#![allow(incomplete_features)]
#![feature(generic_associated_types)]

use std::time::Duration;

use baseplug::{MidiReceiver, Plugin, ProcessContext};
use ringbuf::{Consumer, Producer, RingBuffer};
use serde::{Deserialize, Serialize};

use utils::buffers::*;
use utils::logs::*;

mod tuna;

const BUFFER_LEN: usize = 2 << 10;
const OVERLAP: usize = BUFFER_LEN / 3;

baseplug::model! {
    #[derive(Debug, Serialize, Deserialize)]
    struct RoboTunaModel {
        #[model(min = 0.0, max = 1.0)]
        #[parameter(name = "manual/snap")]
        manual: f32,
        #[model(min = 0.1, max = 2.0)]
        #[parameter(name = "frequency gain")]
        freq_gain: f32,
    }
}

impl Default for RoboTunaModel {
    fn default() -> Self {
        Self {
            manual: 1.0,
            freq_gain: 1.0,
        }
    }
}

struct RoboTuna {
    /// Current midi note
    note: Option<u8>,

    /// Current recording buffer
    /// Input goes here
    recording_buffer: Buffers<BUFFER_LEN>,
    /// The next recording buffer we'll use. It gets a bit of the end of the `recording_buffer`
    /// so we can do overlap
    next_recording_buffer: Buffers<BUFFER_LEN>,
    /// Current playing buffer
    /// Output comes from here
    playing_buffer: Buffers<BUFFER_LEN>,
    /// Next playing buffer we'll use
    /// We start using it at the end of the previous buffer so we can overlap
    next_playing_buffer: Buffers<BUFFER_LEN>,

    /// Ringbuf producer so we can send audio chunks to the processing thread
    recordings: Producer<tuna::ProcessChunk>,
    /// Ringbuf consumer so we can receive processed buffers from the processing threads
    processed: Consumer<Buffers<BUFFER_LEN>>,

    /// Contains some empty buffers so we can reuse them instead of doing allocations
    /// Buffers here are not actually empty, since we don't spend any time clearing them
    /// But since they will be overwritten, this isn't an issue
    empty_buffers: Vec<Buffers<BUFFER_LEN>>,
}

// LMAO let's go, i think this works

impl Plugin for RoboTuna {
    const NAME: &'static str = "robotuna";
    const PRODUCT: &'static str = "robotuna";
    const VENDOR: &'static str = "unnieversal";

    const INPUT_CHANNELS: usize = 2;
    const OUTPUT_CHANNELS: usize = 2;

    type Model = RoboTunaModel;

    #[inline]
    fn new(_sample_rate: f32, _model: &RoboTunaModel) -> Self {
        setup_logging("robotuna.log");

        let (recordings, recording_rx) = RingBuffer::<tuna::ProcessChunk>::new(10).split();
        let (processed_tx, processed) = RingBuffer::<Buffers<BUFFER_LEN>>::new(10).split();

        // Spawn analysis thread
        std::thread::spawn(move || {
            tuna::tuna(recording_rx, processed_tx);
        });

        // keep some empty buffer around so we can swap them
        let mut empty_buffers = Vec::with_capacity(50);
        const BUF: Buffers<BUFFER_LEN> = Buffers::new();
        empty_buffers.append(&mut vec![BUF; 30]);

        log::info!("finished init");

        Self {
            note: None,
            recording_buffer: Buffers::new(),
            next_recording_buffer: Buffers::new(),
            playing_buffer: Buffers::new(),
            next_playing_buffer: Buffers::new(),
            recordings,
            processed,
            empty_buffers,
        }
    }

    #[inline]
    fn process(&mut self, model: &RoboTunaModelProcess, ctx: &mut ProcessContext<Self>) {
        let input = &ctx.inputs[0].buffers;
        let output = &mut ctx.outputs[0].buffers;

        for i in 0..ctx.nframes {
            // Record

            // Add to main buffer
            let full = self
                .recording_buffer
                .write_advance(input[0][i], input[1][i]);
            // If we're in overlap section, also add to next buffer
            if self.recording_buffer.idx > BUFFER_LEN - OVERLAP {
                self.next_recording_buffer
                    .write_advance(input[0][i], input[1][i]);
            }
            // If we finish the buffer, switch them
            if full {
                // get the empty buffer from unused buffer list
                let mut buf = self
                    .empty_buffers
                    .pop()
                    .expect("should have an empty buffer");
                buf.reset();
                std::mem::swap(&mut buf, &mut self.recording_buffer);
                buf.reset();

                std::mem::swap(&mut self.next_recording_buffer, &mut self.recording_buffer);

                let _ = self.recordings.push(tuna::ProcessChunk {
                    buffers: buf,
                    sample_rate: ctx.sample_rate as u32,
                    note: self.note,
                    manual: model.manual[i] <= 0.5,
                    freq_gain: model.freq_gain[i],
                });
            }

            // Play

            // Get values from main buffer
            let (mut l, mut r, full) = self.playing_buffer.read_advance();
            // If we're in overlap section, also play from next buffer
            if self.playing_buffer.idx > BUFFER_LEN - OVERLAP {
                let (l1, r1, _) = self.next_playing_buffer.read_advance();

                // How much into overlap we are, from 0 to 1
                let overlap =
                    (OVERLAP - (BUFFER_LEN - self.playing_buffer.idx)) as f32 / OVERLAP as f32;

                // Linearly crossfade
                // lineal crossfade works well for two waves that are highly correlated
                l *= 1. - overlap;
                r *= 1. - overlap;
                l += overlap * l1;
                r += overlap * r1;
            }
            // If we finish the buffer, switch them
            if full {
                // We try to switch like with the recording buffer, but since there might not be a processed
                // buffer yet, we do it in a loop and retry every 1 millisecond
                // After 10 iterations we give up. Since we didn't swap the buffer, we're gonna play the last one
                // again. This isn't ideal, but it's better than silence ig (it might not be, idk)

                // The 10 iterations is arbitrary, as is the 1 millisecond wait time

                for _ in 0..10 {
                    if let Some(mut buf) = self.processed.pop() {
                        buf.reset();
                        std::mem::swap(&mut buf, &mut self.playing_buffer);
                        buf.reset();

                        std::mem::swap(&mut self.next_playing_buffer, &mut self.playing_buffer);

                        // Stick buf in unused buffer list
                        self.empty_buffers.push(buf);

                        // Exit loop
                        break;
                    } else {
                        log::info!("didn't have a processed buffer to swap to, retrying");
                    }
                    std::thread::sleep(Duration::from_millis(1));
                }
            }

            output[0][i] = l;
            output[1][i] = r;
        }
    }
}
impl MidiReceiver for RoboTuna {
    fn midi_input(&mut self, _model: &RoboTunaModelProcess, data: [u8; 3]) {
        match data[0] {
            // note on
            0x90 => {
                self.note = Some(data[1]);
            }
            // note off
            0x80 => {
                // only set note to None if it's the same one we currently have
                if let Some(n) = self.note {
                    if n == data[1] {
                        self.note = None;
                    }
                }
            }

            _ => (),
        }
    }
}

baseplug::vst2!(RoboTuna, b"tuna");