pub const SEPARATOR: char = '.';
pub const MAX_SUBJECT_LEN: usize = 255;
pub const MAX_TOKEN_LEN: usize = 64;

fn is_token_char(c: char) -> bool {
    !(c.is_whitespace() || c.is_control() || matches!(c, '.' | '*' | '>' | '/' | '\\' | '$'))
}

pub fn is_specific(subject: &str) -> bool {
    !subject.is_empty()
        && subject.len() <= MAX_SUBJECT_LEN
        && subject.split(SEPARATOR).all(|token| {
            !token.is_empty() && token.len() <= MAX_TOKEN_LEN && token.chars().all(is_token_char)
        })
}

pub fn normalize(value: &str) -> String {
    value.trim().trim_matches(SEPARATOR).to_owned()
}