use anyhow::bail;

pub mod matroska;
pub mod read;
pub mod write;

#[derive(Debug, Clone)]
pub enum Master {
    Start,
    End,
}

pub trait ValueFromBuf: Sized {
    fn from_buf(buf: &[u8]) -> anyhow::Result<Self>;
}

impl ValueFromBuf for u64 {
    fn from_buf(buf: &[u8]) -> anyhow::Result<Self> {
        // if buf.len() != 8 {
        //     bail!("u64 is not 64 bits long")
        // }
        // Ok((buf[0] as u64) << 24
        //     | (buf[1] as u64) << 16
        //     | (buf[2] as u64) << 8
        //     | (buf[3] as u64) << 0)
        if buf.len() > 8 {
            bail!("u64 too big")
        }
        let mut val = 0u64;
        for byte in buf {
            val <<= 8;
            val |= *byte as u64;
        }
        Ok(val)
    }
}
impl ValueFromBuf for Vec<u8> {
    fn from_buf(buf: &[u8]) -> anyhow::Result<Self> {
        Ok(buf.to_vec())
    }
}
impl ValueFromBuf for String {
    fn from_buf(buf: &[u8]) -> anyhow::Result<Self> {
        Ok(String::from_utf8(Vec::from(buf))?)
    }
}