use crate::marker::PhantomData;
use crate::slice;

use libc::{iovec, c_void};

#[repr(transparent)]
pub struct IoVec<'a> {
    vec: iovec,
    _p: PhantomData<&'a [u8]>,
}

impl<'a> IoVec<'a> {
    #[inline]
    pub fn new(buf: &'a [u8]) -> IoVec<'a> {
        IoVec {
            vec: iovec {
                iov_base: buf.as_ptr() as *mut u8 as *mut c_void,
                iov_len: buf.len()
            },
            _p: PhantomData,
        }
    }

    #[inline]
    pub fn as_slice(&self) -> &[u8] {
        unsafe {
            slice::from_raw_parts(self.vec.iov_base as *mut u8, self.vec.iov_len)
        }
    }
}

pub struct IoVecMut<'a> {
    vec: iovec,
    _p: PhantomData<&'a mut [u8]>,
}

impl<'a> IoVecMut<'a> {
    #[inline]
    pub fn new(buf: &'a mut [u8]) -> IoVecMut<'a> {
        IoVecMut {
            vec: iovec {
                iov_base: buf.as_mut_ptr() as *mut c_void,
                iov_len: buf.len()
            },
            _p: PhantomData,
        }
    }

    #[inline]
    pub fn as_slice(&self) -> &[u8] {
        unsafe {
            slice::from_raw_parts(self.vec.iov_base as *mut u8, self.vec.iov_len)
        }
    }

    #[inline]
    pub fn as_mut_slice(&mut self) -> &mut [u8] {
        unsafe {
            slice::from_raw_parts_mut(self.vec.iov_base as *mut u8, self.vec.iov_len)
        }
    }
}