pub struct Tcp<'p> {
	src: u16,
	dst: u16,
	payload: &'p [u8],
}

impl<'p> Tcp<'p> {
	pub fn new(buffer: &'p [u8]) -> Self {
		let src = u16::from_be_bytes([buffer[0], buffer[1]]);
		let dst = u16::from_be_bytes([buffer[2], buffer[3]]);
		let data_offset = (buffer[12].to_be() & 0b1111_0000) >> 4;
		// Offset is number of 32-bit words
		let true_offset = data_offset as usize * 4;

		Self {
			src,
			dst,
			payload: &buffer[true_offset..],
		}
	}

	pub fn source_port(&self) -> u16 {
		self.src
	}

	pub fn destination_port(&self) -> u16 {
		self.dst
	}

	pub fn payload(&self) -> &[u8] {
		self.payload
	}
}

pub struct Udp<'p> {
	src: u16,
	dst: u16,
	payload: &'p [u8],
}

impl<'p> Udp<'p> {
	pub fn new(buffer: &'p [u8]) -> Self {
		let src = u16::from_be_bytes([buffer[0], buffer[1]]);
		let dst = u16::from_be_bytes([buffer[2], buffer[3]]);
		let _len = u16::from_be_bytes([buffer[4], buffer[5]]);

		Self {
			src,
			dst,
			payload: &buffer[8..],
		}
	}

	pub fn source_port(&self) -> u16 {
		self.src
	}

	pub fn destination_port(&self) -> u16 {
		self.dst
	}

	pub fn payload(&self) -> &[u8] {
		self.payload
	}
}