Swift5 Result Type

resultType.swift

struct HolidayResponse: Codable {
    let response: Holidays
}

struct Holidays: Codable {
    let holidays: [HolidayDetail]
}
struct HolidayDetail:Codable {
    let name: String
    let date: HolidayDate
}
struct HolidayDate: Codable {
    let iso : String
}


enum HolidayError: Error {
    case noDataAvailable
    case canNotProcessData
}

struct HolidayRequest {
    let resourceURL: URL
    let API_KEY = "YOUR_API_KEY"
    
    init(countryCode:String) {
        let date = Date()
        let format = DateFormatter()
        format.dateFormat = "yyyy"
        let currentYear = format.string(from: date)
        let resourceString = "https://calendarific.com/api/v2/holidays?api_key=\(API_KEY)&country=\(countryCode)&year=\(currentYear)"
        
        guard let resourceURL = URL(string: resourceString) else {
            fatalError()
        }
        
        self.resourceURL = resourceURL
    }
    
    func getHolidays(completion: @escaping(Result<[HolidayDetail],HolidayError>) -> Void) {
        let dataTask = URLSession.shared.dataTask(with: resourceURL) { (data, _, _) in
            guard let jsonData = data else {
                completion(.failure(.noDataAvailable))
                return
            }
            
            do {
                let decoder = JSONDecoder()
                let holidayResponse = try decoder.decode(HolidayResponse.self, from: jsonData)
                print("Holiday Res: \(holidayResponse)")
                let holidayDetails = holidayResponse.response.holidays
                completion(.success(holidayDetails))
            }
            catch {
                completion(.failure(.canNotProcessData))
            }
        }
        
        dataTask.resume()
    }
}



func startRestApi(){
    let holidayRequest = HolidayRequest(countryCode: "RU")
    holidayRequest.getHolidays { (result) in
        print(result)
    }
    holidayRequest.getHolidays { [weak self] result in
        switch result {
        case .failure(let error):
            print(error)
        case .success(let holidays):
            self?.holidayArray = holidays
        }
    }
}