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use bp3d_debug::trace;

use crate::buffer::{BufferView, Location};

use crate::component::{Component, ComponentType, util::DiscoverTool};

pub struct Optional<T: ComponentType>(pub T);

impl<T: ComponentType> Component for Optional<T> {

    fn read(&self, view: &mut BufferView, items: &mut DiscoverTool) -> bp3d_proto::message::Result<()> {

        view.location_mut().size = 1;

        let v = view.buffer().as_bytes()[0];

        if v != 0 {

  Branch (39:12): [Folded - Ignored]

  Branch (39:12): [True: 2, False: 4]

            trace!({v}, "discover child");

            items.discover_child(&self.0, Location {

                offset: -1,

                size: 0,

                fixed: false

            });

        }

        Ok(())

    }

    fn shape(&self, view: &mut BufferView, _: &Vec<BufferView>) -> bp3d_proto::message::Result<()> {

        if view.buffer().is_empty() {

  Branch (51:12): [Folded - Ignored]

  Branch (51:12): [True: 2, False: 4]

            trace!("allocate optional");

            view.buffer_mut().set_bytes(b"\0");

        }

        if !view.is_empty() {

  Branch (55:12): [Folded - Ignored]

  Branch (55:12): [True: 2, False: 4]

            trace!("child found");

            view.buffer_mut().as_bytes_mut()[0] = 1;

            unsafe { view.iter_mut().next().unwrap_unchecked() }.location_mut().offset = 1;

        } else {

            trace!("no children");

            view.buffer_mut().as_bytes_mut()[0] = 0;

        }

        Ok(())

    }

}