/*
 * Smart Waste Management - IoT Sensor Simulation
 * Wokwi ESP32 Integration with Ultrasonic Sensor
 * Sends data to FastAPI backend via HTTP POST
 */

#include <WiFi.h>
#include <HTTPClient.h>
#include <ArduinoJson.h>

// WiFi credentials (Wokwi simulation)
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// Backend API endpoint (will be replaced with ngrok URL)
String serverURL = "https://noncalculative-javion-unquoted.ngrok-free.dev/api/v1/iot/sensor-data";
http.begin(serverName);
http.addHeader("ngrok-skip-browser-warning", "true"); // Αυτό παρακάμπτει τη σελίδα της ngrok
int httpResponseCode = http.GET();
// Sensor pins
const int trigPin = 5;
const int echoPin = 18;
const int ledPin = 2;

// Bin configuration
const String BIN_ID = "WOKWI_BIN_001";
const String SENSOR_ID = "ULTRASONIC_HC_SR04";
const float BIN_HEIGHT_CM = 100.0; // Total bin height in cm

// Timing
unsigned long lastReading = 0;
const unsigned long READING_INTERVAL = 30000; // 30 seconds

void setup() {
  Serial.begin(115200);
  
  // Initialize pins
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(ledPin, OUTPUT);
  
  // Connect to WiFi
  WiFi.begin(ssid, password);
  Serial.print("Connecting to WiFi");
  
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  
  Serial.println();
  Serial.println("✅ WiFi connected!");
  Serial.print("📡 IP address: ");
  Serial.println(WiFi.localIP());
  Serial.println("🗑️ Smart Waste Sensor Ready");
  Serial.println("📊 Sending data to: " + serverURL);
  Serial.println("--------------------------------------------------");
  
  // Initial LED blink
  for(int i = 0; i < 3; i++) {
    digitalWrite(ledPin, HIGH);
    delay(200);
    digitalWrite(ledPin, LOW);
    delay(200);
  }
}

void loop() {
  unsigned long currentTime = millis();
  
  if (currentTime - lastReading >= READING_INTERVAL) {
    // Read ultrasonic sensor
    float distance = readUltrasonicSensor();
    
    if (distance > 0) {
      // Calculate fill level percentage
      float fillLevel = calculateFillLevel(distance);
      
      // Read additional sensor data
      float temperature = 20.0 + random(-5, 15); // Simulated temperature
      float humidity = 45.0 + random(-10, 20);   // Simulated humidity
      float batteryLevel = 85.0 + random(-5, 15); // Simulated battery
      float signalStrength = -45.0 + random(-15, 10); // Simulated RSSI
      
      // Send data to backend
      sendSensorData(distance, fillLevel, temperature, humidity, batteryLevel, signalStrength);
      
      // Update LED based on fill level
      updateStatusLED(fillLevel);
      
      lastReading = currentTime;
    }
  }
  
  delay(1000); // Small delay for stability
}

float readUltrasonicSensor() {
  // Clear trigger pin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  
  // Send 10us pulse
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  // Read echo pin
  long duration = pulseIn(echoPin, HIGH, 30000); // 30ms timeout
  
  if (duration == 0) {
    Serial.println("⚠️ Sensor timeout");
    return -1;
  }
  
  // Calculate distance in cm
  float distance = (duration * 0.034) / 2;
  
  Serial.print("📏 Distance: ");
  Serial.print(distance);
  Serial.println(" cm");
  
  return distance;
}

float calculateFillLevel(float distance) {
  // Fill level = (bin_height - distance) / bin_height * 100
  float fillLevel = ((BIN_HEIGHT_CM - distance) / BIN_HEIGHT_CM) * 100.0;
  
  // Constrain between 0-100%
  fillLevel = constrain(fillLevel, 0.0, 100.0);
  
  Serial.print("📊 Fill Level: ");
  Serial.print(fillLevel);
  Serial.println("%");
  
  return fillLevel;
}

void sendSensorData(float distance, float fillLevel, float temperature, float humidity, float batteryLevel, float signalStrength) {
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    http.begin(serverURL);
    http.addHeader("Content-Type", "application/json");
    
    // Create JSON payload
    StaticJsonDocument<512> doc;
    doc["bin_id"] = BIN_ID;
    doc["sensor_id"] = SENSOR_ID;
    doc["fill_level"] = fillLevel;
    doc["distance_cm"] = distance;
    doc["temperature"] = temperature;
    doc["humidity"] = humidity;
    doc["battery_level"] = batteryLevel;
    doc["signal_strength"] = signalStrength;
    doc["voltage"] = 3.3;
    doc["device_type"] = "wokwi_esp32";
    doc["firmware_version"] = "1.0.0";
    
    String jsonString;
    serializeJson(doc, jsonString);
    
    Serial.println("📡 Sending data to backend...");
    Serial.println("📦 Payload: " + jsonString);
    
    int httpResponseCode = http.POST(jsonString);
    
    if (httpResponseCode > 0) {
      String response = http.getString();
      Serial.print("✅ HTTP Response: ");
      Serial.println(httpResponseCode);
      Serial.println("📥 Response: " + response);
    } else {
      Serial.print("❌ HTTP Error: ");
      Serial.println(httpResponseCode);
    }
    
    http.end();
  } else {
    Serial.println("❌ WiFi not connected");
  }
}

void updateStatusLED(float fillLevel) {
  if (fillLevel >= 90) {
    // Critical - Fast blink
    for(int i = 0; i < 5; i++) {
      digitalWrite(ledPin, HIGH);
      delay(100);
      digitalWrite(ledPin, LOW);
      delay(100);
    }
  } else if (fillLevel >= 70) {
    // Warning - Slow blink
    digitalWrite(ledPin, HIGH);
    delay(500);
    digitalWrite(ledPin, LOW);
    delay(500);
  } else {
    // Normal - Solid on for 1 second
    digitalWrite(ledPin, HIGH);
    delay(1000);
    digitalWrite(ledPin, LOW);
  }
}