use std::{str, net, io};
use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
use ser::{Serializable, Stream, Deserializable, Reader, Error as ReaderError};

#[derive(Debug, PartialEq, Clone, Copy)]
pub struct IpAddress(net::IpAddr);

impl From<net::IpAddr> for IpAddress {
	fn from(ip: net::IpAddr) -> Self {
		IpAddress(ip)
	}
}

impl From<IpAddress> for net::IpAddr {
	fn from(ip: IpAddress) -> Self {
		ip.0
	}
}

impl From<&'static str> for IpAddress {
	fn from(s: &'static str) -> Self {
		s.parse().unwrap()
	}
}

impl str::FromStr for IpAddress {
	type Err = <net::IpAddr as str::FromStr>::Err;

	fn from_str(s: &str) -> Result<Self, Self::Err> {
		s.parse().map(IpAddress)
	}
}

impl Serializable for IpAddress {
	fn serialize(&self, stream: &mut Stream) {
		match self.0 {
			net::IpAddr::V4(address) => {
				stream
					.append_slice(&[0u8; 12])
					.append_slice(&address.octets());
			},
			net::IpAddr::V6(address) => {
				for segment in &address.segments() {
					stream.write_u16::<BigEndian>(*segment).unwrap();
				}
			},
		}
	}
}

impl Deserializable for IpAddress {
	fn deserialize<T>(reader: &mut Reader<T>) -> Result<Self, ReaderError> where T: io::Read {
		let bytes: &mut [u8] = &mut [0u8; 12];
		try!(reader.read_slice(bytes));
		if bytes == &[0u8; 12] {
			let mut address: &mut [u8] = &mut [0u8; 4];
			try!(reader.read_slice(address));
			let address = net::Ipv4Addr::new(address[0], address[1], address[2], address[3]);
			Ok(IpAddress(net::IpAddr::V4(address)))
		} else {
			// compiler needs some help here...
			let mut b = bytes as &[u8];
			let address = net::Ipv6Addr::new(
				try!(b.read_u16::<BigEndian>()),
				try!(b.read_u16::<BigEndian>()),
				try!(b.read_u16::<BigEndian>()),
				try!(b.read_u16::<BigEndian>()),
				try!(b.read_u16::<BigEndian>()),
				try!(b.read_u16::<BigEndian>()),
				try!(reader.read_u16::<BigEndian>()),
				try!(reader.read_u16::<BigEndian>())
			);
			Ok(IpAddress(net::IpAddr::V6(address)))
		}
	}
}

#[cfg(test)]
mod test {
	use std::net;
	use ser::{serialize, deserialize};
	use super::IpAddress;

	#[test]
	fn test_ip_serialize() {
		let ip = IpAddress(net::IpAddr::V6("::ffff:a00:1".parse().unwrap()));
		assert_eq!(serialize(&ip), vec![0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0x0a, 0x00, 0x00, 0x01].into());
		let ip = IpAddress(net::IpAddr::V4("10.0.0.1".parse().unwrap()));
		assert_eq!(serialize(&ip), vec![0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0a, 0x00, 0x00, 0x01].into());
	}

	#[test]
	fn test_ip_deserialize() {
		let ip: IpAddress = deserialize(&[0x00u8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0x0a, 0x00, 0x00, 0x01] as &[u8]).unwrap();
		assert_eq!(ip, IpAddress(net::IpAddr::V6("::ffff:a00:1".parse().unwrap())));
		let ip: IpAddress = deserialize(&[0x00u8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0a, 0x00, 0x00, 0x01] as &[u8]).unwrap();
		assert_eq!(ip, IpAddress(net::IpAddr::V4("10.0.0.1".parse().unwrap())));
	}
}
