#![no_std]
#![no_main]

use core::time::Duration;

use rslibc::{format, print, println, vec, String, Vec};

const FRAMES: [&str; 4] = ["|", "/", "-", "\\"];
const WIDTH: usize = 20;
const STEPS: usize = 10;

fn bar(done: usize) -> String {
    let mut out = String::new();
    for i in 0..WIDTH {
        out.push(if i < done { '#' } else { '-' });
    }
    out
}

fn load(step: usize) -> rslibc::Result<u32, &'static str> {
    // Pretend to do work and return a checksum-like value.
    let mut total = 0u32;
    for value in vec![1, 2, 3, 4, 5] {
        total = total.wrapping_add(value * step as u32);
    }
    Ok(total)
}

#[rslibc_macros::main]
async fn main() {
    println!("rslibc loading example");
    let mut log: Vec<String> = Vec::new();

    for step in 0..STEPS {
        match load(step) {
            Ok(value) => {
                let frame = FRAMES[step % FRAMES.len()];
                let percent = 100 * (step + 1) / STEPS;
                print!(
                    "\r  [{}] {:>3}% {}",
                    bar((step + 1) * WIDTH / STEPS),
                    percent,
                    frame
                );
                log.push(format!("step {step} -> {value}"));
            }
            Err(message) => println!("error: {message}"),
        }

        rslibc::runtime::sleep(Duration::from_millis(60));
    }

    println!("\r  [{}] 100% done", bar(WIDTH));
    println!("log = {log:?}");
}