#include <EEPROM.h>
#include <TimerOne.h>
#include <avr/wdt.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);

#define NUM_SENSORS 3
#define NUM_REMOTE_KEYS 4

const int sensorPins[NUM_SENSORS] = {2, 3, 4};
const int remotePins[NUM_REMOTE_KEYS] = {6, 7, 8, 9};
const int buzzerPin = 5;
const int ledArmedPin = 10;
const int ledDisarmedPin = 11;
const int ledSilentPin = 12;
const int ledSensorPins[NUM_SENSORS] = {A0, A1, A2};

const int batteryRelayPin = A5;
const int batteryAnalogPin = A3;
const float batteryStartCharge = 12.4;
const float batteryStopCharge  = 12.6;
const float batteryDividerRatio = 2.6;

#define EEPROM_ADDR_ARMED 0
#define EEPROM_ADDR_SILENT 1
#define EEPROM_MAGIC_ADDR 10
#define EEPROM_MAGIC_VALUE 0xAB
#define EEPROM_ADDR_SENSOR_LATCHED 20

bool systemArmed = false;
bool silentMode = false;
bool buzzerActive = false;
bool sensorTriggered = false;
bool sensorLatched[NUM_SENSORS] = {false};
bool remoteLock[NUM_REMOTE_KEYS] = {false};
bool isCharging = false;
unsigned long lastMotionTime = 0;
const unsigned long alarmDuration = 20000;

// PIR Filtering
int pirHitCount[NUM_SENSORS] = {0};
unsigned long pirLastWindow[NUM_SENSORS] = {0};
const unsigned long PIR_WINDOW = 600;
const int PIR_REQUIRED_HITS = 2;

// LCD Control
unsigned long lcdBacklightTimer = 0;
bool lcdBacklightState = true;
const unsigned long LCD_BACKLIGHT_TIMEOUT = 10000;

// LCD Sensor Trigger Display
bool lcdSensorMsgActive = false;
unsigned long lcdSensorMsgTimer = 0;
const unsigned long LCD_SENSOR_MSG_DURATION = 20000;

// Buzzer
volatile bool beepRequested = false;
volatile int beepCount = 0;

// Battery Monitoring
int lastBatteryPercent = -1;
bool lastChargingState = false;
String lastModeLabel = "";

void saveSystemState() {
  EEPROM.write(EEPROM_ADDR_ARMED, systemArmed);
  EEPROM.write(EEPROM_ADDR_SILENT, silentMode);
  EEPROM.write(EEPROM_MAGIC_ADDR, EEPROM_MAGIC_VALUE);
}

void loadSystemState() {
  byte magic = EEPROM.read(EEPROM_MAGIC_ADDR);
  if (magic == EEPROM_MAGIC_VALUE) {
    systemArmed = EEPROM.read(EEPROM_ADDR_ARMED);
    silentMode = EEPROM.read(EEPROM_ADDR_SILENT);
    Serial.println(systemArmed ? (silentMode ? "✅ دزدگیر فعال (سایلنت)" : "✅ دزدگیر فعال") : "❌ دزدگیر غیرفعال");
  } else {
    systemArmed = false;
    silentMode = false;
    saveSystemState();
    Serial.println("⚠️ تنظیمات پیش‌فرض بارگذاری شد");
  }
}

void saveSensorLatchState() {
  for (int i = 0; i < NUM_SENSORS; i++) {
    EEPROM.write(EEPROM_ADDR_SENSOR_LATCHED + i, sensorLatched[i]);
  }
}

void loadSensorLatchState() {
  for (int i = 0; i < NUM_SENSORS; i++) {
    sensorLatched[i] = EEPROM.read(EEPROM_ADDR_SENSOR_LATCHED + i);
    digitalWrite(ledSensorPins[i], sensorLatched[i]);
  }
}

bool isReliablePIR(int index) {
  if (digitalRead(sensorPins[index]) == HIGH) {
    unsigned long now = millis();
    if (now - pirLastWindow[index] > PIR_WINDOW) {
      pirHitCount[index] = 1;
      pirLastWindow[index] = now;
    } else {
      pirHitCount[index]++;
      pirLastWindow[index] = now;
      if (pirHitCount[index] >= PIR_REQUIRED_HITS) {
        pirHitCount[index] = 0;
        return true;
      }
    }
  }
  return false;
}

void requestBeep(int times) {
  if (!beepRequested) {
    beepCount = times * 2;
    beepRequested = true;
  }
}

void timerISR() {
  static bool buzzerState = false;
  static int intervalCounter = 0;

  if (beepRequested && beepCount > 0) {
    if (intervalCounter == 0) {
      buzzerState = !buzzerState;
      digitalWrite(buzzerPin, buzzerState);
      if (!buzzerState && --beepCount == 0)
        beepRequested = false;
      intervalCounter = 2;
    } else intervalCounter--;
  }
}

void activateAlarm() {
  if (!silentMode) {
    buzzerActive = true;
    digitalWrite(buzzerPin, HIGH);
  }
}

void updateStatusLEDs() {
  digitalWrite(ledArmedPin, systemArmed && !silentMode);
  digitalWrite(ledSilentPin, systemArmed && silentMode);
  digitalWrite(ledDisarmedPin, !systemArmed);
  for (int i = 0; i < NUM_SENSORS; i++) {
    digitalWrite(ledSensorPins[i], sensorLatched[i]);
  }
}

void resetSensorLEDs() {
  for (int i = 0; i < NUM_SENSORS; i++) {
    sensorLatched[i] = false;
    digitalWrite(ledSensorPins[i], LOW);
  }
  saveSensorLatchState();
}

void handleRemoteCommand(int key) {
  lcdBacklightState = true;
  lcdBacklightTimer = millis();
  lcd.backlight();

  switch (key) {
    case 0:
      if (!systemArmed || silentMode) {
        systemArmed = true;
        silentMode = false;
        sensorTriggered = false;
        resetSensorLEDs();
        saveSystemState();
        requestBeep(1);
        Serial.println("✅ دزدگیر فعال شد");
      }
      break;
    case 1:
      if (systemArmed) {
        systemArmed = false;
        silentMode = false;
        buzzerActive = false;
        sensorTriggered = false;
        digitalWrite(buzzerPin, LOW);
        saveSystemState();
        requestBeep(1);
        Serial.println("❌ دزدگیر غیرفعال شد");
      }
      break;
    case 2:
      if (!systemArmed || !silentMode) {
        systemArmed = true;
        silentMode = true;
        sensorTriggered = false;
        resetSensorLEDs();
        saveSystemState();
        requestBeep(1);
        Serial.println("🔇 دزدگیر فعال شد (سایلنت)");
      }
      break;
    case 3:
      if (buzzerActive) {
        buzzerActive = false;
        digitalWrite(buzzerPin, LOW);
        requestBeep(1);
        Serial.println("🛑 آژیر دستی خاموش شد");
      }
      break;
  }
  updateStatusLEDs();
}

void checkBattery() {
  int rawBattery = analogRead(batteryAnalogPin);
  float voltageBattery = (rawBattery * 5.0 / 1023.0) * batteryDividerRatio;

  if (!isCharging && voltageBattery < batteryStartCharge) {
    digitalWrite(batteryRelayPin, HIGH);
    isCharging = true;
    Serial.println("🔋 شارژ باتری شروع شد");
  } else if (isCharging && voltageBattery >= batteryStopCharge) {
    digitalWrite(batteryRelayPin, LOW);
    isCharging = false;
    Serial.println("✅ شارژ باتری متوقف شد");
  }

  float percentage = ((voltageBattery - 11.0) / (12.6 - 11.0)) * 100.0;
  percentage = constrain(percentage, 0, 100);
  int percentInt = round(percentage);

  if (percentInt != lastBatteryPercent) {
    lastBatteryPercent = percentInt;
    Serial.print("🔋 درصد شارژ باتری: ");
    Serial.print(percentInt);
    Serial.println(" %");
  }

  if (isCharging != lastChargingState) {
    lastChargingState = isCharging;
  }
}

void updateLCDStatus() {
  if (lcdSensorMsgActive) return;

  lcd.setCursor(0, 0);
  lcd.print("Mode: ");
  lcd.print(systemArmed ? (silentMode ? "Silent     " : "Active     ") : "Disarmed   ");
  lcd.print(" ");

  lcd.setCursor(0, 1);
  if (isCharging)
    lcd.print("Charging        ");
  else {
    lcd.print("Battery ");
    lcd.print(lastBatteryPercent);
    lcd.print("%       ");
  }
}

void setup() {
  wdt_enable(WDTO_8S);
  Serial.begin(9600);

  for (int i = 0; i < NUM_SENSORS; i++) {
    pinMode(sensorPins[i], INPUT);
    pinMode(ledSensorPins[i], OUTPUT);
  }

  for (int i = 0; i < NUM_REMOTE_KEYS; i++) pinMode(remotePins[i], INPUT);

  pinMode(buzzerPin, OUTPUT);
  pinMode(ledArmedPin, OUTPUT);
  pinMode(ledDisarmedPin, OUTPUT);
  pinMode(ledSilentPin, OUTPUT);
  pinMode(batteryRelayPin, OUTPUT);
  digitalWrite(batteryRelayPin, LOW);

  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Alarm System    ");
  lcd.setCursor(0, 1);
  lcd.print("Initializing... ");
  delay(1000);
  lcd.clear();

  Timer1.initialize(10000);
  Timer1.attachInterrupt(timerISR);

  loadSystemState();
  loadSensorLatchState();
  updateStatusLEDs();
  updateLCDStatus();
}

void loop() {
  wdt_reset();

  for (int i = 0; i < NUM_REMOTE_KEYS; i++) {
    if (digitalRead(remotePins[i]) == HIGH && !remoteLock[i]) {
      handleRemoteCommand(i);
      remoteLock[i] = true;
    } else if (digitalRead(remotePins[i]) == LOW) {
      remoteLock[i] = false;
    }
  }

  if (systemArmed) {
    for (int i = 0; i < NUM_SENSORS; i++) {
      if (isReliablePIR(i)) {
        sensorTriggered = true;
        lastMotionTime = millis();
        if (!silentMode) activateAlarm();

        if (!sensorLatched[i]) {
          sensorLatched[i] = true;
          saveSensorLatchState();
        }

        Serial.print("🚨 تحریک سنسور ");
        Serial.print(i + 1);
        Serial.println();

        updateStatusLEDs();

        lcd.clear();
        lcd.setCursor(0, 0);
        char line1[17];
        snprintf(line1, 17, "Sensor %d Triggered", i + 1);
        lcd.print(line1);
        lcd.setCursor(0, 1);
        lcd.print("Mode: ");
        lcd.print(silentMode ? "Silent     " : "Active     ");

        lcdSensorMsgTimer = millis();
        lcdSensorMsgActive = true;
      }
    }
  }

  if (buzzerActive && millis() - lastMotionTime > alarmDuration) {
    buzzerActive = false;
    digitalWrite(buzzerPin, LOW);
    Serial.println("🔕 آژیر خودکار قطع شد");
  }

  if (lcdSensorMsgActive && millis() - lcdSensorMsgTimer > LCD_SENSOR_MSG_DURATION) {
    lcdSensorMsgActive = false;
    lcd.clear();
    updateLCDStatus();
  }

  if (lcdBacklightState && millis() - lcdBacklightTimer > LCD_BACKLIGHT_TIMEOUT) {
    lcdBacklightState = false;
    lcd.noBacklight();
  }

  checkBattery();
  updateLCDStatus();
}