vendoo_v1.0/Vendoo/SignInViewController.swift

//
//  FirstViewController.swift
//  Vendoo
//
//  Created by Okechi Onyeje on 5/22/16.
//  Copyright © 2016 Okechi Onyeje. All rights reserved.
//


import UIKit
import FirebaseAuth
import Locksmith


class SignInViewController: UIViewController {
    //class variables
    var isValidated: Bool! = false

    //IBOutlets
    @IBOutlet weak var email: UITextField!
    @IBOutlet weak var password: UITextField!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        
        
        //set up delegates
        self.email.delegate = self
        self.password.delegate = self
        
        //check if there is a user logged in
        if NSUserDefaults.standardUserDefaults().boolForKey("signedIn"){
            
            //load user account from keychain
            self.email.text = NSUserDefaults.standardUserDefaults().objectForKey("email") as? String
            
            let dictionary = Locksmith.loadDataForUserAccount(self.email.text!, inService: "vendoo")
            self.password.text = dictionary!["pass"] as? String
            
            signInUser(self)
        }else{
            print("user not found")
        }
        
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
}

//IBActions
extension SignInViewController {
    //sign in current or returning user
    @IBAction func signInUser(sender: AnyObject) {
        //add validation
        let finalEmail = email!.text!.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet())
        
        if isValidEmail(finalEmail){
            FIRAuth.auth()?.signInWithEmail(email.text!, password: password.text!) { (user, error) in
                if error != nil {
                    //alert for wrong pass
                    if ( error!.userInfo["error_name"] as! String == "ERROR_WRONG_PASSWORD"){
                        
                        var alert = UIAlertController(title: "Incorrect Password", message: "The password was invalid for the email given, please reenter the correct password.", preferredStyle: .Alert)
                        
                        alert.addAction(UIAlertAction(title: "OK", style: .Default, handler: {(action: UIAlertAction!) in
                        }))
                        self.presentViewController(alert, animated: true, completion: nil)
                        
                        //alert for invalid email
                    }else if (error!.userInfo["error_name"] as! String == "ERROR_INVALID_EMAIL"){
                        
                        var alert = UIAlertController(title: "Email Invalid", message: "The email given was not valid, please enter a valid email.", preferredStyle: .Alert)
                        
                        alert.addAction(UIAlertAction(title: "OK", style: .Default, handler: {(action: UIAlertAction!) in
                        }))
                        self.presentViewController(alert, animated: true, completion: nil)
                        
                        //alert for disabled account
                    }else if (error!.userInfo["error_name"] as! String == "ERROR_USER_DISABLED"){
                        var alert = UIAlertController(title: "User Account Disabled", message: "Your account has temporarily been disabled, please contact support for more information.", preferredStyle: .Alert)
                        
                        alert.addAction(UIAlertAction(title: "OK", style: .Default, handler: {(action: UIAlertAction!) in
                        }))
                        self.presentViewController(alert, animated: true, completion: nil)
                    
                        //if request fails due to connectivity, then retry the login request
                    }else if (error?.userInfo["NSUnderlyingError"]?.code == -1005 || error?.code == 17020){
                        
                        var alert = UIAlertController(title: "Network Error", message: "There has been a problem connecting to the server. This could be due to various reasons such as having a slow or non existent connection or using an anonymity tool like a VPN service. Would you like to attempt to reconnect?", preferredStyle: .Alert)
                        
                        alert.addAction(UIAlertAction(title: "OK", style: .Default, handler: {(action: UIAlertAction!) in
                            
                            dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), {() -> Void in
                                var downloadGroup = dispatch_group_create()
                                dispatch_group_enter(downloadGroup)
                                dispatch_group_wait(downloadGroup, dispatch_time(DISPATCH_TIME_NOW, 5000000000))
                                // Wait 5 seconds before trying again.
                                dispatch_group_leave(downloadGroup)
                                dispatch_async(dispatch_get_main_queue(), {() -> Void in
                                    //Main Queue stuff here
                                    //Redo the function that made the Request.
                                    self.signInUser(self)

                                })
                            })
                        }))
                        alert.addAction(UIAlertAction(title: "Cancel", style: .Cancel, handler: {(action: UIAlertAction!) in
                        }))
                        self.presentViewController(alert, animated: true, completion: nil)
                        
                        return
                    }
                } else {
                    
                    dispatch_async(dispatch_get_main_queue(), { () -> Void in
                        
                        /*If the user has not already signed in then save their log in info*/
                        if !(NSUserDefaults.standardUserDefaults().boolForKey("signedIn")){
                            NSUserDefaults.standardUserDefaults().setBool(true, forKey: "signedIn")
                            NSUserDefaults.standardUserDefaults().setObject(self.email.text, forKey: "email")

                            
                            //save data to keychain
                            do{
                                try Locksmith.saveData(["pass": self.password.text!], forUserAccount: self.email.text!, inService: "vendoo")
                                print("account credentials saved")
                            }
                            catch{
                                //could not save data to keychain
                                print("account credentials could not be saved")
                                
                            }
                            print("User saved")
                        }
                        
                        self.performSegueWithIdentifier("HomeScreenSegue", sender:nil)
                        
                    })
                }
            }
        }else {
            //alert for invalid email
            let alert = UIAlertController(title: "Bad Email Given", message: "The email given was not valid. Please enter a valid email", preferredStyle: .Alert)
            
            alert.addAction(UIAlertAction(title: "OK", style: .Default, handler: {(action: UIAlertAction!) in
            }))
            self.presentViewController(alert, animated: true, completion: nil)
        }
        
        
    }
    
}



//Mark: - TextField Delegate Methods
extension SignInViewController: UITextFieldDelegate {
    
    func textFieldShouldReturn(textField: UITextField) -> Bool {
        //dismissKeyboard()
        self.view.endEditing(true)
        return false
    }
    
}

//MARK: - Navigation Methods
extension SignInViewController {
    
    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        switch (segue.identifier!) {
            
        case "HomeScreenSegue":
            //logic to prepare user for application use after firebase login
            //Testing OAuth
            
            break
        default:
            //default logic for any other segues
            break
            
        }
    }
}


//Private Class Helper Methods
extension SignInViewController {
    //Validate Email/Username
    func isValidEmail(testStr:String) -> Bool {
        
        print("Validate emilId: \(testStr)")
        
        let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,}"
        
        let emailTest = NSPredicate(format:"SELF MATCHES %@", emailRegEx)
        
        let result = emailTest.evaluateWithObject(testStr)
        
        return result
        
    }
}