use helix_core::Position;
use std::path::{Path, PathBuf};

/// Parse arg into [`PathBuf`] and position.
pub fn parse_file(s: &str) -> (PathBuf, Position) {
    let def = || (PathBuf::from(s), Position::default());
    if Path::new(s).exists() {
        return def();
    }
    split_path_row_col(s)
        .or_else(|| split_path_row(s))
        .unwrap_or_else(def)
}

/// Split file.rs:10:2 into [`PathBuf`], row and col.
///
/// Does not validate if file.rs is a file or directory.
fn split_path_row_col(s: &str) -> Option<(PathBuf, Position)> {
    let mut s = s.rsplitn(3, ':');
    let col: usize = s.next()?.parse().ok()?;
    let row: usize = s.next()?.parse().ok()?;
    let path = s.next()?.into();
    let pos = Position::new(row.saturating_sub(1), col.saturating_sub(1));
    Some((path, pos))
}

/// Split file.rs:10 into [`PathBuf`] and row.
///
/// Does not validate if file.rs is a file or directory.
fn split_path_row(s: &str) -> Option<(PathBuf, Position)> {
    let (path, row) = s.rsplit_once(':')?;
    let row: usize = row.parse().ok()?;
    let path = path.into();
    let pos = Position::new(row.saturating_sub(1), 0);
    Some((path, pos))
}