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use bczhc_lib::char::CharsTrait;
use bczhc_lib::utf8::encode_utf8;
use clap::{App, Arg};
use std::io::{stdin, stdout, Write};

fn main() {
    let matches = App::new("wrap")
        .about("Wrap lines")
        .author("bczhc <bczhc0@126.com>")
        .arg(
            Arg::with_name("columns")
                .default_value("50")
                .required(false),
        )
        .get_matches();

    let columns = matches.value_of("columns").unwrap();
    let columns: usize = columns.parse().unwrap();

    let stdin = stdin();
    let stdin = stdin.lock();
    let char_reader = stdin.chars();
    let stdout = stdout();
    let mut stdout = stdout.lock();
    let mut out_bytes = [0_u8; 4];

    let mut count = 0_usize;
    for c in char_reader {
        count += 1;
        if count % columns == 0 {
            println!();
        }
        let size = encode_utf8(c as u32, &mut out_bytes);
        stdout.write_all(&out_bytes[..size]).unwrap();
    }
}