Enum Example

enum Router: URLRequestConvertible {
        static let baseURLString = "http://dev.example.com"
        static var OAuthToken: String?
    
        case MapView(Int)
        case PhotoInfo(Int, ImageSize)
        case Comments(Int, Int)
        
        var URLRequest: NSURLRequest {
            let (path: String, parameters: [String: AnyObject]) = {
                switch self {
                case .MapView(let page):
                    let params = ["page": "\(page)"]
                    return ("/map", params)
                case .PhotoInfo(let photoId, let imageSize):
                    var params = ["image_size": "\(imageSize.rawValue)"]
                    return ("/photos/\(photoId)", params)
                case .Comments(let photoId, let commentsPage):
                    var params = [ "comments": "1",
                        "comments_page": "\(commentsPage)"]
                    return ("/photos/\(photoId)/comments", params)
                }
                }()
            
            let URL = NSURL(string: Router.baseURLString)!
            let mutableURLRequest = NSMutableURLRequest(URL: URL.URLByAppendingPathComponent(path))
            let encoding = Alamofire.ParameterEncoding.URL
            
            if let token = Router.OAuthToken {
                mutableURLRequest.setValue("Bearer \(token)", forHTTPHeaderField: "Authorization")
            }
            
            return encoding.encode(mutableURLRequest, parameters: parameters).0
            
        }