import UIKit

class LoginViewController: UIViewController {

    @IBOutlet weak var userUsernameTextField: UITextField!
    @IBOutlet weak var userPasswordTextField: UITextField!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

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


    @IBAction func loginButtonTapped(_ sender: Any)
    {

        let userUsername = userUsernameTextField.text
        let userPassword = userPasswordTextField.text

        if(userUsername!.isEmpty || userPassword!.isEmpty)
        {
            // Display an alert message
            let myAlert = UIAlertController(title: "Alert", message:"All fields are required to fill in", preferredStyle: UIAlertControllerStyle.alert);
            let okAction = UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler:nil)
            myAlert.addAction(okAction);
            self.present(myAlert, animated: true, completion: nil)
            return
        }

        let myUrl = URL(string: "http://cgi.soic.indiana.edu/~team10/userLogin.php");

        var request = URLRequest(url:myUrl!);
        request.httpMethod = "POST";
        request.addValue("application/json", forHTTPHeaderField: "Content-Type")

        let postString = "username=(userUsername!)&password=(userPassword!)";

        request.httpBody = postString.data(using: String.Encoding.utf8);

        let task = URLSession.shared.dataTask(with: request) { (data: Data?, response: URLResponse?, error: Error?) in

            DispatchQueue.main.async
                {

                    if(error != nil)
                    {
                        //Display an alert message
                        let myAlert = UIAlertController(title: "Alert", message: error!.localizedDescription, preferredStyle: UIAlertControllerStyle.alert);
                        let okAction = UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler:nil)
                        myAlert.addAction(okAction);
                        self.present(myAlert, animated: true, completion: nil)
                        return
                    }



                    do {
                        let json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers) as? NSDictionary

                        if let parseJSON = json {

                            let userId = parseJSON["userId"] as? String
                            if(userId != nil)
                            {
                                // take user to a protected page

                            } else {
                                // display an alert message
                                let userMessage = parseJSON["message"] as? String
                                let myAlert = UIAlertController(title: "Alert", message: userMessage, preferredStyle: UIAlertControllerStyle.alert);
                                let okAction = UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler:nil)
                                myAlert.addAction(okAction);
                                self.present(myAlert, animated: true, completion: nil)
                            }

                        }
                    } catch
                    {
                        print(error)
                    }


            }



        }

        task.resume()

    }

}

let postString = "username=(userUsername!)&password=(userPassword!)"

let parameters = ["username":userUsername!,"password":userPassword!]
do{
    let data = try JSONSerialization.data(withJSONObject: parameters, options: .prettyPrinted)
    request.httpBody = data
}
catch{
        print(error)
}