/*
 * ESP32 Smart Doorbell with Notifications
 * 
 * Features:
 * - Doorbell button with debouncing
 * - PIR motion detection
 * - Camera simulation (visitor detection)
 * - Multi-tone doorbell chime
 * - OLED display with visitor info
 * - RGB LED status indicator
 * - Web dashboard for monitoring
 * - Real-time notifications (Email/SMS simulation)
 * - Visitor log with timestamps
 * - Remote door monitoring
 * - Night mode (motion-activated light)
 * - Two-way communication simulation
 */

#include <WiFi.h>
#include <WebServer.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

// WiFi Credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// Web Server
WebServer server(80);

// Pin Definitions
#define DOORBELL_BUTTON_PIN 14   // Doorbell push button
#define PIR_SENSOR_PIN 13        // Motion sensor
#define BUZZER_PIN 25            // Doorbell chime
#define RED_LED_PIN 26           // RGB Red
#define GREEN_LED_PIN 27         // RGB Green
#define BLUE_LED_PIN 12          // RGB Blue
#define CAMERA_TRIGGER_PIN 33    // Camera simulation
#define RELAY_DOOR_PIN 32        // Door lock relay
#define LIGHT_SENSOR_PIN 34      // Light sensor (day/night)

// OLED Display
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// System State
struct DoorbellState {
  int visitorCount;
  unsigned long lastRingTime;
  bool motionDetected;
  bool nightMode;
  bool doorbellPressed;
  String lastVisitorTime;
  int lightLevel;
  bool cameraActive;
  bool doorLocked;
};

DoorbellState doorbell;

// Visitor Log
struct VisitorLog {
  String timestamp;
  String event;        // "Ring", "Motion", "Camera"
  bool notificationSent;
};

VisitorLog visitorHistory[20];
int historyIndex = 0;

// Button debouncing
unsigned long lastDebounceTime = 0;
unsigned long debounceDelay = 50;
int lastButtonState = HIGH;
int buttonState = HIGH;

// Timing
unsigned long lastMotionCheck = 0;
unsigned long lastDisplayUpdate = 0;
const long motionCheckInterval = 500;
const long displayUpdateInterval = 100;

// Doorbell melodies
const int melody1[] = {523, 587, 659, 784};  // C, D, E, G
const int melody2[] = {784, 659, 523};       // G, E, C
const int noteDurations[] = {200, 200, 200, 400};

void setup() {
  Serial.begin(115200);
  
  // Initialize pins
  pinMode(DOORBELL_BUTTON_PIN, INPUT_PULLUP);
  pinMode(PIR_SENSOR_PIN, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(RED_LED_PIN, OUTPUT);
  pinMode(GREEN_LED_PIN, OUTPUT);
  pinMode(BLUE_LED_PIN, OUTPUT);
  pinMode(CAMERA_TRIGGER_PIN, OUTPUT);
  pinMode(RELAY_DOOR_PIN, OUTPUT);
  pinMode(LIGHT_SENSOR_PIN, INPUT);
  
  // Initialize OLED
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("OLED failed"));
  } else {
    display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(SSD1306_WHITE);
    display.setCursor(0, 0);
    display.println("SMART DOORBELL");
    display.println("");
    display.println("Initializing...");
    display.display();
    delay(2000);
  }
  
  // Initialize state
  doorbell.visitorCount = 0;
  doorbell.lastRingTime = 0;
  doorbell.motionDetected = false;
  doorbell.nightMode = false;
  doorbell.doorbellPressed = false;
  doorbell.lastVisitorTime = "None";
  doorbell.lightLevel = 0;
  doorbell.cameraActive = false;
  doorbell.doorLocked = true;
  
  // Initial door lock state
  digitalWrite(RELAY_DOOR_PIN, HIGH);
  
  // Connect to WiFi
  WiFi.begin(ssid, password);
  Serial.print("Connecting to WiFi");
  
  display.clearDisplay();
  display.setCursor(0, 0);
  display.println("Connecting WiFi...");
  display.display();
  
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  
  Serial.println("\n✓ WiFi connected!");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
  
  // Setup web server routes
  server.on("/", handleRoot);
  server.on("/status", handleStatus);
  server.on("/history", handleHistory);
  server.on("/ring", handleTestRing);
  server.on("/unlock", handleUnlock);
  server.on("/lock", handleLock);
  server.on("/camera", handleCamera);
  server.on("/clear", handleClear);
  
  server.begin();
  Serial.println("✓ Web server started!");
  
  Serial.println("\n╔═══════════════════════════════════╗");
  Serial.println("║   SMART DOORBELL SYSTEM ONLINE   ║");
  Serial.println("╚═══════════════════════════════════╝");
  Serial.print("Dashboard: http://");
  Serial.println(WiFi.localIP());
  Serial.println();
  
  // Ready indicator
  setRGBColor(0, 255, 0); // Green
  playStartupChime();
  delay(500);
  setRGBColor(0, 0, 0); // Off
  
  updateDisplay();
}

void loop() {
  server.handleClient();
  
  unsigned long currentMillis = millis();
  
  // Check doorbell button
  checkDoorbellButton();
  
  // Check motion sensor
  if (currentMillis - lastMotionCheck >= motionCheckInterval) {
    lastMotionCheck = currentMillis;
    checkMotionSensor();
    checkLightLevel();
  }
  
  // Update display
  if (currentMillis - lastDisplayUpdate >= displayUpdateInterval) {
    lastDisplayUpdate = currentMillis;
    updateDisplay();
  }
}

void checkDoorbellButton() {
  int reading = digitalRead(DOORBELL_BUTTON_PIN);
  
  if (reading != lastButtonState) {
    lastDebounceTime = millis();
  }
  
  if ((millis() - lastDebounceTime) > debounceDelay) {
    if (reading != buttonState) {
      buttonState = reading;
      
      // Button pressed (LOW because of INPUT_PULLUP)
      if (buttonState == LOW) {
        handleDoorbellRing();
      }
    }
  }
  
  lastButtonState = reading;
}

void handleDoorbellRing() {
  doorbell.doorbellPressed = true;
  doorbell.visitorCount++;
  doorbell.lastRingTime = millis();
  doorbell.lastVisitorTime = getTimestamp();
  
  Serial.println("\n╔═══════════════════════════════════╗");
  Serial.println("║        🔔 DOORBELL RANG! 🔔      ║");
  Serial.println("╚═══════════════════════════════════╝");
  Serial.print("Visitor #");
  Serial.println(doorbell.visitorCount);
  Serial.print("Time: ");
  Serial.println(doorbell.lastVisitorTime);
  
  // Log event
  logVisitor("Doorbell Ring");
  
  // Visual indicator
  setRGBColor(0, 0, 255); // Blue
  
  // Activate camera
  activateCamera();
  
  // Play doorbell chime
  playDoorbellChime();
  
  // Send notification
  sendNotification("DOORBELL", "Someone is at your door!");
  
  // Flash display
  flashDisplay("VISITOR AT DOOR!");
  
  delay(500);
  setRGBColor(0, 0, 0); // Off
  
  doorbell.doorbellPressed = false;
}

void checkMotionSensor() {
  bool motion = digitalRead(PIR_SENSOR_PIN);
  
  if (motion && !doorbell.motionDetected) {
    doorbell.motionDetected = true;
    
    Serial.println("👁️ Motion detected at front door");
    
    // Log event
    logVisitor("Motion Detected");
    
    // Visual indicator
    setRGBColor(255, 255, 0); // Yellow
    
    // If night mode, turn on light
    if (doorbell.nightMode) {
      Serial.println("🌙 Night mode - Activating light");
      setRGBColor(255, 255, 255); // White (light)
    }
    
    // Activate camera for motion
    activateCamera();
    
    // Send motion notification
    sendNotification("MOTION", "Motion detected at front door");
    
    delay(1000);
    setRGBColor(0, 0, 0);
  } else if (!motion && doorbell.motionDetected) {
    doorbell.motionDetected = false;
  }
}

void checkLightLevel() {
  int lightRaw = analogRead(LIGHT_SENSOR_PIN);
  doorbell.lightLevel = map(lightRaw, 0, 4095, 0, 100);
  
  // Detect night (less than 30% light)
  if (doorbell.lightLevel < 30 && !doorbell.nightMode) {
    doorbell.nightMode = true;
    Serial.println("🌙 Night mode activated");
  } else if (doorbell.lightLevel >= 30 && doorbell.nightMode) {
    doorbell.nightMode = false;
    Serial.println("☀️ Day mode activated");
  }
}

void activateCamera() {
  doorbell.cameraActive = true;
  digitalWrite(CAMERA_TRIGGER_PIN, HIGH);
  
  Serial.println("📷 Camera activated - Capturing image");
  Serial.println("📸 Image saved: visitor_" + String(doorbell.visitorCount) + ".jpg");
  
  delay(2000); // Simulate capture time
  
  digitalWrite(CAMERA_TRIGGER_PIN, LOW);
  doorbell.cameraActive = false;
}

void playDoorbellChime() {
  // Pleasant doorbell melody
  for (int i = 0; i < 4; i++) {
    tone(BUZZER_PIN, melody1[i], noteDurations[i]);
    delay(noteDurations[i] + 50);
  }
  noTone(BUZZER_PIN);
}

void playStartupChime() {
  tone(BUZZER_PIN, 1000, 100);
  delay(150);
  tone(BUZZER_PIN, 1500, 100);
}

void setRGBColor(int red, int green, int blue) {
  analogWrite(RED_LED_PIN, red);
  analogWrite(GREEN_LED_PIN, green);
  analogWrite(BLUE_LED_PIN, blue);
}

void updateDisplay() {
  display.clearDisplay();
  display.setTextSize(1);
  display.setCursor(0, 0);
  
  // Title
  display.println("SMART DOORBELL");
  display.drawLine(0, 9, 128, 9, SSD1306_WHITE);
  
  // Status
  display.setCursor(0, 12);
  display.print("Visitors: ");
  display.println(doorbell.visitorCount);
  
  display.setCursor(0, 22);
  display.print("Last: ");
  display.println(doorbell.lastVisitorTime);
  
  display.setCursor(0, 32);
  if (doorbell.motionDetected) {
    display.println("MOTION DETECTED!");
  } else {
    display.print("Motion: None");
  }
  
  display.setCursor(0, 42);
  display.print("Door: ");
  display.println(doorbell.doorLocked ? "LOCKED" : "UNLOCKED");
  
  display.setCursor(0, 52);
  if (doorbell.nightMode) {
    display.print("Night Mode");
  } else {
    display.print("Day Mode");
  }
  
  if (doorbell.cameraActive) {
    display.setCursor(80, 52);
    display.print("CAM ON");
  }
  
  display.display();
}

void flashDisplay(String message) {
  for (int i = 0; i < 3; i++) {
    display.clearDisplay();
    display.setTextSize(2);
    display.setCursor(0, 20);
    display.println(message);
    display.display();
    delay(500);
    
    display.clearDisplay();
    display.display();
    delay(300);
  }
}

void sendNotification(String type, String message) {
  Serial.println("\n╔═══════════════════════════════════╗");
  Serial.println("║    📱 NOTIFICATION SENT 📱       ║");
  Serial.println("╠═══════════════════════════════════╣");
  Serial.print("║ Type: ");
  Serial.println(type);
  Serial.print("║ Message: ");
  Serial.println(message);
  Serial.println("║                                   ║");
  Serial.println("║ ✉️  Email: [email protected]      ║");
  Serial.println("║ 📱 SMS: +1-234-567-8900          ║");
  Serial.println("║ 🔔 Push: Mobile App              ║");
  Serial.println("╚═══════════════════════════════════╝\n");
}

void logVisitor(String event) {
  visitorHistory[historyIndex].timestamp = getTimestamp();
  visitorHistory[historyIndex].event = event;
  visitorHistory[historyIndex].notificationSent = true;
  
  historyIndex = (historyIndex + 1) % 20;
}

String getTimestamp() {
  unsigned long seconds = millis() / 1000;
  unsigned long minutes = seconds / 60;
  unsigned long hours = minutes / 60;
  
  seconds = seconds % 60;
  minutes = minutes % 60;
  hours = hours % 24;
  
  String timestamp = "";
  if (hours < 10) timestamp += "0";
  timestamp += String(hours) + ":";
  if (minutes < 10) timestamp += "0";
  timestamp += String(minutes) + ":";
  if (seconds < 10) timestamp += "0";
  timestamp += String(seconds);
  
  return timestamp;
}

// Web Server Handlers
void handleRoot() {
  String html = "<!DOCTYPE html><html><head>";
  html += "<meta name='viewport' content='width=device-width,initial-scale=1'>";
  html += "<meta http-equiv='refresh' content='3'>";
  html += "<title>Smart Doorbell</title>";
  html += "<style>";
  html += "body{margin:0;font-family:Arial;background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;padding:20px}";
  html += ".container{max-width:1000px;margin:0 auto}";
  html += "h1{text-align:center;font-size:2.5em;margin-bottom:10px;text-shadow:2px 2px 4px rgba(0,0,0,0.3)}";
  html += ".subtitle{text-align:center;opacity:0.9;margin-bottom:30px}";
  html += ".stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:15px;margin-bottom:30px}";
  html += ".stat{background:rgba(255,255,255,0.2);padding:20px;border-radius:10px;text-align:center}";
  html += ".stat-value{font-size:2.5em;font-weight:bold}";
  html += ".stat-label{font-size:0.9em;opacity:0.8;margin-top:5px}";
  html += ".card{background:rgba(255,255,255,0.15);backdrop-filter:blur(10px);padding:25px;border-radius:15px;margin-bottom:20px;border:1px solid rgba(255,255,255,0.18)}";
  html += ".status-item{display:flex;justify-content:space-between;padding:10px;border-bottom:1px solid rgba(255,255,255,0.1)}";
  html += ".status-indicator{display:inline-block;width:15px;height:15px;border-radius:50%;margin-right:10px}";
  html += ".on{background:#4CAF50;box-shadow:0 0 10px #4CAF50}";
  html += ".off{background:#666}";
  html += ".btn{padding:15px 30px;border:none;border-radius:8px;cursor:pointer;font-size:1em;margin:5px;color:#fff;text-decoration:none;display:inline-block;font-weight:600}";
  html += ".btn-primary{background:#2196F3}";
  html += ".btn-success{background:#4CAF50}";
  html += ".btn-danger{background:#f44336}";
  html += ".btn-warning{background:#ff9800}";
  html += ".controls{text-align:center;margin-top:20px}";
  html += ".event-log{max-height:300px;overflow-y:auto;background:rgba(0,0,0,0.2);padding:15px;border-radius:10px}";
  html += ".event-item{padding:10px;border-left:3px solid #2196F3;margin-bottom:10px;background:rgba(255,255,255,0.1)}";
  html += ".camera-view{background:#000;height:200px;border-radius:10px;display:flex;align-items:center;justify-content:center;margin:20px 0;border:2px solid rgba(255,255,255,0.3)}";
  html += "</style></head><body>";
  html += "<div class='container'>";
  
  html += "<h1>🔔 Smart Doorbell</h1>";
  html += "<div class='subtitle'>Remote Monitoring Dashboard</div>";
  
  // Stats
  html += "<div class='stats'>";
  
  html += "<div class='stat'>";
  html += "<div class='stat-value'>" + String(doorbell.visitorCount) + "</div>";
  html += "<div class='stat-label'>👥 Total Visitors</div>";
  html += "</div>";
  
  html += "<div class='stat'>";
  html += "<div class='stat-value'>" + doorbell.lastVisitorTime + "</div>";
  html += "<div class='stat-label'>🕐 Last Activity</div>";
  html += "</div>";
  
  html += "<div class='stat'>";
  html += "<div class='stat-value'>" + String(doorbell.lightLevel) + "%</div>";
  html += "<div class='stat-label'>💡 Light Level</div>";
  html += "</div>";
  
  html += "</div>";
  
  // Camera View
  html += "<div class='card'>";
  html += "<h3>📷 Camera View</h3>";
  html += "<div class='camera-view'>";
  if (doorbell.cameraActive) {
    html += "<div>📹 RECORDING...</div>";
  } else if (doorbell.motionDetected) {
    html += "<div>👁️ MOTION DETECTED</div>";
  } else {
    html += "<div>No Activity</div>";
  }
  html += "</div>";
  html += "<button onclick=\"window.location='/camera'\" class='btn btn-primary'>📸 Capture Photo</button>";
  html += "</div>";
  
  // System Status
  html += "<div class='card'>";
  html += "<h3>⚙️ System Status</h3>";
  
  html += "<div class='status-item'>";
  html += "<span><span class='status-indicator " + String(doorbell.motionDetected ? "on" : "off") + "'></span>Motion Sensor</span>";
  html += "<span>" + String(doorbell.motionDetected ? "ACTIVE" : "Standby") + "</span>";
  html += "</div>";
  
  html += "<div class='status-item'>";
  html += "<span><span class='status-indicator " + String(doorbell.cameraActive ? "on" : "off") + "'></span>Camera</span>";
  html += "<span>" + String(doorbell.cameraActive ? "RECORDING" : "Ready") + "</span>";
  html += "</div>";
  
  html += "<div class='status-item'>";
  html += "<span><span class='status-indicator " + String(doorbell.doorLocked ? "on" : "off") + "'></span>Door Lock</span>";
  html += "<span>" + String(doorbell.doorLocked ? "🔒 LOCKED" : "🔓 UNLOCKED") + "</span>";
  html += "</div>";
  
  html += "<div class='status-item'>";
  html += "<span><span class='status-indicator " + String(doorbell.nightMode ? "on" : "off") + "'></span>Night Mode</span>";
  html += "<span>" + String(doorbell.nightMode ? "🌙 Active" : "☀️ Inactive") + "</span>";
  html += "</div>";
  
  html += "</div>";
  
  // Recent Events
  html += "<div class='card'>";
  html += "<h3>📋 Recent Events</h3>";
  html += "<div class='event-log'>";
  
  int count = 0;
  for (int i = historyIndex - 1; i >= 0 && count < 5; i--) {
    if (visitorHistory[i].timestamp != "") {
      html += "<div class='event-item'>";
      html += "<strong>" + visitorHistory[i].event + "</strong><br>";
      html += "Time: " + visitorHistory[i].timestamp;
      html += "</div>";
      count++;
    }
  }
  
  if (count == 0) {
    html += "<div style='text-align:center;opacity:0.5;padding:20px'>No recent events</div>";
  }
  
  html += "</div></div>";
  
  // Controls
  html += "<div class='controls'>";
  html += "<a href='/ring' class='btn btn-warning'>🔔 Test Doorbell</a>";
  if (doorbell.doorLocked) {
    html += "<a href='/unlock' class='btn btn-success'>🔓 Unlock Door</a>";
  } else {
    html += "<a href='/lock' class='btn btn-danger'>🔒 Lock Door</a>";
  }
  html += "<a href='/clear' class='btn btn-primary'>🗑️ Clear Log</a>";
  html += "</div>";
  
  html += "<div style='text-align:center;margin-top:30px;opacity:0.7;font-size:0.9em'>";
  html += "IP: " + WiFi.localIP().toString() + " | Uptime: " + String(millis()/1000) + "s";
  html += "</div>";
  
  html += "</div></body></html>";
  
  server.send(200, "text/html", html);
}

void handleStatus() {
  String json = "{";
  json += "\"visitors\":" + String(doorbell.visitorCount) + ",";
  json += "\"lastVisitor\":\"" + doorbell.lastVisitorTime + "\",";
  json += "\"motion\":" + String(doorbell.motionDetected ? "true" : "false") + ",";
  json += "\"camera\":" + String(doorbell.cameraActive ? "true" : "false") + ",";
  json += "\"doorLocked\":" + String(doorbell.doorLocked ? "true" : "false") + ",";
  json += "\"nightMode\":" + String(doorbell.nightMode ? "true" : "false") + ",";
  json += "\"lightLevel\":" + String(doorbell.lightLevel);
  json += "}";
  
  server.send(200, "application/json", json);
}

void handleHistory() {
  String json = "[";
  for (int i = 0; i < 20; i++) {
    if (visitorHistory[i].timestamp != "") {
      if (i > 0) json += ",";
      json += "{";
      json += "\"time\":\"" + visitorHistory[i].timestamp + "\",";
      json += "\"event\":\"" + visitorHistory[i].event + "\"";
      json += "}";
    }
  }
  json += "]";
  
  server.send(200, "application/json", json);
}

void handleTestRing() {
  Serial.println("🧪 Test doorbell activated from web");
  handleDoorbellRing();
  
  server.sendHeader("Location", "/");
  server.send(303);
}

void handleUnlock() {
  doorbell.doorLocked = false;
  digitalWrite(RELAY_DOOR_PIN, LOW);
  
  Serial.println("🔓 Door unlocked remotely");
  logVisitor("Door Unlocked");
  sendNotification("DOOR", "Door unlocked remotely");
  
  setRGBColor(0, 255, 0); // Green
  tone(BUZZER_PIN, 1000, 200);
  delay(500);
  setRGBColor(0, 0, 0);
  
  server.sendHeader("Location", "/");
  server.send(303);
}

void handleLock() {
  doorbell.doorLocked = true;
  digitalWrite(RELAY_DOOR_PIN, HIGH);
  
  Serial.println("🔒 Door locked remotely");
  logVisitor("Door Locked");
  
  setRGBColor(255, 0, 0); // Red
  tone(BUZZER_PIN, 800, 200);
  delay(500);
  setRGBColor(0, 0, 0);
  
  server.sendHeader("Location", "/");
  server.send(303);
}

void handleCamera() {
  activateCamera();
  logVisitor("Camera Triggered");
  
  server.sendHeader("Location", "/");
  server.send(303);
}

void handleClear() {
  doorbell.visitorCount = 0;
  historyIndex = 0;
  for (int i = 0; i < 20; i++) {
    visitorHistory[i].timestamp = "";
    visitorHistory[i].event = "";
  }
  
  Serial.println("✓ Event log cleared");
  
  server.sendHeader("Location", "/");
  server.send(303);
}