#include <WiFi.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Keypad.h>
#include <ESP32Servo.h>
#include "ThingSpeak.h"

// -------- WiFi --------
const char* ssid = "YOUR_SSID";
const char* passwordWiFi = "YOUR_PASSWORD";

// -------- ThingSpeak --------
WiFiClient client;
unsigned long channelNumber = YOUR_CHANNEL_ID;
const char * writeAPIKey = "YOUR_API_KEY";

// -------- LCD --------
LiquidCrystal_I2C lcd(0x27, 16, 2);

// -------- Ultrasonic --------
#define TRIG 5
#define ECHO 18

// -------- Servo --------
Servo myServo;
#define SERVO_PIN 19

// -------- Buzzer --------
#define BUZZER 4

// -------- Keypad --------
const byte ROWS = 4;
const byte COLS = 4;

char keys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};

byte rowPins[ROWS] = {13, 12, 14, 27};
byte colPins[COLS] = {26, 25, 33, 32};

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

// -------- Password --------
String correctPassword = "1234";
String inputPassword = "";

void setup() {
  Serial.begin(115200);

  pinMode(TRIG, OUTPUT);
  pinMode(ECHO, INPUT);
  pinMode(BUZZER, OUTPUT);

  myServo.attach(SERVO_PIN);
  myServo.write(0);

  lcd.init();
  lcd.backlight();
  lcd.setCursor(0,0);
  lcd.print("System Ready");

  // WiFi connect
  WiFi.begin(ssid, passwordWiFi);
  while(WiFi.status() != WL_CONNECTED){
    delay(500);
    Serial.print(".");
  }

  Serial.println("WiFi Connected");
  ThingSpeak.begin(client);
}

long getDistance() {
  digitalWrite(TRIG, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG, LOW);

  long duration = pulseIn(ECHO, HIGH);
  long distance = duration * 0.034 / 2;

  return distance;
}

void loop() {

  long distance = getDistance();
  Serial.println(distance);

  lcd.setCursor(0,1);
  lcd.print("Dist:");
  lcd.print(distance);
  lcd.print(" cm   ");

  if(distance < 20) {
    lcd.clear();
    lcd.print("Enter Password:");

    inputPassword = "";

    while(inputPassword.length() < 4) {
      char key = keypad.getKey();
      if(key) {
        inputPassword += key;
        lcd.setCursor(0,1);
        lcd.print(inputPassword);
      }
    }

    if(inputPassword == correctPassword) {
      lcd.clear();
      lcd.print("Access Granted");
      digitalWrite(BUZZER, LOW);

      myServo.write(90); // Open
      delay(3000);
      myServo.write(0);  // Close

      ThingSpeak.writeField(channelNumber, 1, distance, writeAPIKey);
      ThingSpeak.writeField(channelNumber, 2, 1, writeAPIKey); // success

    } else {
      lcd.clear();
      lcd.print("Wrong Password");
      digitalWrite(BUZZER, HIGH);
      delay(2000);
      digitalWrite(BUZZER, LOW);

      ThingSpeak.writeField(channelNumber, 2, 0, writeAPIKey); // fail
    }

    delay(2000);
    lcd.clear();
  }

  delay(1000);
}