use std::sync::Arc;

use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
use std::ops::{Add, AddAssign, Sub};
use parking_lot::RwLock;
use std::time::Duration;
use std::thread;
use cpal::SampleFormat;
use crate::beep::osc::{Instrument, Oscillator};

pub mod osc;

struct AudioContext {
    device: cpal::Device,
    sample_format: SampleFormat,
    config: cpal::StreamConfig
}

fn al_init() -> Result<AudioContext, anyhow::Error> {
    let host = cpal::default_host();

    let device = host.default_output_device()
        .ok_or_else(|| anyhow::anyhow!("No audio output device!"))?;

    let config = device.default_output_config()?;

    Ok(AudioContext {
        device,
        sample_format: config.sample_format(),
        config: config.into()
    })
}

pub fn beep() -> Result<(), anyhow::Error> {
    let ac = al_init()?;

    match ac.sample_format {
        cpal::SampleFormat::F32 => run::<f32>(&ac.device, &ac.config.into())?,
        cpal::SampleFormat::I16 => run::<i16>(&ac.device, &ac.config.into())?,
        cpal::SampleFormat::U16 => run::<u16>(&ac.device, &ac.config.into())?,
    }

    Ok(())
}


fn run<T>(device: &cpal::Device, config: &cpal::StreamConfig) -> Result<(), anyhow::Error>
    where
        T: cpal::Sample,
{
    let sample_rate = config.sample_rate.0 as f32;
    let channels = config.channels as usize;

    println!("SR={}",sample_rate);

    // Produce a sinusoid of maximum amplitude.

    let mut ins = Instrument::new(vec![
        Oscillator::new(440.0, 1.0, sample_rate),
        //Oscillator::new(441.0, 1.0, sample_rate),
    ], sample_rate);

    let instrument = Arc::new(parking_lot::RwLock::new(ins));

    let err_fn = |err| eprintln!("an error occurred on stream: {}", err);

    let m_instrument = instrument.clone();
    let stream = device.build_output_stream(
        config,
        move |data: &mut [T], _: &cpal::OutputCallbackInfo| {
            write_data(data, channels, &m_instrument)
        },
        err_fn,
    )?;
    stream.play()?;

    // instrument.write().normalize(false);
    // instrument.write().set_amp(1.0);
    // thread::sleep(Duration::from_millis(500));
    //
    // instrument.write().set_amp(0.0);
    // thread::sleep(Duration::from_millis(250));

    instrument.write().set_amp(1.0);
    instrument.write().normalize(true);
    thread::sleep(Duration::from_millis(500));

    instrument.write().set_amp(0.0);
    thread::sleep(Duration::from_millis(250));

    instrument.write().set_amp(0.5);
    thread::sleep(Duration::from_millis(500));

    instrument.write().set_amp(0.0);
    thread::sleep(Duration::from_millis(250));

    instrument.write().fade_amp(1.0, Duration::from_millis(10));
    instrument.write().waveforms[0].fade_balance(-1.0, Duration::from_millis(10));
    thread::sleep(Duration::from_millis(500));
    instrument.write().fade_amp(0.0, Duration::from_millis(10));
    thread::sleep(Duration::from_millis(500));


    /*

    //instrument.write().set_amp_fade(0.0, 4.0);

    thread::sleep(Duration::from_millis(1000));
    instrument.write().waveforms[1].fade_amp(0.0, Duration::from_millis(500));
    thread::sleep(Duration::from_millis(500));

    instrument.write().waveforms[0].fade_balance(-1.0, Duration::from_millis(1000));
    thread::sleep(Duration::from_millis(1000));
    instrument.write().waveforms[0].fade_balance(1.0, Duration::from_millis(2000));
    instrument.write().waveforms[0].fade_freq(880.0, Duration::from_millis(1000));
    thread::sleep(Duration::from_millis(2000));
    instrument.write().waveforms[0].fade_balance(-1.0, Duration::from_millis(1000));
    instrument.write().waveforms[0].fade_amp(0.0, Duration::from_millis(1000));
    thread::sleep(Duration::from_millis(1000));
*/

    // for _ in 0..10
    // {
    //     instrument.write().harmonics[0].set_balance_fade(-1.0, 0.1);
    //     thread::sleep(Duration::from_millis(100));
    //     instrument.write().harmonics[0].set_balance_fade(1.0, 0.1);
    //     thread::sleep(Duration::from_millis(100));
    // }
    //
    // instrument.write().harmonics[0].set_balance_fade(0.0, 0.5);
    // instrument.write().harmonics[0].set_amp_fade(0.0, 0.05);
    // thread::sleep(Duration::from_millis(200));

    Ok(())
}

fn write_data<T>(output: &mut [T], channels: usize, instrument: &Arc<RwLock<Instrument>>)
    where
        T: cpal::Sample,
{
    let mut instrument = instrument.write();
    for frame in output.chunks_mut(channels) {
        let sample = instrument.sample();

        if channels == 1 {
            frame[0] = cpal::Sample::from::<f32>(&((sample.left + sample.right) / 2.0));
        } else {
            frame[0] = cpal::Sample::from::<f32>(&sample.left);
            frame[1] = cpal::Sample::from::<f32>(&sample.right);
        }
    }
}