#define BLYNK_TEMPLATE_ID "TMPL3cBID8qbJ"
#define BLYNK_TEMPLATE_NAME "Servomotor"
#define BLYNK_AUTH_TOKEN "Qj6bPKwkNHbuIEtCe6ZsUnuVQuBQmfEQ"

#include <WiFi.h>
#include <BlynkSimpleEsp32.h>
#include <ESP32Servo.h>

// WiFi credentials
char ssid[] = "Wokwi-GUEST";
char pass[] = "";

// Pin Definitions
#define PIN_TRIG 19
#define PIN_ECHO 4
const int servoPin = 5;

Servo servo;

// Blynk control variables
int mode = 0;           // 0 = Auto (Ultrasonic), 1 = Manual (Slider)
int servoAngle = 0;     // Angle from slider

// Blynk Virtual Pin V0 - Slider for angle
BLYNK_WRITE(V0) {
  servoAngle = param.asInt();
}

// Blynk Virtual Pin V1 - Switch for mode
BLYNK_WRITE(V1) {
  mode = param.asInt();
  Serial.print("Mode: ");
  Serial.println(mode ? "Manual" : "Automatic");
}

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

  // Connect to WiFi
  Serial.print("Connecting to WiFi");
  WiFi.begin(ssid, pass);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected ✅");

  // Connect to Blynk
  Blynk.begin(BLYNK_AUTH_TOKEN, ssid, pass);

  // Pin setup
  pinMode(PIN_TRIG, OUTPUT);
  pinMode(PIN_ECHO, INPUT);
  servo.attach(servoPin, 500, 2400);  // for ESP32
}

void loop() {
  Blynk.run();

  if (mode == 1) {
    // Manual mode
    servo.write(servoAngle);
    Serial.print("Manual Angle from Blynk: ");
    Serial.println(servoAngle);
  } else {
    // Automatic mode using ultrasonic sensor
    digitalWrite(PIN_TRIG, LOW);
    delayMicroseconds(2);
    digitalWrite(PIN_TRIG, HIGH);
    delayMicroseconds(10);
    digitalWrite(PIN_TRIG, LOW);

    long duration = pulseIn(PIN_ECHO, HIGH, 30000);  // timeout: 30ms
    float distance_cm = (duration > 0) ? duration * 0.0343 / 2 : 0;
    int angle = map(constrain(distance_cm, 0, 400), 0, 400, 0, 180);

    servo.write(angle);

    Serial.print("Auto Distance: ");
    Serial.print(distance_cm);
    Serial.print(" cm → Servo Angle: ");
    Serial.println(angle);
  }

  delay(500);
}