// Rust Bitcoin Library
// Written in 2014 by
//     Andrew Poelstra <apoelstra@wpsoftware.net>
//
// To the extent possible under law, the author(s) have dedicated all
// copyright and related and neighboring rights to this software to
// the public domain worldwide. This software is distributed without
// any warranty.
//
// You should have received a copy of the CC0 Public Domain Dedication
// along with this software.
// If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
//

//! Bitcoin network addresses
//!
//! This module defines the structures and functions needed to encode
//! network addresses in Bitcoin messages.
//!

use std::fmt;
use std::io;
use std::net::{Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6};

use consensus::encode::{self, Decoder, Encoder};
use consensus::encode::{Decodable, Encodable};

/// A message which can be sent on the Bitcoin network
pub struct Address {
    /// Services provided by the peer whose address this is
    pub services: u64,
    /// Network byte-order ipv6 address, or ipv4-mapped ipv6 address
    pub address: [u16; 8],
    /// Network port
    pub port: u16,
}

const ONION: [u16; 3] = [0xFD87, 0xD87E, 0xEB43];

impl Address {
    /// Create an address message for a socket
    pub fn new(socket: &SocketAddr, services: u64) -> Address {
        let (address, port) = match socket {
            &SocketAddr::V4(ref addr) => (addr.ip().to_ipv6_mapped().segments(), addr.port()),
            &SocketAddr::V6(ref addr) => (addr.ip().segments(), addr.port()),
        };
        Address {
            address: address,
            port: port,
            services: services,
        }
    }

    /// extract socket address from an address message
    /// This will return io::Error ErrorKind::AddrNotAvailable if the message contains a Tor address.
    pub fn socket_addr(&self) -> Result<SocketAddr, io::Error> {
        let addr = &self.address;
        if addr[0..3] == ONION {
            return Err(io::Error::from(io::ErrorKind::AddrNotAvailable));
        }
        let ipv6 = Ipv6Addr::new(
            addr[0], addr[1], addr[2], addr[3], addr[4], addr[5], addr[6], addr[7],
        );
        if let Some(ipv4) = ipv6.to_ipv4() {
            Ok(SocketAddr::V4(SocketAddrV4::new(ipv4, self.port)))
        } else {
            Ok(SocketAddr::V6(SocketAddrV6::new(ipv6, self.port, 0, 0)))
        }
    }
}

fn addr_to_be(addr: [u16; 8]) -> [u16; 8] {
    [
        addr[0].to_be(),
        addr[1].to_be(),
        addr[2].to_be(),
        addr[3].to_be(),
        addr[4].to_be(),
        addr[5].to_be(),
        addr[6].to_be(),
        addr[7].to_be(),
    ]
}

impl<S: Encoder> Encodable<S> for Address {
    #[inline]
    fn consensus_encode(&self, s: &mut S) -> Result<(), encode::Error> {
        self.services.consensus_encode(s)?;
        addr_to_be(self.address).consensus_encode(s)?;
        self.port.to_be().consensus_encode(s)
    }
}

impl<D: Decoder> Decodable<D> for Address {
    #[inline]
    fn consensus_decode(d: &mut D) -> Result<Address, encode::Error> {
        Ok(Address {
            services: Decodable::consensus_decode(d)?,
            address: addr_to_be(Decodable::consensus_decode(d)?),
            port: u16::from_be(Decodable::consensus_decode(d)?),
        })
    }
}

impl fmt::Debug for Address {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        // TODO: render services and hex-ize address
        write!(
            f,
            "Address {{services: {:?}, address: {:?}, port: {:?}}}",
            self.services,
            &self.address[..],
            self.port
        )
    }
}

impl Clone for Address {
    fn clone(&self) -> Address {
        Address {
            services: self.services,
            address: self.address,
            port: self.port,
        }
    }
}

impl PartialEq for Address {
    fn eq(&self, other: &Address) -> bool {
        self.services == other.services
            && &self.address[..] == &other.address[..]
            && self.port == other.port
    }
}

impl Eq for Address {}

#[cfg(test)]
mod test {
    use super::Address;
    use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr};
    use std::str::FromStr;

    use consensus::encode::{deserialize, serialize};

    #[test]
    fn serialize_address_test() {
        assert_eq!(
            serialize(&Address {
                services: 1,
                address: [0, 0, 0, 0, 0, 0xffff, 0x0a00, 0x0001],
                port: 8333
            }),
            vec![
                1u8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, 0x0a, 0, 0, 1,
                0x20, 0x8d
            ]
        );
    }

    #[test]
    fn deserialize_address_test() {
        let mut addr: Result<Address, _> = deserialize(&[
            1u8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, 0x0a, 0, 0, 1,
            0x20, 0x8d,
        ]);
        assert!(addr.is_ok());
        let full = addr.unwrap();
        assert!(match full.socket_addr().unwrap() {
            SocketAddr::V4(_) => true,
            _ => false,
        });
        assert_eq!(full.services, 1);
        assert_eq!(full.address, [0, 0, 0, 0, 0, 0xffff, 0x0a00, 0x0001]);
        assert_eq!(full.port, 8333);

        addr = deserialize(&[
            1u8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, 0x0a, 0, 0, 1,
        ]);
        assert!(addr.is_err());
    }

    #[test]
    fn test_socket_addr() {
        let s4 = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(111, 222, 123, 4)), 5555);
        let a4 = Address::new(&s4, 9);
        assert_eq!(a4.socket_addr().unwrap(), s4);
        let s6 = SocketAddr::new(
            IpAddr::V6(Ipv6Addr::new(
                0x1111, 0x2222, 0x3333, 0x4444, 0x5555, 0x6666, 0x7777, 0x8888,
            )),
            9999,
        );
        let a6 = Address::new(&s6, 9);
        assert_eq!(a6.socket_addr().unwrap(), s6);
    }

    #[test]
    fn onion_test() {
        let onionaddr = SocketAddr::new(
            IpAddr::V6(Ipv6Addr::from_str("FD87:D87E:EB43:edb1:8e4:3588:e546:35ca").unwrap()),
            1111,
        );
        let addr = Address::new(&onionaddr, 0);
        assert!(addr.socket_addr().is_err());
    }
}