use crate::av::as_ptr::{AsMutPtr, AsPtr};
use ffmpeg_sys_next::{avio_close_dyn_buf, avio_open_dyn_buf, AVIOContext};
use std::ptr::null_mut;

struct Dynbuf {
    ptr: *mut AVIOContext,
    freed: bool,
}

impl Dynbuf {
    fn new() -> Dynbuf {
        let mut ctx = null_mut();
        unsafe {
            avio_open_dyn_buf(&mut ctx);
        }

        Dynbuf {
            ptr: ctx,
            freed: false,
        }
    }

    fn close(&mut self) -> Vec<u8> {
        let mut buffer = null_mut();
        self.freed = true;
        unsafe {
            let size = avio_close_dyn_buf(self.ptr, &mut buffer);
            Vec::from_raw_parts(buffer, size as usize, size as usize)
        }
    }
}

impl Drop for Dynbuf {
    fn drop(&mut self) {
        if self.freed {
            return;
        }

        unsafe {
            avio_close_dyn_buf(self.ptr, null_mut());
        }
    }
}

impl AsPtr<AVIOContext> for Dynbuf {
    fn as_ptr(&self) -> *const AVIOContext {
        self.ptr
    }
}

impl AsMutPtr<AVIOContext> for Dynbuf {
    fn as_mut_ptr(&self) -> *mut AVIOContext {
        self.ptr
    }
}