use crate::errors::*;
use crate::ser::packet::{DnsPacketData, DnsPacketWriteContext};
use crate::ser::text::{next_field, DnsTextContext, DnsTextData, DnsTextFormatter};
use bytes::Bytes;
use std::fmt;
use std::io::{Cursor, Read};

fn fmt_eui_hyphens(data: &[u8], f: &mut fmt::Formatter) -> fmt::Result {
	write!(f, "{:02x}", data[0])?;
	for v in &data[1..] {
		write!(f, "-{:02x}", v)?;
	}
	Ok(())
}

fn parse_eui_hyphens(dest: &mut [u8], source: &str) -> Result<()> {
	let mut pos = 0;
	for octet in source.split('-') {
		failure::ensure!(
			pos < dest.len(),
			"too many octets for EUI{}",
			dest.len() * 8
		);
		failure::ensure!(octet.len() == 2, "invalid octet {:?}", octet);
		match u8::from_str_radix(octet, 16) {
			Ok(o) => {
				dest[pos] = o;
				pos += 1;
			},
			Err(_) => {
				failure::bail!("invalid octet {:?}", octet);
			},
		}
	}
	failure::ensure!(
		pos == dest.len(),
		"not enough octets for EUI{}",
		dest.len() * 8
	);
	Ok(())
}

#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
pub struct EUI48Addr(pub [u8; 6]);

impl fmt::Display for EUI48Addr {
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
		fmt_eui_hyphens(&self.0, f)
	}
}

impl fmt::Debug for EUI48Addr {
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
		fmt_eui_hyphens(&self.0, f)
	}
}

impl std::str::FromStr for EUI48Addr {
	type Err = failure::Error;

	fn from_str(s: &str) -> Result<Self> {
		let mut buf = [0u8; 6];
		parse_eui_hyphens(&mut buf, s)?;
		Ok(EUI48Addr(buf))
	}
}

impl DnsPacketData for EUI48Addr {
	fn deserialize(data: &mut Cursor<Bytes>) -> Result<Self> {
		let mut buf = [0u8; 6];
		check_enough_data!(data, 6, "not enough bytes for EUI48Addr");
		data.read_exact(&mut buf)?;
		Ok(EUI48Addr(buf))
	}

	fn serialize(&self, _context: &mut DnsPacketWriteContext, packet: &mut Vec<u8>) -> Result<()> {
		packet.extend_from_slice(&self.0);
		Ok(())
	}
}

impl DnsTextData for EUI48Addr {
	fn dns_parse(_context: &DnsTextContext, data: &mut &str) -> Result<Self> {
		next_field(data)?.parse()
	}

	fn dns_format(&self, f: &mut DnsTextFormatter) -> fmt::Result {
		write!(f, "{}", self)
	}
}

impl From<[u8; 6]> for EUI48Addr {
	fn from(v: [u8; 6]) -> Self {
		EUI48Addr(v)
	}
}

impl Into<[u8; 6]> for EUI48Addr {
	fn into(self) -> [u8; 6] {
		self.0
	}
}

#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
pub struct EUI64Addr(pub [u8; 8]);

impl fmt::Display for EUI64Addr {
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
		fmt_eui_hyphens(&self.0, f)
	}
}

impl fmt::Debug for EUI64Addr {
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
		fmt_eui_hyphens(&self.0, f)
	}
}

impl std::str::FromStr for EUI64Addr {
	type Err = failure::Error;

	fn from_str(s: &str) -> Result<Self> {
		let mut buf = [0u8; 8];
		parse_eui_hyphens(&mut buf, s)?;
		Ok(EUI64Addr(buf))
	}
}

impl DnsPacketData for EUI64Addr {
	fn deserialize(data: &mut Cursor<Bytes>) -> Result<Self> {
		let mut buf = [0u8; 8];
		check_enough_data!(data, 8, "not enough bytes for EUI64Addr");
		data.read_exact(&mut buf)?;
		Ok(EUI64Addr(buf))
	}

	fn serialize(&self, _context: &mut DnsPacketWriteContext, packet: &mut Vec<u8>) -> Result<()> {
		packet.extend_from_slice(&self.0);
		Ok(())
	}
}

impl DnsTextData for EUI64Addr {
	fn dns_parse(_context: &DnsTextContext, data: &mut &str) -> Result<Self> {
		next_field(data)?.parse()
	}

	fn dns_format(&self, f: &mut DnsTextFormatter) -> fmt::Result {
		write!(f, "{}", self)
	}
}

impl From<[u8; 8]> for EUI64Addr {
	fn from(v: [u8; 8]) -> Self {
		EUI64Addr(v)
	}
}

impl Into<[u8; 8]> for EUI64Addr {
	fn into(self) -> [u8; 8] {
		self.0
	}
}