URLSession.swift

extension URLSession {

    
    func handleTaskOrCache(with request: URLRequest, completionHandler: @escaping (Data?, URLResponse?, Error?) -> Void) {
        
        let cachedDataForRequest = fetchCachedResponse(request: request)
        
        guard let dateCache = dateFromResponse(cachedResponse: cachedDataForRequest) else {
            handleDataTask(request: request, completionHandler: completionHandler)
            return
        }
        
        if dateCache.isAllowRefreshDate(offsetTime: AppURLSession.shared.OFFSET_TIME_REFRESH_CACHE){
            removeCachedFor(request: request)
            handleDataTask(request: request, completionHandler: completionHandler)
        }else{
            completionHandler(cachedDataForRequest?.data, cachedDataForRequest?.response, nil)
        }
    }
    
    
    private func handleDataTask(request: URLRequest, completionHandler: @escaping (Data?, URLResponse?, Error?) -> Void){
        self.dataTask(with: request) { data, response, error in
            completionHandler(data, response, error)
        }.resume()
    }
    
    private func removeCachedFor(request: URLRequest){
        URLSession.shared.configuration.urlCache?.removeCachedResponse(for: request)
    }
    
    private func fetchCachedResponse(request: URLRequest) -> CachedURLResponse?{
        return URLSession.shared.configuration.urlCache?.cachedResponse(for: request)
    }
    
    private func dateFromResponse(cachedResponse: CachedURLResponse?) -> Date?{
       return  (cachedResponse?.response as? HTTPURLResponse)?.value(forHTTPHeaderField: "Date")?.formatResponseHeaderDate()
    }
}