//! Client-to-Server IRC protocol.
pub mod client;
pub mod server;

use nom::{
    branch::alt,
    bytes::complete::{tag, take, take_while},
    IResult,
};

type ByteVec = Vec<u8>;

/// Single message tag value.
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct Tag {
    key: ByteVec,
    value: Option<u8>,
}

fn receiver(input: &[u8]) -> IResult<&[u8], &[u8]> {
    take_while(|i| i != b'\n' && i != b'\r' && i != b' ')(input)
}

fn token(input: &[u8]) -> IResult<&[u8], &[u8]> {
    take_while(|i| i != b'\n' && i != b'\r')(input)
}

#[derive(Clone, Debug, PartialEq, Eq)]
pub enum Chan {
    /// #<name> — network-global channel, available from any server in the network.
    Global(ByteVec),
    /// &<name> — server-local channel, available only to connections to the same server. Rarely used in practice.
    Local(ByteVec),
}

fn chan(input: &[u8]) -> IResult<&[u8], Chan> {
    fn chan_global(input: &[u8]) -> IResult<&[u8], Chan> {
        let (input, _) = tag("#")(input)?;
        let (input, name) = receiver(input)?;
        Ok((input, Chan::Global(name.to_vec())))
    }

    fn chan_local(input: &[u8]) -> IResult<&[u8], Chan> {
        let (input, _) = tag("&")(input)?;
        let (input, name) = receiver(input)?;
        Ok((input, Chan::Local(name.to_vec())))
    }

    alt((chan_global, chan_local))(input)
}