//
//  UserController.swift
//  OnboardingApp
//
//  Created by Josh Broomberg on 2016/05/28.
//  Copyright © 2016 iXperience. All rights reserved.
//

import Foundation

class UserManager {
    class var sharedInstance: UserManager {
        struct Static {
            static var instance:UserManager?
            static var token: dispatch_once_t = 0
        }

        dispatch_once(&Static.token)    {
            Static.instance = UserManager()
        }
        return Static.instance!
    }

    struct User {
        var username: String
        var password: String
    }

    private var users: [User] = []

    var logged_in_user: User?

    func registerUser(new_username: String, new_password: String) -> (failure_message: String?, user: User?) {
        for user in users {
            if user.username == new_username {
                return ("Username taken", nil)
            }
        }
        let user = User(username: new_username, password: new_password)
        users.append(user)
        logged_in_user = user
        print("User with username: \(new_username) has been registered by the UserManager.")
        return (nil, user)
    }

    func loginUser(supplied_username: String, supplied_password: String) -> (failure_message: String?, user: User?){
        for user in users {
            if user.username == supplied_username {
                if user.password == supplied_password {
                    logged_in_user = user
                    print("User with username: \(supplied_username) has been logged in by the UserManager.")
                    return (nil, user)
                } else {
                    return ("Password incorrect", nil)
                }
            }
        }

        return ("No user with that username", nil)
    }
}