extern crate rusty_dsp;

use rusty_dsp::error::DspError;

pub struct SymbolGenerator<'a> {
    space_freq: f32,
    mark_freq: f32,
    iterator: Box<dyn Iterator<Item = Result<bool, DspError>> + 'a>,
}

impl<'a> SymbolGenerator<'a> {
    pub fn from<I>(iterator: I, space_freq: f32, mark_freq: f32) -> SymbolGenerator<'a>
    where
        I: Iterator<Item = Result<bool, DspError>> + 'a,
    {
        SymbolGenerator {
            space_freq: space_freq,
            mark_freq: mark_freq,
            iterator: Box::new(iterator),
        }
    }
}

impl<'a> Iterator for SymbolGenerator<'a> {
    type Item = Result<f32, DspError>;

    fn next(&mut self) -> Option<Self::Item> {
        match self.iterator.next() {
            Some(Ok(b)) => {
                if b {
                    Some(Ok(self.mark_freq))
                } else {
                    Some(Ok(self.space_freq))
                }
            }
            None => None,
            Some(Err(e)) => Some(Err(e)),
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_symbolgenerator() {
        let input = vec![true, false, true];

        let generator = SymbolGenerator::from(input.into_iter().map(|x| Ok(x)), 23000.0, 42000.0);

        let result_data: Result<Vec<f32>, DspError> = generator.collect();
        assert_eq!(result_data, Ok(vec![42000.0, 23000.0, 42000.0]));
    }
}