//! Foreign function interface utilities.

use crate::durandal::err::*;
pub use std::{ffi::*, os::raw::*, ptr::{null, null_mut}};

/// Creates a C string from a literal.
#[macro_export]
macro_rules! c_str {
   ($s:expr) => {concat!($s, "\0").as_ptr() as *const c_char};
}

impl CStringVec
{
   /// Creates a new empty CStringVec.
   pub fn new() -> Self
   {
      Self::default()
   }

   /// Creates a new `CStringVec` from an iterator.
   pub fn new_from_iter<'a, I: Iterator<Item = &'a str>>(it: I)
      -> ResultS<Self>
   {
      let mut v = Self::new();

      for st in it {
         v.push(CString::new(st)?);
      }

      Ok(v)
   }

   /// Pushes a new `CString`.
   pub fn push(&mut self, st: CString)
   {
      self.cv.push(st.as_c_str().as_ptr());
      self.sv.push(st);
   }

   /// Returns the FFI pointer.
   pub fn as_ptr(&self) -> *const *const c_char
   {
      self.cv.as_ptr()
   }

   /// Returns the FFI pointer mutably.
   pub fn as_mut_ptr(&mut self) -> *mut *const c_char
   {
      self.cv.as_mut_ptr()
   }
}

/// An owned FFI-compatible string vector.
#[derive(Default)]
pub struct CStringVec
{
   sv: Vec<CString>,
   cv: Vec<*const c_char>,
}

// EOF