//
//  NetworkServiceCities.swift
//  Wallet
//
//  Created by Saveliy Stavitsky on 10/23/20.
//  Copyright © 2020 List. All rights reserved.
//

import Foundation
import CoreLocation

extension Network.Service.Cities {
    typealias Model = Common.Model.City
}

extension Network.Service {
    class Cities: Common.Service.Provider {
        init() {}
        private var collection = [Language: [Model]]()
    }
}

extension Network.Service.Cities {
    func fetch(lang: Language, completion: @escaping ([Model]) -> Void) {
        fetchLocal(lang: lang, completion: completion)
    }
}

extension Network.Service.Cities {
    private func fetchLocal(lang: Common.Model.Language, completion: @escaping ([Common.Model.City]) -> Void) {
        if let list = collection[lang] { completion(list);return }
        DispatchQueue.global().async {
            guard let url = Bundle.main.url(forResource: "Cities_\(lang.rawValue)", withExtension: "json"),
                  let data = try? Data(contentsOf: url) else {
                DispatchQueue.main.async { completion([]) }
                return
            }
            
            let collection: [City] = data.jsonDecoded(type: [City].self) ?? []
            
            DispatchQueue.main.async {
                self.collection[lang] = collection
                completion(collection)
            }
        }
    }
}