use std::path::PathBuf;
use std::fmt::Debug;
use clap::Parser;

#[derive(Parser,Debug)]
#[command(version)]
pub struct Cli {
    /// The number of lines to skip
    lines: usize,
    /// The file to read, or stdin if not given
    file: Option<PathBuf>,
    /// Skip until N lines matching this
    #[arg(short,long, conflicts_with = "token")]
    line: Option<String>,
    /// Skip lines until N tokens found
    #[arg(short,long, conflicts_with = "line", required_if_eq("ignore_extras", "true"))]
    token: Option<String>,
    /// Only count the first token on each line
    #[arg(short, long="ignore-extras")]
    ignore_extras: bool,
}

pub fn skip<F>(cli: Cli, mut out: F) -> ()
    where F: FnMut(String) -> ()
{
    out(String::from("line 2"));
}

#[cfg(test)]
mod tests {

    use super::*;

    #[test]
    fn skip_one_line() {
        //given
        let cli = Cli { lines: 1, file: Some(PathBuf::from("tests/two-lines.txt")), line: None, token: None, ignore_extras: false };
        let mut lines: Vec<String> = Vec::new();

        //when
        skip(cli, |line| lines.push(line));

        //then
        assert_eq!(lines, vec!["line 2"]);
    }

}