//
//  TrafficUsage.swift
//  PrivadoVPN
//
//  Created by Zhandos Bolatbekov on 12.02.2021.
//  Copyright © 2021 Privado LLC. All rights reserved.
//

import Foundation

final class TrafficUsage {
    
    enum Unit {
        static let byte: UInt64 = 1
        static let kiloByte = byte * 1000
        static let megaByte = kiloByte * 1000
        static let gigaByte = megaByte * 1000
    }
    
    static let key = "TrafficUsage"
    static var instance = TrafficUsage()
    
    private var bytesCount: UInt64 {
        get {
            UserDefaults.standard.value(forKey: Self.key) as? UInt64 ?? 0
        }
        set {
            UserDefaults.standard.setValue(newValue, forKey: Self.key)
            self.bytesCountEmitter.invoke(newValue)
            // print("Traffic usage: \(newValue)")
        }
    }
    
    let bytesCountEmitter = Emitter<UInt64>()
    
    // MARK: - Init
    
    private init() { }
    
    // MARK: - Interface
    
    func get() -> UInt64 {
        return self.bytesCount
    }
    
    func add(bytes: UInt64) {
        self.bytesCount += bytes
    }
    
    func set(bytes: UInt64) {
        self.bytesCount = bytes
    }
    
    func reset() {
        self.bytesCount = 0
    }
}