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mod data;
mod error;
mod fd_data;
mod id;
mod remote;

use crate::sys;
pub use data::DataFrame;
pub use error::ErrorFrame;
pub use fd_data::FdDataFrame;
pub use id::Id;
pub use remote::RemoteFrame;
use std::mem::{size_of, size_of_val, MaybeUninit};
use std::os::raw::c_void;

#[non_exhaustive]
#[derive(Clone, Copy, Debug)]
#[cfg_attr(test, derive(PartialEq))]
pub enum Frame {
    Data(DataFrame),
    FdData(FdDataFrame),
    Remote(RemoteFrame),
    #[doc(hidden)]
    Error(ErrorFrame),
}

impl Frame {
    pub(crate) unsafe fn from_raw(
        frame: MaybeUninit<sys::canfd_frame>,
        size: usize,
    ) -> Option<Self> {
        if size == size_of::<sys::can_frame>() {
            let inner = *(frame.as_ptr() as *const sys::can_frame);
            if inner.can_id & sys::CAN_RTR_FLAG != 0 {
                Some(Self::Remote(RemoteFrame(inner)))
            } else if inner.can_id & sys::CAN_ERR_FLAG != 0 {
                Some(Self::Error(ErrorFrame(inner)))
            } else {
                Some(Self::Data(DataFrame(inner)))
            }
        } else if size == size_of::<sys::canfd_frame>() {
            let inner = frame.assume_init();
            assert_eq!(inner.can_id & (sys::CAN_RTR_FLAG | sys::CAN_ERR_FLAG), 0);
            Some(Self::FdData(FdDataFrame(inner)))
        } else {
            None
        }
    }

    pub(crate) fn as_ptr(&self) -> *const c_void {
        match self {
            Self::Data(DataFrame(inner))
            | Self::Remote(RemoteFrame(inner))
            | Self::Error(ErrorFrame(inner)) => inner as *const _ as _,
            Self::FdData(FdDataFrame(inner)) => inner as *const _ as _,
        }
    }

    pub(crate) fn size(&self) -> usize {
        match self {
            Self::Data(DataFrame(inner))
            | Self::Remote(RemoteFrame(inner))
            | Self::Error(ErrorFrame(inner)) => size_of_val(inner),
            Self::FdData(FdDataFrame(inner)) => size_of_val(inner),
        }
    }
}

#[cfg(test)]
mod tests;