using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Windows.ApplicationModel;
using Windows.Storage;
using Windows.UI;
using Windows.UI.Text;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;

namespace JpInkRecognizer.ViewModel
{
    public class HandWriterViewModel: BaseViewModel
    {

        public RichEditBox NameInputREBControl { get; set; }

        public InkCanvas InkCanvasControl { get; set; }

        public async void NameInput_Loaded(object sender, RoutedEventArgs e)
        {
            this.allowProcess = WinAppConstant.StrProcessAllow;
            this.LoadInit();
            string textStr = this.GetTextFromRichEditBox(this.NameInputREBControl);
            this.NameInputREBControl.Document.Selection.StartPosition = textStr.Length;
            await this.ChangeTextColor(this.NameInputREBControl, textStr, Colors.Red);
            this.NameInputREBControl.Focus(FocusState.Programmatic);
        }

        private void LoadInit()
        {
            // Init inkcanvas
            this.InialInkCanvas(this.InkCanvasControl, this.NameInputREBControl);

            // Collect strokes
            this.InkCanvasControl.InkPresenter.StrokesCollected += this.InkPresenter_StrokesCollected;

            // Event Register
            this.NameInputREBControl.AddHandler(UIElement.PointerPressedEvent, new PointerEventHandler(TextBox_OnPointerPressed), true);
        }

        private string GetTextFromRichEditBox(RichEditBox richEditBox)
        {
            string temp;
            richEditBox.Document.GetText(Windows.UI.Text.TextGetOptions.None, out temp);
            var range = richEditBox.Document.GetRange(0, temp.Length - 1);
            string textStr;
            range.GetText(Windows.UI.Text.TextGetOptions.None, out textStr);
            return textStr;
        }

        public async void BtnSpace_Click(object sender, RoutedEventArgs e)
        {
            if (this.allowProcess == WinAppConstant.StrProcessAllow)
            {
                this.allowProcess = WinAppConstant.StrProcessDenied;

                this.Blank();
                string textStr = this.GetTextFromRichEditBox(this.NameInputREBControl);
                await this.ChangeTextColor(this.NameInputREBControl, textStr, Colors.Red);
                this.allowProcess = WinAppConstant.StrProcessAllow;
            }
            else
            {
                return;
            }
        }

        public async void BtnDelete_Click(object sender, RoutedEventArgs e)
        {

            if (this.allowProcess == WinAppConstant.StrProcessAllow)
            {
                this.allowProcess = WinAppConstant.StrProcessDenied;

                this.DeleteOneWord();
                string textStr = this.GetTextFromRichEditBox(this.NameInputREBControl);
                await this.ChangeTextColor(this.NameInputREBControl, textStr, Colors.Red);
                this.allowProcess = WinAppConstant.StrProcessAllow;
            }
            else
            {
                return;
            }
        }

        public void BtnDeleteAll_Click(object sender, RoutedEventArgs e)
        {
            if (this.allowProcess == WinAppConstant.StrProcessAllow)
            {
                this.allowProcess = WinAppConstant.StrProcessDenied;

                this.DeleteAllWord();
                this.allowProcess = WinAppConstant.StrProcessAllow;
            }
            else
            {
                return;
            }
        }

        public void Button_Click_Right(object sender, RoutedEventArgs e)
        {
            if (this.allowProcess == WinAppConstant.StrProcessAllow)
            {
                this.allowProcess = WinAppConstant.StrProcessDenied;
                
                string textStr;
                this.NameInputREBControl.Document.GetText(TextGetOptions.None, out textStr);
                if (this.NameInputREBControl.Document.Selection.StartPosition < textStr.Length - 1)
                {
                    this.NameInputREBControl.Focus(FocusState.Programmatic);
                    this.NameInputREBControl.Document.Selection.StartPosition = this.NameInputREBControl.Document.Selection.StartPosition + 1;
                    this.NameInputREBControl.Document.Selection.SetRange(this.NameInputREBControl.Document.Selection.StartPosition, this.NameInputREBControl.Document.Selection.StartPosition);
                }
                else
                {
                    this.NameInputREBControl.Focus(FocusState.Programmatic);
                    this.NameInputREBControl.Document.Selection.StartPosition = textStr.Length;
                    this.NameInputREBControl.Document.Selection.SetRange(textStr.Length, textStr.Length);
                }

                this.ClearCanvas();
                this.allowProcess = WinAppConstant.StrProcessAllow;
            }
            else
            {
                return;
            }
        }

        public void Button_Click_Left(object sender, RoutedEventArgs e)
        {
            if (this.allowProcess == WinAppConstant.StrProcessAllow)
            {
                this.allowProcess = WinAppConstant.StrProcessDenied;
                if (this.NameInputREBControl.Document.Selection.StartPosition > 0)
                {
                    this.NameInputREBControl.Focus(FocusState.Programmatic);
                    this.NameInputREBControl.Document.Selection.StartPosition = this.NameInputREBControl.Document.Selection.StartPosition - 1;
                    this.NameInputREBControl.Document.Selection.SetRange(this.NameInputREBControl.Document.Selection.StartPosition, this.NameInputREBControl.Document.Selection.StartPosition);
                }
                else
                {
                    this.NameInputREBControl.Focus(FocusState.Programmatic);
                    this.NameInputREBControl.Document.Selection.StartPosition = 0;
                    this.NameInputREBControl.Document.Selection.SetRange(0, 0);
                }

                this.ClearCanvas();
                this.allowProcess = WinAppConstant.StrProcessAllow;
            }
            else
            {
                return;
            }
        }
    }
}