use serde::{Deserialize, Serialize};

#[derive(Serialize, Deserialize)]
pub struct Message {
    pub init: Option<Init>,
    pub segment: Option<Segment>,
}

#[derive(Serialize, Deserialize)]
pub struct Init {}

#[derive(Serialize, Deserialize)]
pub struct Segment {
    pub track_id: u32,
}

impl Message {
    pub fn new() -> Self {
        Message {
            init: None,
            segment: None,
        }
    }

    pub fn serialize(&self) -> anyhow::Result<Vec<u8>> {
        let str = serde_json::to_string(self)?;
        let bytes = str.as_bytes();
        let size = bytes.len() + 8;

        let mut out = Vec::with_capacity(size);
        out.extend_from_slice(&(size as u32).to_be_bytes());
        out.extend_from_slice(b"warp");
        out.extend_from_slice(bytes);

        Ok(out)
    }
}