use std::{fs::File, io::Write};

use criterion::{black_box, criterion_group, criterion_main, Criterion};

fn write_buf(w: &mut impl Write) -> Result<(), std::io::Error> {
    let mut buf = [0u8; 10];
    buf[0] = 0;
    buf[1] = 1;
    buf[2] = 2;
    buf[3] = 3;
    buf[4] = 4;
    buf[5] = 5;
    buf[6] = 6;
    buf[7] = 7;
    buf[8] = 8;
    buf[9] = 9;
    w.write_all(&buf)?;
    Ok(())
}

fn write_many(w: &mut impl Write) -> Result<(), std::io::Error> {
    w.write_all(&[0])?;
    w.write_all(&[1])?;
    w.write_all(&[2])?;
    w.write_all(&[3])?;
    w.write_all(&[4])?;
    w.write_all(&[5])?;
    w.write_all(&[6])?;
    w.write_all(&[7])?;
    w.write_all(&[8])?;
    w.write_all(&[9])?;
    Ok(())
}

pub fn criterion_benchmark(c: &mut Criterion) {
    _ = std::fs::remove_file("/tmp/write_buf");
    let mut file = File::create("/tmp/write_buf").unwrap();
    c.bench_function("write_buf", |b| {
        b.iter(|| write_buf(&mut file).expect("written"))
    });
    _ = std::fs::remove_file("/tmp/write_many");
    let mut file = File::create("/tmp/write_many").unwrap();
    c.bench_function("write_many", |b| {
        b.iter(|| write_many(&mut file).expect("written"))
    });

    _ = std::fs::remove_file("/tmp/write_many_buf");
    let file = File::create("/tmp/write_many_buf").unwrap();
    let mut w = std::io::BufWriter::new(file);
    c.bench_function("write_many_buf", |b| {
        b.iter(|| write_many(&mut w).expect("written"))
    });

    _ = std::fs::remove_file("/tmp/write_buf_buf");
    let file = File::create("/tmp/write_buf_buf").unwrap();
    let mut w = std::io::BufWriter::new(file);
    c.bench_function("write_buf_buf", |b| {
        b.iter(|| write_buf(&mut w).expect("written"))
    });
}

criterion_group!(benches, criterion_benchmark);
criterion_main!(benches);