use crate::*;
use paste::paste;
use std::{convert::TryFrom, ffi::c_void, mem::size_of};

// Can't be autogenerated by bindgen since these are defined in a header.
macro_rules! apk_array_funcs {
    ($x:ident) => {
        impl Drop for $x {
            fn drop(&mut self) {
                if self.num != 0 {
                    unsafe { apk_array_resize(self as *mut Self as *mut c_void, 0, 0) };
                }
            }
        }
    };
    ($x:ident, $type:ty) => {
        apk_array_funcs!($x);

        paste! {
            pub unsafe fn [<$x _resize>](a: *mut *mut $x, size: usize) {
                *a = apk_array_resize(*a as *mut c_void, size, size_of::<$type>()) as *mut $x
            }

            pub unsafe fn [<$x _add>](a: *mut *mut $x) -> *mut $type {
                let size = (*(*a)).num + 1;
                [<$x _resize>](a, size);
                &mut (*(*a)).item.as_mut_slice(size)[size - 1] as *mut $type
            }

            pub unsafe fn [<$x _copy>](a: *mut *mut $x , b: *mut $x) {
                if *a == b {
                    return;
                }

                [<$x _resize>](a, (*b).num);
                std::ptr::copy_nonoverlapping((*b).item.as_ptr(), (*(*a)).item.as_mut_ptr(), (*b).num);
            }
        }

        impl $x {
            pub fn as_slice(&self) -> Result<&[$type], std::num::TryFromIntError> {
                Ok(unsafe { self.item.as_slice(usize::try_from(self.num)?) })
            }

            pub fn as_mut_slice(&mut self) -> Result<&mut [$type], std::num::TryFromIntError> {
                Ok(unsafe { self.item.as_mut_slice(usize::try_from(self.num)?) })
            }

            pub fn iter(&self) -> Result<std::slice::Iter<$type>, std::num::TryFromIntError> {
                self.as_slice().map(|s| s.iter())
            }

            pub fn iter_mut(
                &mut self,
            ) -> Result<std::slice::IterMut<$type>, std::num::TryFromIntError> {
                self.as_mut_slice().map(|s| s.iter_mut())
            }
        }
    };
}

apk_array_funcs!(apk_string_array, *mut std::os::raw::c_char);
apk_array_funcs!(apk_hash_array, hlist_head);
apk_array_funcs!(apk_xattr_array, apk_xattr);
apk_array_funcs!(apk_provider_array, apk_provider);
apk_array_funcs!(apk_dependency_array, apk_dependency);
apk_array_funcs!(apk_package_array, *mut apk_package);
apk_array_funcs!(apk_name_array, *mut apk_name);
apk_array_funcs!(apk_protected_path_array, apk_protected_path);
apk_array_funcs!(apk_change_array, apk_change);

impl Drop for apk_changeset {
    fn drop(&mut self) {
        unsafe { apk_array_resize(self.changes.cast(), 0, 0) };
    }
}