//
//  String.swift
//  EmployeeDirectory
//
//  Created by Matt Bruce on 3/4/25.
//
import Foundation

extension String {
    /// Formats a string into a US phone number format (XXX-XXX-XXXX).
    /// Non-numeric characters are removed, and formatting is applied based on the length of the string.
    /// - Returns: A formatted phone number as a string.
    internal func formatUSNumber() -> String {
        let mask = "XXX-XXX-XXXX"
        let digits = filter { $0.isNumber }
        var index = digits.startIndex
        return mask.reduce(into: "") { result, char in
            if char == "X", index < digits.endIndex {
                result.append(digits[index])
                index = digits.index(after: index)
            } else {
                result.append(char)
            }
        }
    }
}