/*
 * Copyright (c) 2020-2021 Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

use std::f64::consts::PI;
use std::ops::Mul;

use crate::{IQSample, Scalar};
use super::Signal;
use super::{Gain, Mixer};

pub struct Sinusoid {
    rate: u64,
    time: u64,
    exp: Vec<IQSample>,
}

impl Sinusoid {
    pub fn new(rate: u64, freq: i64) -> Sinusoid {
        let mut exp = Vec::<IQSample>::with_capacity(rate as usize);
        for i in 0..rate {
            let t = i as Scalar / rate as Scalar;
            let f = freq as Scalar;

            exp.push(IQSample::new(0., 2. * (PI as Scalar) * f * t).exp());
        }

        Sinusoid {
            rate: rate,
            time: 0,
            exp: exp,
        }
    }
}

impl Signal for Sinusoid {
    fn sample_rate(&self) -> u64 {
        self.rate
    }

    fn sample_size(&self) -> usize {
        std::mem::size_of::<IQSample>()
    }

    fn sample_shift(&self) -> u64 {
        0
    }

    fn freq(&self) -> u64 {
        0 /* the center frequency is always 0 */
    }
}

impl Iterator for Sinusoid {
    type Item = IQSample;

    fn next(&mut self) -> Option<Self::Item> {
        let t = self.time as usize;

        self.time = (self.time + 1) % self.rate;

        Some(self.exp[t])
    }
}

include!("math.rs");
signal_math!(Sinusoid);