main.swift

import Foundation

typealias JSON      = AnyObject
typealias JSONDict  = Dictionary<String, JSON>
typealias JSONArray = Array<JSON>

struct User {
    let id: Int
    let name: String
    let email: String
}

final class Box<A> {
    let value: A
    init(_ value: A) {
        self.value = value
    }
}

enum Result<A> {
    case Error(NSError)
    case Value(Box<A>)
}

func makeRequest() {
    println("makeRequest called")
    let url = NSURL(string: "http://104.131.48.79/api/user/test")
    getUser(url) { result in
        switch result {
        case let .Value(boxedValue):
            println(".Value")
            let user = boxedValue.value
            println("id: \(user.id) \nname: \(user.name) \nemail: \(user.email)")
        case let .Error(error):
            println(error)
        }
    }
}

func getUser(url: NSURL?, callback: (Result<User>) -> ()) {
    let request = NSURLRequest(URL: url!)
    let session = NSURLSession.sharedSession()
    let queue = NSOperationQueue()
    
    var responseHandler = {(response: NSURLResponse!, data: NSData!, error: NSError!) -> Void in
        println("getUser task started")
        
        if error != nil {
            callback(.Error(error))
            return
        }
        
        var jsonErrorOpt: NSError?
        let jsonOptional: JSON! = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: &jsonErrorOpt)
        
        if jsonErrorOpt != nil {
            callback(Result.Error(jsonErrorOpt!))
            return
        }
        
        if let json = jsonOptional as? JSONDict {
            if let id = json["id"] as AnyObject? as? Int {
                if let name = json["name"] as AnyObject? as? String {
                    if let email = json["email"] as AnyObject? as? String {
                        let user = User(id: id, name: name, email: email)
                        callback(.Value(Box(user)))
                        return
                    }
                }
            }
        }
        
        // if we couldn't parse all the properties then send back an error
        callback(.Error(NSError()))
    }
    
    NSURLConnection.sendAsynchronousRequest(request, queue: queue, completionHandler: responseHandler)
    
    println("getUser task called")
}


makeRequest()