use cpal::traits::HostTrait;
use cpal::traits::DeviceTrait;
use cpal::traits::StreamTrait;

use eframe;
use eframe::egui;
use egui::plot::*;

use std::io::Write;

use std::time::{Duration, Instant};
use rustfft::num_complex::Complex32;

use fftw::array::AlignedVec;
use fftw::plan::*;
use fftw::types::*;
use std::f64::consts::PI;

use std::time;
use std::thread;
use std::sync::mpsc;

use std::fs::File;
use std::path::Path;


struct App {
    val: bool,
    it: u32,
}

impl Default for App {
    fn default() -> Self {
        Self {
            val: false,
            it: 0,
        }
    }
}

impl eframe::App for App {
    fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
        egui::SidePanel::left("side_panel").show(ctx, |ui| {
            let sin: PlotPoints = (0..1000).map(|i| {
                let x = i as f64 * 0.01;
                [x, x.sin() * (self.it as f64 * 0.01).cos()]
            }).collect();
            
            
            
            if self.val {
                ui.ctx().request_repaint();
                self.it += 1;
            }
        
            let line = Line::new(sin);
        
            Plot::new("plot").view_aspect(2.0).center_y_axis(true).show(ui, |plui| plui.line(line));
        
            ui.checkbox(&mut self.val, "Animate");
            println!("{}", &self.val);
            
            // std::thread::sleep(std::time::Duration::from_millis(1))
        });
        
        egui::TopBottomPanel::top("top").show(ctx, |_ui| {
            _ui.label("lol");
        
        });
    }
}



struct SamplePacket {
    sample_rate: u32,
    data: Box<[Complex32]>
}

impl SamplePacket {
    fn new(sample_rate: u32, data: Box<[Complex32]>) -> Self {
        Self {
            sample_rate: sample_rate,
            data: data
        }
    }
}

trait Process {
    fn process(&mut self, src: SamplePacket) -> SamplePacket;
}

struct PipelineBuilder {
    input: mpsc::SyncSender<SamplePacket>,
    output: mpsc::Receiver<SamplePacket>
}

impl PipelineBuilder {
    fn new() -> Self {
        let (input, output) = mpsc::sync_channel(1);
    
        Self {
            input: input,
            output: output
        }
    }

    fn pipe<T>(mut self, mut proc: T) -> Self
    where
    T: Process + Send + 'static
    {
        let (proc_out, output) = mpsc::sync_channel(1);
        
        let proc_in = std::mem::replace(&mut self.output, output);
    
        thread::spawn(move || {
            loop {
                let src = match proc_in.recv() {
                    Ok(s) => s,
                    Err(_) => break,
                };
                
                let dst = proc.process(src);
                
                if proc_out.send(dst).is_err() {
                    break;
                }
            }
        });
        
        self
    }
    
    fn finish(self) -> (mpsc::SyncSender<SamplePacket>, mpsc::Receiver<SamplePacket>) {
        (self.input, self.output)
    }
}

struct Squarer;
impl Process for Squarer {
    fn process(&mut self, mut src: SamplePacket) -> SamplePacket {
        for sample in src.data.iter_mut() {
            sample.re = (sample.re * 10.0) as i32 as f32 / 10.0;
            sample.im = (sample.im * 10.0) as i32 as f32 / 10.0;
        }
        
        src
    }
}

struct BandFilter {
    wrap_around: Box<[f32]>,
    window_filter: Box<[f32]>,
    test: usize,
    agc: f32,
    phase: f32
}

impl BandFilter {
    fn new(window_size: usize) -> Self {
        let mut window_filter = vec![0.0f32; window_size].into_boxed_slice();
        
    
        Self {
            wrap_around: vec![0.0f32; window_size - 1].into_boxed_slice(),
            window_filter: window_filter,
            test: 0,
            agc: 1.0,
            phase: 0.0
        }
    }
}

impl Process for BandFilter {
    fn process(&mut self, mut src: SamplePacket) -> SamplePacket {
        if src.data.len() != 250000 {
            println!("smh {}", src.data.len());
            return src;
        }
        
        use rustfft::{Fft, FftDirection, algorithm::Radix4};
        use rustfft::num_complex::Complex32;
        
        let mut fft_planner = rustfft::FftPlannerAvx::new().unwrap();
        
        let len = 250000;
        let fft = fft_planner.plan_fft_forward(len);
        let ifft = fft_planner.plan_fft_inverse(len);
        
        src.data.iter_mut().enumerate().for_each(|(i, c)| {
            let phase = i as f32 / len as f32 * 2.0 * 3.14159265359 * 0.0;
            
            *c *= Complex32 { re: phase.cos(), im: phase.sin() };
        });
    
    
        fft.process(&mut src.data);
        
        src.data[100000..len-100000].iter_mut().for_each(|c| *c = Complex32::default());
        
        ifft.process(&mut src.data);
        
        src.data.iter_mut().enumerate().for_each(|(i, c)| {
            *c /= len as f32;
    
            //let (_, phase) = c.to_polar();
            let (_, phase) = c.to_polar();
            
            let mut diff = phase - self.phase;
           
            if diff > 3.141592 {
                diff -= 2.0 * 3.141592;
            } else if diff <= -3.141592 {
                diff += 2.0 * 3.141592;
            }
            
            let deriv = diff * 250000.0 / 1000000.0;
            self.phase = phase;           

            c.re = deriv;
            c.im = 0.0;
            
            let bytes = unsafe { std::mem::transmute::<Complex32, [u8;8]>(*c) };
            
            // std::io::stdout().write(&bytes);
        });
    
        src
    }
}

struct Resampler {
    output_rate: u32,
}

impl Resampler {
    fn new(output_rate: u32) -> Self {
        Self {
            output_rate: output_rate,
        }
    }
}

impl Process for Resampler {
    fn process(&mut self, src: SamplePacket) -> SamplePacket {
        if src.sample_rate == self.output_rate {
            return src;
        }
    
        let skip = src.sample_rate as f32 / self.output_rate as f32;
        let length = (src.data.len() as f32 / skip) as usize;
    
        let mut dst = vec![Complex32::default();length].into_boxed_slice();
        
        //dst.copy_from_slice(&src.data);
        let mut idx = 0.0f32;
        let mut isrc = idx as usize;
        let mut idst = 0;
        while idst < dst.len() && isrc < src.data.len() {
            dst[idst] = src.data[isrc];
        
            idx += skip;
            isrc = idx as usize;
            idst += 1;
        }
        
        SamplePacket::new(self.output_rate, dst)
    }
}

struct AudioSink {
    recv: mpsc::Receiver<SamplePacket>,
    buffer: Option<SamplePacket>,
    idx: usize
}

impl AudioSink {
    fn new(recv: mpsc::Receiver<SamplePacket>) -> Self {
        Self {
            recv: recv,
            buffer: None,
            idx: 0,
        }
    }
    
    fn pour(&mut self, mut dst: &mut [f32]) {
        loop {
            match self.buffer.as_ref() {
                Some(src) => {
                    let src = &src.data;
                    let src_new = &src[self.idx..];
                    let count = std::cmp::min(src_new.len(), dst.len());
                    let src_new = &src_new[..count];
                    let dst_new = &mut dst[..count];
                    
                    dst_new.iter_mut().zip(src_new.iter())
                        .for_each(|(d, s)| *d = s.re);
                    
                    self.idx += count;
                    
                    if self.idx >= src.len() {
                        self.buffer = None;
                        self.idx = 0;
                    }
                    
                    if dst.len() > count {
                        dst = &mut dst[count..];
                        continue;
                    }
                    
                    return;
                },
                None => {
                    self.buffer = Some(self.recv.recv().unwrap());
                }
            };
        }
    }
}

fn main() {
    eframe::run_native(
        "λ",
        eframe::NativeOptions::default(),
        Box::new(|_cc| Box::new(App::default()))
    );

    let host = cpal::default_host();
    let dev = host.default_output_device().expect("no audio device found");
    
    let cfg: cpal::StreamConfig = dev.supported_output_configs()
        .expect("couldn't find configs")
        .next()
        .expect("bogus device")
        .with_max_sample_rate().into();
    let sample_rate = cfg.sample_rate.0 * cfg.channels as u32;
    let denom = cfg.sample_rate.0 as f32 * cfg.channels as f32;

    //println!("sample_rate{}", sample_rate);
    
    let mut inp_file = File::open(Path::new("baseband_100100000Hz_19-35-33_03-11-2022.wav")).unwrap();
    let (header, data) = wav::read(&mut inp_file).unwrap();
    let data = match data {
        wav::BitDepth::ThirtyTwoFloat(d) => d,
        wav::BitDepth::TwentyFour(s) => s.into_iter().map(|m: i32| m as f32 / (1<<23) as f32).collect::<Vec<f32>>(),
        wav::BitDepth::Sixteen(s) => s.into_iter().map(|m: i16| m as f32 / i16::MAX as f32).collect::<Vec<f32>>(),
        _ => panic!("unsupported bit depth")
    };
    
    
    let (send, recv) = PipelineBuilder::new()
        .pipe(BandFilter::new(1024))
        .pipe(Resampler::new(sample_rate))
        .finish();

    let mut snk = AudioSink::new(recv);

    let mut snum: f32 = 0.0;
    let stream = dev.build_output_stream(
        &cfg,
        move |data: &mut [f32], _: &cpal::OutputCallbackInfo| {
            snk.pour(data);
        },
        move |err| {
            println!("err: {}", err);
        }
    ).expect("could not build stream");

    stream.play().unwrap();

    let mut snum: usize = 0;
        

    //println!("{}", header.channel_count);
    
    let sampling_rate = header.sampling_rate as usize;
    let channel_count = header.channel_count as usize;
    
    let mut i = 0;
    while i + sampling_rate*channel_count < data.len() {
        let mut samples = vec![Complex32::default();sampling_rate].into_boxed_slice();
        
        samples.iter_mut().zip(data[i..i + sampling_rate*channel_count].chunks(2))
            .for_each(|(a, b)| *a = Complex32 { re: b[0], im: b[1] });
        
        send.send(SamplePacket::new(header.sampling_rate, samples)).unwrap();
        i += sampling_rate*channel_count;
    }
}