use super::*;

/// Client-to-server command.
#[derive(Clone, Debug, PartialEq, Eq)]
pub enum ClientMessage {
    /// CAP. Capability-related commands.
    Capability {
        subcommand: CapabilitySubcommand,
    },
    /// PING
    Ping {
        token: ByteVec,
    },
    Pong {
        token: ByteVec,
    },
}

pub fn client_message(input: &[u8]) -> IResult<&[u8], ClientMessage> {
    alt((
        client_message_capability,
        client_message_ping,
        client_message_pong,
    ))(input)
}

fn client_message_capability(input: &[u8]) -> IResult<&[u8], ClientMessage> {
    let (input, _) = tag("CAP ")(input)?;
    let (input, subcommand) = capability_subcommand(input)?;

    Ok((input, ClientMessage::Capability { subcommand }))
}

fn client_message_ping(input: &[u8]) -> IResult<&[u8], ClientMessage> {
    let (input, _) = tag("PING ")(input)?;
    let (input, token) = token(input)?;

    Ok((
        input,
        ClientMessage::Ping {
            token: token.to_owned(),
        },
    ))
}

fn client_message_pong(input: &[u8]) -> IResult<&[u8], ClientMessage> {
    let (input, _) = tag("PONG ")(input)?;
    let (input, token) = token(input)?;

    Ok((
        input,
        ClientMessage::Pong {
            token: token.to_owned(),
        },
    ))
}

#[derive(Clone, Debug, PartialEq, Eq)]
pub enum CapabilitySubcommand {
    /// CAP LS {code}
    List { code: [u8; 3] },
    /// CAP END
    End,
}

fn capability_subcommand(input: &[u8]) -> IResult<&[u8], CapabilitySubcommand> {
    alt((capability_subcommand_ls, capability_subcommand_end))(input)
}

fn capability_subcommand_ls(input: &[u8]) -> IResult<&[u8], CapabilitySubcommand> {
    let (input, _) = tag("LS ")(input)?;
    let (input, code) = take(3usize)(input)?;

    Ok((
        input,
        CapabilitySubcommand::List {
            code: code.try_into().unwrap(),
        },
    ))
}

fn capability_subcommand_end(input: &[u8]) -> IResult<&[u8], CapabilitySubcommand> {
    let (input, _) = tag("END")(input)?;
    Ok((input, CapabilitySubcommand::End))
}

#[cfg(test)]
mod test {
    use assert_matches::*;

    use super::*;
    #[test]
    fn test_client_message_cap_ls() {
        let input = b"CAP LS 302";
        let expected = ClientMessage::Capability {
            subcommand: CapabilitySubcommand::List { code: *b"302" },
        };

        let result = client_message(input);
        assert_matches!(result, Ok((_, result)) => assert_eq!(expected, result));
    }

    #[test]
    fn test_client_message_cap_end() {
        let input = b"CAP END";
        let expected = ClientMessage::Capability {
            subcommand: CapabilitySubcommand::End,
        };

        let result = client_message(input);
        assert_matches!(result, Ok((_, result)) => assert_eq!(expected, result));
    }

    #[test]
    fn test_client_message_ping() {
        let input = b"PING 1337";
        let expected = ClientMessage::Ping {
            token: b"1337".to_vec(),
        };

        let result = client_message(input);
        assert_matches!(result, Ok((_, result)) => assert_eq!(expected, result));
    }
    #[test]
    fn test_client_message_pong() {
        let input = b"PONG 1337";
        let expected = ClientMessage::Pong {
            token: b"1337".to_vec(),
        };

        let result = client_message(input);
        assert_matches!(result, Ok((_, result)) => assert_eq!(expected, result));
    }
}