use nom::{
    bytes::complete::tag,
    character::complete::{char, one_of},
    combinator::{map_res, recognize},
    multi::{many0, many1},
    sequence::{preceded, terminated},
};

use crate::IResult;

pub fn decimal(input: &str) -> IResult<&str, u64> {
    map_res(
        recognize(many1(terminated(one_of("0123456789"), many0(char('_'))))),
        |out: &str| out.parse::<u64>(),
    )(input)
}

pub fn hexadecimal(input: &str) -> IResult<&str, u64> {
    map_res(
        preceded(
            tag("h"),
            recognize(many1(terminated(
                one_of("0123456789abcdefABCDEF"),
                many0(char('_')),
            ))),
        ),
        |out: &str| u64::from_str_radix(&str::replace(&out, "_", ""), 16),
    )(input)
}

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

    #[test]
    fn test_dec() {
        assert_eq!(decimal("123").unwrap().1, 123);
        assert_eq!(decimal("0123").unwrap().1, 123);
    }

    #[test]
    fn test_hex() {
        assert_eq!(hexadecimal("hfF").unwrap().1, 0xff);
        assert_eq!(hexadecimal("hF").unwrap().1, 0xf);
    }
}