use std::time::Duration;

use rand::Rng;
use rodio::{
    source::{SineWave, Zero},
    OutputStream, Sink, Source,
};

fn main() {
    let (_stream, stream_handle) = OutputStream::try_default().unwrap();
    let sink = Sink::try_new(&stream_handle).unwrap();

    let bpm = 140.0;
    let seconds_per_beat = (1.0 / bpm) * 60.0;

    loop {
        let mut rng = rand::thread_rng();
        let freq = (440.0
            * (2f32.powf(1.0 / 12.0)).powf(rng.gen_range((12 * -2)..=(12 * 0)) as f32))
            as u32;
        let wave = SineWave::new(freq);
        let zero: Zero<f32> = Zero::new(1, 48_000);
        let length = (rng.gen_range(1..4) as f32) / 4.0 * seconds_per_beat;
        let source = wave
            .take_crossfade_with(zero, Duration::from_secs_f32(length))
            .amplify(0.20);
        sink.append(source);

        // The sound plays in a separate thread. This call will block the current thread until the sink
        // has finished playing all its queued sounds.
        sink.sleep_until_end();
    }
}