use regex::Regex;
use std::convert::TryFrom;
use std::error::Error;
use std::fmt;

#[derive(Debug, Clone)]
pub struct RegionParseError;

impl fmt::Display for RegionParseError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "Unable to parse region file name")
    }
}

impl Error for RegionParseError {}

/// Struct to store information about the region
pub struct Region {
    /// x position of the region
    pub x: i64,
    /// y position of the region
    pub y: i64,
}

impl TryFrom<String> for Region {
    type Error = RegionParseError;

    /// Try from string
    fn try_from(value: String) -> Result<Self, Self::Error> {
        let re = Regex::new(r"r\.(?P<x>-?[0-9]*)+\.(?P<y>-?[0-9]*)").unwrap();
        if re.is_match(&value) {
            let captures = re.captures(value.as_str()).unwrap();

            return Ok(Region {
                x: captures["x"].parse::<i64>().unwrap(),
                y: captures["y"].parse::<i64>().unwrap(),
            });
        }

        Err(RegionParseError)
    }
}