use binrw::{binrw, BinRead, BinWrite};
use std::ops::{Deref, DerefMut};

/// Wrapper to prefix array of single type
#[binrw]
#[derive(Debug, PartialEq)]
pub struct ArrayOf<T>
where
    // Static bounds due to https://github.com/jam1garner/binrw/issues/199
    T: for<'a> BinRead<Args<'a> = ()> + 'static,
    T: for<'a> BinWrite<Args<'a> = ()> + 'static,
{
    // Temporary variable that holds number of elements
    #[br(temp)]
    #[bw(try_calc(u32::try_from(value.len())))]
    count: u32,

    #[br(count = count)]
    pub value: Vec<T>,
}

impl<T> Deref for ArrayOf<T>
where
    T: for<'a> BinRead<Args<'a> = ()> + 'static,
    T: for<'a> BinWrite<Args<'a> = ()> + 'static,
{
    type Target = Vec<T>;

    fn deref(&self) -> &Self::Target {
        &self.value
    }
}

impl<T> DerefMut for ArrayOf<T>
where
    T: for<'a> BinRead<Args<'a> = ()> + 'static,
    T: for<'a> BinWrite<Args<'a> = ()> + 'static,
{
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.value
    }
}

impl<T> From<Vec<T>> for ArrayOf<T>
where
    T: for<'a> BinRead<Args<'a> = ()> + 'static,
    T: for<'a> BinWrite<Args<'a> = ()> + 'static,
{
    fn from(value: Vec<T>) -> Self {
        Self { value }
    }
}