use std::io::{Read, Result as IOResult};

macro_rules! archive_datatype {
    {
        $vis:vis struct $struct_name:ident {
            $(
                $($fix_field_name:ident: $fix_field_type:ty)?
                $([const] $const_field_name:ident: $const_field_type:ty = $const_field_value:expr)?
                ,
            )*
        }
    }
    => {
        #[derive(Debug)]
        $vis struct $struct_name { $($(pub $fix_field_name: $fix_field_type,)?)* }

        #[allow(unused)]
        impl $struct_name {
            $($(pub const $const_field_name: $const_field_type = $const_field_value;)?)*
        }


        impl ArchiveDatatype<{$($((<$fix_field_type>::BITS as usize / 8)+)?)* 0}> for $struct_name {
            fn parse(buf: [u8; Self::SIZE]) -> Self {
                let mut byte = 0;

                $($(
                    byte += (<$fix_field_type>::BITS / 8) as usize;
                    let $fix_field_name = <$fix_field_type>::from_le_bytes(buf[byte - (<$fix_field_type>::BITS as usize / 8)..byte].try_into().unwrap());
                )?)*

                Self { $($($fix_field_name,)?)* }
            }

            fn dump(&self) -> [u8; Self::SIZE] {
                [$($(&self.$fix_field_name.to_le_bytes()[..],)?)*]
                .concat()
                .try_into()
                .unwrap()
            }
        }
    }
}
pub(crate) use archive_datatype;

pub trait ReadHelper: Read {
    fn read2buf<const SIZE: usize>(&mut self) -> IOResult<[u8; SIZE]> {
        let mut buf = [0; SIZE];
        self.read(&mut buf)?;
        Ok(buf)
    }

    fn read2vec(&mut self, size: usize) -> IOResult<Vec<u8>> {
        let mut buf = vec![0; size];
        self.read(&mut buf)?;
        Ok(buf)
    }
}

impl<R: Read> ReadHelper for R {}