glrss_parser

@external(erlang, "glrss_parser_ffi", "current_year")
@external(javascript, "../glrss_parser_ffi.mjs", "currentYear")
fn current_year() -> Int

@internal
pub fn year_2digit_to_full(year_2digit) {
  //> 2024
  let current_year = current_year()
  //> 2000
  let current_century_year = current_year / 100 * 100

  //  + 1 for dates slightly in the future.
  //> 25
  let current_2digit = current_year % 100 + 1
  case year_2digit > current_2digit {
    True ->
      // In the 1900s
      year_2digit + current_century_year - 100

    // 80 -> 1980
    False ->
      // In the 2000s
      year_2digit + current_century_year
    // 24 -> 2024
  }
}

@internal
pub fn try_unwrap(
  result: Result(a, e),
  unwrap: b,
  apply fun: fn(a) -> Result(b, e),
) -> b {
  case result {
    Ok(a) ->
      case fun(a) {
        Ok(b) -> b
        Error(_) -> unwrap
      }
    Error(_) -> unwrap
  }
}