#define BLYNK_TEMPLATE_ID "TMPL5gSEQ64Uf"
#define BLYNK_TEMPLATE_NAME "Smart Fire Detector"
#define BLYNK_AUTH_TOKEN "9Cj5smxpz9WfT6pvI38KKxlz3FtoQyiN"

#include <WiFi.h>
#include <BlynkSimpleEsp32.h>
#include <DHTesp.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// Firebase Includes
#include <FirebaseESP32.h>
#include <WiFiClientSecure.h>
#include "addons/TokenHelper.h"
#include "addons/RTDBHelper.h"

// Firebase Configuration
#define DATABASE_URL "https://smartfiredetection-10df0-default-rtdb.firebaseio.com"
#define DATABASE_SECRET "3L2oFshye7sggdAHUTtZ03hAzQ3iGutGD4TJjVwJ"

FirebaseData fbdo;
FirebaseAuth auth;
FirebaseConfig config;

char ssid[] = "Wokwi-GUEST";
char pass[] = "";

// Pin Definitions
#define DHTPIN 21
#define GAS_SENSOR_PIN 34
#define FLAME_SENSOR_PIN 33
#define BUZZER_PIN 5
#define LED_ANODE_PIN 18
#define LED_CATHODE_PIN 19
#define POWER_SENSOR_PIN 35

#define TEMP_THRESHOLD 57.0
#define GAS_THRESHOLD 3000
#define HUMIDITY_THRESHOLD 80.0
#define FLAME_THRESHOLD 2000
#define POWER_THRESHOLD 1000

DHTesp dht;
LiquidCrystal_I2C lcd(0x27, 16, 2);

bool manualOverride = false;
float simTemperature = 24.0;
float simHumidity = 40.0;
int simGasValue = 1500;
int simFlameValue = LOW;
bool gasInitialized = false;

unsigned long previousBlinkTime = 0;
bool alarmState = LOW;
const unsigned long blinkInterval = 500;

String zoneStatus[3] = {"Safe", "Safe", "Safe"};
unsigned long dangerStartTime = 0;
const unsigned long dangerHoldDuration = 10000;
bool previousFireDetected = false;
int lastDangerZone = -1;

BLYNK_WRITE(V4) {
  manualOverride = param.asInt();
  Serial.println(manualOverride ? "✅ Manual override ENABLED from app" : "🔄 Manual override DISABLED from app");
}

void setup() {
  Serial.begin(115200);
  dht.setup(DHTPIN, DHTesp::DHT22);

  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(LED_ANODE_PIN, OUTPUT);
  pinMode(LED_CATHODE_PIN, OUTPUT);
  pinMode(POWER_SENSOR_PIN, INPUT);

  digitalWrite(BUZZER_PIN, LOW);
  digitalWrite(LED_ANODE_PIN, LOW);
  digitalWrite(LED_CATHODE_PIN, LOW);

  Wire.begin(23, 22);
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Fire Detector");
  delay(1500);
  lcd.clear();

  Blynk.begin(BLYNK_AUTH_TOKEN, ssid, pass);
  Serial.println("🔥 Fire Detection System with Blynk Started");

  // Firebase Config
  config.database_url = DATABASE_URL;
  config.signer.tokens.legacy_token = DATABASE_SECRET;
  Firebase.begin(&config, &auth);
  Firebase.reconnectWiFi(true);
  Serial.println("✅ Firebase Initialized");
}

void assignStableDangerZone(bool fireDetected) {
  if (!fireDetected) {
    if (previousFireDetected) {
      for (int i = 0; i < 3; i++) zoneStatus[i] = "Safe";
      lastDangerZone = -1;
    }
    previousFireDetected = false;
    return;
  }

  if (previousFireDetected && (millis() - dangerStartTime < dangerHoldDuration)) {
    for (int i = 0; i < 3; i++) {
      zoneStatus[i] = (i == lastDangerZone) ? "Danger" : "Safe";
    }
    return;
  }

  lastDangerZone = random(0, 3);
  dangerStartTime = millis();
  previousFireDetected = true;

  for (int i = 0; i < 3; i++) {
    zoneStatus[i] = (i == lastDangerZone) ? "Danger" : "Safe";
  }

  Serial.println("⚠️ Fire hazard in Zone " + String(char('A' + lastDangerZone)));
}

void sendZoneStatusToBlynk() {
  for (int i = 0; i < 3; i++) {
    String zoneLabel = "Zone " + String(char('A' + i)) + ": " + zoneStatus[i];
    Blynk.virtualWrite(V6 + i, zoneLabel);
    Blynk.virtualWrite(V10 + i, zoneStatus[i] == "Safe" ? 0 : 1);
  }
}

void recommendEvacuationPath(bool fireDetected) {
  if (!fireDetected) {
    Blynk.virtualWrite(V9, "✅ All Zones Safe");
    return;
  }

  String safeZones = "";
  for (int i = 0; i < 3; i++) {
    if (zoneStatus[i] == "Safe") {
      safeZones += String(char('A' + i)) + " ";
    }
  }

  if (safeZones.length() > 0) {
    Blynk.virtualWrite(V9, "🏃 Evacuate to Zone(s): " + safeZones);
  } else {
    Blynk.virtualWrite(V9, "❌ All zones unsafe! Stay put & wait for help");
  }
}

void updateLCD() {
  lcd.clear();
  if (lastDangerZone != -1) {
    lcd.setCursor(0, 0);
    lcd.print("Danger: Zone ");
    lcd.print((char)('A' + lastDangerZone));
    lcd.setCursor(0, 1);
    lcd.print("Safe: ");
    for (int i = 0; i < 3; i++) {
      if (i != lastDangerZone) {
        lcd.print((char)('A' + i));
        lcd.print(" ");
      }
    }
  } else {
    lcd.setCursor(0, 0);
    lcd.print("System Normal");
    lcd.setCursor(0, 1);
    lcd.print("All Zones Safe");
  }
}

void checkPowerLoss() {
  int powerValue = analogRead(POWER_SENSOR_PIN);
  bool powerLoss = powerValue < POWER_THRESHOLD;

  Serial.print("🔋 Power level: ");
  Serial.println(powerValue);

  if (powerLoss) {
    Blynk.virtualWrite(V4, "⚠️ Power Loss Detected!");
  } else {
    Blynk.virtualWrite(V4, "🔋 Power OK");
  }
}

void reconnectWiFi() {
  if (WiFi.status() != WL_CONNECTED) {
    Serial.println("🔌 WiFi disconnected, trying to reconnect...");
    WiFi.disconnect();
    WiFi.begin(ssid, pass);
  }
}

void uploadToFirebase(float temp, float hum, int gas, int flame, bool fireDetected) {
  Firebase.setFloat(fbdo, "/temperature", temp);
  Firebase.setFloat(fbdo, "/humidity", hum);
  Firebase.setInt(fbdo, "/gasValue", gas);
  Firebase.setInt(fbdo, "/flameDetected", flame);
  Firebase.setBool(fbdo, "/fireDetected", fireDetected);
  Firebase.setString(fbdo, "/zoneA", zoneStatus[0]);
  Firebase.setString(fbdo, "/zoneB", zoneStatus[1]);
  Firebase.setString(fbdo, "/zoneC", zoneStatus[2]);
}

void loop() {
  Blynk.run();
  reconnectWiFi();

  float temperature, humidity;
  int gasValue, flameDetected;

  if (manualOverride) {
    temperature = simTemperature;
    humidity = simHumidity;
    gasValue = simGasValue;
    flameDetected = simFlameValue;
  } else {
    TempAndHumidity data = dht.getTempAndHumidity();
    temperature = isnan(data.temperature) ? 25.0 : data.temperature;
    humidity = isnan(data.humidity) ? 50.0 : data.humidity;

    int rawGas = analogRead(GAS_SENSOR_PIN);
    if (!gasInitialized) {
      gasValue = 1500;
      gasInitialized = true;
    } else {
      gasValue = rawGas;
    }

    int flameAnalog = analogRead(FLAME_SENSOR_PIN);
    flameDetected = (flameAnalog > FLAME_THRESHOLD) ? HIGH : LOW;
  }

  Serial.printf("🌡 Temp: %.2f°C | 💧 Humidity: %.2f%% | 🧪 Gas: %d | 🔥 Flame: %s\n",
                temperature, humidity, gasValue, flameDetected == HIGH ? "Yes" : "No");

  Blynk.virtualWrite(V0, temperature);
  Blynk.virtualWrite(V1, humidity);
  Blynk.virtualWrite(V2, gasValue);
  Blynk.virtualWrite(V3, flameDetected == HIGH ? 1 : 0);

  bool fireDetected = (temperature > TEMP_THRESHOLD) || (gasValue > GAS_THRESHOLD) ||
                      (flameDetected == HIGH) || (humidity > HUMIDITY_THRESHOLD);

  assignStableDangerZone(fireDetected);
  sendZoneStatusToBlynk();
  recommendEvacuationPath(fireDetected);
  updateLCD();
  checkPowerLoss();

  // Firebase upload
  uploadToFirebase(temperature, humidity, gasValue, flameDetected, fireDetected);

  if (fireDetected) {
    Blynk.virtualWrite(V5, "🚨 FIRE DETECTED! Please check immediately!");
    unsigned long currentMillis = millis();
    if (currentMillis - previousBlinkTime >= blinkInterval) {
      previousBlinkTime = currentMillis;
      alarmState = !alarmState;
      if (alarmState) {
        tone(BUZZER_PIN, 1000);
        digitalWrite(LED_ANODE_PIN, HIGH);
        digitalWrite(LED_CATHODE_PIN, LOW);
      } else {
        noTone(BUZZER_PIN);
        digitalWrite(LED_ANODE_PIN, LOW);
        digitalWrite(LED_CATHODE_PIN, LOW);
      }
    }
  } else {
    noTone(BUZZER_PIN);
    digitalWrite(LED_ANODE_PIN, LOW);
    digitalWrite(LED_CATHODE_PIN, LOW);
    alarmState = LOW;
    Blynk.virtualWrite(V5, "Safe");
  }

  delay(500);
}