use crate::{    borrowed::{Error, Signature},    BStr, ByteSlice, Sign, Time,};use btoi::btoi;use nom::{    branch::alt,    bytes::complete::{is_not, tag, take, take_until, take_while_m_n},    character::is_digit,    combinator::{peek, recognize},    multi::many1_count,    sequence::{preceded, terminated, tuple},    IResult,}; pub(crate) const NL: &[u8] = b"\n";pub(crate) const SPACE: &[u8] = b" "; pub(crate) fn header_field_multiline<'a>(i: &'a [u8], name: &'static [u8]) -> IResult<&'a [u8], &'a [u8], Error> {    let (i, o) = peek(preceded(        terminated(tag(name), tag(SPACE)),        recognize(tuple((            is_not(NL),            tag(NL),            many1_count(terminated(tuple((tag(SPACE), take_until(NL))), tag(NL))),        ))),    ))(i)?;    assert!(!o.is_empty());    let end = &o[o.len() - 1] as *const u8 as usize;    let start_input = &i[0] as *const u8 as usize;    Ok((&i[end - start_input + 1..], &o[..o.len() - 1]))} pub(crate) fn header_field<'a, T>(    i: &'a [u8],    name: &'static [u8],    parse_value: impl Fn(&'a [u8]) -> IResult<&'a [u8], T, Error>,) -> IResult<&'a [u8], T, Error> {    terminated(preceded(terminated(tag(name), tag(SPACE)), parse_value), tag(NL))(i)} fn is_hex_digit_lc(b: u8) -> bool {    match b {        b'0'..=b'9' => true,        b'a'..=b'f' => true,        _ => false,    }} pub(crate) fn hex_sha1(i: &[u8]) -> IResult<&[u8], &BStr, Error> {    take_while_m_n(40usize, 40, is_hex_digit_lc)(i).map(|(i, o)| (i, o.as_bstr()))} pub(crate) fn signature(i: &[u8]) -> IResult<&[u8], Signature, Error> {    let (i, (name, email, time_in_seconds, tzsign, tzhour, tzminute)) = tuple((        terminated(take_until(&b" <"[..]), take(2usize)),        terminated(take_until(&b"> "[..]), take(2usize)),        terminated(take_until(SPACE), take(1usize)),        alt((tag(b"-"), tag(b"+"))),        take_while_m_n(2usize, 2, is_digit),        take_while_m_n(2usize, 2, is_digit),    ))(i)    .map_err(Error::context(        "tagger <name> <<email>> <time seconds since epoch> <+|-><HHMM>",    ))?;     let sign = if tzsign[0] == b'-' { Sign::Minus } else { Sign::Plus };    let hours = btoi::<i32>(&tzhour)        .map_err(|e| nom::Err::Error(Error::ParseIntegerError("invalid 'hours' string", tzhour.into(), e)))?;    let minutes = btoi::<i32>(&tzminute)        .map_err(|e| nom::Err::Error(Error::ParseIntegerError("invalid 'minutes' string", tzminute.into(), e)))?;    let offset = (hours * 3600 + minutes * 60) * if sign == Sign::Minus { -1 } else { 1 };     Ok((        i,        Signature {            name: name.as_bstr(),            email: email.as_bstr(),            time: Time {                time: btoi::<u32>(time_in_seconds).map_err(|e| {                    nom::Err::Error(Error::ParseIntegerError(                        "Could parse to seconds",                        time_in_seconds.into(),                        e,                    ))                })?,                offset,                sign,            },        },    ))} #[cfg(test)]mod tests {    mod parse_signature {        use crate::{            borrowed::{parse, Signature},            ByteSlice, Sign, Time,        };         fn signature(            name: &'static str,            email: &'static str,            time: u32,            sign: Sign,            offset: i32,        ) -> Signature<'static> {            Signature {                name: name.as_bytes().as_bstr(),                email: email.as_bytes().as_bstr(),                time: Time { time, offset, sign },            }        }         #[test]        fn tz_minus() {            assert_eq!(                parse::signature(b"Sebastian Thiel <byronimo@gmail.com> 1528473343 -0230")                    .unwrap()                    .1,                signature("Sebastian Thiel", "byronimo@gmail.com", 1528473343, Sign::Minus, -9000)            );        }         #[test]        fn tz_plus() {            assert_eq!(                parse::signature(b"Sebastian Thiel <byronimo@gmail.com> 1528473343 +0230")                    .unwrap()                    .1,                signature("Sebastian Thiel", "byronimo@gmail.com", 1528473343, Sign::Plus, 9000)            );        }         #[test]        fn negative_offset_0000() {            assert_eq!(                parse::signature(b"Sebastian Thiel <byronimo@gmail.com> 1528473343 -0000")                    .unwrap()                    .1,                signature("Sebastian Thiel", "byronimo@gmail.com", 1528473343, Sign::Minus, 0)            );        }         #[test]        fn empty_name_and_email() {            assert_eq!(                parse::signature(b" <> 12345 -1215").unwrap().1,                signature("", "", 12345, Sign::Minus, -44100)            );        }    }}