use crate::protocol::codec::Decode;
use nom::number;
use nom::IResult;

/******************************************************************************
 * Struct
 ******************************************************************************/

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum IPProtocol {
    IPV6HOP,
    ICMP,
    IGMP,
    GGP,
    IPINIP,
    ST,
    TCP,
    CBT,
    EGP,
    IGP,
    BBNRCCMON,
    NVPII,
    PUP,
    ARGUS,
    EMCON,
    XNET,
    CHAOS,
    UDP,
    IPV6,
    IPV6ROUTING,
    IPV6FRAGMENT,
    GRE,
    ESP,
    AUTH,
    ICMP6,
    IPV6DEST,
    Other(u8),
}

/******************************************************************************
 * API
 ******************************************************************************/

impl From<u8> for IPProtocol {
    fn from(raw: u8) -> Self {
        match raw {
            0 => IPProtocol::IPV6HOP, // IPv6 Hop-by-Hop Options
            1 => IPProtocol::ICMP,
            2 => IPProtocol::IGMP,
            3 => IPProtocol::GGP,
            4 => IPProtocol::IPINIP,
            5 => IPProtocol::ST,
            6 => IPProtocol::TCP,
            7 => IPProtocol::CBT,
            8 => IPProtocol::EGP,
            9 => IPProtocol::IGP,
            10 => IPProtocol::BBNRCCMON,
            11 => IPProtocol::NVPII,
            12 => IPProtocol::PUP,
            13 => IPProtocol::ARGUS,
            14 => IPProtocol::EMCON,
            15 => IPProtocol::XNET,
            16 => IPProtocol::CHAOS,
            17 => IPProtocol::UDP,
            41 => IPProtocol::IPV6,
            43 => IPProtocol::IPV6ROUTING,  // IPv6 Routing Header
            44 => IPProtocol::IPV6FRAGMENT, // IPv6 Fragment Header
            47 => IPProtocol::GRE,          // GRE encapsulation [RFC2784][RFC2890]
            50 => IPProtocol::ESP,          // Encap Security Payload [RFC4303]
            51 => IPProtocol::AUTH,         // Authentication Header [RFC4302]
            58 => IPProtocol::ICMP6,
            60 => IPProtocol::IPV6DEST, // IPv6 Destination Options
            other => IPProtocol::Other(other),
        }
    }
}

impl IPProtocol {
    pub fn is_ipv6_ext_header(next_header: IPProtocol) -> bool {
        match next_header {
            IPProtocol::IPV6HOP => true,
            IPProtocol::IPV6ROUTING => true,
            IPProtocol::IPV6FRAGMENT => true,
            // IPProtocol::ESP => true,
            IPProtocol::AUTH => true,
            IPProtocol::IPV6DEST => true,
            _ => false,
        }
    }
}

impl Decode for IPProtocol {
    type Iterm = IPProtocol;
    fn decode(input: &[u8]) -> IResult<&[u8], IPProtocol> {
        let (input, protocol) = number::streaming::be_u8(input)?;

        Ok((input, protocol.into()))
    }
}