//
//  Preferences.swift
//  Reader
//
//  Created by Shadowfacts on 1/16/22.
//

import UIKit

class Preferences: Codable, ObservableObject {
    
    private static let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
    private static let archiveURL = Preferences.documentsDirectory.appendingPathComponent("preferences").appendingPathExtension("plist")
    private static let decoder = PropertyListDecoder()
    private static let encoder = PropertyListEncoder()
    
    static var shared = load()
    
    private static func load() -> Preferences {
        if let data = try? Data(contentsOf: archiveURL),
           let prefs = try? decoder.decode(Preferences.self, from: data) {
            return prefs
        } else {
            return Preferences()
        }
    }
    
    static func save() {
        if let data = try? encoder.encode(shared) {
            try? data.write(to: archiveURL, options: .noFileProtection)
        }
    }
    
    init() {
    }
    
    required init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
        self.appearance = try container.decode(UIUserInterfaceStyle.self, forKey: .appearance)
    }
    
    func encode(to encoder: Encoder) throws {
        var container = encoder.container(keyedBy: CodingKeys.self)
        try container.encode(appearance, forKey: .appearance)
    }
    
    var appearance = UIUserInterfaceStyle.unspecified {
        willSet {
            objectWillChange.send()
        }
        didSet {
            NotificationCenter.default.post(name: .userInterfaceStyleChanged, object: nil)
        }
    }
    
    private enum CodingKeys: String, CodingKey {
        case appearance
    }
    
}

extension UIUserInterfaceStyle: Codable {
}

extension Notification.Name {
    static let userInterfaceStyleChanged = Notification.Name("userInterfaceStyleChanged")
}