);
    writeLastTankEventTimesToEEPROM();
    displayMessage("Pump Off - Water Level Full");
  } else if (level < 100 && lastTankFullTime != 0 && lastTankEmptyTime == 0) {
    lastTankEmptyTime = time(nullptr);
    writeLastTankEventTimesToEEPROM();
  }
}

void readLastTankEventTimesFromEEPROM() {
  EEPROM.get(EEPROM_ADDR_LAST_TANK_FULL, lastTankFullTime);
  EEPROM.get(EEPROM_ADDR_LAST_TANK_EMPTY, lastTankEmptyTime);
}

void writeLastTankEventTimesToEEPROM() {
  EEPROM.put(EEPROM_ADDR_LAST_TANK_FULL, lastTankFullTime);
  EEPROM.put(EEPROM_ADDR_LAST_TANK_EMPTY, lastTankEmptyTime);
}

void controlLED(int level) {
  if (level < 25) {
    digitalWrite(ledPin1, HIGH);
    digitalWrite(ledPin2, HIGH);
    ledState = false;
  } else if (level >= 25 && level < 75) {
    digitalWrite(ledPin1, LOW);
    digitalWrite(ledPin2, HIGH);
    ledState = false;
  } else if (level >= 75 && level < 100) {
    digitalWrite(ledPin1, HIGH);
    digitalWrite(ledPin2, LOW);
    ledState = true;
  } else {
    digitalWrite(ledPin1, LOW);
    digitalWrite(ledPin2, LOW);
    ledState = false;
  }
}

void displayMessage(String message) {
  lcd.setCursor(0, 3);
  lcd.print(message);
}