#include <WiFi.h>
#include <PubSubClient.h>
#include <ESP32Servo.h>
#include <Keypad.h>

// WiFi & MQTT Secure Config
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "broker.mydomain.com";  // Secure Broker
const char* mqtt_user = "mohdy";
const char* mqtt_password = "M_baby01";

WiFiClient espClient;
PubSubClient client(espClient);
Servo lockerServo;

// Pin Assignments
#define SERVO_PIN 17
#define PIR_PIN 5
#define ULTRASONIC_TRIG 18
#define ULTRASONIC_ECHO 19
#define BUZZER_PIN 23
#define LED_PIN 2

// Keypad Setup
const byte ROWS = 4, COLS = 3;
char keys[ROWS][COLS] = { {'1','2','3'}, {'4','5','6'}, {'7','8','9'}, {'*','0','#'} };
byte rowPins[ROWS] = {32, 33, 25, 26};
byte colPins[COLS] = {27, 12, 13};
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

String enteredCode = "";
const String accessCode = "1234";  // TODO: Implement hashed access code storage

bool isUnlocked = false;
unsigned long unlockTime = 0;
const unsigned long autoLockDuration = 5 * 60 * 1000; // 5 minutes

void connectMQTT() {
    while (!client.connected()) {
        Serial.print("Connecting to MQTT...");
        if (client.connect("ESP32Locker", mqtt_user, mqtt_password)) {
            Serial.println("Connected!");
            client.subscribe("locker/command");
            client.publish("locker/status", "Locker Online");
        } else {
            Serial.println("Retrying in 2 sec...");
            delay(2000);
        }
    }
}

void setup() {
    Serial.begin(115200);
    
    WiFi.begin(ssid, password);
    while (WiFi.status() != WL_CONNECTED) {
        delay(1000);
        Serial.println("Connecting...");
    }
    Serial.println("Connected to WiFi");

    client.setServer(mqtt_server, 1883);  // Non-TLS for debugging. Change to 8883 with TLS in production.
    client.setCallback(mqtt_callback);

    connectMQTT();

    pinMode(PIR_PIN, INPUT);
    pinMode(ULTRASONIC_TRIG, OUTPUT);
    pinMode(ULTRASONIC_ECHO, INPUT);
    pinMode(BUZZER_PIN, OUTPUT);
    pinMode(LED_PIN, OUTPUT);

    lockerServo.attach(SERVO_PIN);
    lockerServo.write(0); // Locked by default
}

void loop() {
    client.loop();
    
    if (!client.connected()) connectMQTT();

    // Motion Detection
    if (digitalRead(PIR_PIN)) {
        Serial.println("🚨 Unauthorized Access Detected!");
        digitalWrite(BUZZER_PIN, HIGH);
        delay(500);
        digitalWrite(BUZZER_PIN, LOW);
        client.publish("locker/status", "ALERT: Motion Detected");
    }

    // Ultrasonic Object Detection
    long duration;
    int distance;
    digitalWrite(ULTRASONIC_TRIG, LOW);
    delayMicroseconds(2);
    digitalWrite(ULTRASONIC_TRIG, HIGH);
    delayMicroseconds(10);
    digitalWrite(ULTRASONIC_TRIG, LOW);
    duration = pulseIn(ULTRASONIC_ECHO, HIGH, 30000);  // 30ms timeout

    distance = (duration > 0) ? duration * 0.034 / 2 : 999;
    Serial.printf("Distance: %d cm\n", distance);
    
    if (distance > 0 && distance < 30) {
        Serial.println("✅ Object Detected in Locker.");
        digitalWrite(LED_PIN, HIGH);
    } else {
        Serial.println("❌ No Object Detected.");
        digitalWrite(LED_PIN, LOW);
    }

    // Keypad Access Logic
    char key = keypad.getKey();
    if (key) {
        Serial.printf("Key Pressed: %c\n", key);
        if (key == '#') {
            if (enteredCode == accessCode) {
                Serial.println("🔓 Access Granted!");
                lockerServo.write(90);
                isUnlocked = true;
                unlockTime = millis();
                client.publish("locker/status", "Locker Unlocked Successfully!");
            } else {
                Serial.println("❌ Access Denied!");
                digitalWrite(BUZZER_PIN, HIGH);
                delay(1000);
                digitalWrite(BUZZER_PIN, LOW);
                client.publish("locker/status", "Access Denied!");
            }
            enteredCode = "";  // Reset entry
        } else {
            enteredCode += key;
        }
    }

    // Auto-lock after timeout
    if (isUnlocked && millis() - unlockTime >= autoLockDuration) {
        lockerServo.write(0);
        isUnlocked = false;
        client.publish("locker/status", "Locker Auto-Locked");
        Serial.println("🔒 Locker auto-locked.");
    }
}

// MQTT Callback Handling
void mqtt_callback(char* topic, byte* message, unsigned int length) {
    String msg;
    for (int i = 0; i < length; i++) msg += (char)message[i];
    
    Serial.printf("MQTT Command Received: %s\n", msg.c_str());
    
    if (msg == "open") {
        lockerServo.write(90);
        isUnlocked = true;
        unlockTime = millis();
        client.publish("locker/status", "Locker Opened via Cloud Command!");
        Serial.println("🔓 Locker opened remotely.");
    } else if (msg == "close") {
        lockerServo.write(0);
        isUnlocked = false;
        client.publish("locker/status", "Locker Closed via Cloud Command!");
        Serial.println("🔒 Locker closed remotely.");
    }
}