use alloc::{boxed::Box, vec, vec::Vec};
use core::{convert::TryFrom, marker::PhantomData};
use crate::codec::{Codec, Decode, Encode};
use crate::io::{Read, Seek, SeekFrom, Write};
#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
pub struct RawValue<C> {
data: Box<[u8]>,
_p: PhantomData<C>,
}
impl<C> RawValue<C> {
fn new(data: Box<[u8]>) -> Self {
Self {
data,
_p: PhantomData,
}
}
}
impl<C> AsRef<[u8]> for RawValue<C> {
fn as_ref(&self) -> &[u8] {
&self.data
}
}
impl<C> From<RawValue<C>> for Box<[u8]> {
fn from(value: RawValue<C>) -> Self {
value.data
}
}
impl<C> From<RawValue<C>> for Vec<u8> {
fn from(value: RawValue<C>) -> Self {
value.data.into()
}
}
pub trait SkipOne: Codec {
fn skip<R: Read + Seek>(&self, r: &mut R) -> anyhow::Result<()>;
}
impl<C: Codec + SkipOne> Decode<C> for RawValue<C> {
fn decode<R: Read + Seek>(c: C, r: &mut R) -> anyhow::Result<Self> {
let p0 = r.seek(SeekFrom::Current(0)).map_err(anyhow::Error::msg)?;
c.skip(r)?;
let p1 = r.seek(SeekFrom::Current(0)).map_err(anyhow::Error::msg)?;
anyhow::ensure!(p1 > p0);
let len = usize::try_from(p1 - p0).map_err(anyhow::Error::msg)?;
r.seek(SeekFrom::Start(p0)).map_err(anyhow::Error::msg)?;
let mut buf = vec![0u8; len];
r.read_exact(&mut buf).map_err(anyhow::Error::msg)?;
Ok(Self::new(buf.into()))
}
}
impl<C: Codec> Encode<C> for RawValue<C> {
fn encode<W: Write>(&self, _: C, w: &mut W) -> anyhow::Result<()> {
w.write_all(&self.data).map_err(anyhow::Error::msg)?;
Ok(())
}
}
#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Default)]
pub struct IgnoredAny;
impl<C: Codec + SkipOne> Decode<C> for IgnoredAny {
fn decode<R: Read + Seek>(c: C, r: &mut R) -> anyhow::Result<Self> {
c.skip(r)?;
Ok(Self)
}
}