TodosApp/Todos/ViewModel/URLHintArray.swift

//
//  URLHintArray.swift
//  Todos
//
//  Created by Sam Jaffe on 3/1/26.
//

import Foundation
import SwiftData
internal import Combine

typealias URLHintArray = [URLHint]

/**
 * @brief Provides a UserDefaults-compatibiliy layer for Array<URLHint> that
 * allows seamless reading/writing on program startup and changes.
 * We bind this type to its JSON-String representation rather than, say, an
 * Array of dictionaries because @AppStorage only operates on scalar types.
 *
 * @author Sam Jaffe
 * @author KD Knowledge Diet https://paigeshin1991.medium.com/saving-custom-codable-types-in-appstorage-or-scenestorage-in-swiftui-0073032f3f94
 *
 * The \@retroactive guards against the Swift developers changing Array<T> to
 * comply w/ RawRepresentable in the future
 */
extension URLHintArray : @retroactive RawRepresentable {
  public init?(rawValue: String) {
    guard let data = rawValue.data(using: .utf8),
          let result = try? JSONDecoder().decode(URLHintArray.self, from: data)
    else {
      return nil
    }
    self = result
  }
  
  public var rawValue: String {
    guard let data = try? JSONEncoder().encode(self),
          let result = String(data: data, encoding: .utf8)
    else {
      return "[]"
    }
    return result
  }
}