#!/usr/bin/env -S cargo +nightly -Zscript

---
[package]
edition = "2024"
[dependencies]
argh = "0.1"
---

use std::io::{BufRead, BufReader, Write};
use std::net::{Shutdown, TcpStream};

use argh::FromArgs;

const FLUSH_COMMAND: &str = "FLUSHALL\r\n";

#[derive(FromArgs)]
#[argh(description = "Flush the cache of a redis instance.")]
struct App {
    #[argh(
        option,
        description = "host for the redis instance.",
        default = "\"127.0.0.1\".to_string()"
    )]
    host: String,

    #[argh(option, description = "port redis is listening on.", default = "6379")]
    port: u16,
}

fn main() {
    let app: App = argh::from_env();

    let address = format!("{}:{}", app.host, app.port);
    let mut stream = TcpStream::connect(address).expect("should be able to connect to redis");

    stream
        .write(FLUSH_COMMAND.as_bytes())
        .expect("should be able to write flush command");
    stream
        .flush()
        .expect("should be able to send flush command");
    stream
        .shutdown(Shutdown::Write)
        .expect("should be able to shutdown writer");

    let mut stream = BufReader::new(stream);

    let mut output = String::new();
    let _ = stream
        .read_line(&mut output)
        .expect("should be able to read response");
    println!("{}", &output);
}