use crate::proc::{Procer, ProcerData, Update};
use crate::notes::{Note, NoteValue, ProcerNote};
use crate::outputers::{Outputer, Outputers, SimpleOutputer};
use crate::rfft::RFftProcer;
use realfft::FftNum;
use rustfft::num_traits::float::Float;
use alsa::{Direction, ValueOr};
use alsa::pcm::{PCM, HwParams, Format, Access, State};
use derive_more::Display;
use std::fmt::Debug;
use std::io::Write;
//use std::collections::VecDeque;

pub enum Procers<I: Default + Clone + FftNum + Float, const US: usize, const BS: usize> {
    Rfft(RFftProcer<I, US, BS>),
    // XXX: if i add a fir filter that doesn't need a buffer i think
    // i can just spec it as Fir12Tet(Fir12TetProcer<I, US>) or similar
    // here
}

#[derive(Display)]
#[display(fmt="StaticBuffer(rate={}, psize={}, channels={}, opsize={}, adev=(name={}), outdev=(name={:?}), cperiods={}, operiods={})", rate, period_size, channels, out_period_size, adev_name, outdev_name, capture_periods, output_periods)]
pub struct StaticBuffer<'nl, I: Default + Debug + Clone + FftNum + Float + NoteValue, const US: usize, const BS: usize> {
    pub rate: u32,
    pub period_size: usize,
    pub channels: u32,
    pub out_period_size: usize,
    pub procers: Vec<(Procers<I, US, BS>, ProcerData<'nl, I>)>,
    pub adev_name: String,
    pub adev: PCM,
    pub outdev_name: Option<String>,
    pub outdev: Option<PCM>,
    pub outputer: Outputers,
    pub capture_periods: u32,
    pub output_periods: u32,
}

impl<'nl, I: Default + Debug + Clone + FftNum + Float + From<i16> + NoteValue, const US: usize, const BS: usize> StaticBuffer<'nl, I, US, BS> {
    pub fn new(rate: u32, channels: u32, procers: Vec<(Procers<I, US, BS>, ProcerData<'nl, I>)>, adev_name: String, outdev_name: Option<String>, outputer: Outputers) -> Self {
        let mut adev = PCM::new(&adev_name, Direction::Capture, true).unwrap();
        let mut capture_periods = 0;
        {
            let hwp = HwParams::any(&adev).unwrap();
            hwp.set_channels(channels).unwrap();
            //hwp.set_rate_resample(false);
            hwp.set_rate(rate, ValueOr::Nearest).unwrap();
            hwp.set_format(Format::s16()).unwrap();
            hwp.set_access(Access::MMapInterleaved).unwrap();
            hwp.set_period_size(US as i64, ValueOr::Nearest).unwrap();
            hwp.set_periods(8, ValueOr::Nearest).unwrap();
            // TODO: directly using the ALSA ring buffer and copying directly from it instead of
            // going through the Update/VecDeque might be interesting in the future, i think it'd
            // require changing the const sizes to runtime determined sizes though, so future
            // changes to try~
            adev.hw_params(&hwp).unwrap();
            capture_periods = hwp.get_periods().unwrap();
            println!("capture periods: {}", capture_periods);
        }
        let (outdev, out_period_size, output_periods) = match &outdev_name {
            None => (None, 0, 0),
            Some(od_name) => {
                let mut outdev = PCM::new(&od_name, Direction::Playback, true).unwrap();
                let mut output_periods = 0;
                let mut out_period_size = 0;
                {
                    let hwp = HwParams::any(&outdev).unwrap();
                    hwp.set_channels(channels).unwrap();
                    hwp.set_rate(rate, ValueOr::Nearest).unwrap();
                    hwp.set_format(Format::s16()).unwrap();
                    hwp.set_access(Access::RWInterleaved).unwrap();
                    //hwp.set_period_size(US as i64, ValueOr::Nearest).unwrap();
                    //hwp.set_periods(8, ValueOr::Nearest).unwrap();
                    outdev.hw_params(&hwp).unwrap();
                    output_periods = hwp.get_periods().unwrap();
                    out_period_size = hwp.get_period_size().unwrap() as usize;
                    println!("output periods: {}", output_periods);
                }
                (Some(outdev), out_period_size, output_periods)
            }
        };
        return Self {
            rate, procers, adev_name, adev, outdev_name, outdev,
            period_size: US, out_period_size: out_period_size,
            channels: channels,
            outputer,
            capture_periods, output_periods,
        }
    }

    pub fn capture_loop(&mut self) {
        let empty: Vec<i16> = vec![0i16; US * self.channels as usize];
        //let mut line_str: String = format!("\r{:80}", "");
        let in_io = self.adev.io_i16().unwrap();
        let out_io_opt = {
            match &self.outdev {
            None => (None),
            Some(outdev) => {
                //self.adev.link(&outdev).unwrap();
                let out_io = outdev.io_i16().unwrap();
                // queue up an empty period in the outdev so we can sync between in and out devices
                // with a 4 period latency
                for _i in 0..std::cmp::min(4, self.output_periods/2) {
                    out_io.writei(&empty).unwrap();
                }
                outdev.start();//.unwrap();
                println!("output available: {}", outdev.avail().unwrap());
                Some(out_io)
            }
            }
        };
        self.adev.start();//.unwrap();
        //let vt: I = I::from(112);
        let conv_scale: I = <I as From<i16>>::from(i16::MAX);
        println!("input available: {}", self.adev.avail_update().unwrap());
        let mut latentframes = 0;
        let mut unstarted = false;
        loop {
            /*println!("output available: {}", self.outdev.avail().unwrap());
            println!("input available: {}", self.adev.avail_update().unwrap());*/
            self.adev.wait(None).unwrap();
            //println!("a");
            // should be called right before mmap_begin according to:
            // https://www.alsa-project.org/alsa-doc/alsa-lib/group___p_c_m___direct.html#ga6d4acf42de554d4d1177fb035d484ea4
            let avail_frames = self.adev.avail_update().unwrap();
            in_io.mmap(US, |in_slice| {
                let size = in_slice.len();
                //println!("slice length: {}", size);
                if size == 0 {
                    println!("warning: passed a 0-sized buffer from mmap\n");
                    return 0;
                }
                let stride = self.channels as usize;
                if size != (US * stride) {
                    println!("warning: passed a {} sized buffer from mmap\n\n", size);
                    return 0;
                }
                assert_eq!(size, US * stride);
                let (written, oa) =  match &out_io_opt {
                    Some(out_io) => {
                        let wri = out_io.writei(&in_slice).unwrap();
                        assert_eq!(wri, (size/stride));
                        let oaa = self.outdev.as_ref().unwrap().avail().unwrap();
                        (wri, oaa)
                    }
                    None => (size/stride, 0i64),
                };
                let ia = self.adev.avail_update().unwrap();
                let total_outbuf: i64 = oa - ia;
                /*print!("\rtotal: {}, out: {}, in: {}", total_outbuf, oa, ia);
                std::io::stdout().flush().unwrap();*/
                //return written;
                //let constrained_slice = in_slice[0..US*stride];
                let mut update: Update<I, US> = [I::default(); US];
                // copy over the left channel data (even indexes)
                // TODO/XXX: see if this uses SIMD or needs optimizing :o
                // using iter and map/function that does strides would prob also work well :o
                // gotta scale this from i16::MAX to float, alsa
                // seems to divide by i16::MAX, not sure if there's a better way to do this
                for i in 0..US {
                    update[i] = <I as From<i16>>::from(in_slice[i*stride]) / conv_scale;
                };
                // hmm, i only need to use 1 procer here for displaying, not sure what to do with
                // the rest :o
                //for (procer, pdata) in self.procers { }
                let (ref mut procer, ref mut pdata) = self.procers.first_mut().unwrap();
                let mut processed = false;
                {
                    let mut pnotes = pdata.pnotes.0.as_mut_slice();
                    //let processed = true;
                    processed = procer.process_data(&update, pnotes);
                }
                if processed {
                    self.outputer.handle_pnotes(&mut pdata.pnotes);
                    //let mut position = 1;
                    // TODO: maybe copy, inplace probably works for now though
                    /*pnotes.sort_unstable_by(|pn1, pn2| (-pn1.2).partial_cmp(&-pn2.2).unwrap());
                    print!("\r{:-80}", pdata.pnotes);
                    std::io::stdout().flush();*/
                }
                //let mut position = 0;
                //let mut remaining = in_slice.len();
                //let mut remain_frames = remaining/(self.channels as usize);
                //let mut handled = false;
                //self.outdev.wait(None).unwrap();
                //println!("wrote {} frames", written);
                /*while handled == false {
                    self.outdev.wait(None).unwrap();
                    out_io.mmap(remain_frames, |out_slice| {
                        let outlen = out_slice.len();
                        println!("out slice len: {}", out_slice.len());
                        if outlen == 0 {
                            return 0;
                        }
                        out_slice.clone_from_slice(&in_slice);
                        handled = true;
                        return out_slice.len()/(self.channels as usize);
                    }).unwrap();
                }*/
                /*if latentframes > 0 {
                    latentframes -= 1;
                } else if unstarted {
                    unstarted = false;
                    println!("starting outdev");
                    self.outdev.start().unwrap();
                }*/
                return in_slice.len()/(self.channels as usize);
            }).unwrap();
        }
    }
    //fn new(
}

/*impl StaticBuffer<'nl, B> {
}*/

//impl<'nl, B> StaticBuffer<'nl, A> {
    //pub fn fill_initial(&self, 
    //pub fn new(rate: usize, period_size: usize, out_period_size: usize, procers: Vec<(Procers<f64>, ProcerData<'nl>)>, 
//}


impl<I: Default + Clone + FftNum + Float + NoteValue, const US: usize, const BS: usize> Procer<I, US> for Procers<I, US, BS> {
    fn get_size(&self) -> usize {
        match self {
            Procers::Rfft(rfp) => rfp.get_size(),
        }
    }
    fn get_frequency(&self) -> usize {
        match self {
            Procers::Rfft(rfp) => rfp.get_frequency(),
        }
    }
    fn make_pnotes<'nl>(&self, notes: &'nl [Note]) -> Vec<ProcerNote<'nl, I>> {
        match self {
            Procers::Rfft(rfp) => rfp.make_pnotes(notes),
        }
    }
    fn process_data(&mut self, input: &Update<I, US>, notes: &mut [ProcerNote<I>]) -> bool {
        match self {
            Procers::Rfft(rfp) => rfp.process_data(input, notes),
        }
    }
}