AddressBook Integration using CNContactStore in Swift 3

Contacts_Integration.Swift

//
//  AddressBookHelper.swift
//  AddressBook
//
//  Created by Ranjith Kumar on 11/03/2017.
//  Copyright © 2017 F22Labs. All rights reserved.
//

import Foundation
import Contacts

enum ABAuthorizationStatus:Int {
    case authorized
    case denied
    case notDetermined
}

protocol AddressBookHelperProtocol:class {
    func contactsAreLoaded(contacts:[contactModel])
}

class AddressBookHelper:NSObject {
    
    public weak var delegate:AddressBookHelperProtocol?
    
    func isContactsAuthorized(completion:@escaping ((ABAuthorizationStatus)->())) {
        let status = CNContactStore.authorizationStatus(for: .contacts)
        switch status {
        case .notDetermined:
            let contactStore = CNContactStore.init()
            contactStore.requestAccess(for: .contacts, completionHandler: { (status, error) in
                if status  {
                    self.loadContacts()
                }else {
                    completion(.denied)
                }
            })
        case .authorized: self.loadContacts(); break
        case .denied,
             .restricted:
            completion(.denied)
            break
        }
    }
    
    func loadContacts() {
        let contactStore = CNContactStore.init()
        let keys = [CNContactPhoneNumbersKey,CNContactGivenNameKey,CNContactImageDataKey]
        let request = CNContactFetchRequest.init(keysToFetch: keys as [CNKeyDescriptor])
        
        var contacts:[contactModel] = []
        try! contactStore.enumerateContacts(with: request) { (contact, stop) in
            for object:CNLabeledValue in contact.phoneNumbers {
                let mobileObject  = object.value
                let mobile = mobileObject.value(forKey: "digits") as? String
                var givenName = contact.givenName
                if givenName.isEmpty == true {
                    givenName = "Unknown"
                }
                let cmodel = contactModel.init(name: givenName, phone: mobile!)
                contacts.append(cmodel)
            }
        }
        self.delegate?.contactsAreLoaded(contacts: contacts)
    }
    
}

class contactModel:NSObject {
    var name:String?
    var phone:String?
    var selected:Bool?
    
    init(name:String,phone:String) {
        self.name = name
        self.phone = phone
        self.selected = false
    }
}