#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BMP085.h>
#include <math.h>
#include <LiquidCrystal.h>
#include <WiFi.h>
#include <ThingSpeak.h>

// =======================
// 📡 Wi-Fi Credentials (Optional - remove if not using ThingSpeak)
// =======================
const char* ssid = "YOUR_WIFI_SSID";
const char* password = "YOUR_WIFI_PASSWORD";

// =======================
// 📊 ThingSpeak Settings (Optional)
// =======================
unsigned long channelID = YOUR_CHANNEL_ID;
const char* apiKey = "YOUR_WRITE_API_KEY";
WiFiClient client;

// =======================
// 🔌 Pin Definitions (ESP32 for Wokwi)
// =======================

// HC-SR04 Ultrasonic
#define TRIG    33
#define ECHO    32

// Vibration Sensor (Potentiometer)
#define VIB     36

// Buzzer
#define BUZZER  17

// LCD Pins
#define LCD_RS  26
#define LCD_E   27
#define LCD_D4  18
#define LCD_D5  19
#define LCD_D6  23
#define LCD_D7  25

// Initialize LCD
LiquidCrystal lcd(LCD_RS, LCD_E, LCD_D4, LCD_D5, LCD_D6, LCD_D7);

// =======================
// 🌡️ BMP180 Sensor
// =======================
Adafruit_BMP085 bmp;

// =======================
// 📍 GPS Simulation Variables
// =======================
float latitude = 52.629567;
float longitude = 4.885383;

// =======================
// 📊 Sensor Variables
// =======================
int vibrationValue;
long duration;
float distance;
int16_t AcX, AcY, AcZ;
float angleX, angleY;
float temperature, pressure, altitude;

// =======================
// ⏱️ Timing
// =======================
unsigned long lastUploadTime = 0;
const unsigned long uploadInterval = 15000;

// =======================
// 🚨 Danger flag
// =======================
bool danger = false;

// =======================
// 🟢 SETUP
// =======================
void setup() {
  Serial.begin(115200);
  delay(1000);
  
  Serial.println("");
  Serial.println("=== SMART TANK TRUCK MONITORING SYSTEM ===");
  Serial.println("ESP32 Starting...");
  
  // Initialize pins
  pinMode(TRIG, OUTPUT);
  pinMode(ECHO, INPUT);
  pinMode(BUZZER, OUTPUT);
  
  // Initialize LCD
  lcd.begin(16, 2);
  lcd.print("System Init...");
  delay(2000);
  lcd.clear();
  
  // Initialize I2C
  Wire.begin();
  
  // Wake up MPU6050 (address 0x68)
  Wire.beginTransmission(0x68);
  Wire.write(0x6B);
  Wire.write(0);
  Wire.endTransmission(true);
  Serial.println("MPU6050 initialized");
  
  // Initialize BMP180 using Adafruit library
  if (!bmp.begin()) {
    lcd.clear();
    lcd.print("BMP180 ERROR!");
    Serial.println("BMP180 ERROR - Check wiring");
    while (1) {
      delay(1000);
    }
  }
  Serial.println("BMP180 initialized");
  
  // Optional: Connect to Wi-Fi (remove if not using ThingSpeak)
  lcd.clear();
  lcd.print("System Ready!");
  delay(1500);
  lcd.clear();
  
  // Initialize ThingSpeak (optional)
  // ThingSpeak.begin(client);
}

// =======================
// 🔵 READ ULTRASONIC DISTANCE
// =======================
float readUltrasonic() {
  digitalWrite(TRIG, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG, LOW);
  
  duration = pulseIn(ECHO, HIGH, 30000);
  
  if (duration == 0) {
    return 999;
  }
  
  return duration * 0.034 / 2;
}

// =======================
// 🟣 READ MPU6050 (Tilt Angles)
// =======================
void readMPU6050() {
  Wire.beginTransmission(0x68);
  Wire.write(0x3B);
  Wire.endTransmission(false);
  Wire.requestFrom(0x68, 6, true);
  
  AcX = Wire.read() << 8 | Wire.read();
  AcY = Wire.read() << 8 | Wire.read();
  AcZ = Wire.read() << 8 | Wire.read();
  
  angleX = atan(AcY / sqrt(pow(AcX, 2) + pow(AcZ, 2))) * 180 / PI;
  angleY = atan(-AcX / sqrt(pow(AcY, 2) + pow(AcZ, 2))) * 180 / PI;
}

// =======================
// 🟡 READ BMP180 (Using Adafruit Library - WORKS IN WOKWI!)
// =======================
void readBMP180() {
  temperature = bmp.readTemperature();    // Changes when you move BMP180 slider
  pressure = bmp.readPressure();          // Changes when you move BMP180 slider
  altitude = bmp.readAltitude();          // Calculated from pressure
}

// =======================
// 🟢 UPDATE GPS SIMULATION
// =======================
void updateGPS() {
  latitude += 0.00001;
  longitude += 0.00001;
}

// =======================
// 🧠 DECISION LOGIC (Adjusted for ESP32 12-bit ADC)
// =======================
void evaluateDanger() {
  danger = false;
  
  if (distance < 50) {
    danger = true;
    Serial.println("⚠️ DANGER: Collision imminent!");
  }
  
  // ESP32 ADC is 12-bit (0-4095). 2800 ≈ 68% of max (same as 700 on 10-bit)
  if (vibrationValue > 2800) {
    danger = true;
    Serial.println("⚠️ DANGER: High vibration detected!");
  }
  
  if (abs(angleX) > 30 || abs(angleY) > 30) {
    danger = true;
    Serial.println("⚠️ DANGER: Rollover risk! Tilt angle >30°");
  }
  
  if (pressure < 60000) {
    danger = true;
    Serial.println("⚠️ DANGER: Low pressure detected!");
  }
}

// =======================
// 🔊 CONTROL BUZZER
// =======================
void controlBuzzer() {
  if (danger) {
    tone(BUZZER, 1000);
  } else {
    noTone(BUZZER);
  }
}

// =======================
// 📟 UPDATE LCD DISPLAY
// =======================
void updateLCD() {
  lcd.clear();
  
  lcd.setCursor(0, 0);
  lcd.print("D:");
  lcd.print((int)distance);
  lcd.print("cm T:");
  lcd.print((int)temperature);
  lcd.print("C");
  
  lcd.setCursor(0, 1);
  lcd.print("P:");
  lcd.print((int)(pressure / 100));
  lcd.print("hPa ALT:");
  lcd.print((int)altitude);
  lcd.print("m");
}

// =======================
// 📤 UPLOAD TO THINGSPEAK (Optional)
// =======================
void uploadToThingSpeak() {
  // Uncomment if using ThingSpeak
  /*
  ThingSpeak.setField(1, distance);
  ThingSpeak.setField(2, vibrationValue);
  ThingSpeak.setField(3, angleX);
  ThingSpeak.setField(4, angleY);
  ThingSpeak.setField(5, temperature);
  ThingSpeak.setField(6, pressure / 100);
  ThingSpeak.setField(7, altitude);
  ThingSpeak.setField(8, danger ? 1 : 0);
  ThingSpeak.writeFields(channelID, apiKey);
  */
}

// =======================
// 🖨️ SERIAL DEBUG OUTPUT
// =======================
void serialDebug() {
  Serial.print("DIST:");
  Serial.print(distance);
  Serial.print(",VIB:");
  Serial.print(vibrationValue);
  Serial.print(",AX:");
  Serial.print(angleX);
  Serial.print(",AY:");
  Serial.print(angleY);
  Serial.print(",TEMP:");
  Serial.print(temperature);
  Serial.print(",PRES:");
  Serial.print(pressure);
  Serial.print(",ALT:");
  Serial.print(altitude);
  Serial.print(",LAT:");
  Serial.print(latitude, 6);
  Serial.print(",LON:");
  Serial.print(longitude, 6);
  Serial.print(",ALERT:");
  Serial.print(danger ? "YES" : "NO");
  Serial.println();
}

// =======================
// 🔄 MAIN LOOP
// =======================
void loop() {
  distance = readUltrasonic();
  vibrationValue = analogRead(VIB);
  readMPU6050();
  readBMP180();      // Now reads actual BMP180 values from Wokwi!
  updateGPS();
  
  evaluateDanger();
  controlBuzzer();
  updateLCD();
  serialDebug();
  
  // Optional ThingSpeak upload
  // if (millis() - lastUploadTime >= uploadInterval) {
  //   uploadToThingSpeak();
  //   lastUploadTime = millis();
  // }
  
  delay(200);
}