using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
using Xamarin.Forms;

namespace T4SHubMobile
{
	public partial class MainPage : ContentPage
	{
        // Strings
        string Cookies = null;

        // Ints
        int Redirections;

        // Views
        ScrollView ContainerScrollView;
        StackLayout WrapperStackLayout;
        Image T4Sicon;
        Label HeaderLabel;
        Label ErrorTextLabel;
        Entry UsernameInput;
        Entry PasswordInput;
        Button LoginButton;
        WebView LoginWebView;

		public MainPage()
		{
			InitializeComponent();

            // Get references to views
            ContainerScrollView = this.FindByName<ScrollView>("containerScrollView");
            WrapperStackLayout = this.FindByName<StackLayout>("wrapperStackLayout");
            T4Sicon = this.FindByName<Image>("t4Sicon");
            HeaderLabel = this.FindByName<Label>("headerLabel");
            ErrorTextLabel = this.FindByName<Label>("errorTextLabel");
            UsernameInput = this.FindByName<Entry>("usernameInput");
            PasswordInput = this.FindByName<Entry>("passwordInput");
            LoginButton = this.FindByName<Button>("loginButton");
            LoginWebView = this.FindByName<WebView>("loginWebView");

            // Init variables
            Redirections = 0;

            // logout for testing
            LoginWebView.Source = "https://www.t4shub.com/Account/Signout";
        }

        public void OnLoginButtonClick()
        {
            // Check if input fields are empty, if not then proceed to login
            if (!String.IsNullOrWhiteSpace(UsernameInput.Text) && !String.IsNullOrWhiteSpace(PasswordInput.Text))
            {
                App.Username = UsernameInput.Text;
                App.Password = PasswordInput.Text;

                // Add OnPageFinished method to webview
                LoginWebView.Navigated += OnPageFinished;

                // Login
                Redirections = 0;
                Login();
            }
            else
            {
                ErrorTextLabel.Text = "Username/Password cannot be left empty!";
            }

        }

        public void Login()
        {
            LoginWebView.Source = "https://www.t4shub.com/Account/SignIn";
            //Application.Current.MainPage = new NavigationPage(new SearchPage());
        }

        public void OnPageFinished(object sender, WebNavigatedEventArgs e)
        {
            Debug.WriteLine("PAGE " + e.Url + " FINISHED LOADING!");

            // If the login succeeds and the user is redirected to the t4shub homepage, go to search page
            if (e.Url.Contains("https://www.t4shub.com/") && e.Result == WebNavigationResult.Success)
            {

                Debug.WriteLine("Url contains \"https://www.t4shub.com/\"");
            }
            else if (e.Url.Contains("login.microsoftonline") && Redirections == 2)
            {
                WebView view = sender as WebView;
                InjectScriptFile(view);
            }
            Redirections++; Debug.WriteLine("Redirections: " + Redirections);
        }

        private void InjectScriptFile(WebView view)
        {
            var jscall = "var parent = document.getElementsByTagName('head').item(0);" + "\n" +
                         "var script = document.createElement('script');" + "\n" +
                         "script.type = 'text/javascript';" + "\n" +
                         "var useridView = document.getElementById('cred_userid_inputtext');" + "\n" +
                         "var passwordView = document.getElementById('cred_password_inputtext');" + "\n" +
                         "var signInButton = document.getElementById('cred_sign_in_button');" + "\n" +
                         "var userid = \"" + App.Username + "\";" + "\n" +
                         "var password = \"" + App.Password + "\";" + "\n" +
                         "useridView.value = userid;" + "\n" +
                         "passwordView.value = password;" + "\n" +
                         "signInButton.click();" + "\n" +
                         "parent.appendChild(script);";
            try
            {
                view.Eval(jscall);

                Debug.WriteLine("Javascript:\n\n" + jscall + "\n\nevaluated!");
            }
            catch (IOException e)
            {
                // TODO Auto-generated catch block
                Debug.WriteLine("JAVASCRIPT INJECTION ERROR: " + e);
            }
        }
    }
}