URLResponse+Extensions.swift

//
//  URLResponse+Extensions.swift
//
import Foundation

extension URLResponse {

    var lastModifiedHeader: String? {
        get {
            if let httpResp = self as? HTTPURLResponse, let lastMod = httpResp.allHeaderFields["Last-Modified"] as? String {
                return lastMod
            }
            return nil
        }
    }
    
    var lastModified: Date? {
        get {
            guard let lastModifiedHeader = self.lastModifiedHeader else { return nil }
            let gmtDateFormatter = DateFormatter()
            gmtDateFormatter.dateFormat = "EEEE, dd LLL yyyy HH:mm:ss zzz"
            return gmtDateFormatter.date(from: lastModifiedHeader)
        }
    }
}