eqn.ios/Sources/Earthquake Network/Models/EQNPurchaseUtility.swift

//
//  EQNPurchaseUtility.swift
//  Earthquake Network
//
//  Created by Busi Andrea on 30/07/2020.
//  Copyright © 2020 Earthquake Network. All rights reserved.
//

import Foundation


@objc
public class EQNPurchaseUtility: NSObject {
    
    private static let AppOpenCountForDiscount = 15
    
    // MARK: - Public
    
    /// Check if a discounted price is available and returns the remaining time to get the offer.
    /// If zero, no discounted price is available
    /// - Parameter completion: Completion
    static func offerTimeRemaining(completion: @escaping (_ timeRemaining: Int) -> Void) {
        let appOpenCounter = UserDefaults.standard.integer(forKey:CONTEGGIO_APERTURE_PER_SCONTO)
        if appOpenCounter < Self.AppOpenCountForDiscount {
            completion(0)
            return
        }
        
        let discountExpired = UserDefaults.standard.bool(forKey: PREZZO_SCONTATO_SCADUTO)
        if discountExpired {
            completion(0)
            return
        }
        
        EQNUser.default().downloadOfferTimeRemaining { (timeOffer) in
            if timeOffer == 0 {
                UserDefaults.standard.set(true, forKey: PREZZO_SCONTATO_SCADUTO)
            }
            
            let timeInHours = timeOffer / 60
            completion(timeInHours)
        }
    }
    
    /// Returns availabilities for active subscriptions
    /// - Parameter completion: Completion
    static func availableSubscriptions(completion: @escaping (_ availability: EQNPurchaseAvailability?) -> Void) {
        guard let url = URL(string: EQNServerUrlAvailableSubscriptionsCounter) else {
            completion(nil)
            return
        }
        
        let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
            guard let data = data else {
                completion(nil)
                return
            }
            
            let availability = EQNPurchaseAvailability(data: data)
            completion(availability)
        }
        task.resume()
    }
    
    /// Check if user has bought pro app version
    /// Pro version is enabled also if a yearly subscription is enabled
    @objc public static func isProVersionEnabled() -> Bool {
        var hasProVersion = false
        VersioneProProducts.Identifier.identifierForProVersion.forEach { (identifier) in
            hasProVersion = hasProVersion || UserDefaults.standard.bool(forKey: identifier)
        }
        return hasProVersion
    }
    
    /// Remove saved in-app purchases flags.
    /// Used only during development
    @objc public static func resetInAppPurchases() {
        VersioneProProducts.Identifier.identifiers.forEach { (identifier) in
            UserDefaults.standard.removeObject(forKey: identifier)
        }
        NotificationCenter.default.post(name: .IAPHelperPurchaseNotification, object: nil)
    }
    
    /// Use to simulate the purchase of the Pro version
    @objc public static func simulateProPurchase(identifier: String) {
        // store and notify
        UserDefaults.standard.set(true, forKey: identifier)
        NotificationCenter.default.post(name: .IAPHelperPurchaseNotification, object: identifier)
    }
}