//! # Delay

use super::*;
use std::time::Duration;
use std::collections::VecDeque;

/// Delay modifier, delays a signal by a given amount of time rounded to the
/// nearest sample.
pub struct Delay {
    delay: VecDeque<SampleT>,
}

impl Delay {
    /// Creates a new Delay object from the given duration rounded to the
    /// nearest sample.
    pub fn new(d: Duration) -> Self {
        let mut v = VecDeque::new();

        for _ in 0..((d.as_secs_f64()*SAMPLE_RATE as MathT).round() as usize) {
            v.push_back(SampleT::default());
        }

        Delay {
            delay:v
        }
    }

    /// Returns the delay of the Modifier in a Duration value.
    pub fn get_delay(&self) -> Duration {
        Duration::from_secs_f64(self.delay.len() as MathT / SAMPLE_RATE as MathT)
    }
}

impl Modifier for Delay {
    fn process(&mut self, x: SampleT) -> SampleT {
        self.delay.push_back(x);

        self.delay.pop_front().unwrap()
    }
}

impl Clone for Delay {
    fn clone(&self) -> Self {
        Delay {
            delay: {
                let mut v = VecDeque::new();

                for _ in 0..(self.delay.len() * SAMPLE_RATE as usize) {
                    v.push_back(SampleT::default());
                }

                v
            }
        }
    }
}