src/main.rs

use std::io::{self, Write};
 
trait Command {
    fn execute(&self);
}
 
struct LightOn;
impl Command for LightOn {
    fn execute(&self) {
        println!("💡 Light turned ON.");
    }
}
 
struct LightOff;
impl Command for LightOff {
    fn execute(&self) {
        println!("🔌 Light turned OFF.");
    }
}
 
struct FanOn;
impl Command for FanOn {
    fn execute(&self) {
        println!("🌀 Fan turned ON.");
    }
}
 
struct FanOff;
impl Command for FanOff {
    fn execute(&self) {
        println!("🛑 Fan turned OFF.");
    }
}
 
/// Remote Control that executes boxed commands
struct Remote {
    history: Vec<String>,
}
 
impl Remote {
    fn new() -> Self {
        Remote { history: Vec::new() }
    }
 
    fn press_button(&mut self, label: &str, command: &dyn Command) {
        println!("🔘 Executing '{}'", label);
        command.execute();
        self.history.push(label.to_string());
    }
 
    fn show_history(&self) {
        if self.history.is_empty() {
            println!("📭 No commands executed.");
        } else {
            println!("📜 Command History:");
            for (i, cmd) in self.history.iter().enumerate() {
                println!("{}. {}", i + 1, cmd);
            }
        }
    }
}
 
fn main() {
    let mut remote = Remote::new();
 
    loop {
        println!("\nRemote Control Menu:");
        println!("1. Light ON");
        println!("2. Light OFF");
        println!("3. Fan ON");
        println!("4. Fan OFF");
        println!("5. Show History");
        println!("6. Exit");
 
        let choice = input("Choose an action: ");
 
        match choice.as_str() {
            "1" => remote.press_button("Light ON", &LightOn),
            "2" => remote.press_button("Light OFF", &LightOff),
            "3" => remote.press_button("Fan ON", &FanOn),
            "4" => remote.press_button("Fan OFF", &FanOff),
            "5" => remote.show_history(),
            "6" => {
                println!("👋 Powering down remote.");
                break;
            }
            _ => println!("❌ Invalid choice."),
        }
    }
}
 
fn input(msg: &str) -> String {
    print!("{}", msg);
    io::stdout().flush().unwrap();
    let mut buf = String::new();
    io::stdin().read_line(&mut buf).unwrap();
    buf.trim().to_string()
}