#![crate_type = "lib"]
#![feature(ip_addr)]
#[allow(dead_code)]

use std::fmt;
use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};

// A network
#[derive(Debug)]
pub enum IpNetwork {
    V4(Ipv4Network),
    V6(Ipv6Network),
}

pub struct Ipv4Network {
    addr: Ipv4Addr,
    prefix: u8,
}

pub struct Ipv6Network {
    addr: Ipv6Addr,
    prefix: u8,
}

impl Ipv4Network {
    pub fn new(addr: Ipv4Addr, prefix: u8) -> Ipv4Network {
        Ipv4Network { addr: addr, prefix: prefix }
    }

    pub fn ip(&self) -> &Ipv4Addr {
        &(self.addr)
    }

    pub fn prefix(&self) -> u8 {
        self.prefix
    }

    pub fn mask_int(&self) -> u32 {
        let prefix = self.prefix;
        !(0xffffffff >> prefix)
    }

    pub fn mask(&self) -> Ipv4Addr {
        let mask = self.mask_int();
        Ipv4Addr::from(mask)
    }

    pub fn network_int(&self) -> u32 {
        Ipv4Network::ip_to_int(*(self.ip())) & self.mask_int()
    }

    pub fn network(&self) -> Ipv4Addr {
        Ipv4Addr::from(self.network_int())
    }

    fn ip_to_int(addr: Ipv4Addr) -> u32 {
        let ip = addr.octets();
        ((ip[0] as u32) << 24) + ((ip[1] as u32) << 16) + ((ip[2] as u32) << 8) + (ip[3] as u32)
    }
}

impl Ipv6Network {
    pub fn new(addr: Ipv6Addr, prefix: u8) -> Ipv6Network {
        Ipv6Network { addr: addr, prefix: prefix }
    }

    pub fn ip(&self) -> &Ipv6Addr {
        &(self.addr)
    }

    pub fn prefix(&self) -> u8 {
        self.prefix
    }
}

impl IpNetwork {
    pub fn new(ip: IpAddr, prefix: u8) -> IpNetwork {
        match ip {
            IpAddr::V4(a) => IpNetwork::V4(Ipv4Network::new(a, prefix)),
            IpAddr::V6(a) => IpNetwork::V6(Ipv6Network::new(a, prefix)),
        }
    }

    pub fn ip(&self) -> IpAddr {
        match *self {
            IpNetwork::V4(ref a) => IpAddr::V4(*a.ip()),
            IpNetwork::V6(ref a) => IpAddr::V6(*a.ip()),
        }
    }

    pub fn prefix(&self) -> u8 {
        match *self {
            IpNetwork::V4(ref a) => a.prefix(),
            IpNetwork::V6(ref a) => a.prefix(),
        }
    }
}

impl fmt::Debug for Ipv4Network {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        write!(fmt, "{}/{}", self.ip(), self.prefix())
    }
}

impl fmt::Debug for Ipv6Network {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        write!(fmt, "{}/{}", self.ip(), self.prefix())
    }
}

#[cfg(test)]
mod test {
    use std::net::{Ipv4Addr, Ipv6Addr};
    use super::*;

    #[test]
    fn create_v4() {
        let cidr = Ipv4Network::new(Ipv4Addr::new(77, 88, 21, 11), 24);
        assert_eq!(cidr.prefix(), 24);
    }

    #[test]
    fn create_v6() {
        let cidr = Ipv6Network::new(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1), 24);
        assert_eq!(cidr.prefix(), 24);
    }

    #[test]
    fn mask_int_v4() {
        let cidr = Ipv4Network::new(Ipv4Addr::new(74, 125, 227, 0), 29);
        assert_eq!(cidr.mask_int(), 4294967288);
    }

    #[test]
    fn mask_v4() {
        let cidr = Ipv4Network::new(Ipv4Addr::new(74, 125, 227, 0), 29);
        assert_eq!(cidr.mask(), Ipv4Addr::new(255, 255, 255, 248));
    }

    #[test]
    fn network_int_v4() {
        let cidr = Ipv4Network::new(Ipv4Addr::new(74, 125, 227, 0), 25);
        assert_eq!(cidr.network_int(), 1249764096);
    }

    #[test]
    fn network_v4() {
        let cidr = Ipv4Network::new(Ipv4Addr::new(74, 125, 227, 0), 25);
        assert_eq!(cidr.network(), Ipv4Addr::new(74, 125, 227, 0));
    }
}