use arbitrary_int::u14;

pub use super::shared::Ownership;

/// TX buffer descriptor.
///
/// The user should declare an array of this structure inside uncached memory.
///
/// These descriptors are shared between software and hardware and contain information
/// related to frame reception.
#[repr(C)]
pub struct Descriptor {
    /// The first word of the descriptor which is the byte address of the buffer.
    pub word0: u32,
    /// The second word of the descriptor.
    pub word1: Word1,
}

#[bitbybit::bitenum(u3, exhaustive = true)]
#[derive(Debug, PartialEq, Eq)]
pub enum TransmitChecksumGenerationStatus {
    NoError = 0b000,
    VlanError = 0b001,
    SnapError = 0b010,
    IpError = 0b011,
    NotVlanOrSnapOrIp = 0b100,
    NonSupportedPacketFragmentation = 0b101,
    PacketNotTcpUdp = 0b110,
    PrematureEndOfFrame = 0b111,
}

#[bitbybit::bitfield(u32, default = 0x0)]
#[derive(Debug, PartialEq, Eq)]
pub struct Word1 {
    #[bit(31, rw)]
    ownership: Ownership,
    #[bit(30, rw)]
    wrap: bool,
    #[bit(29, rw)]
    retry_limit_exceeded: bool,
    #[bit(27, rw)]
    transmit_frame_corruption_ahb_error: bool,
    #[bit(26, rw)]
    late_collision: bool,
    #[bits(20..=22, rw)]
    checksum_status: TransmitChecksumGenerationStatus,
    #[bit(16, rw)]
    no_crc_generation: bool,
    #[bit(15, rw)]
    last_buffer: bool,
    #[bits(0..=13, rw)]
    tx_len: u14,
}

impl Descriptor {
    #[inline]
    pub fn set_ownership(&mut self, ownership: Ownership) {
        self.word1.set_ownership(ownership);
    }

    /// Set the wrap bit, which should be done for the last descriptor in the descriptor list.
    #[inline]
    pub fn set_wrap_bit(&mut self) {
        self.word1.set_wrap(true);
    }

    /// Set the information for a transfer.
    pub fn set_tx_transfer_info(
        &mut self,
        tx_len: u14,
        last_buffer: bool,
        no_crc_generation: bool,
    ) {
        self.word1.set_tx_len(tx_len);
        self.word1.set_last_buffer(last_buffer);
        self.word1.set_no_crc_generation(no_crc_generation);
    }
}