use std::sync::Arc;

/// shared interleaved-stereo pcm bundle paired with the track's sample rate and dsp frame size.
#[derive(Debug, Clone)]
pub struct TrackData {
    pub pcm: Arc<[f32]>,
    pub sample_rate: u32,
    pub frame_size: usize,
}

impl TrackData {
    /// builds a zero-length placeholder at 48 kHz with a 4096-sample frame.
    pub fn empty() -> Self {
        Self {
            pcm: Arc::from(Vec::<f32>::new()),
            sample_rate: 48_000,
            frame_size: 4096,
        }
    }

    /// counts stereo frames (pcm length divided by two channels).
    pub fn total_samples(&self) -> usize {
        self.pcm.len() / 2
    }

    /// reports whether the pcm slice holds any samples.
    pub fn is_valid(&self) -> bool {
        !self.pcm.is_empty()
    }
}

impl Default for TrackData {
    fn default() -> Self {
        Self::empty()
    }
}