//! cp source dest -- copy a file. If `dest` is a directory the copy goes
//! inside it with the same name (shell alias: copy).
#![no_std]
#![no_main]

extern crate alloc;

#[macro_use]
#[path = "ulib.rs"]
mod ulib;

use alloc::{format, string::String};
use ulib::*;

fn main() -> i64 {
    let (Some(src), Some(dst), 3) = (arg(1), arg(2), argc()) else {
        eprintln!("usage: cp source dest");
        return 2;
    };
    let mut st = Stat::default();
    let mut dst = String::from(dst);
    if stat(&dst, &mut st) == 0 && st.kind == KIND_DIR {
        let name = src.rsplit('/').next().unwrap_or(src);
        dst = format!("{}/{}", dst.trim_end_matches('/'), name);
    }
    let from = open(src, 0);
    if from < 0 {
        eprintln!("cp: {}: {}", src, strerror(from));
        return 1;
    }
    let to = open(&dst, O_CREAT | O_TRUNC);
    if to < 0 {
        eprintln!("cp: {}: {}", dst, strerror(to));
        close(from);
        return 1;
    }
    let mut buf = [0u8; 512];
    let mut status = 0;
    loop {
        let n = read(from, &mut buf);
        if n <= 0 || write_all(to, &buf[..n.max(0) as usize]) < 0 {
            if n < 0 {
                eprintln!("cp: {}: {}", src, strerror(n));
                status = 1;
            }
            break;
        }
    }
    close(from);
    close(to);
    status
}